Mini Review Sickle Cell Pulmonary Hypertension: Pathogenesis and Diagnosis

Sickle cell disease (SCD) refers to the inherited disorder of red blood cells (RBCs). The disorder is marked by point mutation occurring in the beta (β)-globin chain of hemoglobin. This results in the amino acid substitution of valine in place of glutamic acid at position 6 (Glu6Val) of the chain, leading to the formation of abnormal sickle hemoglobin (HbS) [1]. On exposure to low-oxygen tension, HbS loses its solubility capacity, resulting in polymerization and aggregation of mutated hemoglobin inside sickle RBCs as they traverse in microcirculation [2]. The sickled RBCs obstruct blood vessels and impede free blood flow in the affected vessel causing oxygen deprivation, vascular congestion, lactate acidosis, anaerobic glycolysis, and pain [3]. In general, SCD manifestations are secondary to ischemia from vessel occlusion and hemolysis from rupture of sickle cells with less deformable RBCs [4]. However, the severity of complications varies between patients.