Enterococcus raffinosus infection with atypical hemolytic uremic syndrome in a multiple myeloma patient after autologous stem cell transplant

Autologous hematopoietic stem cell transplant (AHSCT) is the standard of care in the treatment of multiple myeloma worldwide. Infections are one of the most common complications of the chemotherapy regimen and AHSCT. Thrombotic microangiopathies are one of the rare but potentially life-threatening complications of infections associated with AHSCT. Thrombotic thrombocytopenic purpura and hemolytic uremic syndrome (HUS) are two most common type of thrombotic microangiopathies. The HUS is classically related to diarrheal illness such as with <em>E.coli</em> strain O157: H7 that produce Shiga-like toxins. But it has never been described with <em>Enterococcus</em> <em>raffinosus</em> urinary tract infections (UTI). Here we are describing a case of atypical HUS associated with <em>Enterococcus</em> <em>raffinosus</em> UTI in a patient with multiple myeloma after AHSCT. The management of atypical HUS especially after AHSCT is challenging. Eculizumab, a humanized monoclonal antibody against complement protein C5, and thrombomodulin have emerging role in the management of some cases, but more studies are needed to define evidence-based management of this condition.