Mycobacterial infections in lung transplant recipients

Immunosuppression and chronic lung disease are known risk factors for mycobacterial infection and might be expected to develop with an increased frequency in lung transplant recipients. We therefore sought to document the incidence and type of mycobacterial infections in a large lung transplant program.

A retrospective review of 219 transplant procedures (60 single lung transplants and 159 double lung transplants) in 210 patients was conducted. All patients had scheduled surveillance bronchoscopies at 3, 6, 9, 12, 18, and 24 months, and yearly thereafter. BAL samples were processed routinely for mycobacterium.

Eight patients (3.8%) had evidence of infection (5 men, 3 women; age range, 26 to 63 years). The reasons for transplant were obstructive lung disease (six), cystic fibrosis (one), and pulmonary fibrosis (one). Five recipients had infection in their native lungs; two of five cultured mycobacterium from BAL following transplantation. At least four of five patients had nontuberculous mycobacterium (one showed acid fast bacilli and granuloma on a biopsy specimen that was not sent for culture). None of the five developed disease (mean follow-up = 22 months; range, 3 to 30 months). The organisms were Mycobacterium avium complex (three), Mycobacterium xenopi (one), and unidentified (one). Of the three remaining patients who developed infection after transplantation, one grew Mycobacterium chelonae and the others grew Mycobacterium tuberculosis (both received double lung transplants and had no evidence of mycobacterium in their native lungs). The only definite symptomatic disease occurred in the patients with M tuberculosis, one of whom had evidence of dissemination. The patients with M tuberculosis responded to standard treatment. There have been no deaths due to mycobacterium.

Mycobacterial disease rarely occurs following lung transplantation. Cultures for mycobacterium in surveillance BALs in the absence of symptoms are likely unnecessary.