Detection of capsular polysaccharide antigen of Cryptococcus neoformans in patients with AIDS and neurocryptococcosis in São Paulo, Brazil

Capsular polysaccharide antigen (AgPC) of Cryptococcus neoformans was detected by latex agglutination technique (LA) in cerebrospinal fluid and serum of patients with AIDS during their first central nervous system manifestation of the disease. Direct mycological examination and culture were used as controls. Sensitivity was 100% by LA allowing an early specific treatment of cryptococcosis. Initial titres of AgPC in such patients can be > 1000000 and it appears that when such titres are present in the serum they are related to mortality during treatment. Surviving patients showed positivity of the direct mycological examination and AgPC of C. neoformans in cerebrospinal fluid and sera even after treatment and clinical recovery.