The impact of anti-mould prophylaxis on Aspergillus PCR blood testing for the diagnosis of invasive aspergillosis

Abstract Background The performance of the galactomannan enzyme immunoassay (GM-EIA) is impaired in patients receiving mould-active antifungal therapy. The impact of mould-active antifungal therapy on Aspergillus PCR testing needs to be determined. Objectives To determine the influence of anti-mould prophylaxis (AMP) on the performance of PCR blood testing to aid the diagnosis of proven/probable invasive aspergillosis (IA). Methods As part of the systematic review and meta-analysis of 22 cohort studies investigating Aspergillus PCR blood testing in 2912 patients at risk of IA, subgroup analysis was performed to determine the impact of AMP on the accuracy of Aspergillus PCR. The incidence of IA was calculated in patients receiving and not receiving AMP. The impact of two different positivity thresholds (requiring either a single PCR positive test result or ≥2 consecutive PCR positive test results) on accuracy was evaluated. Meta-analytical pooling of sensitivity and specificity was performed by logistic mixed-model regression. Results In total, 1661 (57%) patients received prophylaxis. The incidence of IA was 14.2%, significantly lower in the prophylaxis group (11%–12%) compared with the non-prophylaxis group (18%–19%) (P