Mycobacteria Tales Post Lung Transplantation: An Indian Experience

Abstract

Purpose Post-lung transplant infection is one of the leading causes of morbidity and mortality. The diagnosis of pulmonary tuberculosis can be even more challenging in the setting of lung transplantation where other pulmonary complications can make diagnosis difficult. Infection may be caused by reactivation of a primary infection in the recipient, reactivation of a lesion from the donor lung, or primary infection. We present a retrospective study from India to define the incidence, clinical presentation, and course of Mycobacterial infections in a cohort of lung transplant recipients. Methods Between 1 April 2017 and 1 September 2020, 140 lung transplants were performed. Serial bronchoscopies with transbronchial biopsies and bronchioalveolar lavages were performed during follow-up. Explant Histopathological findings were taken into consideration. Pleural based interventions in the form of Tapping or CT guided Pleural biopsy were noted. Similarly, NTM infections were documented with species identification on cultures. Results 12 (8.57%) Recipients had Mycobacterial Infections post lung transplant. Mycobacterium Tuberculosis species was diagnosed in 9 patients (75%). Rest 3 recipients (25%) had Non-Tuberculosis Mycobacterium species (2 Mycobacterium abscessus and 1 Mycobacterium fortuitum). In 4 MTB patients, diagnosis was determined from the explanted lungs histopathology. The remainder were diagnosed during postoperative period. Median time to diagnosis was 40.5 days . Radiographic findings (HRCT scan) were Consolidations (n=3), Pleural Effusion (n=3), Tree in Bud (n=1), Cavity (n=1), no typical radiographical presentations (n=4) All patients responded well to anti-mycobacterial therapy. 3 recipients with NTM received individualised treatment for the same. Among these 12 recipients, 3 recipients expired with death attributable to Mycobacterial disease in only 1 recipient. Conclusion Mycobacterial Infection is not rare in lung transplant recipients and can be managed successfully with individualised antimycobacterial therapy. Non-Rifampicin based AntiMycobacterial treatment strategy is preferred to avoid drug interactions with immunosuppressants. Explant Lung Histopathology is an important tool to diagnose Tuberculosis specifically in Indian settings. NTM infection is not uncommon post lung transplantation & should have low threshold for diagnosis.