Diagnosis of disseminated candidiasis in hospitalized patients using the Cand-Tec latex agglutination assay

Abstract

A total of 1,303 sera from 202 patients at risk for disseminated candidiasis were analyzed for the presence of Candida antigen using a commercially available latex agglutination test (Cand-Tec). Twenty-three patients had disseminated candidiasis documented by positive blood cultures, deep biopsy culture and histopathology or autopsy. Six patients had transient candidemia, 15 patients had candiduria, 62 patients were not colonized yet treated empirically with amphotericin B, and 46 patients were not colonized and not treated with amphotericin B. The sensitivity and specificity of the Candida antigen test for the diagnosis of disseminated candidiasis was 87% and 36% (threshold titer of greater than or equal to 1:2), 70% and 60% (greater than or equal to 1:4), and 30% and 85% (greater than or equal to 1:8), respectively. In contrast to previous studies we were unable to demonstrate a prognostic role for the Candida antigen test in patients with documented disseminated candidiasis. The lack of sensitivity and specificity of the Cand-Tec Candida antigen test precludes its use in the diagnosis of disseminated candidiasis.

Diagnostic Immunology

“…Of the available tests, the earliest was the Cand-Tec LA assay (Ramco Laboratories, Stafford, TX), which was designed to detect circulating Candida antigen in patients with serious, disseminated infection. Unfortunately, there are conflicting reports on its overall sensitivity and specificity, especially in patients with renal failure or rheumatoid factor positivity, making it difficult to confirm the diagnosis of candidiasis by the Cand-Tec assay alone [20,21]. The mannan component of the Candida cell wall is a major antigen and the target of many serum detection assays.…”