Blood Transfusion in Sickle Cell Disease

Abstract

Sickle cell anemia is an inherited disease that causes chronic hemolytic anemia. Its pathognomonic signs and symptoms are caused by hemoglobin (Hb) S, which results from a single nucleotide substitution in the β-globin gene that places the amino acid valine with glutamic acid at codon 6 of the β-globin chain. Hb S is an insoluble Hb that crystalizes at low oxygen tension and other precipitating conditions leading to rigidity of red cells and clumping in small blood vessels. Patients with sickle cell disease have a variable Hb level that may range from 7.0 to 11.0 g/dL in their steady state condition. The most common cause of hospital presentation is due to acute painful crisis that results from vaso-occlusion by sickled cells. These episodes are treated with hydration and analgesia and do not require blood transfusion. Blood transfusion should be aimed to increase tissue delivery of oxygen. Hb S is known to be a low affinity Hb and so delivers oxygen at a lower partial pressure of oxygen compared to Hb A. Even with adequate pre transfusion testing and precautions, blood transfusion is never totally safe and short or long term complications may occur. Blood transfusion in patients with sickle cell disease has only limited indications such as acute hemolytic, aplastic or sequestration crises. Chronic transfusion protocols are implemented in cases of strokes or high cerebral blood flow ultrasonic studies as a prophylactic measure. Exchange blood transfusion is used in some complications of the disease such as acute chest syndrome (ACS), priapism or peri operatively. Once it is decided to transfuse blood, the transfused blood should be Hb S negative, Rh and Kell antigen matched.

Prophylactic transfusion for pregnant women with sickle cell disease: a systematic review and meta-analysis

“…32,33 Although indiscriminate use of transfusion must be avoided, given its potential adverse effects of alloimmunization, acute and delayed transfusion reactions, transfusionrelated infectious morbidity, and iron overload, 13 transfusion in the appropriate context has merit and may even be lifesaving.…”

Current Treatments and Prospective Therapies to Manage Sickle Cell Disease

“…2 The inherited genetic mutation stems from a single nucleotide substitution, amino acid valine with glutamic acid, in the β-globulin gene and produces an abnormal type of hemoglobin (Hb), namely, hemoglobin S (HbS). 5 The HbS results in sickle-shaped red blood cells (RBCs), as opposed to normal biconcave disks (Image 1). 6 The sickle-shaped RBCs stick to the vascular endothelium and block the small and large vessels (Image 2).…”

“…3,9 Complications Anemia is a major complication associated with SCD. 5 The degree of anemia varies among patients; if it is severe, it can require blood transfusions to increase oxygen delivery to the tissues. 2,5 Patients with sickle cell anemia receive blood transfusions as a successful means of support.…”

“…5 The degree of anemia varies among patients; if it is severe, it can require blood transfusions to increase oxygen delivery to the tissues. 2,5 Patients with sickle cell anemia receive blood transfusions as a successful means of support. 5 The transfusions benefit the patient by increasing the oxygencarrying capacity of the RBCs, decreasing blood viscosity, and decreasing the sickling of the RBCs.…”

Sickle Cell Disease in Nigeria -----------A Review

“…[57][58] Regular blood transfusions may lead to iron overload hence chelating agent like desferoxamine should be given orally to such patients. [59] 9.4 Supplemental oxygen Oxygen by face mask or nasal prongs is indicated in sickle cell crisis especially anaemic crisis.…”