Twenty-year survival following lung transplantation

Background: Lung transplantation median survival has seen improvements due to recognition of short-term survival factors but continues to trail behind other solid organs due to limited understanding of long-term survivorship. Given the creation of the United Network for Organ Sharing (UNOS) database in 1986, it was difficult to accrue data on long-term survivors until recently. This study characterizes factors impacting lung transplant survival beyond 20 years, conditional to 1-year survival.

Methods: Lung transplant recipients listed in UNOS from 1987 to 2002 who survived to 1 post-transplant year were reviewed. Kaplan-Meier and adjusted Cox regression analyses were performed at 20 and 10 years to identify risk factors associated with long-term outcomes independent of their short-term effects.

Results: A total of 6,172 recipients were analyzed, including 472 (7.6%) recipients who lived 20+ years. Factors associated with increased likelihood of 20-year survival were female-to-female gender match, recipient age 25-44, waitlist time >1 year, human leukocyte antigen (HLA) mismatch level 3, and donor cause of death: head trauma. Factors associated with decreased 20-year survival included recipient age ≥55, chronic obstructive pulmonary disease/emphysema (COPD/E) diagnosis, donor smoking history >20 pack-years, unilateral transplant, blood groups O&AB, recipient glomerular filtration rate (GFR) <10 mL/min, and donor GFR 20-29 mL/min.

Conclusions: This is the first study identifying factors associated with multiple-decade survival following lung transplant in the United States. Despite its challenges, long-term survival is possible and more likely in younger females in good waitlist condition without COPD/E who receive a bilateral allograft from a non-smoking, gender-matched donor of minimal HLA mismatch. Further analysis of the molecular and immunologic implications of these conditions are warranted.