       GMHC Treatment Issues, Volume 10, Number 11 - November 1996
       -----------------------------------------------------------
       published by Gay Men's Health Crisis, Treatment Education,
       129 West 20th Street, New York, NY 10011


       Outrunning HIV to Protect Immune Defenses
       by Dave Gilden

Last month we looked at the reasons people fail to respond to
the new aggressive anti-HIV combination therapies. One of the
striking features behind lack of response in the face of
drugs that should have a tremendous impact on HIV replication
is the immune system's inability to control the virus,
leaving the drugs to do the entire job alone. But we also
looked last month at various anti-HIV strategies based on
further suppressing the immune system. These approaches stem
from a philosophy that the central cause of AIDS lies in the
progression of HIV infection and that the immune system
response is on balance counterproductive.

Many researchers are beginning to think that HIV establishes
an equilibrium in the body based only on the susceptibility
of target cells, and this equilibrium gradually breaks down.
The chronic activation of the immune system to fight HIV
helps the virus more than it hinders it by providing more and
more target cells susceptible to HIV infection and by
concentrating HIV in the lymph nodes, where those susceptible
CD4 cells also converge. A recent theoretical paper went so
far as to suggest that antiviral therapy plus immune
suppressive chemotherapy that reduces the number of CD4 cells
to slightly below the natural HIV-CD4 cell balance will cause
the HIV infection to gradually wind down due to lack of
sufficient target cells in which to reproduce.1

A possibly related observation is the experience of people
who have their spleens removed (splenectomy) to correct HIV-
related conditions (principally to improve low platelet
counts). The spleen, which is packed with both macrophages
and CD4 lymphocytes, is a major site of HIV replication.
According to a French group who reported their observations
in September,2 patients with HIV who had their spleens
removed had only one-eighth the risk of death and one-quarter
the risk of an AIDS-defining infection as a comparable group
who still had their spleens.

Splenectomy is not for the faint of heart: previous reports
have indicated that taking out this piece of the immune
system increases the risk of certain bacterial infections as
well as carrying with it the various risks of infection and
trauma inherent in a surgical procedure. Splenectomy also
produces a misleading boost in CD4 counts in the blood3 while
effecting little or no reduction in HIV levels.4

There might be a useful lesson from the performance of
splenectomized patients, but most scientists think that
suppressive therapy of this nature is highly questionable.
The traditional view is that the immune system does play an
active role in initially limiting the spread of HIV
infection. Mario Clerici, M.D., of the Universit degli Studi
di Milano in Italy, notes, for example, that "the switch from
NSI to SI HIV variant [a common evolution within the body
that portends accelerated disease progression] occurs
preferentially when CD4 counts fall below a critical
threshold, suggesting that immune impairment is a
prerequisite for cytopathic HIV variants to emerge."

The pattern of immune response seems to indicate who is
stable and who has progressive HIV disease. Long-term
nonprogressors have CD4 T-cells that, when activated, produce
IL-2 and other so-called TH-1 cytokines, which stimulate the
cytotoxic CD8 T-lymphocytes (CTLs) that kill virus-infected
cells. CD4 T-cells from those whose immune systems are
declining tend to produce more IL-10 and other TH-2 cytokines
that promote antibody production.5 In fact, the concentration
and type of HIV in the body (less virulent NSI or more
virulent SI) is closely correlated with the stimulated CD4
cells' IL-2 to IL-10 ratio. (Note that in a therapeutic
context, IL-10 might actually help block HIV replication --
for the subtleties of this immune suppressive approach, see
the October, 1996 Treatment Issues, pages 5-6.)

It also seems that the quality of the CD8 cell defense
shortly after infection with HIV influences people's
prognosis: A reaction by CD8 lymphocytes that vigorously
searches out relatively few HIV protein sequences leads to
quicker disease progression, whereas progression is slower
when the CTL response is more generalized, involving moderate
proliferation by many CD8 lymphocyte subfamilies.6 A vicious
cycle may be going on here, whereby a deficient immune
response allows for more HIV, which in turn leads to further
immune defects, such as a waning of anti-HIV CTL activity. If
an increasingly improper immune response to HIV plays a
central role in allowing disease progression, the trick would
be to carefully manipulate that response to make it more
effective or to restore it as immune defenses degrade in the
later, symptomatic stages of HIV infection.

"CD4 Lymphocyte Growth Factor"

Of course, the greatest change in the immune system during
HIV infection is the decimation of CD4 cells. An obvious
immune-boosting therapy would be one that elevates CD4 T-
lymphocyte proliferation so as to stabilize the CD4 count.
And one of the most obvious substances to look at is IL-2,
which causes replication of a broad number of white blood
cells, including CD4 and CD8 lymphocytes, monocytes and
natural killer cells.

"IL-2 is just CD4 lymphocyte growth factor," claims Clifford
Lane, M.D., of the National Institute of Allergy and
Infectious Diseases (NIAID). When you give it to people and
their CD4 counts go up, they don't get sick."
Dr. Lane's group has just published the results of a 12-month
controlled trial of IL-2 plus nucleoside analogs in 60
volunteers.7 The starting IL-2 dose was 18 million
international units (IU) per day, administered as a
continuous five-day infusion every two months. After the 12
month trial period, members of the control group, which had
been receiving only nucleoside analogs, were permitted to
receive IL-2 also. Follow-up data were reported out to 30
months.

Starting with an average CD4 count of 427 cells/mm3, the IL-2
group gained about 37 cells per month, ending with an average
count of over 900 after one year. During the follow-up
period, this group's count stabilized (the IL-2 was only
administered as needed to maintain the previous gains) while
the CD4 counts of the initial control group caught up. The
price of these gains was high: 90% of the volunteers on IL-2
at some point suffered severe fatigue, headache, diarrhea or
other flu-like symptoms during and after an IL-2 infusion. By
the end of the trial's initial phase, the IL-2 dose had been
reduced to an average of about 8 million IU per day of
infusion. According to Joseph Kovacs, M.D., the study's lead
author, "We went for the maximum tolerated dose and then
worked our way down." That optimum dose has yet to be
determined and may differ for different people, in particular
those with higher CD4 counts may require smaller amounts.

One proposal to reduce the onerous nature of IL-2 therapy is
to replace the five-day infusions with twice daily
subcutaneous (under the skin) injections. Rather than be
hospitalized, patients could administer IL-2 themselves at
home. One study presented at the International AIDS
Conference in Vancouver this summer found that after the
first three months, CD4 counts had risen by 50% or 80% among
the volunteers getting 15 million IU per day for five days
every four or eight weeks, respectively.8 People on a lower
dose (3 million IU/day) received less benefit, but since the
starting CD4 counts were over 500 (i.e., near normal), it is
questionable whether an 80% increase in CD4 cells is
necessary. Just a slight gain or merely stabilization of CD4
count may be all that is necessary. The cost in terms of side
effects remained high for subcutaneous IL-2, though less than
with IV administration in other studies, and was dose-
related. It is noteworthy that the one study that has
directly compared intravenous and subcutaneous IL-2 found
that side effects were distinctly fewer from subcutaneous
administration, but the CD4 increases were a lot less, too.9
This study used a less active and now disfavored formulation,
though, that joined the IL-2 molecules with polyethylene
glycol for improved stability.

While Dr. Lane's group works from the highest tolerable dose
of IL-2 back down to a more benign therapeutic intervention,
others are starting with lower doses in an effort to create a
nontoxic regimen. Kendall Smith, M.D., and colleagues at
Cornell Medical Center reported in September on what they
call a "rational" IL-2 therapy.10 These investigators use
comparatively small doses designed to limit the IL-2 to the
high affinity IL-2 receptors present on activated CD4 T
cells, B cells and a small subset of NK cells (a type of
antiviral lymphocyte that works independently of CD4 cells).
In this way, the lower affinity receptors present on most NK
cells would be missed, leaving these cells in a quiescent
state. The NK cells activated only by high-dose IL-2 produce
many of the inflammatory compounds (such as tumor necrosis
factor) that are implicated in IL-2's toxic effects.

In the Cornell group's recent report, ten HIV-positive
volunteers who received about 270,000 to 375,000 IU of IL-2
daily for six months as subcutaneous injections responded
with an average CD4 count boost of 27 cells per month (from a
baseline mean of 383 to a final count at six months of 543).
This is a figure remarkably similar to the gains reported
with high dose IL-2 at the NIH. Volunteers who received
higher amounts of IL-2 in the Cornell study suffered from
side effects and had their dose reduced. Those receiving
lower doses had no benefit -- in fact their average CD4 count
declined by 28 cells per month.

The difference in CD4 cell response between the higher and
lower doses in this trial was statistically significant, but
only because of the surprising decline in the low-dose arm of
the trial. Other trials using "low dose" IL-2 have not
observed CD4 cell gains. Just last spring, the AIDS Research
Alliance in Los Angeles reported that its 16-week trial of
IL-2 (at 360,000 or 720,000 IU per day) plus gamma interferon
detected no consistent changes in CD4 count.11 Granted, the
Los Angeles trial involved advanced AIDS patients (average
CD4 count of 47).

Increases in NK cells, which are depressed by HIV infection,
were dramatic in both the New York and Los Angeles studies.
For the Research Alliance cohort on the combined IL-2/IFN-g
regimens, the jump in NK cells seemed associated with
decreases in HIV viral load. If this could be confirmed, it
would be the first time a viral load decrease could be
effected by a therapy involving IL-2. The other IL-2 trials
have found no decrease in HIV levels, or even a transitory
increase in people not on anti-HIV medications. For this
reason, IL-2 trials have required participants to be on anti-
HIV therapy with approved nucleoside analogs.

The lack of viral load reduction with IL-2 can be taken as a
sign that the IL-2's expansion of immune system cells is not
creating any functional improvement. But it should be noted
that a substantial increase in CD4 cells without any
enhancement of the anti-HIV defenses should lead to
permanently heightened levels of HIV, since the virus' "food
supply" -- the proliferating CD4 T-cells -- would be
increased. (This could be what is happening when IL-2 is
administered to people with actual AIDS: In trial
participants with CD4 counts under 200, permanent increases
in viral load with little if any CD4 cell count improvement
has occurred.)

Besides a reduction in HIV levels, another definitive sign
that the increased cell counts due to IL-2 are actually doing
some good would be a reduction in the number of opportunistic
infections contracted by people receiving the cytokine. So
far, the only data available is contained in a small "meta-
analysis" combining three placebo-controlled high dose IL-2
studies with a total of 157 participants, all of whom
received open-label IL-2 after the first year. Since the
start of each study, there were six OIs in the IL-2 cohorts
and 14 in the placebo groups. This difference is not
statistically significant, and the analysis is very vague in
any case since the individuals under observation were all on
IL-2 for varying lengths of time. Dr. Lane presented this
very loose data set on November 3 at the Third International
Congress on Drug Therapy in HIV Infection (in Birmingham,
UK). He also claimed that all the opportunistic infections
occurred at the expected CD4 counts, although he did not
present a specific analysis of the correlation between OIs
and CD4 counts.

According to Dr. Lane, a definitive study of IL-2 documenting
disease progression would require as many as 3,000 people
with initially asymptomatic HIV infection who would be
followed for five years. The total cost could be upwards of
$50 million. No one has come forth as yet with this kind of
commitment. Although the Chiron Corporation spent at least
that much to obtain FDA approval for its Proleukin brand of
IL-2 as treatment for a type of kidney cancer, corporate
sources say that it would be "very difficult to pull off"
this kind of additional investment for HIV. Considering that
large clinical endpoint trials have already been successfully
completed, such as the one comparing AZT, ddI, AZT/ddI and
AZT/ddC (ACTG 175) or saquinavir, ddC and ddC/saquinavir
(Roche NV14256), it seems difficult to comprehend why the
same cannot be done for IL-2. Then again, if the optimum
dose, dosing schedule and route of administration for IL-2
has not been settled, it seems that all the preparatory work
for a large clinical endpoint trial has not yet been done.
But there are nevertheless late reports of progress, with
discussions continuing at both the level of AIDS Clinical
Trials Group and internationally to conduct the clinical
endpoint trial using subcutaneous IL-2 administration in HIV-
positive volunteers with CD4 counts over 400.

       Adding a Little HAART

Laboratory tests of immune cell proliferation do indicate
that the additional cells created under IL-2's influence are
responsive to foreign antigens, but specific lost immune
responses, such as those to vaccines, are only occasionally
recovered. As indicated by the lack of decrease in plasma HIV
levels, people's immune control of HIV is not restored to the
way it was just after primary infection even though their
nominal, IL-2-influenced CD4 counts may be normal or even
higher than normal.

IL-2 may help to ensure stability and even reinforcement of
available immunity by increasing the sheer numbers and
concentration of existing cells. The new naive CD4 T-cells
needed to expand the immune system's "repertoire" of
responses to invading pathogens do not seem to appear under
the influence of IL-2, perhaps because HIV damages the
thymus, where many naive cells mature. Still, over the long-
run IL-2 could expand any rare CD4 cells that already exist
to produce detectable responses to antigens where previously
none existed. The chances of this occurring would be
increased if HIV levels were suppressed to the maximum
possible using the new highly active antiretroviral therapy
(HAART) drug combinations. The less HIV, the more the
existing cells will be able to replicate. Conversely, IL-2
could reinforce HAART by maximizing the increase in CD4
counts.

Ronald Mitsuyasu, M.D., at University of California Los
Angeles is now planning ACTG 328, a 150-person trial with IL-
2 plus the protease inhibitor indinavir and any two
nucleoside analogs (one has to be new to the individual trial
participant). This trial's population will have advanced
disease, with CD4 counts of 50 to 300, but no prior protease
inhibitor treatment. If 12 weeks of the triple drug
combination reduces their plasma viral loads to below 5,000,
participants will be assigned to receive continued HAART plus
either intermittent cycles of intravenous IL-2, intermittent
subcutaneous IL-2 or nothing. Therapy will switch to
subcutaneous administration after three cycles for those in
the IV IL-2 group who are responding to therapy. The trial's
goal is to monitor the resulting immunological and viral load
changes, not prove a benefit in terms of disease progression.
The latter would require a significantly larger trial
enrollment. If IL-2 can be made to work in an advanced
population, the required size for a trial generating disease
progression data would be much smaller than the one discussed
above for earlier patients -- only about 300 participants
would be required, Dr. Mitsuyasu says.

There already is some indication that HAART and IL-2
reinforce each other. A study chaired by Judy Falloon, M.D.,
of the National Institute of Allergy and Infectious Diseases
has reported one-year observational data on 24 people who had
previously failed IL-2 therapy and had CD4 counts less than
300. For 14 weeks, participants received either intermittent
IL-2 plus daily indinavir (600 mg four times a day),
intermittent IL-2 plus the indinavir only on days when
actually receiving the IL-2, or daily indinavir alone. After
12 weeks everyone received IL-2, indinavir and whatever other
antiviral drugs they requested. Baseline CD4 count averaged
165 and the average initial viral load was about 100,000. By
14 weeks, the IL-2 plus daily indinavir group witnessed their
average CD4 count increase from 186 to 382 but their viral
load was little changed. In contrast, the daily indinavir
monotherapy group saw their CD4 counts increase from 144 to
only 229, while mean viral load fell about five-fold. (Little
improvement was observed in the intermittent IL-
2/intermittent indinavir group.) At one year, the CD4 count
for the total group (all on open-label IL-2/indinavir therapy
since week 14) averaged 433, while the overall average viral
load had been kept down to 37,000.

It is difficult to say in this trial what therapy provided
what benefit, but clearly, adding antiviral drugs created a
response to IL-2 where it previously did not exist. The IL-2,
meanwhile, may have helped boost CD4 counts more than the
average 100 to 150 cell gain usually seen with HAART
combinations alone. There is a hint here that relieving the
pressure from HIV, now possible for the first time, will
allow immune therapies to work, aiding the immune system to
provide some backup for antiviral drug therapy. Such support
could help clear the virus more quickly and thoroughly. A
functional immune defense against HIV, even if only partial,
would help avoid the drug resistance and breakthrough HIV
infection problems that frequently arise in patients now
relying only on HAART.

Before IL-2 can be combined freely with HAART, however, many
basic questions once again have yet to be answered. The toxic
nature of IL-2's inflammatory effects will make high doses of
the agent difficult for most people to tolerate. HAART should
allow IL-2 doses to be dropped to a greater extent than would
less effective anti-HIV therapies, but since the optimum CD4
boost has yet to be ascertained, the amount of IL-2 to be
used with HAART cannot be settled. Nor can the scheduling of
IL-2 administration: One of the hopes expressed by proponents
of high dose IL-2 is that only a few bimonthly cycles will
prove necessary to achieve acceptable CD4 counts with
continued highly suppressive antiviral cover. After that,
administration will be needed at most only a few times a year
to keep the CD4 count stable.

Next month Treatment Issues will look at strategies designed
to improve the immune system's specifically anti-HIV
activity.

              1 De Boer RJ and Boucher CAB. Proceeding of the Royal
       Society of London. B. July 22, 1996; 263(1372):899-905.

              2 Morlat P et al. AIDS. September, 1996; 10(10):1170-2.

              3 Zurlo JJ et al. Clinical Infectious Diseases. April,
       1995; 20(4):768-71.

              4 Henry K et al. Third Conference on Retroviruses and
       Opportunistic Infections. January, 1996; (abstract 245).

              5 Clerici M et al. AIDS Research and Human Retroviruses.
       1996; 12(11):1053-61.

              6 Fauci AS. Third Conference on Retroviruses and
       Opportunistic Infections. January, 1996; (abstract S2).

              7 Kovacs JA et al. New England Journal of Medicine. Oct.
       31, 1996; 335(18):1350-6.

              8 Davey RT et al. XI International Conference on AIDS.
       July 7-11, 1996; (abstract We.B.290).

              9 Carr A et al. XI International Conference on AIDS. July
       7-11, 1996; (abstract We.B.292).

             10 Jacobson EL et al. Procceedings of the National Academy
       of Science USA. Sept., 1996; 93:10405-10.

             11 Hale P. Searchlight. Spring, 1996; pages 10-15.


       Responding to CMV Neurologic Infections
       by Theo Smart

CMV infections of the central nervous system (brain and
spinal cord) could be the most under-recognized neurologic
complication of AIDS, according to researchers such as J.
Allen McCutchan, M.D., of the University of California, San
Diego. Usually by the time CMV neurologic disease is
diagnosed, most cases are unresponsive to treatment, and
death comes within weeks. CMV CNS disease may be a common
cause of death in patients with CMV retinitis, particularly,
says Dr. McCutchan, in those who "go blind, give up, and
withdraw without being aggressively diagnosed." Prospects for
earlier diagnosis and improved treatment are increasing,
though, as tests that measure CMV DNA in the cerebrospinal
fluid become more widely used, and new treatments for CMV
become available.

CMV can cause a number of distinct neurologic syndromes (in
addition to retinal infections). These include mononeuropathy
multiplex (inflammation or disease involving individual
nerves in unrelated portions of the body),
myelitis/polyradiculopathy (inflammation of a large number of
spinal nerves accompanied by pain, muscle wasting and
paralysis) and two forms of encephalitis (or brain disease):
diffuse micronodular encephalitis (DME) and
ventriculoencephalitis (VE).

Mononeuropathy multiplex occurs when CMV infects the cranial
and peripheral nerves resulting in face, wrist and foot
palsies (for example, drooping muscles in the face similar to
what occurs in people who have suffered a stroke). Mild forms
that resolve spontaneously often strike patients fairly early
in the course of HIV disease. Polyradiculopathy is strictly a
late-stage AIDS event. It starts out as weakness or pain in
the legs or back, but within a couple of weeks can progress
to paralysis of the lower extremities and loss of bladder
control leading to an inability to urinate or loss of anal-
sphincter control. Polyradiculopathy or myelopathy may
accompany or lead to CMV encephalitis.

The two CMV-encephalitic syndromes are distinguished
primarily by the site of infection within the CNS. For both
syndromes, symptoms of dementia, delirium, confusion, apathy
and lethargy are common.1,2 Some symptoms of DME depend upon
the location of the nodular lesions (as is often the case in
toxoplasmosis, CNS lymphoma and PML). Patients with VE,
meanwhile, often experience cranial nerve palsies and
nystagmus (rhythmic involuntary eye movement). Both
conditions are rapidly fatal. In one study of patients with
VE, the median survival was only five weeks,3 while in
another study those diagnosed with DME had a slightly longer
median survival of 8.5 weeks.4

The actual rate of CMV infection of CNS is unclear. One two-
year study reported that CMV encephalitis was found in only
1% of patients with advanced AIDS.5 This figure may
accurately reflect the rate of diagnosis, but not the rate of
incidence. In neurological autopsy studies, CMV infection of
the CNS is found in between 20% and 28% of the brains
studied.6,7 Some researchers believe that the rate of CMV
neurologic disease is increasing as people live longer in an
immune-compromised state. Others, such as David Clifford of
Washington University and the Neurologic Subcommittee of the
AIDS Clinical Trial Group, believe that there merely may be
an increase in diagnosis: "Some of the cases we believed were
HIV encephalopathy may actually have been caused by CMV --
there has been misclassification over the years. We've only
known how to diagnose CMV encephalopathy over the last few
years."

Other rates of incidence have been measured by the University
of California, San Diego -- the site of the HIV
Neurobehavioral Research Center funded by the National
Institute of Mental Health. According to Dr. McCutchan, the
site has been able to prospectively conduct neurocognitive
tests on AIDS patients that come to the university's AIDS
clinic, and then frequently perform neurological autopsy in
the event of death. In one recent study, researchers from the
center calculated that autopsy-confirmed CMV encephalitis
occurs in about 42% of patients with CMV retinitis.8 The rate
was almost 75% in more advanced cases of retinitis.
Meanwhile, it was very uncommon in people without CMV
retinitis.

Not all of the CMV neurologic disease detected upon autopsy
in this study was rapidly progressive or caused the patients'
death, but there is substantial evidence suggesting that
patients are adversely affected by these undiagnosed
infections. One study by Dr. McCutchan notes that even less
advanced CMV infections can affect neurocognitive function.
His team compared 16 patients with newly diagnosed CMV
retinitis (but no evidence of outright dementia) to 322
matched controls with similar CD4 cell counts, age and
education. They found neuropsychologic impairment (most
commonly attention and verbal deficits) in a third of the
patients with newly diagnosed CMV retinitis "caused by CMV
rather than HIV." Evidence of physical harm to the central
nervous system was detectable by MRI brain scans
approximately twice as often in the patients with retinitis
than in the matched controls.9 Dr. Clifford, however, does
not agree with the methodology used in the report and says
that there is a need for a "more focused and conservative
study. I think this was a seriously flawed study because
patients were sicker than the control group since they had an
opportunistic infection and these were very mild
neurocognitive deficits that could have been affected by the
fever associated with CMV infection as well as visual
problems associated with CMV retinitis."

In another study from San Diego's Neurobehavioral Center,
though, researchers reported that the risk of cognitive
impairment associated with CMV encephalopathy was seven-fold
higher than that associated with HIV encephalopathy.10 The
authors concluded that "unrecognized CMV encephalitis may be
an important cause of both mild and severe neurocognitive
impairment in patients with advanced HIV infection."

       Recognizing the Infection

In aggressive cases, the onset of symptoms is so abrupt, and
the progression so rapid, that the encephalopathy may kill
the patient within the time it takes clinicians to
distinguish it from other AIDS-related neurologic conditions.
There are some distinctive features of CMV neurologic
disease, though. For example, CMV encephalitis occurs very
late in the course of HIV disease, while signs of the most
common alternate diagnosis, HIV encephalopathy, appear
earlier and more gradually. Other hallmarks of CMV CNS
infection, such as electrolyte abnormalities, pleocytosis (an
abnormally high level of white blood cells in the CSF) and
contrast enhancement of the brain's ventricles on MRI brain
scans suggest CMV infection, particularly in the presence of
CMV retinitis. These markers allow for a presumptive, but not
a definitive diagnosis, since they also may occur in other
neurologic conditions as well.

Until recently, finding proof of active CMV infection in the
CNS has been difficult without conducting a brain biopsy.
Even though the CSF is believed to be the primary route
through which CMV enters the CNS (particularly in the case of
VE and polyradiculopathy), the virus can only rarely be
cultured from the CSF.11

"The one thing that has helped is the CMV DNA PCR test in the
[cerebral] spinal fluid," notes Dr. McCutchan. Some studies
report that such assays are dramatically more sensitive than
culturing, and that the virus is usually only detected in
cases of active CMV CNS infection.12 One study by Achim et
al. found that the test was not as specific as reported by
other groups, since CMV DNA was detected by PCR in the CSF of
58% of the patients without CMV-associated neurological
conditions.13 Lack of experience using the new tests may
explain some of these contrasting results. Also, this was a
study of autopsy specimens, and McCutchan points out that
there is a strong possibility that the virus could have
entered the CSF post-mortem. "I am very suspicious that
things can change after death. I think we need to look at the
CSF during life."

It stands to reason that even if CMV DNA can be found in the
CSF of people who do not have clinical CMV CNS disease,
quantitative assays may provide a better indication of who is
at risk for disease. A German study suggests that CMV DNA
loads in the CNS were ten- to 1,000-fold higher in patients
with CMV neurologic disease than in those without.14
Researchers from Roche Molecular Systems and University of
California San Francisco reported at September's ICAAC that
CMV DNA was detected in 24 of 26 patients with
polyradiculopathy, and that levels were consistently above
1,000 CMV DNA copies per ml (except in one case of a patient
on anti-CMV therapy).15 CMV DNA levels were generally under
100 copies per ml of CSF in patients with other CMV
neurologic conditions, though. Another group of researchers
recently published data correlating the presence of CMV DNA
in the CSF of all but one of 13 patients with CMV CNS
disease, while no CMV DNA was found in control subjects. High
levels of CMV DNA (1,000 copies per 8 ml) were associated
with severe disease, VE in particular, and uniformly shorter
survival.16

       Treatment Options

There have been no prospectively controlled studies of the
treatment of CMV CNS disease, and the case reports are scant.
Thus, there are no clear data on what is the best drug or
dose to use or the duration of treatment. There are case
reports of clinical responses to ganciclovir or foscarnet,
but there is reason to believe that standard treatments of
CMV retinitis may be inadequate as therapy for CMV infections
in the brain. Dr. McCutchan compared case studies of treated
patients with polyradiculopathy to those of untreated
patients, and he found that half of the treated patients
survived for a median of eleven weeks while all seven
untreated patients died within four weeks. It is hard to
construe less than two months additional survival as a great
success, though.

Also, there have been a number of reports that CMV
encephalitis developing in patients while receiving
maintenance therapy for CMV retinitis. Researchers from
Australia have reported on the development of VE in one
patient on ganciclovir who then failed to respond to
treatment with foscarnet.17 Another group described two cases
of CMV encephalitis emerging in patients while on
ganciclovir, who then failed to respond to the higher
ganciclovir doses used for induction therapy.18 Yet another
team noted five cases of CMV encephalitis that failed to
respond to ganciclovir therapy, even though retinitis was
stable in four of these same patients.19

Some of the treatment failure may be due to drug resistance.
One team reported on culturing ganciclovir-resistant virus
from a patient who subsequently developed polyradiculopathy
while on ganciclovir therapy.20 Other researchers published a
case of polyradiculopathy that was caused by a ganciclovir-
resistant CMV, though the patient eventually responded to
foscarnet and ganciclovir combination therapy.21

In addition, there are little data to suggest that either
ganciclovir or foscarnet is absorbed into the central nervous
system. In early pharmacokinetic studies, the level of
ganciclovir in the CSF was found to be substantially lower
than in the plasma.22 On the other hand, the blood-brain-
barrier may be compromised by CMV infection of the CSF.
Lawrence Drew, M.D., of the University of California San
Francisco, presented an abstract at the Second National
Conference on Human Retroviruses with data demonstrating that
ganciclovir, with or without foscarnet, can lower CMV load in
the CSF. Using the CMV bDNA assay, his team reported that
treatment had antiviral activity in the CSF in seven out of
eight patients with CMV neurologic disease.23 Dr. Drew
concluded that the failure of treatment in these patients
must have been due to some other factor such as the "advanced
degree of disease."

Dr. McCutchan has another possible explanation for treatment
failure, "The pathology suggests that some of the damage is
irreversible. When infection in the nervous system is diffuse
(as in DME), there may be recovery on treatment, but when the
infection is in the retina or the nerve roots (as in
polyradiculopathy or VE), there's no recovery of necrotized
[dead] nerves. Early neuropathological autopsy studies by Dr.
Clayton Wiley show massive brain destruction, as CMV has
burnt past [the layers of the central nervous system] until
you reach normal looking brain, full of viral antigens.

There's not much active CMV until you reach the active
burning at the edges of tissue damage and heating in the next
level full of virus. In retinitis studies, even after
treatment is initiated, this 'fire' always moves just a
little further." In this scenario, only earlier detection and
treatment may advert permanent nerve damage.

More hopeful data were presented by French researchers at the
Third Conference on Human Retroviruses last January.24 The
team reported rapid clinical improvement (within 10 to 13
days) in all of four patients with CMV neurological disorders
(three cases of encephalopathy and one polyradiculopathy) on
a combination regimen of ganciclovir at 5 mg/kg of body
weight every 12 hours, and foscarnet 60 mg/kg every eight
hours as induction therapy, followed by ganciclovir at 5
mg/kg, and foscarnet 90 mg/kg every day for maintenance. CMV
DNA became undetectable in both of two patients within whom
this was evaluated. No one stopped treatment due to toxicity,
although one case of anemia and one case of leucopenia were
observed.

These results provide additional justification for ACTG 305,
a six month multicenter study of high dose, aggressive
combination foscarnet/ganciclovir therapy in at least 30
patients with recently diagnosed encephalopathy or
polyradiculopathy. Participants will be treated for 28 days
with foscarnet 90 mg/kg and ganciclovir 5 mg/kg both twice
daily followed by maintenance therapy with the same doses,
but on a once-a-day basis. If they can tolerate it, those
with prior experience on ganciclovir will receive higher
ganciclovir doses (7.5 mg/kg twice a day for induction
therapy, and 10 mg/kg once a day for maintenance therapy). Up
to ten patients who cannot tolerate either agent will be
treated with the alternate drug as a monotherapy. If patients
fail on maintenance therapy, higher induction therapy doses
will be reinitiated.

ACTG 305 seeks to answer many of the nagging questions
surrounding CMV CNS disease. The study will evaluate both
quantitative CMV DNA PCR and CMV bDNA as assays for disease
severity, progression and response to therapy. The study also
will investigate the role of drug resistance in the evolution
of CMV CNS disease and in treatment failure. Finally,
researchers will try to perform as many brain autopsies as
possible on those patients who die during the study to
determine the level of drug that actually penetrates the
brain.

According to Dr. Clifford, the study should be open by the
time Treatment Issues goes to press.

       The Next Frontier

It is hard to predict what effect the recent improvement in
the treatment of CMV-retinitis will have upon the development
of CMV-related neurological syndromes. The addition of
cidofovir to the approved anti-CMV armamentarium may increase
the options of treatment. Lobucavir, adefovir, and other new
compounds (from Gilead and Glaxo Wellcome) are waiting in the
wings. It is unclear whether the use of oral ganciclovir will
decrease the rate of extra-ocular disease or merely engender
resistance by supplying suboptimal levels of the drug.
Finally, the growing use of localized therapies for CMV-
retinitis that do not treat extra-ocular CMV disease, such as
the ganciclovir implants, may allow the infection to spread
to the CNS more often.

"Local therapy worries me the most," says Dr. McCutchan. "We
are doing ganciclovir implants and now cidofovir intraocular
injections at our site, but we don't have the funding to
prospectively follow these patients to see whether there is
an increase in the rate of CMV disease in the CNS."
Even if the use of localized therapy does increase the
incidence of CMV encephalopathy or polyradiculopathy, Dr.
McCutchan believes that with viral load monitoring of the CSF
and an increased awareness of the conditions, the prospects
for treating CMV CNS disease are improving. "One of the
reasons to look at these endstage diseases is that we're
going to get better and better at bringing people back from
the brink. Of course, what we'd really like to do is to keep
people from ever reaching that brink."

              1 Holland NR et al. Neurology. March, 1994; 44(3 Pt
       1):507-14.

              2 Kalayjian RC et al. Medicine (Baltimore). March, 1993;
       72(2):67-77.

              3 Kalayjian, RC et al. Ibid.

              4 Holland NR et al. Op cit.

              5 Gallant JE et al. Journal of Infectious Diseases.
       December, 1992; 166(6):1223-7.

              6 Morgello S et al. Human Pathology. March, 1987;
       18(3):289-97.

              7 Cinque P et al. Scandinavian Journal of Infectious
       Diseases-Supplementum. 1995; 99:92-4.

              8 Bylsma SS et al. Archives of Ophthalmology. January,
       1995; 113(1):89-95.

              9 McCutchan JA et al. Second National Conference on Human
       Retroviruses and Related Infections. January 29-February 2,
1995; 107(abstract 289).

             10 Ellis R et al. Second National Conference on Human
       Retroviruses and Related Infections. January 29-February 2,
1995; 107(abstract 288).

             11 So YT, Olney RK. Annals of Neurology. January, 1994;
       35(1):53-8.

             12 Cinque P et al. Op cit.

             13 Achim CL et al. Journal of Infectious Diseases. March,
       1994; 169(3):623-7.

             14 Kuhn JE et al. Journal of Medical Virology. September,
       1995; 47(1):70-82.

             15 Long CM et al. Thirty-Sixth Interscience Conference on
       Antimicrobial Agents and Chemotherapy, September 15-18, 1996;
(abstract H033).

             16 Arribas JR et al. Journal of Infectious Diseases.
       August, 1995; 172(2):527-31.

             17 Paterson DL et al. Seventh Annual Conference of the
       Australian Society of HIV Medicine. November 16-19, 1995;
81(abstract 91).

             18 Mastroianni CM et al. Journal of Infection. November,
       1994; 29(3):331-7.

             19 Berman SM, and Kim RC. American Journal of Medicine.
       May, 1994; 96(5):415-9.

             20 Smith IL et al. Journal of Infectious Diseases. June
       1996; 173(6):1481-4.

             21 Jokela JA et al. Thirty-fourth Interscience Conference
       of Antimicrobrial Agents Chemotherapies. October 4-7, 1994;
209(abstract H97).

             22 Shepp D et al. Annals of Internal Medicine. September,
       1985; 103(3):368-73.

             23 Drew L et al. Second National Conference on Human
       Retroviruses and Related Infections. January 29-February 2,
1995; 117(abstract 338).

             24 Couderc L-J et al. Third National Conference on Human
       Retroviruses and Related Infections. January 28-February 1,
1996; 84(abstract 173).


       Tuberculosis Therapy and the New Protease Inhibitors
       by Gabriel Torres, M.D.

Aggressive treatment for tuberculosis (TB) requires
combination therapy, usually with four drugs (isoniazid,
rifampin, ethambutol and pyrazinamide) administered over nine
to 12 months. TB treatment regimens that contain rifampin are
far superior to those that do not contain rifampin. Rifampin-
containing regimens are usually much shorter (six to nine
versus 18 to 24 months) and have faster clearance of the
tubercle bacterium from the sputum, higher cure rates and
fewer relapses.

Rifamycins, the class of drugs that includes rifampin and
rifabutin unfortunately pose a significant problem for TB
patients who are also HIV-positive (one-third the total TB
caseload in New York City). Rifampin and rifabutin heighten
the activity of the liver's drug-metabolizing cytochrome P450
enzyme system, leading to subtherapeutic blood levels of the
anti-HIV protease inhibitors (saquinavir, indinavir and
ritonavir). At the same time, the protease inhibitors inhibit
the P450 enzymes, causing higher levels of rifampin and
rifabutin with an accompanying increased risk of serious side
effects (including bone marrow suppression and inflammation
of various tissues and organs).

The New York City Bureau of Tuberculosis Control of the
Department of Health has recently issued a series of
recommendations for HIV-positive patients with tuberculosis
who also require treatment with protease inhibitors. The
agency recommends that:

       1. HIV-positive patients with tuberculosis who have already
begun therapy with saquinavir or ritonavir should switch to
indinavir and change from rifampin to rifabutin since
rifabutin does not induce the cytochrome P450 system as
strongly as rifampin. Saquinavir levels are reduced by 40% in
the presence of rifabutin whereas ritonavir increases the
levels of rifabutin, causing excess toxicity. Rifabutin is
probably equivalent to rifampin for the treatment of
tuberculosis and should be substituted for rifampin in a
nine-month TB regimen. In recent studies, the standard 300 mg
per day of rifabutin taken with 2,400 mg/day of indinavir
caused indinavir blood levels to decrease by 30% and
rifabutin levels to double. The advised regimen is 150 mg per
day rifabutin taken along with the usual indinavir dose of
800 mg three times a day.

       2. HIV-positive patients with newly diagnosed tuberculosis,
CD4 counts still over 200 and no prior protease inhibitor
therapy should hold off on protease inhibitor therapy until
they have completed at least two, and preferably six, months
of a rifampin-containing regimen. Other antiretroviral agents
(nucleoside analogs and non-nucleoside reverse transcriptase
inhibitors) can be used during the six months of TB therapy.
Patients with lower CD4 counts have one of three options: a)
initial two months with a four-drug, rifampin-containing
regimen, followed by four to seven months of isoniazid and
rifabutin, with indinavir added after two months; b) begin
indinavir along with the TB regimen, but use rifabutin
instead of rifampin for the first two months along with three
other drugs, and continue with rifabutin and isoniazid for
the last four to seven months; c) initial two months with a
four-drug, rifampin-containing regimen, followed by a ten-
month course of an non-rifampin three-drug regimen, with
indinavir begun after the first two months.

       3. If rifampin or rifabutin cannot be included in the TB
regimen (because of patient intolerance, say), the regimen
should include an injectable anti-TB drug for the first two
to six months of treatment, in combination with other anti-TB
agents. This TB regimen should be continued for at least 18
months. Patient mortality is heightened if rifampin or
rifabutin cannot be included.

       4. Therapy with protease inhibitors should not be interrupted
because patients can develop HIV that may be resistant to
both the protease inhibitor they were taking as well as
others they might take in the future. Similarly, therapy for
TB should not be interrupted because the tuberculosis
bacterium may develop multi-drug resistance and become
impossible to eradicate. Patients with TB who are also
receiving protease inhibitors should therefore receive
directly observed therapy (DOT), in which caseworkers record
their compliance with the treatment regimen, the side effects
and drug-drug interactions. DOT will help ensure the success
of therapy and avoid the development of resistance and cross-
resistance to either class of drugs.

       5. Patients who are beginning treatment with a protease
inhibitor should be carefully screened for latent TB
infection and disease and given complete preventive therapy
with isoniazid, if necessary.

Note: The Centers for Disease Control have just issued
similar, although somewhat more conservative, guidelines as
the NYC DOH. It recommends completion of a six-month TB
regimen containing rifampin for all HIV positive patients
with active TB regardless of CD4 cell count. For TB patients
already on protease inhibitor therapy, the CDC believes one
option is discontinuing therapy with protease inhibitors and
completing a six-month course with a rifampin-containing TB
regimen. The agency concurs with the second New York DOH
option of switching from rifampin to rifabutin (150 mg per
day) and to indinavir from other protease inhibitors but
suggests treating patients with a four-drug rifabutin-
containing TB regimen for nine months. The CDC also
recommends measuring rifabutin plasma concentrations -- such
tests are available only at specialized centers in the US. A
third additional option proposed by the CDC is a four-drug
rifampin-containing regimen for two months or until the
sputum culture has converted to negative, followed by 16
months of continued TB treatment with isoniazid (INH) at 15
mg/kg of body weight and ethambutol at 50 mg/kg, given twice
weekly. Some experts also recommend adding a third drug such
as streptomycin for the continuation phase. This regimen
allows for reintroduction of protease inhibitor therapy after
the second month of TB therapy. This third option is not
recommended for patients with INH-resistant TB.

This advice is based on the best guesses of experts in the
fields of HIV, TB and drug metabolism. The regimens have not
been formally tested since most trials of protease inhibitors
excluded patients requiring rifampin or rifabutin. The
recommendations are a good starting point that will encourage
practitioners who care for people with TB not to withhold
potent antiretroviral therapy from patients who also have
HIV. As TB is known to accelerate the rate of HIV disease,
intervention with protease inhibitor therapy in this patient
population is crucial.

       Treatment Briefs
       NTZ for Cryptosporidiosis

The Food and Drug Administration (FDA) has given Unimed
Pharmaceuticals permission to increase the size of the
company's expanded access program for nitazoxanide (NTZ), a
new treatment for cryptosporidiosis. There now is no limit to
the number of people with HIV-related cryptosporidiosis who
can access the drug through the open label program.

There are currently no approved treatments for
cryptosporidiosis, and numerous agents have failed to show a
significant effect on this parasite in clinical trials
involving people with HIV. The data on NTZ are much more
encouraging, though.

A Mexican study presented at the 1996 International
Conference on AIDS claimed that NTZ reduced the symptoms of
cryptosporidiosis and cleared the parasite from the
intestines in most of the 30 patients treated. Those who
failed NTZ at doses of 500 mg or 1,000 mg per day, responded
when the dose was increased to 4,000 mg per day (abstract
TH.B.4213).

Results have not been quite as dramatic in U.S. dose-ranging
study. Data on the first 22 patients to complete the study
were reported at this year's Interscience Conference on
Antimicrobial Agents and Chemotherapies (abstract LM50).
Participants received either 500, 1,000, 1,500 or 2,000 mg
per day. Overall, after four weeks of treatment, at least
half of the participants experienced at least a 25% reduction
in number of daily bowel movements. 18% of the patients had a
complete resolution of diarrhea, and 41% had a reduction of
cryptosporidia in their stool samples. There was a trend
toward better results on the higher dose arms, and no dose-
limiting toxicity was observed. (According to Andy Young, of
the PWA Health Group, a New York City AIDS buyers' club that
sells NTZ, the only side effect reported to his organization
is a green tint to urine and other bodily secretions.)

In the expanded access program, participants will be
randomized to receive either 1,000 or 2,000 mg per day of NTZ
for one month. If the treatment produces no response, the
dose may be increased each month to a maximum of 3,000 mg per
day. The program is open to people with concurrent
microsporidiosis, though it excludes those who have
concurrent intestinal CMV, MAC or KS. For more information,
call 800/864-6330, extension 3032. Unimed plans to begin
phase II/III studies, in collaboration with the AIDS Clinical
Trials Group, by the end of the year.

Meanwhile, despite much harassment from the Food and Drug
Administration, including confiscated shipments and fines,
the PWA Health Group in New York still offers NTZ to anyone
with a prescription who does not qualify for the expanded
access program or who does not want to participate in the
phase II/III study. Call 212/255-0520 for further
information.

ddI and d4T Plus Protease Inhibitors

Despite the popularity of AZT/3TC, there are a number of
reasons not to use these two drugs plus a protease inhibitor
as part of your first strike against HIV. First, if the
regimen is not a complete success and resistance occurs, it
is not clear whether people who have become resistant to 3TC
will receive any benefit from switching to ddI or ddC, since
the mutation that confers resistance to 3TC could make the
virus resistant to the latter drugs as well. However, this
mutation, at amino acid number 184 on HIV's reverse
transcriptase enzyme, is only rarely observed to develop in
patients using ddI or ddC, which could indicate that patients
may be able to switch to 3TC after failure on either of these
two drugs. Second, the peripheral neuropathy caused by ddI,
ddC or d4T is most commonly reported in late-stage patients.

This observation indicates that combination regimens
including ddI, d4T or ddC probably should be administered
earlier in the course of disease, with the relatively benign
AZT/3TC combination reserved for more advanced patients.
The ddI/d4T combination is a possible competitor to AZT/3TC,
but there has been little information on how to use ddI/d4T
in conjunction with protease inhibitors, indinavir in
particular. The problem is that both ddI and indinavir must
be taken on an empty or nearly empty stomach. Additionally,
ddI's buffer interferes with the absorption of indinavir, so
they should be taken at least one hour apart. Fortunately,
d4T can be given with or without food.

Bristol-Myers Squibb, manufacturer of ddI and d4T, recommends
the following dosing schedule when combining ddI/d4T with
indinavir:

Indinavir should be taken just before a light breakfast (if
you must eat something), d4T with your dry toast and black
coffee, and ddI at least two hours afterwards and at least 30
minutes before lunch. Indinavir then should be taken in the
afternoon (at least two hours after lunch and one before
dinner). d4T can be taken with dinner, and ddI at least two
hours after dinner but at least one hour before ending your
evening with a dose of indinavir. Though, not formally
recommending it, Bristol-Myers concedes that many clinicians
are simply foregoing all this complication and prescribing
ddI in one 400 mg dose each day.

The dosing regimen would of course be simpler with ritonavir
or ritonavir/saquinavir, but the gastrointestinal side
effects of ddI combined with those of ritonavir may make it
difficult to start using these two agents at the same time.
Those who endure the first few weeks of ritonavir may be able
to add ddI/d4T at this point since the nausea, vomiting and
diarrhea associated with ritonavir have usually diminished by
then.

       Nerve Growth Factor Study Opens

ACTG 291, a study of recombinant human nerve growth factor
(NGF) in people with HIV-associated neuropathy opened this
past summer and currently has enrolled seventy patients. NGF
is a chemically synthesized version of a human protein that
specifically stimulates the growth and survival of nerve
cells in the peripheral nervous system. The trial should be
fully enrolled by the spring of 1997, which would be a record
accrual rate for a neurological study conducted by the AIDS
Clinical Trials Group.

The trial will assign 180 people to receive either 0.1 or 0.3
mg per kg of body weight of NGF as a subcutaneous injection
twice each week. It is open to people with HIV with
peripheral neuropathy that is not inherited, or caused by
diabetes, vitamin B12 deficiency, or treatment with
neurotoxic drugs such as ddC or d4T. Pregnant women or those
who will not consent to practice birth control are excluded.
The study is being conducted at numerous sites in the US.
Call 800/TRIALS-A for more information.

Data from a six month placebo-controlled study of NGF in 250
patients with neuropathy caused by diabetes were presented at
the American Neurology Association conference in October. The
study found that NGF improved neurologic function and
produced an increase in the patients' ability to sense
cooling or painful heat. Genentech, the company that makes
NGF, is planning a follow-up phase III study in over 1,600
patients. The study is currently on hold though, because the
company has a shortage of the drug.

This also may prove to be a problem in the current ACTG
study. Although, there is enough NGF to complete the trial,
Genentech claims that it does not have enough of the drug to
promise to continue treating study participants when the
trial is over.

Ironically, according to David Clifford, M.D., of Washington
University, and a member of the ACTG's Neurology
Subcommittee, "Ninety-nine percent of the drug is being
thrown away." This happens because the drug, administered in
very small doses, must be administered immediately after the
manufactured concentrate is diluted. Dr. Clifford says that
the vials in which Genentech supplies the NGF contain enough
to treat around 40 patients -- if they all showed up at the
same time. Since they do not, the rest must be thrown out.
Less wasteful packaging and closer co-ordination of study
participants' visits are possible solutions to the supply
problem. According to Kathleen Rinehart, manager of
Genentech's corporate communications department: "When we
were making the multi-use vial, we didn't know what dose of
NGF would end up being used or whether it would be used
subcutaneously or intravenously, so we made vials large
enough to cover the range of what might be needed. Right now,
we are currently working on a reconfiguration of those
vials."

       Cytarabine Nixed for PML

The first well-controlled clinical trial to be performed in
persons with Progressive Multifocal Leukoencephalopathy
(PML), ACTG 243, closed last summer after finding that
treatment with cytarabine (also known as ARA-C) offered no
benefit. The trial compared high-dose antiretroviral drugs
alone to high doses of both intravenous and intrathecal
(spinal) cytarabine. The study was closed early, after the
Protocol Safety Monitoring Board reviewed the data on the
first 62 subjects in the study and found no statistical
difference in survival either between the three arms
individually or between the two cytarabine arms compared to
placebo. Manageable, but slightly higher rates of bone marrow
toxicity were observed on the IV cytarabine arms. A higher
dropout rate occurred on the intrathecal arm, which involved
the administration of the drug through a needle inserted into
the membranes surrounding the spinal cord.

The results of the study came as no surprise, since there
were reports that people treated with cytarabine die faster
than those who received no treatment and since there was at
least one published case of cytarabine causing PML in a
person with cancer by suppressing the immune system. (See TL
Hwang et al. Journal of Neuro-Oncology. April, 1986;
3(4):335-9.) ACTG 243 may yet yield useful information on the
natural history of PML. For one thing, it gathered useful
data that should confirm whether a PCR (polymerase chain
reaction) test that detects JC virus in the cerebrospinal
fluid, can be used to diagnose PML. (JC virus is believed to
cause this brain disease.)

       More Free Viral Loads

Roche Diagnostic System's introductory offer of two free HIV
viral load tests with its Amplicor PCR assay (see last May's
Treatment Issues, page 12) has been a victim of its own huge
success -- or poor planning, depending on how you look at it.
At the end of October, some 25,000 plasma specimens had still
to be assayed for HIV level, out of a total of 80,000 sent
in. Some people have been waiting since July for the results,
which are supposed provide two baseline values for gauging
future disease progression and treatment effects.

Roche now hopes to clean up the backlog by mid-December, but
of what use are results from months-old test specimens? To
make up for its program's failure to deliver in a timely
fashion, Roche is now planning to send doctors a letter
offering them two coupons for every patient who had not
received the two test results by October 18. The coupons will
be good for six months. Roche is trying to ensure that the
labs performing the tests will report the viral load results
within ten days of receiving a specimen. To prevent a new
backup, it has signed up more medical laboratories and will
sent out the coupons in staggered fashion.

Coupon distribution is supposed to begin December 16.
Patients who may qualify for these coupons should contact
their doctor to make sure that he or she has applied for
them.
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