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.