P85 | Atypical presentation of an uncommon disease: a paradigmatic case

Case report: An 81-year-old woman came to our attention for hematic diarrhea, dehydration and postural instability. Laboratory findings showed anemia (Hb 8.9 g/dL), neutrophilic leukocytosis, thrombocytopenia (PLTs 80000/µL), acute renal injury (SCr 4.26 mg/dL), hyponatremia and elevated serum LDH (783 U/L). While in ER, she suffered from a single tonic-clonic seizure, which was treated with Diazepam. CT-scan and angiography of the head were negative for any findings; the EEG revealed widespread epileptiform abnormalities. Abdomen ultrasound ruled out a urinary tract obstruction. SCr levels remained stable despite infusion with NaCl 0.9%. Due to worsening of anemia (Hb 6.9 g/dL), the following additional tests were performed: D-dimer (22000 ng/mL), serum haptoglobin (low), total serum bilirubin (normal), complement C3 (normal), direct antiglobulin test (negative), and peripheral blood smear (schistocytes 4.2%). This data, combined with clinical features, lead us to suspect thrombotic microangiopathy. ADAMTS-13 activity (36%) ruled out thrombotic thrombocytopenic purpura. Contextually, a sample of urine cultures tested positive for E. coli and Shiga toxin was found in a stool sample, therefore the diagnosis of Shiga toxin-producing E. coli associated hemolytic uremic syndrome (STEC-HUS) was made. Conclusions: Intravenous fluids and antibiotic therapy were continued, leading to resolution of diarrhea and normalization of laboratory findings (at discharge Hb 9.3 g/dL, PLT 380000/µL, SCr 1.11 mg/dl). STEC-HUS, despite being typical of childhood, must always be considered in hospitalized complex patients.