Bevacizumab-induced atypical hemolytic uremic syndrome and treatment with eculizumab.

Bevacizumab (Avastin) is a recombinant humanized monoclonal antibody used for the management of various solid malignancies including colorectal, lung, brain, renal, and ovarian cancers as well as age-related macular degeneration of the eye. It is a vascular endothelial growth factor inhibitor which exhibits its action by blocking the growth of blood vessels in cancerous tissue. Common side effects include hypertension, fatigue, headaches, and increased risk of infections. Atypical hemolytic uremic syndrome is a serious side effect associated with bevacizumab due to its anti-angiogenic effect. It encompasses the clinical triad of thrombocytopenia, microangiopathic hemolytic anemia, and acute renal failure, without any association with Shiga toxins. Eculizumab is a terminal complement inhibitor used in the treatment of atypical hemolytic uremic syndrome. Herein, we present three cases of bevacizumab-induced atypical hemolytic syndrome treated successfully with eculizumab.