Treatment outcomes of nontuberculous mycobacterial pulmonary disease in lung transplant recipients

Abstract

Background: Lung transplant (LTX) recipients are at risk miscellaneous infections, among whom the clinical significance of nontuberculous mycobacteria (NTM) is increasingly recognized. Despite anti-mycobacterial therapy becoming standardized worldwide, there is a lack of data on treatment outcomes in LTX recipients who develop NTM-pulmonary disease (PD). We aimed to review the treatment outcomes of NTM-PD among LTX recipients in our center. Methods: Patients who underwent LTX from January 2013 to December 2014 were consecutively enrolled in the retrospective cohort, with follow-up of data retrieved to December 2017. Clinical and radiological improvement and culture conversion after anti-mycobacterial therapy were reviewed in those who developed post-transplant NTM-PD. Results: Sixteen of 230 LTX recipients developed post-transplant NTM-PD. Ten of 16 patients with post-transplant NTM-PD were treated with macrolide-containing anti-mycobacterial therapy, leading to clinical improvement in 5/10 (50%), radiological improvement in 5/10 (50%) and culture conversion in 6/10 (60%) patients. Conclusion:Anti-mycobacterial therapy may relieve pulmonary symptoms and reduce microbial load among individuals with post-transplant NTM-PD. K E Y W O R D Slung transplant (LTX), Mycobacterium avium (MAC), nontuberculous mycobacteria (NTM), respiratory infection, treatment outcome future study. Third, we were also unable to address, in patients with a history of NTM-PD pre-or peri-operatively who were diagnosed with the same species of NTM-PD post-operatively, whether the disease was relapsing with the same strain or a re-infection with a new environmental strain. This issue is further complicated by the large proportion of patients with polyclonal infections in cohorts of patients with NTM-PD. 27 Because of a lack of genotypic analyses in large numbers of specimens from each patient we are unable to address this complex issue.To sum up, treatment outcomes of post-transplant NTM-PD after anti-mycobacterial therapy were reviewed in a large LTX center. A small fraction of LTX recipients developed post-transplant NTM-PD, of whom two third required macrolide-containing antimycobacterial therapy, resulting in clinical and radiological improvement and culture conversion in half patients. It appears that initiating anti-mycobacterial therapy leads to microbiologically favorable outcomes in patients with NTM-PD post-lung transplantation, but larger investigations are required to improve our understanding of this challenging clinical problem and its management. | E THIC AL CONS IDER ATIONThe study protocol (Research Ethics Board # 18-5209) was reviewed by Institutional Review Board of University Health Network. The requirement of informed consent was waived in consideration of the retrospective design.

Prevention and Management of Infections in Lung Transplant Recipients

“…The majority of lung transplant centers require respiratory culture negativity prior to transplant. On the other hand, routine post-transplant bronchoscopies help in the detection of NTM, and timely management can result in improved outcomes [ 4 , 19 , 20 , 21 ].…”