Pulmonary hypertension of sickle cell disease: more than just another lung disease.

Pulmonary hypertension (PH) of sickle cell disease (SCD), as defined by a tricuspid regurgitant jet velocity by echocardiogram of >or=2.5 m/sec, occurs in approximately 1/3 of HbSS adults and is an independent risk factor for mortality. Although studies of the past few years have greatly expanded our knowledge of the clinical manifestations and pathogenesis of PH in SCD, many questions remain. Two of the key issues addressed by manuscripts in the issue of the American Journal of Hematology are the prevalence of PH in the large African SCD population and the association of PH with renal disease and systemic hypertension. Because of its high impact on mortality, the assessment of PH in the African population is crucial from a public health standpoint. The association of PH with systemic disease in SCD suggests that a more widespread vasculopathy occurs in these patients that may be one of the mechanisms responsible for the observed increase in mortality. It is through studies such as these that a greater understanding of the pathogenesis and treatment of pulmonary hypertension is sickle cell disease can ve achieved.