Roles of the multiplex real-time PCR assay and β-D-glucan in a high-risk population for intra-abdominal candidiasis (IAC)

Abstract

Multiplex quantitative real-time PCR (MRT-PCR) using blood can improve the diagnosis of intra-abdominal candidiasis (IAC). We prospectively studied 39 patients with suspected IAC in the absence of previous antifungal therapy. Blood cultures, MRT-PCR, and β-D-glucan (BDG) in serum were performed in all patients. IAC was defined according to the 2013 European Consensus criteria. For MRT-PCR, the probes targeted the ITS1 or ITS2 regions of ribosomal DNA. Candidaemia was confirmed only in four patients (10%), and IAC criteria were present in 17 patients (43.6%). The sensitivity of MRT-PCR was 25% but increased to 63.6% (P = .06) in plasma obtained prior to volume overload and transfusion; specificity was above 85% in all cases. BDG performance was improved using a cutoff > 260 pg/ml, and improvement was not observed in samples obtained before transfusion. In this cohort of high risk of IAC and low rate of bloodstream infection, the performance of non-culture-based methods (MRT-PCR or BDG) was moderate but may be a complementary tool given the limitations of diagnostic methods available in clinical practice. Volume overload requirements, in combination with other factors, decrease the accuracy of MRT-PCR in patients with IAC.

Keywords: Candida spp; multiplex PCR; peritonitis.