Guidelines for the use of hydroxycarbamide in children and adults with sickle cell disease: A British society for haematology guideline

Sickle cell disease (SCD) is a generic term for an inherited group of disorders that includes homozygous sickle cell anaemia (SS), sickle cell/haemoglobin C (SC) sickle cell/β-thalassemia (S/β thal) and other compound heterozygous conditions. SCD is characterised by the presence of the mutated β‐globin gene, HBBs (also termed βs‐globin). On de‐oxygenation, this forms a polymeric structure resulting in deformed, rigid red blood cells, and is associated with a chronic haemolytic anaemia due to shortened red cell life span and vaso‐occlusion causing frequent episodes of severe bony pain (vaso‐occlusive crises) and other acute and chronic complications. These include an increased risk of stroke, pulmonary hypertension, acute and chronic lung damage, chronic renal failure and leg ulcers. Fetal haemoglobin (haemoglobin F, HbF, α2ϒ2) is protective against these complications and infants are relatively protected in the first few months of life before HbF in infancy is replaced by HbS (α2βS2) rather than adult haemoglobin (HbA, α2β2). Co‐inheritance of raised HbF levels is also associated with a milder phenotype.   Abstract source Full text