Donor-specific antibody in chronic rejection is associated with glomerulopathy, thickening of peritubular capillary basement membrane, but not C4d deposition

The impact of post-transplant donor-specific antibody (DSA) on the development of chronic rejection has been focused recently. The aim of this study was to evaluate the significance of DSA, graft function and pathological factors of chronic rejection. Seventy-three kidney recipients who underwent protocol biopsy were included in the study. The median follow-up period after transplant was 40 months. The presence of anti-HLA antibody (aHLAAb) and DSA was tested using flow beads analysis (FlowPRA (R)). The patients were divided into a group with DSA, a group with non-donor-specific aHLAAb and a group without aHLAAb. Protocol biopsy specimen were compared for transplant glomerulopathy (cg), vasculopathy (cv), C4d deposition at peritubular capillary (PTC), peritubular capillaritis (ptc score 0-3) and thickening of PTC basement membrane (ptcbm score 0-3) as recently proposed. The presence of DSA was significantly associated with the presence of cg, ptcbm. The group with non-donor-specific aHLAAb had ptcbm but did not have cg. The group without aHLAAb rarely showed ptcbm. The presence of DSA was associated with impaired graft function. C4d was not specific for the patients with DSA. These histopathological markers are useful in the detection of immunological chronic rejection. Early detection by screening tests will be important for treatment before irreversible change occurs.