Virologic and immunologic response to highly active antiretroviral therapy

Predictors of change in CD4 lymphocyte count and weight among HIV infected patients on anti-retroviral treatment in Ethiopia: a retrospective longitudinal study

Background

Antiretroviral treatment (ART) has been introduced in Ethiopia a decade ago and continues to be scaled up. However, there is dearth of literature on the impact of ART on changes in CD4 lymphocyte count and weight among patients on treatment.

Objective

To determine the predictors of change in CD4 lymphocyte count and weight among HIV/AIDS infected patients taking antiretroviral treatment in eastern Ethiopia.

Methods

A retrospective cohort study was conducted among HIV/AIDS patients taking ART from 2005 to 2010. A sample of 1540 HIV infected adult patients who started antiretroviral therapy in hospitals located in eastern Ethiopia were included in the study. The primary outcomes of interest were changes in CD4 count and weight. Descriptive statistics and multivariable regression analyses were performed to examine the outcomes among the cohort.

Results

Both the median CD4 lymphocyte counts and weight showed improvements in the follow up periods. The multivariate analysis shows that the duration of ART was an important predictor of improvements in CD4 lymphocyte count (beta 7.91; 95% CI 7.48–8.34; p 0.000) and weight (beta 0.15; 95% CI 0.13–0.18; p 0.000). Advanced WHO clinical stage, lower baseline CD4 cell count, and baseline hemoglobin levels were factors associated with decline in weight. Actively working patients had higher CD4 lymphocyte count and weight compared to those that were ambulatory (p<0.05).

Conclusion

We detected a substantial increment in weight and CD4 lymphocyte count among the patients who were taking ART in eastern Ethiopia. Patients who are of older age, with low initial CD4 lymphocyte count, late stage of the WHO clinical stages and lower hemoglobin level may need special attention. The reasons for the improved findings on CD4 count and weight throughout the five years of follow up merit further investigation.

Outcomes of highly active antiretroviral therapy in the context of universal access to healthcare: the U.S. Military HIV Natural History Study

Background

To examine the outcomes of highly-active antiretroviral therapy (HAART) for individuals with free access to healthcare, we evaluated 2327 patients in a cohort study composed of military personnel and beneficiaries with HIV infection who initiated HAART from 1996 to the end of 2007.

Methods

Outcomes analyzed were virologic suppression (VS) and failure (VF), CD4 count changes, AIDS and death. VF was defined as never suppressing or having at least one rebound event. Multivariate (MV) analyses stratified by the HAART initiation year (before or after 2000) were performed to identify risk factors associated with these outcomes.

Results

Among patients who started HAART after 2000, 81% had VS at 1 year (N = 1,759), 85% at 5 years (N = 1,061), and 82% at 8 years (N = 735). Five years post-HAART, the median CD4 increase was 247 cells/ml and 34% experienced VF. AIDS and mortality rates at 5 years were 2% and 0.3%, respectively. In a MV model adjusted for known risk factors associated with treatment response, being on active duty (versus retired) at HAART initiation was associated with a decreased risk of AIDS (HR = 0.6, 95% CI 0.4-1.0) and mortality (0.6, 0.3-0.9), an increased probability of CD4 increase ≥ 50% (1.2, 1.0-1.4), but was not significant for VF.

Conclusions

In this observational cohort, VS rates approach those described in clinical trials. Initiating HAART on active duty was associated with even better outcomes. These findings support the notion that free access to healthcare likely improves the response to HAART thereby reducing HIV-related morbidity and mortality.

Soluble PD-1 rescues the proliferative response of simian immunodeficiency virus-specific CD4 and CD8 T cells during chronic infection

Phenotypic and functional studies of the programmed death-1 (PD-1) molecule on CD4(+) and CD8(+) T cells were performed on peripheral blood mononuclear cells from uninfected and simian immunodeficiency virus (SIV)-infected rhesus macaques. These data demonstrated a rapid upregulation of PD-1 expression on tetramer-positive CD8(+) T cells from MamuA.01(+) SIV-infected macaques upon infection. Upregulation of PD-1 on total CD8(+) T cells was not detectable. In contrast, CD4(+) T-cell PD-1 expression was markedly higher in total CD4(+) T cells during chronic, but not acute, infection and there was a correlation between the level of PD-1 expression on naive and central memory CD4(+) T cells and the levels of viral loads. Such association was emphasized further by a marked decrease of PD-1 expression on tetramer-positive CD8 T cells as well as on CD4(+) T cells on longitudinal samples collected before and after the initiation of antiretroviral therapy and downregulation of viral replication in vivo. Cloning of PD-1 and its two ligands from several non-human primate species demonstrated > 95% conservation for PD-1 and PD-L2 and only about 91% homology for PD-L1. Functional studies using soluble recombinant PD-1 protein or PD-1-immunoglobulin G fusion proteins induced marked increases in the SIV-specific proliferative responses of both CD4(+) and CD8(+) T cells from rhesus macaques. The results of these studies serve as a foundation for future in vivo trials of the use of rMamu-PD-1 to potentially enhance and/or restore antiviral immune responses in vivo.