Background: Obesity is a common condition that contributes to organ failure. Bariatric surgery is an effective surgical therapy for obesity and has been performed both pre- and post-solid organ transplant (SOT) in small case series. However, bariatric surgery may alter immunosuppression absorption and immune system function potentially increasing the risk for graft rejection. We sought to assess the impact of bariatric surgery on risk of organ rejection among SOT recipients.

Methods: We conducted a retrospective cohort study of all adult (age ≥ 18) SOT recipients from 2000-2015 at a single large academic institution. Data were analyzed using ANOVA, Chi Square, and Fisher Exact tests. Logistic regression analysis was used to assess the association between bariatric surgery status and graft rejection.

Results: We identified 4363 SOT recipients (Heart n=194, Liver n=1090, Kidney n=2824, Pancreas n=223, Intestine n=7, multiorgan=25), of which 55 (12.6%) had a history of bariatric surgery (81% post-SOT, 60% Roux-En-Y gastric bypass). Mean SOT recipient age was 50.2 ± 12.8 years. SOT recipients were 61.3% male, 45.9% white, and 6.4% had obesity prior to transplant. Obesity-related comorbid conditions were common among all candidates: 73.3% had hypertension, 33.0% had diabetes, 10.6% had hyperlipidemia and 4.1% had obstructive sleep apnea. All patients received steroids, 86.8% received a calcineurin-inhibitor (CNI), 80.0% received mycophenolate, 12.9% received a mTOR inhibitor and 9.0% received a monoclonal antibody or fusion inhibitor. On univariate analysis, graft rejection was more common among SOT recipients with a history of bariatric surgery compared to those without bariatric surgery (85.5% vs. 72.5%, p=0.03). In multivariable analysis adjusted for age, transplant type and history of CNI-based immunosuppression, there was a trend towards increased risk of rejection among SOT recipients with bariatric surgery compared to those without bariatric surgery (OR=2.09, 95% CI: 0.98-4.46, p = 0.05).

Conclusion: Our single center data indicate that there may be a relationship between a history of bariatric surgery and increased rate of graft rejection after SOT. In light of the ongoing obesity epidemic and increased utilization of bariatric surgery procedures, a multicenter study is needed to assess the effect of bariatric surgery on immune system function and adaptation in SOT recipients.

CITATION INFORMATION: Soghikian M, Gregory D, Wilcox J, Shetty A, Ladner D, VanWagner L. Impact of Bariatric Surgery on Risk of Organ Rejection Among Solid Organ Transplant Recipients. Am J Transplant. 2017;17 (suppl 3).

« Back to 2017 American Transplant Congress