The Properties of Red Blood Cells from Patients Heterozygous for HbS and HbC (HbSC Genotype)

Abstract

Sickle cell disease (SCD) is one of the commonest severe inherited disorders, but specific treatments are lacking and the pathophysiology remains unclear. Affected individuals account for well over 250,000 births yearly, mostly in the Tropics, the USA, and the Caribbean, also in Northern Europe as well. Incidence in the UK amounts to around 12–15,000 individuals and is increasing, with approximately 300 SCD babies born each year as well as with arrival of new immigrants. About two thirds of SCD patients are homozygous HbSS individuals. Patients heterozygous for HbS and HbC (HbSC) constitute about a third of SCD cases, making this the second most common form of SCD, with approximately 80,000 births per year worldwide. Disease in these patients shows differences from that in homozygous HbSS individuals. Their red blood cells (RBCs), containing approximately equal amounts of HbS and HbC, are also likely to show differences in properties which may contribute to disease outcome. Nevertheless, little is known about the behaviour of RBCs from HbSC heterozygotes. This paper reviews what is known about SCD in HbSC individuals and will compare the properties of their RBCs with those from homozygous HbSS patients. Important areas of similarity and potential differences will be emphasised.

Micro- and macrovascular function in children with sickle cell anaemia and sickle cell haemoglobin C disease

“…Further studies are needed to address the exact mechanisms. Although SC patients are marked by blood hyperviscosity, it appears that NO-dependent vascular function and vessels elasticity are preserved which may enable normalization of vascular resistance and may reduce the risk of painful vaso-occlusive crises [54]. Children with sickle cell haemoglobin C disease had also a low pulse pressure, which is probably the consequence of well-functioned central and peripheral arterial elasticity [55].…”

Differential time-dependent volumetric and surface area changes and delayed induction of new permeation pathways inP. falciparum-infected hemoglobinopathic erythrocytes

“…At low oxygen tension, HbS tends to polymerize when present in homozygous form or as heterozygous HbSC, causing sickling of the erythrocyte (Hebbel, 1991;Nagel, Fabry, & Steinberg, 2003). Patients carrying the HbSS or HbSC alleles frequently develop sickle cell disease (Hannemann et al, 2011;Turgeon, 2011). The consequences of HbC on red blood cell physiology are less severe and include reduced cell deformability and dehydration (Turgeon, 2011).…”

A Retrospective Analysis of the Significance of Haemoglobin SS and SC in Disease Outcome in Patients With Sickle Cell Disease and Dengue Fever

“…Sickle-cell disease (SCD) is considered a major global public health problem ( Serjeant, 2014 ). There are approximately 250,000 births annually ( Hannemann et al, 2011 ). Africa, bears the highest burden of the disease ( Makani et al, 2013 ).…”