Sickle Cell Anemia



Sickle Cell Anemia

Introduction

Sickle cell anemia is a non treatable hereditary problem which has an effect on the potential to produce healthy red blood cells. This disorder has potentially serious complications and early treatment (before symptoms develop) can improve both morbidity and mortality. It affects hemoglobin, a protein that is part of red blood cells and is responsible for oxygen transport. It is characterized by the presence of sickle cells in the bloodstream, which is also known as erythrocyte sickling. This causes difficulties in circulating red blood cells as the blood vessels get clogged and cause symptoms such as pain in the extremities (Bjorklund, 2010).

This disorder develops within the first 2 years and the symptoms can be traced back to two main phenomena which are hemolysis and clots. Hemolysis causes chronic anemia, jaundice, lack of growth and sexual maturation. The vascular occlusions cause crisis musculoskeletal pain, ease to bacterial infections (S. pneumonia, K. pneumonia, Homophiles influenza, etc.), cerebral infarction, renal impairment.

Discussion

Pathophysiological Implication

As a consequence of the mutation, when the hemoglobin is deoxygenated, it spontaneously undergoes polymerization to form a crystalline gel. Each polymer is composed of longitudinal beams 14 of deoxy-Hb which are arranged forming a tactoid body, insoluble and rigid cylindrical structure because these polymers, breaks the cytoskeleton of the erythrocyte, adopting this form of sickle cell trait (Bloom, 1995).

Although the sickling phenomenon is reversible, between 5 and 50% of sickle erythrocytes fail to regain its original shape, being eliminated by the mononuclear phagocyte system. Furthermore, erythrocytes have a large decrease altered corpuscular volume and a large increase in the concentration of hemoglobin. This is because the deoxy-Hb induces alterations of the erythrocyte membrane (modification of the distribution and composition of the phospholipids in the bilayer) which are translated by a deep dehydration. Additionally, sickle exhibits a strong tendency to adhere to vascular endothelium favoring the formation of micro thrombi and peripheral vascular occlusions (Mostafa, Tayel, Abdelrahim, Khamees, Maraghy, Meabed, 2012).

Interestingly hemoglobin S may interact with other forms of hemoglobin, particularly fetal hemoglobin (HbF). The presence of hemoglobin thus reduces the degree of polymerization of HbS, which explains that the sickle is not present during the neonatal period or hereditary persistence of fetal hemoglobin (Peterson, 2008).

Symptoms

The symptom of sickle cell anemia does not follow a single pattern. It has been observed that some people have mild indications and some have very severe indications. However, the fundamental predicament is the same where the red blood cells which are sickle shaped blocks the narrow vessels carrying blood disturbing the flow of blood resulting in a number of conditions.

The first sign of sickle-cell anemia in infants usually are swelling and tenderness of the hands or feet, fatigue, distortion of limbs and sometimes failure of walking. This symptom is a result of blockage of red blood capillaries of small bones in hands and feet, and impaired blood flow. Red blood cells fall out of the liquid part of the blood in the capillaries and get deposited as a ...