Risk factors for nontuberculous mycobacterial infections in solid organ transplant recipients: a case-control study

Background The epidemiology of nontuberculous mycobacteria (NTM) disease in solid organ transplant recipients is poorly defined. Methods We identified all solid organ transplant recipients with NTM disease at a single center over a 7.5‐year period, and collected data on patient demographics, co‐morbidities, immunosuppressive medications, and rejection. We conducted a case–control study to identify risk factors for disease, matching 3 control patients to each case patient by date of transplantation. Results A total of 34 cases of NTM disease occurred during the study period, involving 6 single lung, 13 bilateral lung, 8 heart, 4 liver, 2 kidney, and 1 pancreas‐kidney recipients. Cases were predominantly male (24/34), with a median age of 55 years (interquartile range [IQR]: 46–61 years), and developed after a median of 8 months post transplantation (IQR: 2–87 months). Mycobacterium abscessus and Mycobacterium avium complex were the most common pathogens, and the lung (including pleura) was the most common site of disease. In the adjusted case–control analysis, lung transplant recipients had the highest risk of NTM disease. Conclusions Additional studies are needed to evaluate the role of targeted surveillance measures for NTM disease in high‐risk patients, particularly lung transplant recipients, and to characterize the mechanisms of disease acquisition.