A Tale of Two Strategies: Desensitization and Donor-Specific Antibody-Free Transplant in Highly Sensitized Patients.

Abstract

Objectives: Human leukocyte antigen incompatibility, particularly in broadly sensitized kidney transplant candidates with high calculated panel reactive antibody, poses a significant barrier to transplantation. Two strategies exist: (1 ) virtual crossmatch with a donor -specific antibody -free donor or (2 ) desensitization. We compared immunological risks and posttransplant complications between these 2 approaches.

Materials and methods: We retrospectively screened 50 kidney transplant candidates with calculated panel reactive antibody ≥95 %. Donor -specific antibody positivity was defined as mean fluorescence intensity >750. Of 25 participants (13 male; mean age 36.8 ± 14.3 years ), 12 had calculated panel reactive antibody ≥95 % and no donor -specific antibodies (group A ), whereas 13 showed positivity for donor -specific antibodies and underwent desensitization (plasmapheresis, intravenous immunoglobulin, and rituximab with or without bortezomib; group B ). All but 1 patient received living donor transplants. Sensitization included prior transplant (n = 22 ), transfusions (n = 23 ), and pregnancies (n = 7 ).

Results: Median follow -up was 18 months, with no significant difference in estimated glomerular filtration rate between groups at any time point (at day of discharge; at 1, 3, 6, 12, 18, and 24 months posttransplant, and at most recent follow -up ). One graft loss occurred in group A due to vascular complications at 5 months. Sixteen biopsies were performed. Four episodes of acute antibody -mediated rejection were observed (1 in group A, 3 in group B; P = .728 ). Posttransplant infections occurred in 7 patients (28 % ), all in group B (P = .005 ), including BK virus (n = 5; P = .039 ) and parvovirus B19 (n = 2 ). Four patients in group A remained on immunosuppression versus none in group B (P = .039 ).

Conclusions: In highly sensitized kidney transplant recipients, both virtual crossmatch with donor -specific antibody -free donors and desensitization strategies resulted in comparable short -term graft function. However, desensitized patients showed significantly higher risk of posttransplant infections.