HIV patients with low CD4 cell counts may benefit from cryptococcal antigen screening

Screening for cryptococcal antigens in HIV patients with CD4 cell counts ≤100 cells/mcL and who are at risk for cryptococcal meningitis may reduce incidence of the disease.

Researchers involved in an antiretroviral therapy (ART) program in South Africa conducted a retrospective study involving 707 participants with average CD4 cell counts of 97 cells/mcL (interquartile range, 46-157 cells/mcL).

Cryptococcal antigens were detected in 46 (7%) of the 707 participants. New or relapsed cryptococcal meningitis developed in 13 (28%) of those antigen-positive patients. There were no cases of cryptococcal meningitis among the 661 participants who had negative antigen test results.

Antigenemia was 100% sensitive in predicting the development of cryptococcal meningitis within one year of ART initiation, according to results. Further analysis demonstrated that antigenemia also predicted mortality (95% CI, 1.5-6.6). Fourteen (34%) of 41 patients who tested positive for antigens died during the first year of ART.

Cryptococcal meningitis developed in 92% of patients with CD4 cell counts ≤100 cells/mcL. In patients with no prior history of cryptococcal meningitis, an antigen titer of ≥1:8 was 100% sensitive and 96% specific in predicting disease incidence during the first year of ART.

Jarvis J. Clin Inf Dis. 2009;48:856-862.