Delayed GALT reconstitution in duodenum compared to rectum in hiv-infected patients initiating antiretroviral therapy.

BACKGROUND: We aimed to characterize the impact of ART initiation on GALT at various sites along the gastrointestinal site.

METHODOLOGY: Peripheral blood and duodenal and rectal biopsies were obtained from 12 HIV and 33 treatment-naïve HIV subjects at baseline and after 9-months ART. Tissue was digested for immunophenotyping. Inflammatory, bacterial translocation and intestinal damage markers were measured in plasma.

RESULTS: Twenty-six HIV subjects completed follow-up. The lowest reconstitution of CD4 T-cells and the lowest CD4/CD8 ratio during ART compared to blood were observed in the duodenum with the rectum being either intermediate or approaching blood levels. Regulatory T-cells (Treg) were in higher proportions in the duodenum than the rectum and neither declined significantly during ART. Several correlations with biomarkers of microbial translocation were observed including increases in LTA levels, which reflects gram-positive bacterial translocation, correlated with increases in %CD4 T-cells in duodenum (Rho 0.773, P = 0.033), and with decreases duodenal Treg populations (Rho -0.40, P = 0.045).

CONCLUSIONS: HIV-mediated immunological disruption is greater in the duodenum than rectum and blood before and during ART. Small intestine damage may represent a unique environment for T-cell depletion, which might be attenuated by interaction with gram positive bacteria.