RESUMO
Introduction: Atypical Hemolytic Uremic Syndrome(aHUS) can be triggered by viral infections. So far there has been little data on COVID 19 infection-causing aHUS. We present one such case of acute kidney injury(AKI) secondary to aHUS with COVID-19 infection and its outcome. Case Description: A 55-year-old woman presented with altered mental status and shortness of breath from 2-3 days. The patient tested positive for the COVID-19 virus. Labs showed creatinine of 4.8g/dl from a baseline of 0.8g/dl, with a hemoglobin of 8.9g/dl and a platelet count of 20,000/uL. Peripheral smear showed evidence of a large number of schistocytes and thrombocytopenia. Haptoglobin and reticulocyte counts were 28mg/dl, reticulocyte count 3.8% respectively. In view of her symptoms and laboratory findings, there was high suspicion for Thrombotic thrombocytopenic purpura (TTP). Her PLASMIC score was 6. Treatment with plasma exchange therapy (PEX) and steroids was initiated but there was no significant clinical improvement. An ADAMSTS13 level was sent prior to the initiation of PEX and resulted at 65%, ruling out the diagnosis of TTP. Due to lack of evidence of TTP eculizumab was started for suspected aHUS. She responded remarkably well (within days) with mentation returning to baseline, hemoglobin stabilizing, platelet slowly trending towards normal and peripheral smear, labs showing no signs of hemolysis, and an improvement in her RFP. At 5 month followup, the patient eventually progressed to end-stage renal disease had to be placed on regular dialysis. Discussion: AHUS is a rare variety of thrombotic microangiopathy(TMA) which results in a classic triad of Coombs negative hemolytic anemia, renal injury, and thrombocytopenia. aHUS has a mortality rate of 25%. 50% of patients eventually progress to ESRD or have irreversible brain damage. Multiple triggers have been identified including various non-enteric infections, viruses, drugs, malignancies, transplantation, pregnancy, and other underlying medical conditions. At the time of writing this case report, there is only one other case report of COVID-19 virus-induced aHUS resulting in AKI. In aHUS renal damage is thought to be caused by microthrombi formation in the kidney vasculature. Endothelial damage is further escalated by anaphylatoxins produced by complement activation. aHUS induced AKI is an alternate mechanism for COVID -19 to cause AKI requiring eculizumab for optimal treatment.