Specificity of the latex test for cryptococcal antigen: a rapid, simple method for eliminating interference factors.

An enzymatic method involving a protease (pronase) for the elimination of interference factors in the latex test for cryptococcal antigen was developed and compared with dithiothreitol treatment. The two were equivalent in their ability to remove interference factors; however, the enzymatic method generally yielded higher titers. The method is simple, requires only 20 min, and makes the latex test for cryptococcal antigen specific.