Lo WK, et al. - The relationship was evaluated between post-transplant acid suppression with proton pump inhibitors (PPI) or histamine-2 receptor antagonists (H2RA) and the onset of early allograft injury or chronic rejection following lung transplantation. In lung transplant recipients, post-lung transplant exposure to persistent PPI therapy resulted in the greatest protection against rejection, independent of other clinical predictors including BMI. Therefore, it was suggested that in enhancing allograft protection, PPI could have antireflux or anti-inflammatory effects.

• In 2007–2014, a retrospective cohort study of lung transplant recipients at a tertiary center was performed.
• The researchers excluded patients with pre-transplant antireflux surgery.
• They applied time-to-event analysis using the Cox proportional hazards model to evaluate acid suppression therapy and onset of acute or chronic rejection, defined histologically and clinically.
• To evaluate PPI vs H2RA use, subgroup analyses were performed.

• Inclusion criteria was met by 188 subjects (60% men, mean age 54, follow-up 554 person-years).
• With all-cause mortality of 27.6%, 115 subjects (61.5%) developed rejection during follow-up.
• In univariate analyses, acid suppression and BMI were associated with rejection, but not other patient demographics.
• With use of acid suppression therapy (log-rank p=0.03), the Kaplan-Meier curve showed decreased rejection.
• Acid suppression (HR 0.39, p=0.04) and lower BMI (HR 0.67, p=0.04) were independently predicted against rejection in multivariate analyses.
• In subgroup analyses, the researchers revealed that persistent PPI use was more protective compared to H2RA or no antireflux medications.