HIV-associated central nervous system diseases in the recent combination antiretroviral therapy era

Background and purpose: Data describing the incidence and survival of HIV-related central nervous system diseases (CNS-D) in recent years are sparse. Methods: Between 1996 and 2007, adult subjects without previous CNS-D within a large UK cohort were included (n = 30 954). CNS-D were HIV encephalopathy (HIVe), progressive multifocal leucoencephalopathy (PML), cerebral toxoplasmosis (TOXO) and cryptococcal meningitis (CRYP). Associations between demographic, clinical and laboratory parameters with incidence and survival of CNS-D were evaluated using Poisson regression analysis and Kaplan-Meier techniques. Results: Six hundred and thirteen new CNS-D occurred in 574 subjects (HIVe: 187, PML: 113, TOXO: 184, CRYP: 129). Incidence of all CNS-D declined from 13.1 per 1000 PY in 1996/1997 to 1.0 per 1000 PY in 2006/2007 (P = 0.0001). Current CD4+ cell count below 200 cells/ul and plasma HIV RNA above 100 000 copies/ml were independently associated with the development of CNS-D. Calendar year 1996/1997, older age, prior AIDS diagnosis and PML diagnosis were significantly associated with shorter survival. Conclusions: An ongoing decline in the incidence of CNS-D has been observed in very recent years. Mortality following such a diagnosis remains high.