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Kidney Week

Abstract: PUB040

Atypical Hemolytic Syndrome Post-Transplant

Session Information

Category: Acute Kidney Injury

  • 003 AKI: Clinical and Translational


  • Cholin, Liza, University of Louisville, Louisville, Kentucky, United States
  • Burlen, Jordan, University of Louisville, Louisville, Kentucky, United States
  • Dave, Hitarth S., University of Louisville, Louisville, Kentucky, United States
  • Coventry, Susan C., University of Louisville, Louisville, Kentucky, United States

Introduction: Hemolytic Uremic Syndrome (HUS) is a type of Thrombotic Microangiopathy (TMA); it presents with thrombocytopenia, anemia, and acute renal failure. Atypical HUS (aHUS) accounts for 10% of all HUS cases, and occurs due to defective alternate complement pathway regulation, resulting in injury to endothelial cell lining of small blood vessels. When compared to Shiga-toxin producing Escherichia coli HUS, aHUS has a much poorer prognosis with death and end-stage kidney disease (ESKD) occurring in 53% of patients at three years.

Case Description: A 37 year old female with ESKD status post pancreas-kidney transplant presented with gastroenteritis-like symptoms. Laboratory evaluation showed a creatinine of 2.59 (baseline 0.55), hemoglobin of 10.9, platelets of 38, with schistocytes and polychromasis on peripheral smear. Further testing included a low C3 level, low normal C4, elevated lactate dehydrogenase, normal haptoglobin, negative cultures (blood, urine, stool), normal ADAMTS13 activity, and negative Shiga toxin. Renal biopsy revealed thrombi in rare glomerular capillary loops and acute tubular necrosis, with no signs of acute T-cell mediated or antibody mediated rejection. Genetic testing was negative for a specific quantitative or genetic factor leading to complement dysregulation. Patient was treated with hemodialysis and eculizumab. Renal function improved, and she no longer required dialysis at time of discharge.


Discussion: Initial presentation of aHUS can be indistinguishable from other types of TMAs. Once, you have excluded shiga toxin-producing bacterial infection, ADAMTS13 deficiency, and other systemic diseases, then an aHUS diagnosis can be made. Genetic testing is also helpful to determine if it is a familial or sporadic form. Renal biopsy is typically not necessary; however, it can be beneficial if patient is post-transplant to rule out rejection. Treatment includes therapeutic plasma exchange, steroids, eculizumab, and transplantation (MCP-aHUS only). This case was rare, in that the patient had sporadic aHUS precipitated by a viral gastroenteritis.