The average CD4
cell count at which young people living with HIV in New York City started antiretroviral
therapy increased significantly after US guidelines changed in late 2009 to
recommend therapy at higher counts, investigators report in the online edition
of Clinical Infectious Diseases. The
study also showed that 18% of young people had transmitted drug resistance,
potentially limiting their choice of anti-HIV drugs.
“We found a
significant increase in the mean CD4 count at initiation of ART [antiretroviral
therapy] after…guidelines changed in December 2009,” comment the authors. “Our
findings demonstrate uptake of the 2009 ART initiation guidelines.”
recommendations for young people (adolescents and young adults aged 13 to 24 years)
follow those for adults. US antiretroviral treatment guidelines have been
revised on several occasions in recent years, each time recommending the
earlier initiation of therapy compared to previous editions of the guidelines. In
December 2009, people with CD4 counts between 350 and 500 cells/mm3
became eligible for treatment. In early 2013, guidelines were again revised,
this time recommending treatment for everyone with HIV, regardless of
little is known about the timing of antiretroviral treatment initiation in young people.
There are also important knowledge gaps concerning the prevalence of
transmitted drug resistance in this patient group, with estimates ranging
between 5 and 18%.
therefore designed a retrospective study involving 331 young people newly presenting
for HIV care in New York City between 2007 and 2011. Data were gathered on CD4
cell count and viral load on entry to care and at the time treatment was
started. Results of baseline genotypic resistance tests were available for a
subset of 212 patients. None of the participants had taken pre-exposure
prophylaxis (PrEP) or post-exposure prophylaxis (PEP) and all were
antiretroviral naive. All the patients acquired HIV via sexual
contact or as a result of injecting drug use.
Most (90%) of the
patients were male and 78% were in the men who have sex with men (MSM) risk group.
The mean CD4 cell
count at the time of entry into care was 452 cells/mm3. Average CD4
cell count did not differ between people presenting for care during 2007-2009 vs
In the earlier
period, 33% of patients had a CD4 count below 350 cells/mm3 and thus
qualified for HIV therapy. In 2010-2011, 57% of individuals had a CD4 count
below 500 cells/mm3, fulfilling the revised criteria for the
initiation of therapy.
Mean viral load at
presentation was approximately 128,000 copies/ml. It was similar in both the
earlier and later time periods.
A total of 191
patients (58%) started HIV therapy. Mean CD4 cell count at the time of
treatment initiation in 2007-2009 was 261 cells/mm3 compared to 363
cells/mm3 in 2010-2011, a significant difference (p < 0.001).
patients with CD4 counts between 350 and 500 cells/mm3 had a fivefold
increase in their odds of starting treatment compared to individuals with
similar CD4 counts in 2007-2009 (OR = 5.2; 95% CI, 1.1-25.1).
Six months after
starting treatment, 71% of patients had an undetectable viral load. The
proportion of patients achieving this outcome did not differ between the two
The most commonly
used (64%) HIV treatment combination was Atripla
(efavirenz/FTC/tenofovir). A raltegravir (Isentress)-containing
regimen was prescribed to 12% of patients and 20% were treated with a regimen
containing a ritonavir-boosted protease inhibitor.
There were subtle
changes in prescribing practices over the period covered by the study. Notably
use of Atripla declined (early vs
later time periods = 71 vs 60%, respectively),
whereas prescribing of raltegravir become more common (early vs later time
periods = 8 vs 15%, respectively).
were performed for 212 patients (64%). Patients starting treatment were more
likely to undergo resistance testing than individuals who remained
antiretroviral naive (78 vs 45%).
Overall, 18% of
the tested patients had a major drug resistance mutation, indicating
transmitted resistance increased significantly from 12% in 2007-2009 to 25% in
2010-2011 (p = 0.02).
“Our data suggest
an increasing rate of resistance in ART-naive individuals,” comment the
resistance to non-nucleoside reverse transcriptase inhibitor (NNRTIs) were
found in 60% of those with transmitted resistance. Four patients had resistance
to drugs in two of the major antiretroviral classes.
resistance mutations have implications for choosing initial regimens for ART-naive
adults and young adults,” conclude the authors. “Monitoring the epidemiology of
HIV drug resistance mutations will inform future treatment guidelines and our
findings reinforce the recommendation to perform HIV resistance testing upon
entry into care.”