Arthur W Baker

Background Lung transplant recipients are at increased risk of Mycobacterium abscessus complex (MABC) acquisition and invasive infection. We analyzed risk factors and outcomes of early post-lung transplant MABC acquisition. Methods We conducted a retrospective matched case-control study of patients who underwent lung transplant from 1/1/2012–12/31/2021 at a single large tertiary care facility. Cases had de novo MABC isolation within 90 days post-transplant. Controls had no positive MABC cultures and were matched 3:1 with cases based on age and transplant date. Recipient demographics and pre-/peri-operative characteristics were analyzed, and a regression model was used to determine independent risk factors for MABC acquisition. We also assessed one-year post-transplant outcomes, including mortality. Results Among 1,145 lung transplants, we identified 79 cases and 237 matched controls. Post-transplant mechanical ventilation for >48 hours was independently associated with MABC acquisition (Adjusted OR, 2.46 [95% CI, 1.29–4.72]; P = .007). Compared to controls, cases required more days of hospitalization after the MABC index date (28 vs. 12 days; P = .01) and had decreased one-year post-transplant survival (78% vs. 89%; Log rank P = .02). One year mortality appeared highest for cases who acquired M. abscessus subsp. abscessus (31% mortality) or had extrapulmonary infections (43% mortality). Conclusions In this large case-control study, prolonged post-transplant ventilator duration was associated with early post-lung transplant MABC acquisition, which in turn was associated with increased hospital days and mortality. Further studies are needed to determine the best strategies for MABC prevention, surveillance, and management.