Topics in HIV Medicine® - International AIDS Society-USA

Conference Highlights - Advances in Antiretroviral Therapy Volume 11 Issue 3 May/June 2003
maintaining a plasma HIV-1 RNA level
of less than 5000 copies/mL.
Hecht and colleagues presented data
on behalf of the Acute Infection Early
Disease Research Program (Abstract
519). They compared those who started
antiretroviral therapy within 6 months
of seroconversion and later underwent
STI with those choosing to defer
antiretroviral therapy. After adjusting for
baseline plasma HIV-1 RNA level and
estimated number of weeks since infection,
subjects starting antiretroviral therapy
had a lower plasma HIV-1 RNA level
and a higher CD4+ cell count off
antiretroviral therapy than did those
deferring antiretroviral therapy.
However, the unadjusted analysis did
not show a clear benefit, and the
authors suggested that a randomized
trial is necessary to definitively assess
the role of treatment in primary HIV
infection.
Superinfection
Several studies concerned so-called
superinfection with viral variants phylogenetically
distinct from preceding HIV
isolates. Wong and colleagues (Abstract
485) described 2 cases in which new
clade B strains were retrospectively
identified by phylogenetic analysis of
env clones in female sexworkers who
were also injection drug users. Allen and
colleagues (Abstract 307) described a
single individual who received HAART
at primary infection and later went on
to 4 cycles of STI. Phylogenetic analysis
of gag sequences from 4 time points
demonstrated emergence of a strain
with 12% heterogeneity from the strain
at seroconversion. This second strain
persisted during the second and third
STIs despite the presence of an immunodominant
CD8+ T-cell epitope in p24
common to both viruses. Subbarao and
colleagues (Abstract 486) described cellfree
HIV RNA and proviral DNA levels
using a real-time reverse transcriptase
polymerase chain reaction method
adapted to distinctly quantify subtypes
B and CRF01_AE in a coinfected individual.
Initially, the plasma virus was a
subtype B strain. Subtype CRF01_AE
was detected at 8 and 20 months in
plasma and proviral DNA, respectively.
The plasma HIV-1 RNA level for subtype
B ranged from 7484 to 237,649
copies/mL over 44 months but for
CRF01_AE was consistently lower, ranging
from 3320 to 18,348 copies/mL over
33 months, respectively.
Treatment Strategies
Results of select studies of STIs in
antiretroviral-experienced patients are
summarized in Table 4.
STIs in Persons with Virologic
Suppression
Ananworanich and colleagues presented
the 48-week results of HIV-NAT 001.4
(Abstract 64), a prospective, open-label,
randomized trial conducted in Thailand
that evaluated HIV disease progression
and safety of a STI undertaken in
patients with chronic HIV infection. A
total of 74 Thai patients who had
received 1 year of dual nRTIs followed by
PI-based therapy (saquinavir soft gel
capsule 1600 mg/ritonavir 100 mg once
daily) for 3 years were enrolled. The trial
examined STIs based upon a CD4+
count decline versus 1 week on/1 week
off antiretroviral therapy. When CD4+
count was greater than 350 cells/µL and
plasma HIV-1 RNA was less than 50
copies/mL for at least 6 months, subjects
were randomized to 1 of 3 study arms:
continuous antiretroviral therapy
(n=25), CD4+ count-guided arm
(n=23), or 1 week on/1 week off arm
(n=26). The STI in the CD4+countguided
arm was based on a CD4+ count
of 350 cells/µL or less or a 30% drop or
rise in CD4+ cell count. Treatment failure
was defined as plasma HIV-1 RNA
levels greater than 1000 copies/mL or
CD4+ count of 350 cells/µL or less in
the continuous and week on/week off
study arms. Baseline characteristics
were similar between arms with regard
to sex (49% male), mean age (34 years),
and mean CD4+ count (644 cells/µL).
Preantiretroviral therapy and pre-HAART
plasma HIV-1 RNA levels were higher in
the CD4+ count-guided arm (4.8 and
3.2 log 10 copies/mL, respectively) and in
the week on/week off arm (4.9 and 3.4
log 10 copies/mL, respectively) than in the
continuous arm (4.3 and 2.6 log 10
copies/mL, respectively; P