Antigenic variation within serotypes of Cryptococcus neoformans detected by monoclonal antibodies specific for the capsular polysaccharide.

The serotype-specific polysaccharide was isolated from four to seven strains of each of the four major serotypes of Cryptococcus neoformans. Reactivities of polysaccharides with seven monoclonal antibodies raised against polysaccharides of serotypes A, B, C, and D were assessed by an enzyme-linked immunosorbent assay and double immunodiffusion. The results indicated that there is heterogeneity within all four serotypes in the expression of epitopes reactive with monoclonal antibodies.