Neurocognitive function in HIV-infected persons with asymptomatic cryptococcal antigenemia: a comparison of three prospective cohorts

BACKGROUND: HIV-infected persons with detectable cryptococcal antigen (CrAg) in blood have increased morbidity and mortality compared with HIV-infected persons who are CrAg-negative. This study examined neurocognitive function among persons with asymptomatic cryptococcal antigenemia. METHODS: Participants from three prospective HIV cohorts underwent neurocognitive testing at the time of antiretroviral therapy (ART) initiation. Cohorts included persons with cryptococcal meningitis (N = 90), asymptomatic CrAg + (N = 87), and HIV-infected persons without central nervous system infection (N = 125). Z-scores for each neurocognitive test were calculated relative to an HIV-negative Ugandan population with a composite quantitative neurocognitive performance Z-score (QNPZ-8) created from eight tested domains. Neurocognitive function was measured pre-ART for all three cohorts and additionally after 4 weeks of ART (and 6 weeks of pre-emptive fluconazole) treatment among asymptomatic CrAg + participants. RESULTS: Cryptococcal meningitis and asymptomatic CrAg + participants had lower median CD4 counts (17 and 26 cells/μL, respectively) than the HIV-infected control cohort (233 cells/μL) as well as lower Karnofsky performance status (60 and 70 vs. 90, respectively). The composite QNPZ-8 for asymptomatic CrAg + (−1.80 Z-score) fell between the cryptococcal meningitis cohort (−2.22 Z-score, P = 0.02) and HIV-infected controls (−1.36, P = 0.003). After four weeks of ART and six weeks of fluconazole, the asymptomatic CrAg + cohort neurocognitive performance improved (−1.0 Z-score, P < 0.001). CONCLUSION: Significant deficits in neurocognitive function were identified in asymptomatic CrAg + persons with advanced HIV/AIDS even without signs or sequelae of meningitis. Neurocognitive function in this group improves over time after initiation of pre-emptive fluconazole treatment and ART, but short term adherence support may be necessary. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12883-017-0878-2) contains supplementary material, which is available to authorized users.