The CD4 slope can be a predictor of immunologic recovery in advanced HIV patients: a case-control study

Background/Aims: Advanced human immunodef iciency virus (HIV) infection, despite sustained viral suppression by highly active antiretroviral therapy (HAART), is a risk factor for poor immunologic recovery. However, some patients with advanced infection do show immunologic recovery. In this study, predictive factors of immunologic recovery were analyzed in advanced HIV patients showing sustained viral suppression. Methods: A case-control study was conducted in HIV-infected adult patients with HIV-1 RNA < 50 copies/mL maintained for 4 years or longer and who were receiving HAART. Advanced HIV infection was defined as a baseline CD4 T cell count < $200/mm^3$. Immunologic responders were defined as patients showing immunologic recovery (CD4 T cell counts ${\geq}500/mm^3$ at 4 years with HAART). To analyze the CD4 T cell kinetics, the CD4 slope (monthly changes in the CD4 T cell count) was estimated for each patient using a linear regression between the CD4 T cell count and the time since HAART initiation. Results: Of 102 eligible patients, 73 had advanced HIV, and 33 (45.2%) showed immunologic recovery. The median CD4 slopes ($cells/mm^3$ per month) during 0 to 6 and 0 to 12 months of HAART in the 73 advanced patients were significantly higher in responders than in non-responders (0 to 6 months, 38.6 vs. 22.8; 0 to 12 months, 24.5 vs. 13.5). Multivariate analyses showed opportunistic infections at the start of HAART (adjusted odds ratio [OR], 0.28) and a CD4 slope ${\geq}20$ during 0 to 12 months of HAART (adjusted OR, 10.10) were independently associated with immunologic recovery. Conclusions: The CD4 slope can be an early predictor of long-term immunologic recovery in advanced HIV patients.