Ebv-Associated Atypical Hemolytic Uremic Syndrome Presenting With Diffuse Alveolar Hemorrhage

Abstract

INTRODUCTION: Atypical Hemolytic Uremic Syndrome (aHUS) is a severe form of thrombotic microangiopathy that presents with nonimmune hemolytic anemia, thrombocytopenia, and renal failure. Diffuse alveolar hemorrhage (DAH) due to disruption of alveolar-capillary basement membrane is an exceedingly rare presentation of aHUS. CASE PRESENTATION:A 19-year-old-male presented with acute respiratory distress, hemoptysis, tachypnea, tachycardia, elevated blood pressure, and oliguria. One month prior the patient was diagnosed with infectious mononucleosis associated with thrombocytopenia and splenomegaly. Initial labs demonstrated hemolytic anemia, thrombocytopenia, and acute renal failure. CT chest showed diffuse bilateral central alveolar opacities concerning for alveolar hemorrhage. Patient was stabilized with supplemental oxygen and urgent hemodialysis was initiated. Further studies revealed schistocytes on peripheral blood smear, hypocomplementemia, borderline low activity of ADAMTS-13, positive IgM/IgG to EBV nuclear antigen and a renal biopsy consistent with acute thrombotic microangiopathy affecting nearly all blood vessels and glomeruli. Serologies were negative for ANA, anti-dsDNA, ANCA, Anti-GBM ab, rheumatoid factor, HIV, HBV, and HCV. Patient was diagnosed with EBV infection associated Atypical Hemolytic Uremic Syndrome (aHUS) and received treatment with plasmapheresis and eculizumab. With this treatment, patients' respiratory distress, hemoptysis, and renal function improved, following which he was discharged with outpatient hemodialysis. He continues follow up with hematology and nephrology. DISCUSSION: aHUS is much less frequent than Shiga-toxin mediated hemolytic uremic syndrome. Endothelial injury and thrombotic microangiopathy are hallmarks of this complement mediated process. It is associated with high risk of ESRD. Recent advances in therapeutics targeted at complement regulatory proteins including Eculizumab, have offered better outcomes. DAH is a life-threatening complication that has rarely been reported with aHUS. Treatment of diffuse alveolar hemorrhage depends on etiology. In our patient, diagnosis and targeted management of aHUS helped improve hemoptysis and respiratory distress from DAH.CONCLUSIONS: Atypical HUS can present with acute onset renal failure and diffuse alveolar hemorrhage in some instances. Association with EBV infection is extremely rare.