Utility of BioFire FilmArray Pneumonia Panel Plus in a High-Risk Cohort: Children Post Allogeneic Stem Cell...

Pulmonary complications due to infection contribute significantly to post-haematopoietic stem cell transplant (HCT) morbidity and mortality. Standard microbiological investigations, when performed on bronchoalveolar lavage (BAL) fluid, can take days to weeks to confirm a diagnosis. We aimed to determine the diagnostic performance of the BioFire FilmArray pneumonia panel plus (FA-PP), a multiplex polymerase chain reaction (PCR) panel that detects 18 bacterial and nine viral targets, when applied to BAL obtained by flexible bronchoscopy, in children undergoing HCT.

We performed a single-centre prospective observational study in children undergoing allogeneic HCT, who underwent BAL pre- and post-HCT. To determine the diagnostic performance of the FA-PP, we measured the positive and negative concordance, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV), compared with standard microbiological investigations, which was considered the gold standard. The clinical impact of the FA-PP was also qualitatively measured.

This study enrolled 16 children who had 31 BAL samples collected, both pre- and post-HCT. In total, there were seven patients who underwent eight BALs while symptomatic, and 50% (4/8) of these results were concordant between FA-PP and standard microbiological investigations. In the 13 patients who had 23 BALs collected while asymptomatic, 78% (18/23) of these results were concordant. In the cohort as a whole, sensitivity, specificity, PPV and NPV were 100%, 78%, 54% and 100%, respectively. In 50% (4/8) of patients who underwent a BAL while symptomatic, the FA-PP resulted in a hypothetical or actual clinical change, compared to 22% (5/23) of patients who underwent an asymptomatic BAL.

In conclusion, we report the first prospective evaluation of the diagnostic performance of the FA-PP in BAL, in a high-risk paediatric HCT cohort. We demonstrate that the FA-PP is a potentially useful adjunct to traditional standard microbiological investigations that can provide clinically impactful diagnostic information.