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Kidney Week

Abstract: TH-PO130

Diagnosing Atypical HUS in the Setting of Complement Amplifying Conditions (CAC): A Case Series

Session Information

Category: Trainee Case Report

  • 102 AKI: Clinical, Outcomes, and Trials


  • Kovvuru, Karthik, University of Mississippi Medical Center, Jackson, Mississippi, United States
  • Gonzalez Suarez, Maria Lourdes, University of Mississippi Medical Center, Jackson, Mississippi, United States
  • Kanduri, Swetha Rani, University of Mississippi Medical Center, Jackson, Mississippi, United States

Diagnosing aHUS in the setting of complement amplification conditions (CAC'S) is challenging. We report 2 cases of aHUS which presented as treatment resistant Lupus, and unresolving sepsis from influenza in post partum period.

Case Description

Case 1: 20 Yr old African American woman with Lupus (diagnosed at age 16, chronically low complements, partially controlled with Azathioprine, Rituximab, Mycophenolate and recently started on Cyclophosphamide (CYC) for class IV lupus nephritis, received 3 doses) presented to hospital for confusion and seizures. Started on pulse dose steroids for possible Lupus cerebritis. Labs were significant for microangiopathic hemolytic anemia, thrombocytopenia and low complements. Considering her resistant lupus despite outpatient CYC and inpatient pulse dose steroids, she was started on plasmapharesis (TPE) after sending ADAMTS13 and genetic panel for aHUS. No clinical or lab improvement was noted after 5 sessions of TPE. Genetic panel for aHUS resulted equivocal with heterozygous missense mutations in CFH, CFHR1- CFHR3 gene. Started on Eculizumab (ECU) for aHUS (900 mg/week for 4 weeks). Serum creatinine and hemolysis labs improved significantly. She was maintained on ECU (1200mg/ 2 weeks) for 8 months after which she suffered sudden death. Case 2: 38 Yr old African American woman with hypertension presented with headaches in her 3rd trimester (first pregnancy); underwent C-section at 27 weeks due to pre-eclampsia. Post-op she was transferred to ICU for hypoxic respiratory failure (ARDS) and sepsis. She was treated with antibiotics initially and changed to Oseltamivir due to positive Influenza PCR. She developed AKI requiring CRRT. Due to lack of clinical response, low complements and slowly declining platelet counts, further workup showed microangiopathic hemolytic anemia. TPE was started after sending ADAMTS13 and genetic panel for aHUS. Hemolysis labs and platelet levels partially improved after 10 sessions of TPE. aHUS genetic panel showed heterozygous missense mutation for CFHR3. Started on ECU 900 mg/week for 4 weeks, followed by 1200 mg/ 2 weeks for 3 doses. Her renal function and other lab parameters returned to normal, and remained stable for past 18 months.


Clinicians should have low threshold for suspecting aHUS if CAC's do not respond to appropriate therapy.