Predictive Value of Donor Specific Antibody Measured by Luminex Single Antigen Assay for Antibody Mediated Rejection after Kidney Transplantation

Background: Luminex panel reactive antibody (PRA) is a method that is well known for its high sensitivity and specificity. By using a single antigen assay, the presence or absence of donor specific antibody (DSA) can be determined and its strength can be quantified in terms of the mean fluorescence intensity (MFI). In this study, we analyzed the correlation between the pre-transplant PRA and DSA measured by the Luminex method and the post-transplant clinical features after kidney transplantation. Methods: A total of 123 pre-transplant sera samples from kidney transplanted patients were tested. Luminex-PRA identification tests were performed using a Luminex fluoroanalyzer and a LifeCodes class I, II ID Kits. Single antigen assay by the Luminex method was used for detecting DSA and its MFI. Results: The positive Luminex-PRA group included more highly-sensitized patients such as women, patients with a previously positive lymphocyte cross match test and patients who were undergoing retransplantation. There was no correlation between the acute rejection rate and positive PRA on the Luminex-PRA. However, pretransplant DSA detected by the single antigen assay was significantly associated with episodes of antibody mediated rejection (P=0.047, OR=10.2), and DSA with higher MFI values (MFI≥3,000) was associated with antibody mediated rejection (P=0.023). Conclusions: Although pre-transplant positive PRA was not correlated with acute rejection episodes, the DSA measured by the Luminex single antigen assay seems to have a predictive value for post-transplant antibody mediated rejection.