PCR and other non‐culture methods for diagnosis of invasive Candida infections in allogeneic bone marrow and solid organ transplant recipients

Abstract

In this prospective study 197 serum and 152 urine samples were collected from 40 bone marrow and solid organ transplant recipients with clinically suspected invasive fungal infection before, during and after empirical treatment with lipid formulation of amphotericin B or fluconazole. Serum was analysed by Candida polymerase chain reaction (PCR) and urine by measurement of d/l-arabinitol ratio. One serum from each patient was also tested for concentration of (1→3)-β-glucan and two commercial Candida antigens. Invasive fungal infection was diagnosed in four candidosis and one aspergillosis patients (13%). Positive PCR, elevated d/l-arabinitol ratio, (1→3)-β-glucan concentration and antigens were detected in nine, 15, 17, and seven patients, respectively. The agreement between PCR and d/l-arabinitol assays was poor. However, 56% agreement was observed between positive PCR and β-glucan and/or antigen assays, and 60% agreement between positive d/l-arabinitol and β-glucan and/or antigen assays. Combination of several non-culture assays is needed to diagnose invasive fungal infection in high-risk transplant recipients. No single test was sufficient for diagnosis.