Belatacept Conversion in Simultaneous Pancreas-Kidney and Liver-Kidney Transplant Recipients: A Single-Center Feasibility Cohort and Narrative Review.

BACKGROUND

Calcineurin inhibitor (CNI) nephrotoxicity drives long-term kidney-function decline after simultaneous pancreas-kidney (SPK) and liver-kidney (LK) transplantation, but belatacept conversion, as an alternative strategy, is poorly studied in these recipients, whose non-kidney allograft rejection risk differs.

METHODS

We retrospectively studied six SPK and six LK recipients converted from CNI- to belatacept-based immunosuppression and analyzed the cohorts separately alongside a narrative review of published SPK/LK conversion experiences. Outcomes were estimated glomerular filtration rate (eGFR) trajectories and slopes, donor-specific antibodies (DSA) and rejection, pancreatic, hepatic and metabolic parameters, infections, and survival, reported descriptively with exploratory estimates and 95% confidence intervals (CI).

RESULTS

Conversion occurred a median of 64 (SPK) and 89 (LK) months after transplantation, always with a transient low-dose CNI overlap (target trough 3-4 ng/ml). In SPK recipients, median eGFR rose from 45.4 to 55.5 mL/min/1.73m2 and the median eGFR slope changed from -3.9 to +5.6 mL/min/year (mixed-model slope change +12.6, 95% CI 2.9 to 22.3); in LK recipients, from 38.8 to 46.3 and from -3.1 to +4.1 (estimate +6.3, 95% CI -4.2 to 16.7). No new DSA developed; pre-existing DSA declined or remained stable. Pancreatic and liver function stayed stable. Two infections in LK recipients (Pneumocystis pneumonia, adenovirus) were possibly belatacept-aggravated. Over a median 25 months, 8/12 (67%) remained on belatacept.

CONCLUSIONS

Late belatacept conversion with a transient low-dose CNI overlap was feasible in selected SPK and LK recipients and was associated with stable-to-improved kidney function without a pancreatic or hepatic safety signal. The uncontrolled design supports feasibility, not efficacy.