Transbronchial cryobiopsy in immunocompromised patients with pulmonary infiltrates: A pilot study

Background: In immunocompromised patients with pulmonary infiltrates, transbronchial lung biopsies (TBB) obtained by forceps has been shown to increase the diagnostic yield over simple bronchoalveolar lavage. Cryo-TBB is a novel modality for obtaining lung biopsies. We aimed to evaluate for the first time the efficacy and safety of cryo-TBB in immunocompromised patients. Methods: Fifteen immunocompromised patients with pulmonary infiltrates underwent cryo-TBB. During the procedure two to three biopsy samples were taken. Procedure characteristics, complications, and the diagnostic yield were retrospectively evaluated. Results: Most patients (n = 11) were immunocompromised due to hematological malignancies. The remaining four patients were receiving chronic immunosuppressive treatment due to previous solid-organ transplantation (n = 2) or collagen-vascular disease (n = 2). No major complications occurred in the cryo-TBB group. The mean surface area of the specimen taken by cryo-TBB was 9 mm². The increase in surface area and quality of biopsy samples translated to a high percentage of alveolated tissue (70 %) that enabled a clear histological detection of the following diagnoses: noncaseating granulomatous inflammation (n = 2), acute interstitial pneumonitis consistent with drug reaction (n = 5), nonspecific interstitial pneumonia fibrotic variant (n = 1), diffuse alveolar damage (n = 3), organizing pneumonia (n = 3), and pulmonary cryptococcal pneumonia (n = 1). Diagnostic information obtained by cryo-TBB led to change in the management of 12 patients (80 %). Conclusion: Cryo-TBB in immunocompromised patients with pulmonary infiltrates provides clinically important diagnostic data with a low complication rate. These advantages should be further compared with traditional forceps TBB in a prospective randomized trial.