The New England journal of medicine
-
Acute episodes of pain are the principal symptom of sickle cell disease, but little is known about the epidemiologic features of these episodes or risk factors for them, nor is it known whether patients with high rates of such episodes die prematurely. We prospectively studied the natural history of sickle cell disease in 3578 patients ranging from newborns to persons up to 66 years old who were followed at clinical centers across the United States. ⋯ The "pain rate" (episodes per year) is a measure of clinical severity and correlates with early death in patients with sickle cell anemia over the age of 20. Even when the fetal hemoglobin level is low, one can predict that small increments in the level may have an ameliorating effect on the pain rate and may ultimately improve survival. This outcome is particularly encouraging to investigators studying hydroxyurea and other treatments designed to increase the fetal hemoglobin level.