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Red cell transfusion and alloimmunization in sickle cell disease
Ferrata Storti Foundation
Haematologica 2021 Volume 106(7):1805-1815
Grace E. Linder1 and Stella T. Chou2
1Department of Pathology and Lab Medicine, Children’s Hospital of Philadelphia, and 2Department of Pediatrics, Children’s Hospital of Philadelphia, Philadelphia, PA, USA
ABSTRACT
Red cell transfusion remains a critical component of care for acute and chronic complications of sickle cell disease. Randomized clin- ical trials demonstrated the benefits of transfusion therapy for prevention of primary and secondary strokes and postoperative acute chest syndrome. Transfusion for splenic sequestration, acute chest syn- drome, and acute stroke are guided by expert consensus recommenda- tions. Despite overall improvements in blood inventory safety, adverse effects of transfusion are prevalent among patients with sickle cell dis- ease and include alloimmunization, acute and delayed hemolytic trans- fusion reactions, and iron overload. Judicious use of red cell transfu- sions, optimization of red cell antigen matching, and the use of erythro- cytapheresis and iron chelation can minimize adverse effects. Early recognition and management of hemolytic transfusion reactions can avert poor clinical outcomes. In this review, we discuss transfusion methods, indications, and complications in sickle cell disease with an emphasis on alloimmunization.
Introduction
Transfusion remains a central intervention for sickle cell disease (SCD), with most patients receiving one or more transfusions by adulthood.1 Prospective, ran- domized clinical trials support transfusion for primary and secondary stroke pre- vention, but for many other indications, treatment is based on expert consensus. Guidelines on transfusion management for SCD are limited by availability of well- designed 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 alloimmu- nization, hemolytic transfusion reactions, and iron overload is critical.
Goals of transfusion
Red cell transfusion improves oxygen-carrying capacity and symptoms of ane- mia. For SCD, it may be used to increase a patient’s 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 complica- tions. 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 depend- ing 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 volume (i.e., 10-15 mL/kg), while in adults simple transfusions are provided in units (i.e., 1-2 units). Simple
Correspondence:
STELLA T. CHOU
chous@chop.edu
Received: January 4, 2021. Accepted: March 7, 2021. Pre-published: April 1, 2021.
https://doi.org/10.3324/haematol.2020.270546
©2021 Ferrata Storti Foundation
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