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

The epidemiology of nontuberculous mycobacteria (NTM) disease in solid organ transplant recipients is poorly defined.

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.

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.

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.