INTRODUCTION: Bronchiolitis obliterans syndrome (BOS) and native lung hyperinflation with extrinsic transplant compression causing decline in baseline FEV1 has been described in single lung transplant recipients for severe COPD. Recently restrictive allograft syndrome (RAS) has been described in bilateral lung transplant patients as decline in FEV1 and TLC accompanied by interstitial infiltrate and volume loss of the transplanted lungs. We present a case of progressive FEV1 decline in a single lung recipient with interstitial infiltrates and volume loss suggestive of restrictive allograft syndrome.
CASE PRESENTATION: 62 yo CMV -/+, EBV +/+ three years s/p left lung transplant for severe COPD and alpha one antitrypsin deficiency presents with progressive FEV1 decline. Early post-operative course was complicated by MRSA pneumonia and empyema at 1 month with acute decline in FEV1. Surveillance transbronchial biopsies at 1, 3, and 4 months were negative for rejection. FEV1 improved at 12 months post operatively and remained stable until 30 months when he reported progressive dyspnea. Work-up including transbronchial biopsy and BAL were negative. Diffuse infiltrates were noted in the transplant lung and empiric posaconazole and antibiotics were started at 31 months. Native lung hyperinflation with mediastinal shift to the left was noted. Over a 6 month period, chest imaging demonstrated progressive infiltrate and volume loss in the transplanted lung. Repeat transbronchial biopsy noted ISHLT A1, B0, C0, D1 with organizing pneumonia, diffuse alveolar damage and no bronchiolitis obliterans. Empiric anti-infection as well as high dose pulse steroids given during hospitalization provided no clinical or radiographic improvement. The patient was evaluated for LVRS or repeat lung transplantation and was not a candidate.
DISCUSSIONS: We report a case of progressive transplant lung fibrosis with infiltrates and volume loss in a patient with clinical BOS. Although complicated by infection early post-transplant, subsequent bronchoscopic evaluations were negative for infection, and changes made to immunosuppression and antimicrobials provided no clinical or radiographic improvement. There is recent interest in non-obstructive rejection known as restrictive allograft syndrome, defined by serial drops in TLC > 10% as reported by Sato et al1. Findings of diffuse alveolar damage with alveolar fibrosis were found on biopsy and resulted in subsequent lung restriction. Pakhale et al also noted bilateral upper lobe fibrosis as a unique manifestation of BOS in patients with bilateral transplant presenting with primarily restrictive pattern2. We propose restrictive physiology was not seen in our patient because of severe and progressive underlying native lung emphysematous disease. Unfortunately, allograft dysfunction was not controlled by aggressive immunosuppression or antimicrobial therapy.
CONCLUSION: Fibrosis with significant volume loss may be a manifestation of restrictive allograft syndrome. The question remains as to whether RAS is a variant of BOS or a unique entity of chronic graft dysfunction.
DISCLOSURE: Teng Moua, No Financial Disclosure Information; No Product/Research Disclosure Information