Renal transplantation against a positive crossmatch due to HLA-DP donor-specific antibodies without prior antibody removal – Case report

Background: Antibodies directed against donor mismatched Human Leucocyte Antigens (HLA) are known to cause antibody-mediated rejection and affect the graft survival of transplanted organs. The influence of donor-directed antibodies against the products of HLA class I and II genes in renal transplantation are well described for class I (HLA-A, B and C), but still not clear for class II notably HLA DP. The clinical effects of donor-specific antibodies (DSA) directed against HLA-DP are still controversial.

Methods: We report the outcome of kidney transplants in three highly sensitised individuals with significant sensitisation with donor-directed HLA-DP antibody. These recipients were on the waiting list for 6, 14 and 4 years, respectively and had kidney transplants from donors after brain death (DBD) with positive B cell flow cytometry crossmatch (FCXM). Two cases received induction therapy with a depleting antibody (Thymoglobulin®) while the third received Alemtuzumab followed by standard immunosuppression.

Results: The clinical course of these three patients were different. The first patient developed transplant glomerulopathy, but the graft is still functioning with eGFR 29 mL/min/1.73 m². The second patient did not have any adverse event with eGFR 26 mL/min/1.73 m², while the third patient had severe antibody-mediated rejection (AMR), which was treated successfully with eGFR 32 mL/min/1.73 m².

Conclusion: Patients waiting for a deceased allograft with HLA-DP DSA and a positive FCXM can be transplanted successfully with depleting antibody or Alemtuzumab induction without prior antibody removal followed by standard immunosuppression.