Iron deficiency anemia: an early clinical presentation of cytomegalovirus-induced hemorrhagic colitis in chronic myeloid leukemia patients under dasatinib treatment.

Dasatinib is a second-generation tyrosine kinase inhibitor employed for chronic myeloid leukemia (CML) treatment that achieves high rates of prolonged and complete molecular responses (MR). Among the adverse effects reported, it has been associated with hemorrhagic complications, mainly due to its inhibiting effects on platelet functions. In addition, immune alterations induced by dasatinib may elevate the risk of bleeding and cytomegalovirus (CMV) infection, particularly in the gastrointestinal tract, thus contributing to the development of hemorrhagic colitis. In this case report, we highlight three cases of CML receiving treatment with dasatinib where CMV hemorrhagic colitis occurred. All of them exhibited iron deficiency anemia as a premature clinical manifestation in the absence of intestinal symptoms, unlike cases previously reported in the literature. CMV infection was confirmed with stool samples or tissue quantitative polymerase chain reaction and/or immunohistochemistry staining in colon biopsies. All three cases could be managed with valganciclovir and iron supplements in an outpatient setting. Management strategies of dasatinib during and after CMV infection varied, as they are not yet established and need to be individualized based on the gravity of symptoms and disease state. Iron deficiency anemia during dasatinib treatment should raise suspicion for the potential presence of CMV colitis, prompting endoscopic studies to rule out this complication, even if intestinal symptoms are not present.