Comparing Plasmapheresis plus IVIg with Plasmapheresis plus IVIg plus Rituximab on the Management of Suspicious Antibody-Mediated Acute Rejection in Kidney Transplant Recipients

Background: There is no treatment of choice for the management of acute antibody-mediated rejection (ABMR) in kidney transplant recipients. Plasmapheresis ± intravenous immunoglobulin (IVIg) ± rituximab has been used in different regimens with contradictory results. Objective: To compare three regimens of acute ABMR management including plasmapheresis + IVIg ± rituximab in two different rituximab regimens. Methods: In this prospective, observational study kidney transplant recipients with suspicious ABMR were categorized into three groups. Group 1 patients were treated with plasmapheresis + IVIg. Groups 2 and 3 received weekly rituximab at a dosage of 375 mg/m2 for either 4 doses (group 2 or high dose) or 2 doses (group 3 or low dose) in addition to plasmapheresis + IVIg. Results: 8, 15, and 9 patients were categorized in groups 1, 2, and 3, respectively. There was no difference among the groups in terms of demographic and clinical characteristics of recipients and donors. Although, 1-year graft (37.5%, 60.0%, and 66.7% for groups 1, 2, and 3, respectively; p=0.308) and patients survival (75.0%, 86.7%, and 77.8% for groups 1, 2, and 3, respectively; p=0.730) were not significantly different among studied groups, graft survival was 22%–30% higher in rituximab-treated groups. Estimated glomerular filtration rate at 12th month of follow-up did not differ among groups (56.3±19.6, 57.3±20.6, 48.7±16.1 mL/min/1.73 m2 for groups 1, 2, and 3, respectively; p=0.683). However, kidney function steadily improved over time in rituximab-treated patients. Conclusion: Adding high or low doses of rituximab to plasmapheresis + IVIg comparably increased graft survival in suspicious acute ABMR kidney recipients and steadily improved kidney function among survived allografts over time.