Emphysematous pyelonephritis in renal allograft related to antibody-mediated rejection: A case report and literature review.

Emphysematous pyelonephritis (EPN) is a rare condition which can rapidly progress to sepsis and multiple organ failure with high mortality. We experienced a rare case of EPN in a renal allograft related to antibody-mediated rejection (AMR). The patient received a deceased donor kidney transplant due to end-stage renal disease secondary to diabetes mellitus. Cross-match test was negative but she had remote history of anti-HLA-A2 antibody corresponding with the donor HLA. Surgery concluded without any major events. Anti-thymoglobulin was given perioperatively for induction. She was compliant with her immunosuppressive medications making urine of 2 L/d with serum creatinine of 1.9 mg/dL at discharge on post-operative day (POD) 6. She did well until POD 14 when she presented to the clinic with features of sepsis, pain over the transplanted kidney area and decline in urine volume with elevated serum creatinine. CT revealed extensive gas throughout the transplanted kidney. Renal scan revealed non-functional transplant kidney with no arterial flow. Based on these findings, a decision to perform transplant nephrectomy was made. At laparotomy, the kidney was completely necrotic. Pathology showed non-viable kidney parenchyma with the tubules lacking neutrophilic casts suggestive of ischemic necrosis. Donor-specific antibody (DSA) returned positive with high intensity anti-HLA-A2 antibody. This is the first case of early EPN in allograft considered to have occurred as a result of thrombotic ischemia secondary to AMR. This case suggests consideration of perioperative anti-B-cell and/or anti-plasma cell therapies for historical DSA and strict post-operative follow-up in immunologically high-risk recipients to detect early signs of rejection and avoid deleterious outcomes.