Diagnosis of systemic candidiasis: development of co-counterimmunoelectrophoresis.

To improve the results of counterimmunoelectrophoresis for serological diagnosis of candidiasis, a new method was devised to characterize human sera precipitins: co-counterimmunoelectrophoresis. Cellulose acetate was chosen as the support in order to observe identity reactions between precipitin lines from serum systems run conjointly (thus, co-counterimmunoelectrophoresis). Different experimental antisera (anti-somatic and anti-cytoplasmic antigens and anti-whole fixed germ tube antisera) were tested for reactions of identity with sera from selected patients with systemic candidiasis caused by Candida albicans. The reaction of patient sera and anti-germ tube antiserum with a selected somatic antigen always resulted in an identity reaction as proven by the continuity of major precipitin lines. The precipitating system, named the co-specific precipitin line, involved polysaccharide antigens; it was not present in human control sera.