Management of sickle cell disease: challenges and risks of transfusion

Abstract

Homozygous sickle cell (SS) disease is associated with rapid red cell destruction and a tendency to block flow in blood vessels. The bone marrow expansion needed to compensate for the rapid red cell destruction increases metabolic demands and folate requirements but also renders the bone marrow prone to suppression by renal impairment and infections especially those with human parvovirus B19. The abnormal red cells also tend to block blood vessels impairing flow in the bone marrow (dactylitis, bone pain crisis, hip necrosis), the spleen (acute splenic sequestration, chronic hypersplenism, loss of the normal filtering system rendering patients prone to overwhelming septicemia), the lungs (pulmonary embolism, acute chest syndrome), and the brain (ischemic stroke, hemorrhage). Transfusion plays a role in addressing all of these pathologies. During the acute lowering of hemoglobin due to acute splenic sequestration and aplastic crisis and the persistent lowering of hemoglobin due to chronic hypersplenism and chronic renal failure, top-up transfusions may help in maintaining oxygen delivery and symptomatic relief. Addressing vaso-occlusion is more complex but best documented in preventing recurrent stroke and primary stroke following detection of cerebral vessel stenosis by transcranial Doppler. Although top-up transfusions have minimal side effects, potentially serious complications arise from chronic transfusion, and there are many unanswered questions on the duration of such therapy and the natural history of the underlying complications. These issues are addressed with the knowledge currently available.

Sickle cell disease: Progress made & challenges ahead

“…However, regular blood transfusions are associated with iron overload requiring iron-chelation therapy. By and large, access to regular transfusions is limited in LICs, and even when available, risks of blood-transmitted infections and prohibitive costs of iron-chelation therapies pose insurmountable barriers 8 . Findings from the seminal TWiTCH (TCD With Transfusions Changing to Hydroxyurea)have enabled switching from regular blood transfusions to oral hydroxyurea therapy as a key strategy for maintaining reduced TCD velocities in a large majority of at-risk children 9 .…”

Transfusion Therapy in Sickle Cell Disease

“…Simple transfusion is a method for acute lower haemoglobin levels in acute sequestration crisis, aplastic crisis and chronic low haemoglobin level in chronic renal failure [7]. Simple transfusion is when a few units of bags of blood are given through small tube (blood given set) usually via the vein.…”

“…Chronic transfusion is a kind of transfusion where an individual is transfused at 2-3 units within 3-4 weeks [7] with the therapeutic aim of reducing sickle haemogloin [7,22]. Chronic transfusion can be further divided into the conservative transfusion therapy which is aimed at maintaining the Hb level at 10 to 11 g/dL with 50% reduction in HbSS (hypertransfusion) or the aggressive form (exchange blood transfusion) aimed at reducing sickle Hb level to less than 30% [23].…”

“…Blood transfusion is said to restore the oxygen carrying capacity in patients with SCD and may also help to dilute the circulating Hbs, preventing vaso-occlusion [7]. It also suppresses the marrow from further production of sickle cells.…”

Iron stores in pregnant women with sickle cell disease: a protocol for a systematic review and meta-analysis

“…However, there are no clear guidelines on iron supplementation in the SCD subpopulation. In the SCD subpopulation, chronic haemolysis leads to recurrent transfusions and a risk of iron overload 10. This risk of iron overload among patients with SCD and risk of iron deficiency in pregnancy make supplementation of iron in pregnant women with SCD a difficult decision.…”