Acquired hemophilia associated with vedolizumab in a patient with hemorrhagic rectocolitis

To The Editor:Hemorrhagic rectocolitis is an autoimmune disease that affects the gastrointestinal tract.Treatment of the disease includes 5-aminosalicylic acid drugs such as mesalazine at first-line therapy,with a possible association of corticosteroids.In the case of severe inflammation,treatment with purine analogue(azathioprine),TNF-alpha inhibitor(infliximab,adalimumab),or integrin inhibitor(vedolizumab)may be initiated.