Three serologic tests for candidiasis. Diagnostic value in distinguishing deep or disseminated infection from superficial infection or colonization

Abstract

One hundred fifty-one sera from 100 hospitalized patients with positive cultures for yeasts were assayed using whole-cell agglutination (Aggl.), agar gel diffusion (AGD), and counterimmunoelectrophoresis (CEP) to determine the relative diagnostic values of three serologic tests for anti-Candida antibodies. Serial samples were obtained from 29 patients. Tests were read blindly; correlations of the three test results with culture results and clinical findings were determined only after all data had been accumulated. Thirty-five of 100 patients had Aggl. titers of 1:160 or greater, although 13/35 had no evidence of deep or disseminated disease. Twenty-four of 100 patients had clinical or autopsy evidence of deep or disseminated candidiasis; 22/24 had Aggl. titers of 1:160 or greater. Twenty of the 24 patients were CEP-positive, whereas 18/24 were AGD-positive. In five patients CEP became positive earlier (10--21 days) than AGD. Three patients had false-positive precipitin tests, two by both CEP and AGD and the third by CEP only. In this population, a positive CEP and a positive AGD test showed good correlation with deep or disseminated candidiasis, whereas a negatvie Aggl. test showed the best correlation for excluding deep or systemic candidiasis.