PLoS ONE (2019) Coussement

Nocardia polymerase chain reaction (PCR)-based assay performed on bronchoalveolar lavage fluid after lung transplantation: A prospective pilot study.

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Authors Julien Coussement(1), David Lebeaux(2), Najla El Bizri(3), Vincent Claes(3), Michel Kohnen(3), Deborah Steensels(3), Isabelle Étienne(4), Hélène Salord(5), Emmanuelle Bergeron(6), Veronica Rodriguez-Nava(6) Affiliations (1) Department of Infectious Diseases, CUB-Hôpital Erasme, Université Libre de Bruxelles, Brussels, Belgium. (2) Service de Microbiologie, Unité Mobile de Microbiologie Clinique, Assistance Publique-Hôpitaux de Paris, Hôpital Européen Georges Pompidou, Université Paris Descartes, Sorbonne Paris Cité, Paris, France. (3) Department of Microbiology, CUB-Hôpital Erasme, Université Libre de Bruxelles, Brussels, Belgium. (4) Lung Transplantation Unit, CUB-Hôpital Erasme, Université Libre de Bruxelles, Brussels, Belgium. (5) Laboratoire de Bactériologie, Hôpital de la Croix-Rousse, Lyon, France. (6) Research Group on Bacterial Opportunistic Pathogens and Environment, UMR CNRS5557, INRA1418 Écologie Microbienne, Observatoire Français des Nocardioses, Hospices Civils de Lyon, France, Université de Lyon 1, VetAgro Sup, Lyon, France. In PloS one, (2019) On line

Abstract

BACKGROUND

Transplant recipients are at risk of pulmonary nocardiosis, a life-threatening opportunistic infection caused by Nocardia species. Given the limitations of conventional diagnostic techniques (i.e., microscopy and culture), a polymerase chain reaction (PCR)-based assay was developed to detect Nocardia spp. on clinical samples. While this test is increasingly being used by transplant physicians, its performance characteristics are not well documented. We evaluated the performance characteristics of this test on bronchoalveolar lavage (BAL) fluid samples from lung transplant recipients (LTRs).

METHODS

We prospectively included all BAL samples from LTRs undergoing bronchoscopy at our institution between December 2016 and June 2017 (either surveillance or clinically-indicated bronchoscopies). Presence of microbial pathogens was assessed using techniques available locally (including microscopy and 10-day culture for Nocardia). BAL samples were also sent to the French Nocardiosis Observatory (Lyon, France) for the Nocardia PCR-based assay. Transplant physicians and patients were blinded to the Nocardia PCR results.

RESULTS

We included 29 BAL samples from 21 patients (18 surveillance and 11 clinically-indicated bronchoscopies). Nocardiosis was not diagnosed in any of these patients by conventional techniques. However, Nocardia PCR was positive in five BAL samples from five of the patients (24%, 95% confidence interval: 11-45%); four were asymptomatic and undergoing surveillance bronchoscopy, and one was symptomatic and was later diagnosed with influenza virus infection. None of the five PCR-positive patients died or were diagnosed with nocardiosis during the median follow-up of 21 months after the index bronchoscopy (range: 20-23 months).

CONCLUSIONS

In this prospective study, Nocardia PCR was positive on BAL fluid from one fourth of the LTRs. Nocardia PCR-based assays should be used with caution on respiratory samples from LTRs because of the possible detection of airway colonization using this technique. Larger studies are required to determine the usefulness of the Nocardia PCR-based assay in transplant recipients.

See also

External links

• Link toward PubMed