[Comparative study of 2 technics for the diagnosis of invasive candidiasis]

We evaluate test for the detection of antibodies against-Candida albicans by indirect immunofluorescence (Candida Spot-IF, BioMérieux, Lyon, France and a test developed in our laboratory to detect anti-germ tube antibodies) comparatively for the serodiagnosis of invasive candidiasis.

A total of 121 sera from 62 patients were studied retrospectively. They were divided into two groups: group I included 71 sera from 28 patients with invasive candidiasis and group II, used as control, included 50 sera from 34 patients with non-invasive candidiasis or without evidence of infection by Candida.

Eighty-two percent of group I samples presented anti-germ tube antibodies and 57% of the patients in this group were positive by the Candida Spot-IF test. Both techniques were negative in 5 patients. Five patients in group II showed false positive results by Candida Spot-IF and two of them presented anti-germ tube antibodies also. Both techniques presented a poor correlation (R2 = 0.159; p < 0.001). Detection of anti-germ tube antibodies showed a sensitivity of 82% and a specificity of 94% and Candida Spot-IF showed a sensitivity of 57% and a specificity of 85%. Detection of anti-germ tube antibodies in immunocompetent patients showed a sensitivity of 90% but it decreased to 62% in immunocompromised patients. With the Candida Spot-IF test the sensitivity was 70 and 25%, respectively.

The detection of anti-germ tube antibodies was more sensitive and specific than detection of antibodies by the Candida Spot-IF test and it can be used for the serodiagnosis and follow up of patients with invasive candidiasis.