Vedolizumab-Associated Hypereosinophilia and Hepatoxicity.

Vedolizumab, which is approved for the treatment of ulcerative colitis, has been associated with drug-induced liver injury because of an unclear mechanism. We describe the case of a 29-year-old man who presented with abnormal liver enzymes and peripheral hypereosinophilia after vedolizumab initiation. A complete workup for causes of hepatitis and hypereosinophilia was negative, and liver biopsy showed signs compatible with drug-induced liver injury. After the withdrawal of vedolizumab, the patient's eosinophil count and liver enzymes normalized. As vedolizumab becomes more prominent, it is important to understand the potential side-effect profile of vedolizumab.