P083 Prediction of de novo donor specific HLA antibody production in the follow-up period of kidney transplantation

Abstract

Aim One of the major factors for the graft loss is antibody-mediated rejection caused by the production of donor-specific HLA antibody (DSA). Optimization of multidrug combination therapy of immunosuppressant agents is required to prevent the production of DSA. In this study, we evaluated the relation of clinical variants including immunosuppressant levels to the prediction of DSA production in post-renal transplantation (Tx). Methods We enrolled a total of 160 living kidney transplant patients at our institute from July 2004 to September 2013. The patients were subjected to standard immunosuppressant protocols with basiliximab, tacrolimus (Tac), mycophenolate mofetil (MMF), and steroids. The production of the serum anti-HLA antibody at one-year post-Tx was analyzed by solid-beads assay using Luminex system. HLA specificity of the DSA was identified based on the data of donor HLA typing. In this study, preformed DSA and de novo DSA are defined as that detected at both pre-Tx and one-year post-Tx, and that detected at only one-year post-Tx, respectively. Risk factors for DSA production were statistically evaluated by Mann–Whitney U-test or Fisher’s exist test using clinical variables including the Tac trough levels and incidence of virus infections. Results DSA production at one-year post-Tx was observed in 15 patients including 9 preformed DSA and 7 de novo DSA. In one patient, both preformed and de novo DSA were observed. De novo DSA production was more likely to observed in patients who experienced the low serum Tac level (cut-off value: 3.2 ng/mL), in patients who ceased MMF medication, and in patients who acquired CMV infection within one-year post-Tx (p = 0.008, 0.044 and 0.050, respectively). Conclusions To avoid de novo DSA production at one-year post-Tx, the appropriate control of Tac trough levels, the continuation of MMF intake, and the prevention of CMV infection were important in this study.