Bacterial activity in the genital tract increased the
susceptibility of HIV infection among women, but hormonal contraception did
not, data from two studies suggest.
Researchers from the NIH-funded Microbicide Trials
Network reported the findings during the International Microbicides Conference
in Sydney, Australia, both of which came from the HPTN 035 trial a phase
2/2b clinical trial assessing the safety and effectiveness of two vaginal
For the first study, researchers from the University of
Pittsburgh evaluated whether soluble mucosal immunity affected the risk for
HIV, independent of the use of the microbicide. During the trial, 3,524
endocervical swabs were collected from 2,031 women. Pre- and
post-seroconversion swabs from 26 women who seroconverted on trial were
analyzed and compared with 116 controls.
No significant differences were observed in the swabs
before and after HIV acquisition among the women who seroconverted. Compared
with controls, however, women who acquired HIV had significantly more
anti-Escherichia coli activity and were more likely to have detectable
human beta-defensin-2 in their pre-seroconversion sample. In multivariate
analysis, only total protein and anti-E. coli activity remained
We dont understand exactly what this assay
is telling us other than these women had some underlying level of immune
activity that placed them at greater risk, Charlene Dezzutti, PhD,
of the University of Pittsburgh, said in a press release. Wed like
to be able to identify women who may be more susceptible to HIV before
they become infected but there is still more work ahead. We need to test
the approach in more samples and dig deeper.
In the second study, researchers found that neither
injectable nor oral contraceptives increased the risk for acquiring HIV.
Researchers from the University of Zimbabwe conducted a
retrospective review of data from the HPTN 035 trial that included 2,887 women
from Africa. Among these women, 51% reported using an injectable contraceptive,
21% reported using oral contraceptives and 14% used nonhormonal contraception.
Women who used injectable hormonal contraception had no
statistically significant association of risk to HIV acquisition, with a Hazard
ratio of 1.4. Oral contraceptive users also had no significant risk for HIV
acquisition, with a Hazard ratio of 0.86.
In many ways, our data reflects the overall body
of evidence so far, which has seen inconsistent study results,
Zvavahera Mike Chirenje, MD, of the University of Zimbabwe, said in a
press release. If theres one conclusion to be made from our
analysis, as well as the other studies to date, its that there are no
clear answers about hormonal contraception and HIV risk.
- Chirenje ZM. Association between hormonal contraception
and HIV infection in HPTN 035.
- Dezzutti CS. Increased genital tract inflammation is
associated with HIV-1 seroconversion in women participating in the HPTN 035
- Both presented at: International Microbicides
Conference; April 15-18, 2012; Sydney, Australia.
- The researchers report no relevant financial disclosures.