The role of transbronchial cryobiopsy in the detection of pulmonary GvHD.

Unlabelled: Purpose of the study We investigated the incidence of chronic pulmonary complications in allogeneic hematopoietic cell transplantation (allo-HCT) recipients and analyzed the role of transbronchial cryobiopsy (cryoTBB) as a tool to determine the nature of pulmonary changes and to guide clinical decisions.

Methods: Patients who survived at least 6 months post HCT were included in the study. Pulmonary functional tests (PFTs) were performed in all patients as a screening tool. In case of abnormal results computed tomography (CT) was done to verify inflammatory changes and the presence of air-trapping. Next, patients were qualified for microbiological analysis of bronchoalveolar lavage fluid. If the results of non-invasive tests were inconclusive, cryoTBB was performed.

Results: Among 186 patients, we identified 13 cases (7%) with abnormal PFTs. Mild, moderate, and severe chronic graft versus host disease (GvHD) was diagnosed in 1 (8%), 6 (46%), and 2 (15%) patients, respectively. Four (31%) patients did not present any manifestations of cGvHD at FEV1 decline. Eight 8 (62%) patients met the bronchiolitis obliterans syndrome criteria, 5 (48%) had restrictive disease, or mixed phenotype based on PFTs, only in 1 case air-trapping was present in CT. Pulmonary GvHD was confirmed by cryoTBB histopathology in 5 of 11 (45%) cases. Immunosuppression was either stopped or decreased in 6 patients with negative results for GvHD with further clinical improvement.

Conclusion: CryoTBB can be a helpful tool to verify the cause of chronic pulmonary complications in the HCT population. Based on negative biopsy results, some patients may benefit from IST discontinuation or reduction to mitigate recurrences of infectious complications and further lung destruction.