Sickle cell anemia-associated pulmonary arterial hypertension.

Pulmonary hypertension is a common complication of sickle cell anemia. Despite the fact that the elevations in pulmonary artery pressures are slight, morbidity and mortality are high. In adult sickle cell anemia patients, pulmonary hypertension is emerging as a major risk factor for death. The pathogenesis of sickle cell anemia-related pulmonary hypertension is multifactorial, including hemolysis, impaired nitric oxide bioavailability, chronic hypoxemia, thromboembolism, chronic liver disease and asplenia. In the majority of patients, pulmonary arterial hypertension is the main cause of elevated pulmonary artery pressures. However, pulmonary venous hypertension also plays a role in a subgroup of patients. Specific data on the effects of treatment modalities for pulmonary hypertension in patients with sickle cell anemia are scarce. It is likely that all patients would benefit from maximization of sickle cell anemia therapy, and that patients with the severe form of the disease would benefit from treatment with selective pulmonary vasodilators and antiproliferative agents. Large trials evaluating the effects of treatment for pulmonary hypertension in the sickle cell anemia population are underway.