Coexistence of free antigens, free antibodies and immune complexes in sera from patients with suspected deep-seated candidosis.

Two commercially available latex agglutination tests: Cand-TEC(TM) from RAMCO Laboratories, Inc., Houston, Texas, USA, for the detection of a heat labile Candida antigen, and LA-Candida Antigen Detection System from Immuno-Mycologics (IMMY), Inc., Norman, Oklahoma, USA, for the detection of Candida mannan antigen, and Own LAT, a self-prepared latex agglutination test for the detection of Candida mannan antigen were tested on 467 sera of patients at risk for deep-seated Candidosis. Separate, parallel investigations were made to demonstrate anti-Candida antibodies (3 methods), circulating immune complexes (not antigen-specific, 2 methods), and rheumatoid factor (2 methods). Specificity and sensitivity of the mannan antigen detection systems were studied. Conditions of specific and non-specific mannan binding to antisera were studied in a defined mannan-antiserum system. The potential and the limitations of the Candida mannan antigen and protein antigen detection systems using latex particle agglutination are evaluated.