The role of nonadherence in donor-specific antibodies formation and their effects on kidney transplant function

Introduction. Antibody-mediated rejection is one of the leading causes of graft loss after kidney transplant. Donor-specific antibodies (DSAs) are recognized as biomarkers of transplant rejection. The aim of this study was to describe the association between nonadherence and DSAs formation. Case outline. A 21-year-old patient underwent a living-related donor kidney transplant procedure in October 2017. The donor had the same blood type as the patient with one mismatch at the HLA-B and HLA-DR loci. The presence of pre-transplant human leukocyte antigen donor-specific antibodies (HLA-DSAs) was not confirmed. The postoperative course was uneventful. Three months post-transplant, low tacrolimus levels and consequent increase of serum creatinine were evident. Five months post-transplant, the occurrence of HLA-DSAs was confirmed along with de novo donor-specific anti-HLA-DQB1*06:04, mean fluorescence intensity (MFI) was 20725. Acute antibody-mediated rejection of kidney transplant was diagnosed, and the following treatment was applied: corticosteroid pulses, immunoglobulins, and plasmapheresis. Stable graft function persisted over following one-year period, but over time, low tacrolimus level, increase in serum creatinine and proteinuria reappeared. Heteroanamnestic data indicated an irregular taking of immunosuppressive drugs and an inadequate hygiene-dietary regimen. Repeated anti-HLA-DQB1*06:04 testing revealed MFI 5933. Graft biopsy demonstrated elements of chronic active antibody-mediated rejections, acute T-cell mediated rejection, interstitial fibrosis and tubular atrophy. Despite repeated anti-rejection therapy, total graft loss has occurred. Conclusion. Nonadherence to recommended immunosuppressive regimen brought about the de novo HLA-DSAs formation as well as production of antibody-mediated and T-cell mediated rejection, and consequent total loss of kidney transplant function.