Persistence of HLA-DQ Antibodies in Transplant Patients Following Desensitization Treatment

The functionality of the transplanted graft is considered the most important step in transplant. Both HLA tissue compatibility between recipients and donors and the presence of antibodies against the HLA structure in the recipient's serum play essential roles. The presence of these antibodies can be ascertained either before or after transplant. Although desen-sitization treatment provides the chance of transplant to immunized patients, it also prolongs graft survival in antibody-mediated rejection that develops after transplant. In this retrospective study, we aimed to determine treatment-related responses of anti-HLA antibodies in heart and renal transplant patients diagnosed with antibody-mediated rejection.

We evaluated 60 samples from 18 patients who were followed in our center for at least 4 years and who had treatment before and after desensitization (plasmapheresis, intravenous immunoglobulin, and/or rituximab). Serum samples of the patients were tested for panel reactive antibody screening class I and II (One Lambda, Inc) test by Luminex method and single antigen class I and/or II (One Lambda, Inc) results by Luminex method. Mean fluorescence intensity ≥1000 was considered positive. To determine the presence of donor-specific antibodies, HLA tissue group samples of donors were studied by high-resolution method.

Studied antibodies, particularly those with mean fluorescence intensity >10 000 against class II HLA-DQ, remained resistant to treatment.

Our study results showed that the class II HLA-DQ tissue group and anti-HLA antibodies against it play an important role in reducing the need for desensitization therapy and maintaining graft tissue functionality.