Efficacy of Steroid Pulse to Treat Borderline T-Cell Mediated Rejection on Protocol Kidney Allograft Biopsy.

BACKGROUND

Borderline T-cell mediated rejection (bTCMR) is the most common renal allograft rejection phenotype within 1-year post-transplant and is associated with allograft failure. There is substantial heterogeneity in bTCMR management; steroid pulse therapy is commonly used but data regarding efficacy are lacking.

METHODS

To determine whether steroid pulse improved allograft histology and/or function, we conducted a single-center retrospective cohort study of 201 patients diagnosed with bTCMR on protocol biopsy treated with either steroid pulse therapy (n = 138) or no specific therapy (n = 63).

RESULTS

Baseline characteristics were similar between groups, including Banff i- and t-scores. At follow-up, bTCMR resolved in 62% overall without any differences between the groups. More patients receiving steroid pulse therapy showed worsened interstitial fibrosis (30% vs. 10%; p = 0.020) and tubular atrophy (27% vs. 0%; p < 0.001). Longitudinal eGFR trajectory was lower (8.9 mL/min/1.73 m2 below predicted; 95%CI -15.56 to -2.16; p = 0.009) in steroid-treated individuals. Graft loss or mortality did not differ between groups at median 3.5-year follow-up.

CONCLUSIONS

Steroid therapy for bTCMR identified on protocol biopsy was not associated with histological resolution, reduced fibrosis, or improved graft function, potentially reflecting subtle differences in disease severity among the patients who were treated. Further research is needed to elucidate optimal bTCMR management strategies, considering patient-specific factors and the potential need for more intensive therapies.