| Zusammenfassung |
Sickle cell disease (SCD) is a very common inherited condition with debilitating consequences. It results from the inheritance of an abnormal haemoglobin, the oxygen-carrying pigment of red blood cells. SCD patients have HbS, rather than the normal HbA, in their red cells. Patients may have only HbS (HbSS genotype) but other combinations are possible. The second most common is co-inheritance of HbS with a second abnormal Hb, HbC (HbSC genotype). In this case, patients? red cells contain equal amounts of HbS and HbC. HbSC disease represents about 1/3rd of the cases of SCD, with about 80,000 born annually worldwide. In all cases of SCD, red cell HbS aggregates into rigid rods when oxygen levels in the circulation are low, distorting red cell shape, making them sticky and fragile, thus reducing red cell longevity. It also encourages blockage of small blood vessels leading to organ damage and ultimately untimely death. A range of complications are seen: chronic anaemia plus symptoms of vascular occlusion (including stroke, damage to bone, retina, kidneys and lungs). This is true for HbSC individuals as well as HbSS ones. However, the disease in HbSC patients is significantly different with a different range of complications and different blood cell picture. This means that they should be considered as a discrete subset of SCD patients. Notwithstanding there is very little research pertaining specifically to HbSC patients. In fact, in most studies analysing the abnormal behaviour of red cells containing HbS and also clinical trials of potential new treatments, HbSC patients are specifically excluded. It is likely that the course of HbSC disease differs and that this results from a different abnormalities in the behaviour of their red cells. Central to this difference is the fact that the red cells contain both HbS and HbC. This work will study specifically HbSC patients. The behaviour of their red cells (containing both HbS and HbC) will be correlated with disease severity. Specific ways of stopping HbS polymerisation in HbSC red cells will be sought. Results will enable better management of HbSC patients and amelioration of the complications of SCD in this significant group of patients. |
