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.