Neurologic immune reconstitution inflammatory syndrome in HIV/AIDS: outcome and epidemiology.

OBJECTIVE: To characterize the immune reconstitution inflammatory syndrome in the nervous system (NeuroIRIS) among patients with HIV/AIDS.

BACKGROUND: NeuroIRIS has been recognized as a complication of combination antiretroviral therapy (cART).

METHODS: A retrospective analysis was performed of NeuroIRIS patients fulfilling diagnostic criteria and followed at the Northern or Southern Alberta (HIV) Clinics. A nested epidemiologic study was performed within a subset of patients in whom cART was started from 1999 to 2007.

RESULTS: NeuroIRIS was diagnosed in seven patients initiating cART. All were men (median age, 35 years) and exhibited severe immunosuppression (median CD4(+) T cells, 30 cells/mm(3)). Four patients presented to the Southern Alberta Clinic, representing all NeuroIRIS cases among 461 patients in whom cART was initiated over an 8-year period (incidence 0.9%). New onset of neurologic deterioration (n = 4) or worsening of prior neurologic disabilities (n = 3) due to progressive multifocal leukoencephalopathy, toxoplasmic encephalitis, and cryptococcal meningitis occurred between 2 to 25 weeks after the initiation of cART. All patients demonstrated a robust increase in blood CD4(+) T-cell count in response to cART. A brain biopsy in one patient revealed inflammation and necrosis together with CD68(+) macrophage and CD8(+) T-cell infiltrates, which were also CD40 and CD154 immunoreactive. Two patients received corticosteroids as treatment for NeuroIRIS with an overall survival of 86%, while 14% exhibited fixed neurologic disabilities.

CONCLUSIONS: Immune reconstitution inflammatory syndrome in the nervous system (NeuroIRIS) remains an uncommon complication of combination antiretroviral therapy (cART) but with a potentially poor outcome. Initiation of cART in very immunosuppressed patients requires close monitoring to manage NeuroIRIS in an expedient manner.