Therapeutic erythrocytapheresis, or red cell exchange (RCE) is a non-invasive procedure in which a patient's erythrocytes are removed from the bloodstream while being replaced with erythrocytes from blood donors. RCE is commonly used as a transfusion technique in patients with sickle cell disease (SCD) to help treat and prevent complications associated with sickling of erythrocytes and iron overload. In the rare blood disorders (RBD) clinic at the University of Alberta in Edmonton, Canada, RCE has been utilized as a therapeutic adjunct to traditional chelation therapies for patients with thalassemia major with uncontrolled iron overload. The aim of this study is to describe and review the rate of observed complications or benefits associated with RCE in patients with thalassemia major.
Patients with a documented diagnosis of thalassemia major who were enrolled in the RCE program via the RBD clinic were identified. Charts were retrospectively reviewed from time of initiation of RCE to the time of most recent RCE or clinic follow up. Complications were documented and analyzed, then compared to standard rates of complications of iron overload in patients with thalassemia major.
Seven (7) patients with were identified for analysis. The average age of patients enrolled was 30 years. One hundred percent (100%) of patients had confirmed diagnosis of thalassemia major by hemoglobin electrophoresis. 85.7% of patients were of male sex. Six (85.7%) patients were on chelation therapy (3 patients on Jadenu plus Ferriprox; 3 patients on Jadenu alone). On average RCE was performed every 3.85 weeks. Of the patients analyzed during RCE, 85.7% had hepatic iron overload and 42.9% had cardiac dysfunction. 71.4% had evidence of extramedullary hematopoiesis. Two patients had syncopal events while on RCE. Two patients developed red cell antibodies during RCE. Improvements in iron overload correlated with initiation of dual chelation therapy in the three patients who were on maximal dual chelation.
Although RCE is a useful transfusion strategy in patients with SCD with less iron loading than simple transfusion, it does not appear to have the same benefits in patients with thalassemia major. Improvements in myocardial and hepatic T2* scores correlated with being on dual chelation therapy rather than with the frequency or duration of RCE. There was evidence of significant extramedullary hematopoiesis in 5 of the 7 patients on RCE possibly due to poor hemoglobin increment. Given the observed increase in extramedullary hematopoiesis, syncope, and antibody formation associated with RCE, and lack of benefit in reducing iron overload, we do not recommend its use as a treatment in patients with thalassemia major.
No relevant conflicts of interest to declare.
Asterisk with author names denotes non-ASH members.