ATLANTA, Dec. 11 /PRNewswire/ -- New research has uncovered an important predictor of mortality in patients with sickle cell disease. A build-up of pressure in the arteries that supply the lungs -- a condition known as pulmonary hypertension -- is a common complication of sickle cell disease. Now a biomarker known as BNP can accurately predict this deadly risk factor, according to a study to be presented today during the 47th Annual Meeting of the American Society of Hematology (ASH).
“Although the management of patients with sickle cell disease has improved dramatically in the past 40 years, many patients still have life-threatening but potentially treatable problems,” said James N. George, M.D., professor of medicine at the University of Oklahoma Health Sciences Center and President of ASH. “This important study provides new insight for identifying patients at risk for critical complications.”
When the heart is under a pressure strain, ventricles in the heart release a protein called brain natriuretic peptide, or BNP. Scientists at the National Heart, Lung, and Blood Institute (NHLBI) and investigators affiliated with the Multicenter Study of Hydroxyurea (MSH) Patients’ Follow-Up theorized that the more strain the heart was under, the more BNP would be released, and, therefore, the varying levels of BNP would be able to tell them who had pulmonary hypertension.
BNP levels were measured in 230 patients with sickle cell disease and in 45 healthy controls. BNP was higher in the sickle cell patients with pulmonary hypertension than in patients without pulmonary hypertension or in the healthy controls. An abnormally high BNP level (greater than 160 pg/ml) was a clear predictor of mortality, increasing the risk of death twofold.
To independently confirm the finding, BNP levels were measured in banked blood samples of a separate cohort of 121 patients with sickle cell disease enrolled in the MSH Patients’ Follow-Up study initiated in 1996. A high BNP level, found in 30 percent of the group, was associated with a high prospective risk of death. This measure was an independent predictor of future death even when controlled for other factors, such as the rate of pain episodes.
“Considering that pulmonary hypertension is common and a major risk factor for death in patients with sickle cell disease, a test that could be used to assess this risk is potentially helpful,” said Roberto Machado, M.D., of NHLBI. “This new predictor -- BNP -- adds to the inventory of screening tests that could be used to identify pulmonary hypertension in patients with sickle cell disease.”
“This study also suggests that 10 years ago, almost one-third of patients in the MSH Patients’ Follow-Up had undiagnosed pulmonary hypertension,” said Mark Gladwin, M.D., of NHLBI’s Vascular Medicine Branch. “Perhaps most provocatively, the data suggest that the greatest risk factor for death was not the frequency of painful crisis or the acute chest syndrome, but rather unrecognized pulmonary hypertension.”
The American Society of Hematology (www.hematology.org) is the world’s largest professional society concerned with the causes and treatment of blood disorders. Its mission is to further the understanding, diagnosis, treatment, and prevention of disorders affecting blood, bone marrow, and the immunologic, hemostatic, and vascular systems, by promoting research, clinical care, education, training, and advocacy in hematology.
The American Society of Hematology
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Web site: http://www.hematology.org/