The Platelia Candida antigen and antibody assays (Bio-Rad Laboratories) were used to test serial serum samples from seven neutropenic adult patients with haematological malignancies, who had developed a systemic Candida tropicalis infection. The diagnosis of candidiasis was based on a positive blood culture (all seven cases) and the isolation of C. tropicalis from a normally sterile site (six cases). All patients received early antifungal therapy with amphotericin B and/or an azole derivative, and had a successful outcome. When the combined assays were applied to sera collected at different time points before and after the first positive blood culture, all patients tested positive. In six cases, at least one positive test was obtained on sera collected on average 5 days prior to the first positive blood culture (range: 2•••• 10 days), while blood cultures were constantly negative. A high and persistent mannanaemia was detected in all patients during the neutropenic period. In five cases, an increased antibody response was detected when the patients recovered from aplasia. Controls consisted of 48 serum samples from 12 febrile neutropenic patients with aspergillosis (n = 4), bacteraemia (n = 4), or with no evidence of infection (n = 4). A low level of mannanaemia was detected in one serum sample only, and none showed significant Candida antibody titres. Our data thus confirm the value of the combined detection of mannanaemia and anti-mannan antibodies in individuals at risk of candidaemia, and suggest that in neutropenic patients, an approach based on the regular monitoring of both markers could contribute to the earlier diagnosis of C. tropicalis systemic infection.
Full conference title:
The 15 th Congress of the International Society for Human and Animal Mycology
- ISHAM 15th (2003)