T cell anergy and activation are associated with suboptimal humoral responses to measles revaccination in HIV-infected children on anti-retroviral therapy in Nairobi, Kenya.

HIV-infected children are less capable of mounting and maintaining protective humoral responses to vaccination against measles compared to HIV-uninfected children. This poses a public health challenge in countries with high HIV burdens. Administration of anti-retroviral therapy (ART) and revaccinating children against measles is one approach to increase measles immunity in HIV-infected children, yet it is not effective in all cases. Immune anergy and activation during HIV infection are factors that could influence responses to measles revaccination. We utilized a flow cytometry-based approach to examine whether T cell anergy and activation were associated with the maintenance of measles-specific immunoglobulin (Ig)G antibodies generated in response to measles revaccination in a cohort of HIV-infected children on ART in Nairobi, Kenya. Children who sustained measles-specific IgG for at least 1 year after revaccination displayed significantly lower programmed cell death 1 (PD-1) surface expression on CD8(+) T cells on a per-cell basis and exhibited less activated CD4(+) T cells compared to those unable to maintain detectable measles-specific antibodies. Children in both groups were similar in age and sex, CD4(+) T cell frequency, duration of ART treatment and HIV viral load at enrolment. These data suggest that aberrant T cell anergy and activation are associated with the impaired ability to sustain an antibody response to measles revaccination in HIV-infected children on ART.

Biomarker evaluation of self-reported condom use among women in HIV-discordant couples.

Self-reported condom use is a commonly collected statistic, yet its use in research studies may be inaccurate. We evaluated this statistic among women in HIV-discordant couples enrolled in a clinical trial in Nairobi, Kenya. Vaginal swabs were acquired from 125 women and tested for prostate-specific antigen (PSA), a biomarker for semen exposure, using an enzyme-linked immunosorbent assay. Ten (10%) of 98 women who reported 100% use of condoms in the previous month tested PSA positive. In a bivariate logistic regression analysis, among women who reported 100% condom use in the previous month, those with ≤8 years of school had significantly higher odds of testing PSA-positive (odds ratio [OR] = 8.39, 95% confidence interval [CI] 1.02-69.13) than women with more schooling. Our estimate may be conservative, as the ability to detect PSA may be limited to 24-48 hours after exposure. Less educated women may be a target group for counselling regarding reporting sexual behaviour in clinical trials.

Patient tolerance to carbonic anhydrase inhibitors.

We evaluated carbonic anhydrase inhibitors in a crossover study with a placebo and random allocation of treatment administration. Drugs evaluated included acetazolamide tablets and Sequels, dichlorphenamide, ethoxzolamide, methazolamide, and an ascorbic acid placebo. The best tolerated drug was acetazolamide Sequels. Methazolamide was next. The least tolerated drugs were ethoxzolamide, acetazolamide tablets, and dichlorphenamide.