The analysis of non-HLA antibodies and eplets in recipients with histological chronic antibody mediated rejection after kidney transplantation

Abstract

In kidney transplantation, antibody-mediated rejection (AMR) and the development of donor-specific anti-HLA antibodies (HLA-DSA) can lead to graft failure. However, despite the histological features of AMR and the characteristic lesions of AMR/CAMR as defined by the Banff criteria, there are cases where DSA is not present. In these instances, it is believed that non-HLA antibodies may be involved. In this study, we retrospectively analyzed cases where DSA was not detected in the histopathological manifestation of CAMR after kidney transplantation to investigate which antibodies are involved. In antibody tests conducted at the time of biopsy, eplets associated with DSA were detected in 6 out of 13 cases (46.2%). Among the 34 types of non-HLA antibodies, anti-AT1R antibodies were detected in 2 cases (15.4%), anti-MICA antibodies in 2 cases (15.4%), and protein kinase C eta (PRKCH) in 1 case (7.7%). In 2 cases (15.4%), no antibodies were detected. The necessity of searching for non-HLA antibodies is suggested when CAMR is observed. It is considered that performing eplet analysis and non-HLA antibody tests in cases where rejection is suspected but HLA-DSA is not detected could potentially identify antibodies that may cause CAMR.