Alectinib-induced Hemolytic Anemia with Positive Direct Antiglobulin Test in a Patient with Lung Adenocarcinoma: A Possible Drug-drug Interaction Effect

Recent studies have reported that direct antiglobulin test (DAT) results were negative in cases of alectinibinduced hemolytic anemia with abnormal red blood cell (RBC) morphology. We herein report the case of a 72-year-old female patient who was diagnosed with alectinib-induced hemolytic anemia who - in contrast to previous reports - showed a positive DAT result. After discontinuing famotidine and alectinib, the DAT results turned negative; however, when alectinib was resumed, hemolysis recurred. Although alectinib-induced hemolytic anemia has been previously thought to be associated with abnormal morphological changes of the RBCs, we suggest that alectinib-induced anemia may manifest as DAT-positive immune hemolytic anemia because of a complementary effect with other drugs.