Comparison of immunodiffusion and crossed-immunoelectrophoresis in the diagnosis of invasive candidiasis.

A retrospective single blind study was conducted to compare the efficacy of crossed-immunoelectrophoresis using concanavalin A intermediate gel with double immunodiffusion tests in the diagnosis of invasive candidiasis. On the basis of cytoplasmic antibody detection, crossed-immunoelectrophoresis with concanavalin A differentiated reliably between Candida albicans fungemia and invasive candida infection, whereas double immunodiffusion did not. With regard to sensitivity, specificity, and predictive value crossed-immunoelectrophoresis with concanavalin A was superior to double immunodiffusion. Analysis of double immunodiffusion precipitin bands revealed fuzzy and sharp precipitin bands which corresponded to mannan (fuzzy) and cytoplasmic (sharp) antibodies in the crossed-immunoelectrophoresis with concanavalin A assay. Therefore, the finding of sharp bands in the double immunodiffusion procedure supports the diagnosis of invasive candidiasis.