Increased T cell activation has predictive value for HIV-1 disease progression even before seroconversion. These data support the hypothesis that persistent hyperactivation of the immune system may lead to erosion of the naive T cell pool and CD4 T cell depletion.

The HIV-1 biological phenotype is a practical, binary marker for progression to AIDS, which is independent of decreased CD4+ cell counts and antigenemia. Appearance of SI variants, occurring 2 years before progression to AIDS on the average, is predictive for a significantly increased rate of CD4+ cell decline.

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BackgroundCardiovascular disease (CVD) is the leading cause of adult mortality in low-income countries but data on the prevalence of cardiovascular risk factors such as hypertension are scarce, especially in sub-Saharan Africa (SSA). This study aims to assess the prevalence of hypertension and determinants of blood pressure in four SSA populations in rural Nigeria and Kenya, and urban Namibia and Tanzania.Methods and FindingsWe performed four cross-sectional household surveys in Kwara State, Nigeria; Nandi district, Kenya; Dar es Salaam, Tanzania and Greater Windhoek, Namibia, between 2009–2011. Representative population-based samples were drawn in Nigeria and Namibia. The Kenya and Tanzania study populations consisted of specific target groups. Within a final sample size of 5,500 households, 9,857 non-pregnant adults were eligible for analysis on hypertension. Of those, 7,568 respondents ≥18 years were included. The primary outcome measure was the prevalence of hypertension in each of the populations under study.The age-standardized prevalence of hypertension was 19.3% (95%CI:17.3–21.3) in rural Nigeria, 21.4% (19.8–23.0) in rural Kenya, 23.7% (21.3–26.2) in urban Tanzania, and 38.0% (35.9–40.1) in urban Namibia. In individuals with hypertension, the proportion of grade 2 (≥160/100 mmHg) or grade 3 hypertension (≥180/110 mmHg) ranged from 29.2% (Namibia) to 43.3% (Nigeria). Control of hypertension ranged from 2.6% in Kenya to 17.8% in Namibia. Obesity prevalence (BMI ≥30) ranged from 6.1% (Nigeria) to 17.4% (Tanzania) and together with age and gender, BMI independently predicted blood pressure level in all study populations. Diabetes prevalence ranged from 2.1% (Namibia) to 3.7% (Tanzania).ConclusionHypertension was the most frequently observed risk factor for CVD in both urban and rural communities in SSA and will contribute to the growing burden of CVD in SSA. Low levels of control of hypertension are alarming. Strengthening of health care systems in SSA to contain the emerging epidemic of CVD is urgently needed.

To investigate the effect of persistent HIV infection on the immune system, we studied leukocyte functions in 14 asymptomatic homosexual men (CDC group Il/III) who were at least two years seropositive, but who still had normal numbers of circulating Cfl4+ T cells. Compared with age-matched heterosexual men and HIV-negative homosexual men, the CD4' and CD8' T cells from seropositive men showed decreased proliferation to anti-CD3 monoclohal antibody and decreased CD4' T-helper activity on PWM-driven differentiation of normal donor B cells. Monocytes of HIV-infected homosexual men showed decreased accessory function on normal T cell proliferation induced by CD3 monoclonal antibody. The most striking defect in leukocyte functional activities was observed in the B cells of HIV-infected men.

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OKT3/IL-2 resulted in T cell activation and proliferation, and could stimulate HIV replication in patients having achieved prolonged suppression of plasma viremia. OKT3/IL-2 therapy was toxic and rapidly induced antibodies against OKT3.

The causal relationship between HIVspecific CD4 ؉ T-cell responses and viral control and the effect of these responses on the natural history of HIV infection is unclear. In a detailed longitudinal study, functional HIV-1 Gag-specific CD4 ؉ T cells were analyzed in long-term asymptomatic individuals (LTA; n ‫؍‬ 6) and progressors to AIDS (n ‫؍‬ 7) with a median follow-up of, respectively, 118 and 57 months. Next, HIV-specific CD4 ؉ T-helper cell responses were measured in a prospective cohort study among 96 HIV seroconverters and were related to clinical endpoints using Cox proportional hazard analyses. In the detailed study, no difference for HIV-specific helper-cell responses between LTAs and progressors was observed early in infection, but Gagspecific CD4 ؉ T cells producing IL-2 or IFN␥ were lost in progressors late in infection. Multivariate proportional hazard analyses in the prospective cohort study showed that HIV-specific IL-2 ؉ , IFN␥ ؉ , or IL-2 ؉ IFN␥ ؉ CD4 ؉ T cells early after seroconversion had no prognostic value for the rate of progression to AIDS. Our results are compatible with viral load determining the nature and magnitude of HIV-specific CD4 ؉ T-cell responses, rather than HIV-specific CD4 ؉ T-cell responses controlling HIV plasma viral load. (Blood.