Improving the Management of HIV Disease Vol. 6, no. 5 [World Conference on AIDS (12th: 1998: Geneva)]

International AIDS Society-USA

45. What do you recommend
for a pregnant woman
who has 8oo CD4+ cells/pL
and a plasma viral load
below 400 copies/mL?
DR SCHOOLEY: In this situation, there
are two issues: what is required for the
mother and what is the best approach to
the prevention of perinatal transmission
of HIV-1 to the baby? Although this
mother is less likely to transmit HIV-1 to
her baby than a mother with more
advanced disease, ACTG 076 and other
studies have demonstrated that there is
no floor below which HIV-1 cannot be
transmitted to the baby. In this situation,
were the mother not pregnant, I might
opt to delay therapy. Nonetheless, I
would favor a circumscribed period of
antiretroviral therapy in the prenatal and
perinatal period to prevent transmission
of HIV-1 to the baby. I would opt for a
regimen that would not limit her options
later (ie, one that would not foster resistance by inadequate potency), and would
also treat the baby in the perinatal period. After delivery, I would likely stop
therapy in the mother awaiting a later
period in the illness to reinstitute therapy.
46. What is the role of antiretroviral drug resistance
testing for a woman who
has had extensive antiretroviral experience, has
a detectable plasma viral
load, and becomes preg
DR D'AouILA: A role for resistance testing still needs to be defined for this situation and validated in any setting, but I
would likely use resistance testing as I
would in any patient in whom a regimen
is failing. Current knowledge does suggest it is best for both the woman and the
fetus to optimize HIV suppression. If
plasma HIV RNA was low and stable (eg,
<1000 copies/mL, but detectable), I
would not recommend resistance testing.
I might try intensification with 2 additional drugs this patient had never used
that were not expected to share resistance patterns with any previously used
drug. If the plasma HIV RNA level were
higher or rising, I would still not order
resistance testing as a first step. I would
first try to choose a 3- or 4-drug regimen
that included drugs that had not previously been used and to which cross-resistant virus was not expected to have been
selected by any prior regimen. (I would
likely recommend 4 drugs if the viral
load was higher than about 250,000
copies/mL.) If prior antiretroviral experience was so extensive that this was not
possible and plasma HIV RNA was below
1000 copies/mL, then it would be reasonable to attempt drug resistance testing to help choose the next regimen from
a list of previously used or cross-resistant
drugs. However, the available data indicate that resistance test results predict
failure of a resistant drug much better
than they can predict the success of a
drug to which the patient's virus tests as
susceptible. Major reasons for this
include the technical lack of detection of

a minority of resistant virus that might
be selected in vivo by re-introducing the
old drug and the possibility of drug failure through mechanisms other than drug
resistance. Thus, I would use the resistance test results only to exclude drugs
that were very unlikely to work.
DR CONWAY: The specific goal of antiretroviral therapy in pregnancy is to
reduce the risk of transmission of HIV
from the infected mother to the unborn
child. As such, it may be important to
optimize therapy to reduce circulating
viral load as much as possible, as this has
been associated with a reduced risk of
transmission. In this context, resistance
testing may be helpful to evaluate if genotypic mutations conferring decreased
susceptibility to the agents the mother is
currently taking may have developed.
This may allow for optimization of the
regimen to include 3 drugs to which the
viral isolates are sensitive. The evaluation
of resistance to agents the mother may
have taken in the past would not yield
reliable results, as resistant isolates may
not be present in sufficient numbers to
be detected, but may rapidly emerge if a
specific drug were restarted. Similarly, it
could be assumed that the viral isolates
are susceptible to drugs the mother has
never taken as long as no cross-resistance
is known to exist between such drugs
and any other(s) to which she may have
been exposed.

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IMPROVING THE MANAGEMENT OF HIV DISEASE