Case report: Recurrence of anti-myeloperoxidase pauci-immune crescentic glomerulonephritis in a kidney transplant recipient; potential association with HLA antigens and seropositivity?

Anti-myeloperoxidase (anti-MPO) antineutrophil cytoplasmic antibodies-associated vasculitis (AAV) manifests histologically as pauci-immune crescentic glomerulonephritis. Recurrent anti-MPO AAV after transplantation is rare and poorly understood. In this report, we describe a case of early recurrence of anti-MPO AAV in the kidney allograft of a patient who shared potentially permissive HLA antigens with the donor and who had detectable anti-MPO antibodies post-transplantation. We also share our experience with 13 additional cases of anti-MPO AAV in the native kidney who underwent kidney transplantation but did not develop recurrent disease. Clinicopathologic correlates, focusing on the potential association with post-transplant anti-MPO levels and permissive HLA antigens in the donors and recipients, are discussed. This report provides a brief examination of the immunopathologic features of anti-MPO AAV in the kidney allograft and underscores the potential importance of close monitoring for disease recurrence in patients presumed to be at increased risk for such complication.