Exchange Transfusion In Adult Patients With Sickle Cell Disease With Refractory Vaso-Occlusive Crises

Sickle cell disease occurs in 1/500 African-American births. Pain is one of the most common complications of sickle cell disease and is associated with depression, anxiety, decreased quality of life and poor sleep patterns. Vaso-occlusive crises resulting in three or more hospitalizations per year occur in 48% of patients with sickle cell disease (Annals of Emergency Medicine - May 2009 (Vol. 53, Issue 5, Pages 587-593). Hydroxyurea has been shown to ameliorate the frequency of painful vaso-occlusive crises in sickle cell anemia (Charache et al, Effect of hydroxyurea on the frequency of painful crises in sickle cell anemia. Investigators of the Multicenter Study of Hydroxyurea in Sickle Cell Anemia NEJM. 1995), unfortunately many eligible patients are not treated due to psychosocial reasons and fear of teratogenicity or malignancy or have painful crisis refractory to hydroxyurea. A panel of experts has suggested that RBC exchange transfusion in these patients may decrease ED visits and subsequent hospitalizations based on anecdotal evidence [Best practices for transfusion for pateitns with sickle cell disease. T Wun, K Hagel. Hematology Review 2009, July 1; 1(22); e22]. We present the case of a 31 year old African-American male with Hgb S/beta thalassemia + with complications of sickle cell disease including Parvovirus B19 induced aplastic anemia, iron overload secondary to multiple simple transfusions, multiple vaso-occlusive crises as well as a left lower extremity ulcer precipitated by treatment with hydroxyurea. He was treated with folic acid as well as deferasirox for iron chelation. He began PRBC exchange transfusions every 6 weeks in March of 2011. In the one year prior to exchange transfusion initiation he had 13 ED visits and 4 hospitalizations for vaso-occlusive crises. After initiation of exchange transfusions he had 11 ED visits and 2 hospitalizations for vaso-occlusive crises the following year. An elevated WBC is associated with poor outcomes in sickle cell disease (Miller et al Predictors of adverse outcomes in children with sickle cell disease. N Engl J Med 2000). His average WBC level was 13 x 10⁹/L, which decreased to 11 x 10⁹/L after initiation of exchange transfusion. The patient underwent extended typing for E,C, and Kell RBC antigens to minimize development of antibodies. Though monthly exchange transfusions are costly and carry the attendant risk of antibody formation, this may be offset by reducing the financial and psychological burden of frequent hospitalizations for management of refractory vaso-occlusive crises. Exchange transfusion may also ameliorate the cost associated with long-term iron chelation. Further investigation is warranted to determine whether a program of monthly exchange transfusions can curtail ED visits and hospitalizations in adult patients with sickle cell disease and multiple, refractory vaso-occlusive crises.