detection of antibodies to candida albicans germ tube by immunofluorescence in immunosuppressed mice with experimental systemic candidiasis

the increasing incidence of systemic candidiasis, which parallels the use of invasive and immunosuppressive medical procedures, necessitates development of rapid and cost effective tests for diagnosis of systemic candidiasis. therefore in this study 85 mice were first immunosuppressed by cyclophosphamide and then infected by candida albicans ncpf 3153. other 85 mice were employed as control. the case and control mice were bled and then autopsied. hearts and kidneys were checked by direct, histopathological and cultural examination for systemic candidiasis. the 85 sera from histological proven cases and 85 control mice were adsorbed with heat killed blastospores of same strain of c. albicans . anti-candida albicans germ tube antibodies were detected by indirect immunofluorescence assay for diagnosis of invasive candidiasis in case and control mice. in addition, sera from 35 mice with proven cryptococcosis were also tested. while 84 mice with proven systemic candidiasis (100%) had anti-germ tube antibodies, these antibodies were absent in all controls and mice with cryptococcosis. the specificity was 100%, indicating a high degree of discrimination was possible between systemic candidiasis and cryptococcosis in the mice studied. it must be concluded that anti-germ tube responses did not appear to be significantly reduced in immunocompromised mice.