Complement Factor H and Complement Factor H-Related Protein 5 Mutations Associated with Atypical Hemolytic Uremic Syndrome in a Systemic Lupus Erythematosus Patient: Efficacy of Eculizumab

Atypical hemolytic uremic syndrome (aHUS) is a disorder characterized by a propensity to thrombotic microangiopathy (TMA) due to defective regulation of the alternative complement pathway. Mutations in genes encoding complement factor H (CFH) and complement factor H-related proteins (CFHR) can be related with aHUS and identified in patients with rheumatologic diseases.

Atypical HUS typically presents as acute kidney injury (AKI) associated with microangiopathic hemolytic anemia (MAHA) and thrombocytopenia. We describe a SLE patient with severe AKI due to aHUS related CFH and CFHR5 mutations. The patient was refractory to immunosuppressives and plasmapheresis but responded well to eculizumab.