Nontuberculous mycobacterial infection after lung transplantation: A single-center experience in South Korea.

Abstract

Nontuberculous mycobacteria (NTM) infection is an important issue after lung transplantation. However, a large-scale epidemiological study on this issue in Korea is lacking. We aimed to evaluate the epidemiology of NTM infection after lung transplant surgery in Korea. Between October 2012 and December 2018, we retrospectively evaluated lung transplant recipients in a referral hospital in South Korea. A total of 215 recipients were enrolled. The median age at transplantation was 56 years (range, 17-75), and 62% were men. Bronchoscopy was performed according to the surveillance protocol and clinical indications. A diagnosis of NTM infection was defined as a positive NTM culture from a bronchial washing, bronchoalveolar lavage sample, or two separate sputum samples. We determined NTM pulmonary disease (NTM-PD) according to the American Thoracic Society/Infectious Disease Society of America 2007 guidelines. The Kaplan-Meier method and log-rank test were used for conditional survival analysis in patients with follow-up of ≥12 months. Fourteen patients (6.5%) were diagnosed with NTM infection at a median of 11.8 months (range, 0.3-51.4) after transplantation. Nine patients (4.2%) were diagnosed with NTM-PD, and the incidence rate was 1980/100,000 person-years. Mycobacterium abscessus was the most common species causing NTM-PD (66%), followed by M. avium complex (33%). The presence of NTM infection did not influence all-cause mortality among those who underwent follow-up for ≥12 months (N=133, log-rank P=0.816). The incidence of NTM-PD was considerably high among lung-transplant recipients. M. abscessus was the most common causative species of NTM-PD after lung transplantation.