Aviremic Subjects Research Articles

Multiple measures of HIV burden in blood and tissue are correlated with each other but not with clinical parameters in aviremic subjects.

To determine the levels of residual HIV DNA and RNA in blood and gut reservoirs in aviremic patients, assess correlations among compartmental measurements of HIV burden, and evaluate association with clinical parameters. Cross-sectional analysis of baseline data only, on 40 patients enrolled in phase II study evaluating efficacy of autologous gene-modified CD4+ and CD8+ T cells. All patients were on stable antiretroviral regimen with undetectable plasma HIV RNA (< 50 copies/ml). Measurements repeatedly performed over 8-12 weeks pre-intervention: blood HIV DNA, analysis of rectal mucosa-associated lymphoid tissue for both HIV RNA and HIV DNA, and quantitative co-culture of HIV from CD8-depleted peripheral blood mononuclear cells (PBMC). Quantifiable levels of HIV detected in compartments despite undetectable levels of plasma HIV RNA: HIV co-culture of PBMC (88%), blood HIV DNA (95%), rectal biopsy HIV DNA (95%), rectal biopsy HIV RNA (65%). A significant correlation existed among various measures of HIV burden (HIV co-culture, blood HIV DNA, rectal biopsy HIV RNA and DNA) but not between assays and clinical parameters [duration of highly active antiretroviral therapy (HAART), type of HAART]. All assays had comparable or less variability than in plasma viral load assays; HIV co-culture had the highest coefficient of variability whereas the blood HIV DNA assay had the lowest and was considered the most reliable assay. The data support safety, feasibility and high compliance of quantifying reservoirs of residual HIV in treated subjects with undetectable plasma HIV RNA. Lack of correlation between levels of HIV in residual reservoirs and duration of HAART suggests treatment-mediated viral suppression alone does not lead to reproducible decay in HIV reservoirs.

Accumulation of DC-SIGN+CD40+ dendritic cells with reduced CD80 and CD86 expression in lymphoid tissue during acute HIV-1 infection.

Dendritic cells (DC) are target cells for HIV-1 and play a key role in antigen presentation and activation of T cells. To characterize interdigitating DC in lymphoid tissue (LT) with regard to maturation, expression of cytokines and co-stimulatory molecules in HIV-1-positive patients. DC were characterized by immunohistochemistry and in situ imaging in LT from patients with acute HIV-1 infection (aHI), antiretroviral treated patients, long-term non-progressors/slow progressors with HIV-1 infection (LTNP/SLP), patients with AIDS, HIV-1-negative controls and patients with acute Epstein-Barr virus (EBV) infection. A significant increase of interdigitating DC expressing CD1a, S-100b, CD83 and DC-SIGN was found in LT from patients with aHI (P < 0.02). The co-stimulatory molecules CD80 and CD86 were, however, only partially upregulated and the complete parafollicular network found in acute EBV infection was not generated, despite increased expression of interleukins 1alpha, 1beta, 12; interleukin 1alpha receptor antagonist; interferon alpha; and CD40 expression. LTNP/SLP and treated aviremic subjects had increased frequency of interdigitating DC, albeit lower than in aHI, and low expression of CD80 and CD86. In contrast, patients with AIDS had fewer DC and reduced cytokine expression in LT. In the early phase of HIV-1 infection, there was a migration of DC to LT comparable to that found in acute EBV infection. The infiltration of DC in LT in acute EBV infection was accompanied by upregulation of CD80 and CD86 expression, which did not occur in aHI. This co-stimulatory defect in aHI may have an impact on the development of HIV-1-specific T cell immunity.