Efficacy of Bortezomib as an Adjunctive Therapy for Refractory Chronic Active Antibody-Mediated Rejection in Kidney Transplant Patients: A Single-Center Experience

Background: Chronic active antibody-mediated rejection (CAMR) has unsatisfactory prognosis in spite of intensive standard antihumoral treatment. Efficacy of additional bortezomib in CAMR remains uncertain. Methods: A retrospective chart review was conducted among kidney transplant patients with biopsy-proven CAMR. Our standard CAMR protocol included plasma exchange, intravenous immunoglobulin, and rituximab. Repeated treatment was provided for refractory cases. Patients receiving at least 1 course of bortezomib were enrolled as the bortezomib group. Allograft outcome was compared among patients receiving repeated standard protocol alone and the bortezomib group. Results: Thirteen and 15 patients were assigned to the bortezomib and control groups, respectively. Repeated bortezomib protocol was given for 1, 2, 3, and 4 courses in 6, 4, 1, and 2 patients, respectively. With a median follow-up time after treatment of 41.8 (18.3-47.4) months, the bortezomib group had a lower rate of glomerular filtration rate declination (-4.20 ± 4.89 mL/min/y vs -12.33 ± 10.44 mL/min/y; P =.014), a higher rate of disappearance of donor specific antibodies (69.2% vs 25%; P =.03), a lower rate of allograft loss (15.4% vs 66.7%; P =.006), and better allograft survival (P =.006). Conclusion: In CAMR, additional bortezomib treatment was more effective in eliminating donor specific antibodies and improving allograft survival than standard protocol treatment.