Pretransplant immunologic risk assessment of kidney transplant recipients with donor-specific anti-human leukocyte antigen antibodies

Background: Patients with pretransplantation strong donor-specific anti-human leukocyte antigen (HLA) antibodies (DSA) are at higher risk for rejection. We aimed to study the safety of kidney transplantation in patients with lower strength DSAs in a prospective cohort study. Methods: Three hundred and seventy-three consecutive adult kidney transplant recipients with (DSA+; n=66) and without (DSA-; n=307) DSA were evaluated. Anti-HLA antibodies with mean fluorescence intensity values over 5,000 for HLA-A, HLA-B, and HLA-DR and more than 10,000 for HLA-DQ were reported as unacceptable antigens. Patients received transplant if flow cytometry T-cell and B-cell cross-match channel shift values were less than 150 and 250, respectively, with antithymocyte globulin and intravenous immunoglobulin induction treatment. Results: Patients had a mean number of 1.6±0.8 DSAs with a mean fluorescence intensity value of 2,815±2,550. Twenty-seven percent were flow cytometry cross-match positive with T-cell and B-cell channel shift values of 129±49 and 159±52, respectively. During a median follow-up of 24 months (range, 6-50), there were no statistically significant differences in patient (99% vs. 95%) and graft survival (88% vs. 90%) rates between DSA+ and DSA-groups, respectively. Cumulative acute rejection rates of 11% in the DSA+ group and 12% in the DSA-group were similar. Two DSA+ (3%) and five DSA-(2%) patients developed chronic antibody-mediated rejection (3%). The mean serum creatinine levels were identical between the two groups (1.4±0.6 mg/dL). Conclusion: Similar patient and graft survival, and acute rejection rates can be achieved in DSA+ patients compared to DSAj patients with pretransplantation immunologic risk assessment.