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| Media contacts: Alicia Sands Lurry, 404/616-6389, alurry@emory.edu |
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ATLANTA A study of 299 adult sickle cell patients, drawn from 21 referral centers nationwide, is especially promising because it shows hematologists now have an effective treatment -- the anticancer drug hydroxyurea -- to improve the quality of sickle cell patients’ lives, says one of the study’s 27 co-authors, James Eckman, MD, professor of hematology and oncology and medicine at the Emory Winship Cancer Institute and director of the Georgia Comprehensive Sickle Cell Center at Grady Memorial Hospital. Hydroxyurea can also reduce a patient’s chances of dying from sickle cell, the study, published in the April 2 issue of the Journal of the American Medical Association, suggests. The nine-year study, which started in 1992 and ended in 2001, found that taking hydroxyurea was associated with a 40 percent reduction in mortality compared with patients who did not take the drug. Seventy-five of the original study participants died during the study. "The significant finding of the study is that the patients who have received hydroxyurea have an improved survival over patients who don’t receive it," Dr. Eckman said. "It appears that the reduction in pain episodes, lessening of anemia and the decrease in acute chest syndrome were associated with improved survival. In fact, analysis of the differences between those that survived and those who didn’t show that the individuals with higher hemoglobin levels, less acute chest episodes, higher blood counts, all did better. It also reaffirmed that those individuals who had more than three pain episodes a year had a higher mortality than those who had less frequent pain episodes. That had been shown in other studies but never in a prospective way like this." Hydroxyurea is known to stimulate the body to make fetal hemoglobin, a form of protein that disappears from a baby’s bloodstream soon after birth. The fetal hemoglobin prevents the clumping of sickle hemoglobin. The original study, published in 1995, showed that symptoms of the disease improved dramatically, in terms of less pain crises and less hospitalizations for pain crises. "In that study, we also found the number of acute chest episodes were decreased and the patients tended to have a higher hemoglobin level and required less transfusion," Dr. Eckman said. Dr. Eckman also noted that anyone who has significant problems with sickle cell disease should consider going on the drug. That would include anyone with sickle cell anemia or sickle beta thalassemia (a trait that makes the body less able or even unable to use or synthesize one or more proteins that make up hemoglobin) with three pain episodes or more each year, acute chest syndrome, early kidney disease, or any significant symptomatic disease. "There were also no unpredictable adverse affects with hydroxyurea on treated patients," Dr. Eckman. "So it appears over the nine years that not only was it safe, there is a survival benefit if you’re on it versus if you’re not on it." Some patients, however, resist taking the drug because they are concerned about potential side effects. Patients must be followed carefully because hydroxyurea does lower blood counts. Hydroxyurea is believed to also have the potential to cause cancer, leukemia, and birth defects. Dr. Eckman said that to date, there is no scientific evidence to support these side effects. Nausea, hair loss and darkening of the skin are seen in a few patients. "With that aside, hydroxyurea is a very safe way of treating people," Dr. Eckman said. "This is a drug that hematologists all over the country have used extensively and we know how to use it very well, so we can use it safely. One of the important parts of this paper is that I think it’s probably going to encourage more patients to go on the drug because there clearly is a benefit. It’s one thing to reduce pain, but to reduce pain and to live longer is much more important for most people." Sickle cell disease is one of the most common genetic disorders in the United States, affecting more than 70,000 people, including one out of 400 African Americans, with symptoms that include periodic pain episodes, stroke, increased infections, yellowing of the skin and eyes, and other complications requiring emergency medical intervention. By definition, sickle cell disease is an inherited disorder involving the chemical known as hemoglobin contained in red blood cells. Hemoglobin carries oxygen to all parts of the body. When sickle hemoglobin loses its oxygen, it forms long rods inside the red blood cells, causing the red blood cell to lose its round, donut shape and form a hard, sickle, or crescent, shape. The "sickling" causes the red blood cell to break apart in 15 to 20 days instead of the normal 120 days. The quick turnover in red blood cells in sickle cell patients then causes anemia or a low red blood cell count. Sickled red blood cells can also block the blood vessels preventing the normal flow of oxygen and blood through the body. This blockage causes extreme pain and organ damage. The sickling of red blood cells is aggravated by infections, extreme hot or cold temperatures, poor oxygen intake, not drinking enough fluids, and stress. Sickle cell disease primarily affects people of African descent, but also affects people from Italy, Greece, Israel, India, Pakistan, Spain, Central America, the Caribbean, and many other ethnic groups. In America, approximately 1000 babies are born each year with sickle cell disease. It is estimated that more than 2.5 million Americans have the trait, and over 70,000 have the disease. For more information on sickle cell disease, visit http://www.SCInfo.org. |