A comparison of the specificity and sensitivity of two Candida antigen assay systems for the diagnosis of deep candidiasis in patients with hematologic diseases.

BACKGROUND

Latex agglutination assay for detection of circulating Candida antigen (Cand-Tec, Ramco Laboratories), which is now commercially available, provides a rapid and simple means for the diagnosis and management of deep-seated Candida infections.

MATERIAL/METHODS: The Cand-Tec microtiter system (Cand-Tec MT, Ramco Japan), new latex agglutination assay for Candida antigen, expresses Candida antigen level as the cutoff index (C.I.) value by means of colorimetric analysis and is expected to be more objective method.

RESULTS

In this study, we evaluated the advantages, if any, of Cand-Tec MT compared with the original Cand-Tec for the diagnosis of deep-seated Candida infections in 25 patients with hematologic diseases. A total of 80 serum specimens were taken from the patients when they showed febrile neutropenia and were suspected of having infectious disease. The C.I. value in Cand-Tec MT well correlated with the Cand-Tec titer. The sensitivity and specificity of Cand-Tec MT were 100% and 80%, respectively. The change in C.I. value in the sera was followed up during antifungal therapy. The C.I. value decreased in 75% of cases that responded to antifungal therapy, but did not show any tendency in non-responsive cases. In some cases, the C.I. value showed improvement corresponding to the therapeutic effect, while the Cand-Tec titer did not.

CONCLUSIONS

Cand-Tec MT is a useful method for the early diagnosis and accurate evaluation of the therapeutic effect of systemic candidiasis.