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 alectinib-induced 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.