PRELIMINARY EVALUATION OF PURIFIED ANTIGE N (AG3D9, AG48) USED FOR THE SERODIAGNOSIS OF SYSTEMIC CANDIDOSIS BY ENZYME-LINKED-IMMUNOSORBENT-ASSAY (ELISA)

Purpose. To improve the serological diagnosis of systemic candidiasis, we used two different purified antigens of Candida albicans to study the IgG humoral response by ELISA (Enzyme Linked ImmunoSorbent Assay). Materials and methods. The antigen 48 is a cytoplasmic antigen with a n enolase activity and was purified by ion exchange chromatography. Th e antigen 3D9 is a mannoprotein C. albicans germ-tube specific antigen , purified by gel filtration and hydrophobic interaction chromatograph y. Sera were obtained from patients with systemic candidosis (n = 37), vaginal candidosis (n = 14), aspergillosis (n = 11) and from blood do nors (n = 18). Results. Statistical analysis showed significant differ ences between absorbance values obtained with sera of the population o f patients with systemic candidiasis and with sera of the three other populations (p < 0.0001). On the contrary, there was no significant di fference (p > 0.3) between absorbance values obtained in populations o f patients with vaginal candidosis, aspergillosis and blood donors. We obtained sensitivity and specificity values of 73 and 95,5 % respecti vely with IgG anti-Ag48 and of 78 and 82 % respectively with Ige anti- Ag3D9, Positive predictive value and negative predictive value were 90 and 80 % respectively with IgG anti-Ag48 and they were 84 and 84 % re spectively with IgG anti-Ag3D9. Conclusion. Diagnostic parameters (spe cificity, sensitivity) were satisfactory and showed the usefulness of these antigens to determine IgG anti-Ag3D9 and IgG anti-Ag48 for the d iagnosis of systemic candidosis.