Navigation Links
2 studies provide insight into stroke risk and prevention in young sickle cell anemia patients

Monthly blood transfusions combined with daily medication to remove the resulting excess iron remains the best approach for reducing the risk of recurrent strokes in young patients with sickle cell anemia, according to a preliminary analysis of a multicenter trial that includes St. Jude Children's Research Hospital.

The study compared the efficacy of two treatments for the potentially life-threatening problem of iron overload caused by chronic transfusion therapy. The transfusions are used to guard against additional strokes in young sickle cell anemia patients. The trial, known as SWiTCH or Stroke with Transfusion Changing to Hydroxyurea, was halted in May after an interim safety review determined the alternative therapy was not significantly better than the standard treatment at reducing iron buildup and was associated with an increased stroke risk.

Russell Ware, M.D., Ph.D., chair of the St. Jude Children's Research Hospital Department of Hematology and principal investigator of SWiTCH, discussed the results at the 52nd Annual Meeting of the American Society of Hematology. The meeting is being held December 4 -7 in Orlando, Fla.

Jonathan Flanagan, Ph.D., a staff scientist at St. Jude, presented results of another study that provide the first independent validation of an association between five common genetic variations and stroke risk in young sickle cell patients.

Between 70,000 and 100,000 individuals in the U.S. have sickle cell anemia. They make an abnormal hemoglobin molecule that sometimes takes on a twisted or sickle shape, disrupting blood flow and oxygen delivery throughout the body. Patients are vulnerable to a variety of problems, including organ damage, episodes of acute pain and stroke. Five to 10 percent of patients will suffer strokes before their 20th birthday. Up to 90 percent of patients will experience a recurrence.

Flanagan and his colleagues tried to validate earlier reports linking 38 genetic polymorphisms to stroke risk in sickle cell disease. Researchers compared the genetic makeup of 130 young sickle cell anemia (SCA) patients enrolled in the SWiTCH trial with 103 SCA patients enrolled in another study. The SWiTCH participants had suffered documented strokes while patients in the other trial had not.

Investigators validated the association between stroke risk and five single nucleotide polymorphisms (SNPs) in four genes. SNPs are small inherited variations in the makeup of particular genes and are sometimes used as markers of disease risk. "These findings reinforce earlier observations suggesting there is a genetic component to stroke risk in sickle cell anemia. We are now focusing on how these five SNPs might play a role in stroke development," said Flanagan, the poster's first author. Ware is the senior author.

Investigators also confirmed that the alpha-thalassemia trait is associated with a reduced stroke risk. Affected individuals carry two or three, rather than the usual four, genes for making one of the hemoglobin proteins needed to ferry oxygen throughout the body. Researchers reported no association between another inherited condition, G6PD deficiency, and strokes.

SWiTCH was a Phase III trial funded by the National Heart, Lung, and Blood Institute. Between October 2006 and April 2009, 133 children and adolescents ages 5 through 18 enrolled at one of 25 participating U.S. centers. All had a diagnosis of sickle cell anemia, had an average age of almost 13, had suffered at least one stroke and had undergone monthly blood transfusions for an average of seven years.

Sixty-six were randomly assigned to continue monthly transfusions and to take the drug deferasirox, or Exjade, daily to remove excess iron from their bodies. The remaining 67 patients were assigned to treatment with hydroxyurea daily for 30 months to reduce stroke risk and to undergo monthly blood removal to reduce iron buildup.

Monthly blood transfusions are 90 percent effective at preventing future strokes in sickle cell patients. But Ware said the resulting iron overload and other factors have fueled interest in alternative approaches to stroke prevention.

Hydroxyurea received U.S. Food and Drug Administration approval in 1998 for use in adults with SCA. The medication works by stimulating production of fetal hemoglobin, an alternative form of the molecule. A pilot study found the drug offered a possible alternative for managing stroke risk.

The SWiTCH study was halted after a review of data from 62 patients found no statistically significant difference in iron concentrations in the liver biopsies of the two treatment groups.

As expected, strokes were more common among patients receiving hydroxyurea than those who continued transfusion therapy. Seven of the 67 patients in the hydroxyurea group had another stroke. There were no additional strokes in the chronic transfusion patients.


Contact: Summer Freeman
St. Jude Children's Research Hospital

Related medicine news :

1. Drug-like compound stops thyroid overstimulation in early NIH studies
2. Laboratory studies show promise for new multiple sclerosis treatment
3. A Little Alcohol May Help the Heart: Studies
4. Studies validate use of family health history as gold standard in disease risk assessment
5. Researchers find pathway that drives spread of pediatric bone cancer in preclinical studies
6. Practice-changing studies on how oncologists treat cancer to be presented at ASTRO Annual Meeting
7. Studies show everolimus-eluting stent implantation reduces restenosis and repeat revasculariztion
8. New studies highlight obesitys impact on gastrointestinal health
9. 2 studies present new data on effects of alcohol during pregnancy
10. Studies Tout Alternative HIV Regimens for Women, Babies
11. Hospital readmission studies: Influencing factors identified
Post Your Comments:
(Date:12/1/2015)... ... December 01, 2015 , ... World Patent Marketing ... Jar, a container patent that allows for easier packing and organizing of items into ... worth $90 billion," says Scott Cooper, CEO and Creative Director of World Patent Marketing ...
(Date:12/1/2015)... ... ... Tampa is the first health care provider in the region to offer the vBloc® ... a vagal blocking therapy, delivered via the Maestro® System, for the treatment of adult patients ... 40 to 45 kg, or a BMI of at least 35 to 39.9 kg with ...
(Date:12/1/2015)... ... ... Dr. Paul Vitenas, one of the top cosmetic surgeons in Texas ... the Best Single Physician Practice in the nation. Dr. Vitenas and his practice were ... the industry publication. , Dr. Vitenas said he was very honored to receive ...
(Date:12/1/2015)... , ... December 01, 2015 , ... ... the 7th Annual 2015 Golden Bridge Business Awards under the New Products and ... zero capex web based sample management software that helps labs organize ...
(Date:12/1/2015)... (PRWEB) , ... December 01, 2015 , ... ... facilities, radiographic technicians must mark the film for accurate interpretation by the radiologist. ... of. Fortunately, an inventor from Sacramento, Calif., has found a way to alleviate ...
Breaking Medicine News(10 mins):
(Date:12/1/2015)... -- CytRx Corporation (NASDAQ: CYTR ), a biopharmaceutical ... that it has reached its enrollment target of 400 ... trial of aldoxorubicin in patients with previously treated soft ... in Q1 2016. The Phase 3 trial is a randomized, ... from the FDA at 79 sites in ...
(Date:12/1/2015)... 1, 2015   Craneware, Inc ., the ... today announced the company will showcase a new ... ® solution at the American Society for ... . The new features are focused on simplifying ... and managing enterprise-wide pharmacy charges to ensure compliance ...
(Date:12/1/2015)... Germany , December 1, 2015 /PRNewswire/ ... leading global manufacturer of eye and gaze tracking solutions, ... SMI remote eye trackers as a component of its ... concussions, eye sight, and medical and performance issues in ... part of SMI,s mass-market-ready eye tracking platform, which is ...
Breaking Medicine Technology: