Ibrutinib for treatment of autoimmune cytopenia after hematopoietic stem cell transplantation: report of 2 cases and literature review

Objective To explore the curative effect of ibrutinib in treatment of autoimmune cytopenia (AIC) after hematopoietic stem cell transplantation (HSCT). Methods Two leukemia patients receiving HSCT at our hospital in 2016 and 2018 respectively were enrolled in this study, who were subsequently diagnosed as Evans syndrome (case 2) and pure red cell aplastic Anemia (PRCA) (case 1) respectively after transplantation. Due to failing to the treatment of glucocorticoid, immunoglobulin, immunosuppressants, plasma exchange and blood transfusion support, ibrutinib was tentatively applied to the patients, and its therapeutic effects and the changes of immune indexes were observed. Results After ibrutinib treatment, case 1 needed fewer times of red blood cell transfusion than before, with decreased level of anti-donor blood group antibodies and gradually elevated hemoglobin level. She was gradually relieved of blood transfusion, and then achieved complete remission about 3 months after the treatment. As for case 2, she was released from platelet infusion approximately 2 weeks after the ibrutinib treatment, with progressively improved hemoglobin level and platelet count, got weakly positive result to direct antiglobulin test (DAT) and negative result to autoantibodies, and achieved complete remission as well. No obvious adverse drug reactions or recurrence of primary disease were observed in the 2 patients. Conclusion Ibrutinib has certain efficacy in the treatment for PRCA or Evans syndrome after HSCT.