2026 Eastern States Conference

Title: Incidence of T-cell mediated rejection in obese vs non-obese kidney transplant recipients receiving belatacept maintenance therapy.

Authors: Christopher Bazaco, PharmD, Joshua Hildebrand, PharmD

Objective: The audience members will be able to assess the relationship between obesity and T-cell mediated rejection (TCMR) in kidney transplant patients receiving belatacept maintenance immunosuppression.

Self-Assessment Question: 
Benefits of belatacept maintenance immunosuppression compared to a calcineurin inhibitor do not include:
A: renal-sparing benefits
B: lower incidence of hypertension
C: decreased risk of cellular rejection
D: lower incidence of hyperlipidemia

Background: The belatacept package insert mentions obese patients have increased clearance. A sub-group analysis of the BENEFIT trial found obese patients had increased TCMR. The purpose of this study was to investigate the relationship between obesity and TCMR.

Methods: This was a single-center retrospective chart review study of adult kidney transplant recipients, who received at least 28 days of belatacept therapy from 2016 to 2025. The primary endpoint investigated was the incidence of biopsy proven TCMR within six months of belatacept initiation between obese and non-obese patients. In addition, the following secondary endpoints were investigated between these two groups: patient survival, graft survival, severity of rejection defined via the Banff criteria, development of de novo donor-specific anti-HLA antibodies, mean change in serum creatinine, incidence of CMV infections, and incidence of BK virus infections within six months of belatacept initiation. A secondary subgroup analysis of the primary endpoint was conducted. For this secondary analysis, we stratified our population into four groups based on obesity status and dosing protocol determined by time from belatacept initiation.

Results: Of the 146 patients that were included in this analysis, 57 were obese and 89 were non-obese. There was no difference in baseline characteristics. No difference was found regarding the primary endpoint, with 10 (17.5%) obese patients and 16 (18%) non-obese patients experiencing biopsy proven TCMR (p = 0.95). Our subgroup analysis also revealed no difference: 6 (17.6%) obese patients and 12 (23%) non-obese patients receiving the de novo dosing protocol experienced TCMR (p = 0.55), while 4 (17.4%) obese and 4 (10.8%) non-obese patients experienced TCMR while receiving the conversion dosing protocol (p = 0.47). There was no difference in mean decrease in serum creatinine, patient survival, graft survival, or infection rates.

Conclusion: This study demonstrated that obesity does not appear to impact the incidence of TCMR in patients receiving belatacept, and thus belatacept should remain a viable maintenance immunosuppressive agent for kidney transplant recipients, regardless of BMI status. Obese patients experienced similar safety outcomes and renal-sparing benefits as non-obese patients. Power was not reached in this study however, and thus further assessment is warranted.