VWF and systemic lupus erythematosus: HUS is usually categorized as typical, caused by Shiga toxin-producing Escherichia coli (STEC) infection and as atypical HUS (aHUS), usually caused by complement dysregulation due to mutations or autoantibodies, disorders of the degradation of von Willebrand factor (VWF), or secondary to a coexisting condition like cobalamin metabolism disorders, pregnancy/HELLP Syndrome, certain drugs (Chemotherapeutic drugs, immunosuppressants, antiplatelets etc) and other disorders (e.g. systemic diseases appearing as HUS, such as systemic lupus erythematosus and rejection after transplantation) [8].