Hydroxyurea is the primary treatment for prevention of recurrent ACS. sickle cell disease (SCD), with most patients receiving ODM-203 one or more transfusions by ODM-203 adulthood.1 Prospective, randomized clinical trials support transfusion for primary and secondary stroke prevention, but for many other indications, treatment is based on expert consensus. Guidelines on transfusion management for SCD are limited by availability of welldesigned studies. Thus, many recommendations are based on low or moderate quality evidence or expert consensus, as well as the balance of benefits and harm for any given intervention. 2-5 While transfusion therapy reduces SCD-associated morbidity and mortality, attention to prevention and management of alloimmunization, hemolytic transfusion reactions, and iron overload is critical. Goals of transfusion Red cell transfusion improves oxygen-carrying capacity and symptoms of anemia. For SCD, it may be used to increase a patients hematocrit and/or to reduce endogenous production of red cells containing hemoglobin S (HbS). Episodic transfusions are used for preoperative preparation or treatment of acute complications. Chronic transfusion therapy is utilized when the goal is to sustain a lower HbS level, such as for primary or secondary stroke prevention.2,6,7 A standard goal is to maintain HbS levels 30% or to raise the hemoglobin to 10-12 g/dL depending on the transfusion indication.1-3 Raising the hemoglobin to levels greater than 10-12 g/dL is generally avoided to limit the risk of hyperviscosity.3 Transfusion method Red cell transfusions can be provided by simple or exchange transfusion. In pediatric patients, simple transfusions are dosed by ODM-203 volume (i.e., 10-15 mL/kg), while in adults simple transfusions are provided in units (i.e., 1-2 units). Simple transfusion is convenient, requires one ODM-203 point of peripheral venous access, and utilizes fewer red cell units. Additionally, simple transfusion does not require specialized personnel or devices. Drawbacks of simple transfusion include risks of volume overload and hyperviscosity. Simple transfusion invariably leads to iron overload over time, necessitating treatment with iron chelation or alteration in transfusion modality. Red cell exchange (RCE) procedures involve removal of the patients red cells and replacement with cells from the donor. RCE can be provided via automated (erythrocytapheresis) or manual methods. Manual RCE is performed using a series of repeated phlebotomies and transfusions, is time-consuming, and provides less consistent control of fluid balance during the procedure.8 Erythrocytapheresis requires apheresis machines and operators with technical expertise and may only be available at specialty centers. Since RCE typically replaces one or two times the patients total red cell volume, a higher volume of replacement cells is required. Despite increased exposure to donors with RCE compared to simple transfusion, several studies have shown no increase ODM-203 in alloimmunization rates associated with RCE.9,10 Limited studies indicate that RCE is cost-effective and may decrease hospitalization rates.8,11 Red cell alternative volume and hematocrit can be tightly controlled with RCE, allowing for significant reductions in HbS levels, while minimizing or avoiding iron loading. 12 Erythrocytapheresis requires attract and return lines. Venous access must allow a steady flow of blood and withstand the high bad pressures of the attract line. Most adult individuals have an adequate peripheral venous access to support RCE, but smaller pediatric individuals often require central venous access. Indwelling catheters incur additional risks of illness and thromboembolic events.13 RCE can be further modified to include isovolemic hemodilution, a process that includes initial removal of the individuals red cells and alternative with normal saline or albumin followed by RCE. RCE with isovolemic hemodilution is not recommended in individuals with recent or severe cerebrovascular or cardiopulmonary disease. Potential benefits of isovolemic hemodilution include improved effectiveness of RCE, reduced number of reddish cell devices per exchange, and decreased procedure frequency, however a recent meta-analysis found little evidence to support the use of RCE with isovolemic hemodilution over RCE without isovolemic hemodilution.2 RCE is recommended over simple transfusion for acute ischemic stroke, severe acute chest syndrome, for individuals with high baseline hematocrits requiring transfusion, and for chronically transfused individuals with significant iron overload. Guidelines published from the American Society of Hematology (ASH) suggest using automated RCE in all individuals with SCD receiving chronic transfusion therapy; however, individualized decisions for individuals should consider availability of compatible reddish cell devices and venous access. 2 General transfusion considerations Prior to transfusion, an Rabbit Polyclonal to SLC25A6 extended reddish cell antigen profile, including typing for C/c, E/e, K/k, Fya/Fyb, Jka/Jkb, M/N, and S/s, should be obtained for those individuals with SCD.2 An antigen profile performed by genotyping is preferred, as it provides increased accuracy for C and Fyb antigen expression with this human population. 2 Serological phenotyping may be inaccurate if the patient has been transfused in the preceding 3 months. Extended reddish cell.