Immunologic and virologic consequences of temporary antiretroviral treatment interruption in clinical practice

To determine the long-term immunologic and virologic effects of antiretroviral treatment interruptions, a retrospective analysis of an ongoing observational database was performed at a university HIV clinic. All patients who began highly active antiretroviral therapy (HAART) after January 1, 1996 and (1) were HAART experienced for ≥90 days, (2) had a treatment interruption (TI) for ≥30 days, (3) resumed HAART for ≥30 days, and (4) had CD4+ cell counts performed pre- and post-TI were included. Main outcome measures included the following: Immunologic success was defined as a post-TI CD4+ cell count >90% of the pre-TI CD4+ cell count (post-TI/pre-TI, >90%). Virologic success was defined as a post-TI viral load (VL) less or equal to twice the pre-TI VL (post-TI/pre-TI, ≤2) or a post-TI VL of <1000 copies/ml. The pre-TI (baseline) value was the value at the start of the TI (range, -20 to +7 days); the post-TI value was the highest CD4+ cell count and lowest VL copy achieved during the follow-up window (270 da...