The Outcome of Tapered Steroid Regimen When Used to Treat Acute Borderline Cellular Rejection After Kidney Transplant: A Single-Center Experience.

Background: Treatment of acute borderline cellular rejection (BCR) after kidney transplant has shown mixed results with no consensus on the necessity and modality of interventions. Methods: The emphasis of our study was to assess the histopathologic response when BCR of kidney transplant is being treated with rapid steroid regimen. We analyzed all diagnosed acute BCR between 2018 and 2020. Patients were divided to a treatment responder group (RG) and non-responder group (NRG). All diagnosed BCR were treated with rapid steroid regimen and followed by a biopsy to assess response. Demographic data, recipients' comorbidities and clinical data, donor type, and induction immunosuppression regimen data were collected. Results: Ninety-one patients had acute BCR and were treated with rapid steroid followed by a repeat biopsy. Sixty-three (69%) patients showed persistence BCR and were considered NRG. Age, gender, and race were similar between the two groups. Class I and II calculated panel reactive antibodies were similar between the groups. No significant difference in the median serum creatinine (SCr) was noted between the groups. RG and NRG had a median SCr of 1.6 mg/dL (1.2 - 2.1) and 1.5 mg/dL (1.4 - 2.0), respectively (P < 0.79). The median SCr at the time of the follow-up biopsy was not different between the groups: SCr of 1.6 mg/dL (1.2 - 2.0) vs. 1.4 mg/dL (1.2 - 2.2) for the RG and NRG, respectively (P < 0.93). Conclusion: When rapid steroid regimen was used to treat acute BCR after kidney transplant, only smaller number of patients showed response based on the histology evaluation of the follow-up post-treatment biopsies.