HEMOPHILIA B BREAKTHROUGH
British researchers have treated six patients suffering from the blood-clotting disease known as hemophilia B by injecting them with the correct form of a defective gene, a landmark achievement in gene therapy. Hemophilia B is the first well-known disease to appear treatable by gene therapy, a technique with a 20-year record of almost unbroken failure.
The general concept of gene therapy -- replacing the defective gene in any genetic disease with the intact version -- has long been alluring. But carrying it out in practice has been a struggle. The immune system is all too effective at killing the viruses before the genes can take effect.
The success with hemophilia B, reported online Saturday in the New England Journal of Medicine, embodies several minor improvements developed over many years by different researchers. The delivery virus, carrying a good version of the human gene for the clotting agent known as Factor IX, was prepared by researchers at St. Jude Children's Research Hospital in Memphis. The patients had been recruited and treated with the virus in England by a team led by Dr. Amit Nathwani of University College London; researchers at the Children's Hospital of Philadelphia monitored their immune reactions.
Hemophilia B is caused by a defect in the gene for Factor IX. Fatal if untreated, the disease occurs almost only in men because the Factor IX gene lies on the X chromosome, of which men have only a single copy. About one in 30,000 of newborn boys have the disease.
Nathwani and his team reported that they treated the patients by infusing the delivery virus into their veins. The virus homes in on the cells of the liver, and the gene it carries then churns out correct copies of Factor IX. A single injection enabled the patients to produce small amounts of Factor IX, enough that four of the six could stop the usual treatment, injections of Factor IX concentrate prepared from donated blood. The other two patients continued to need concentrate, but less frequently.
The patients have continued to produce their own Factor IX for up to 22 months, said Dr. Edward Tuddenham, director of the Hemophilia Center at the Royal Free Hospital in London. Twenty more patients will be treated to assess the best dose of the virus.
FDA MUST DECIDE ON BPA BY MARCH 31
The Food and Drug Administration must come up with a decision by March 31 on whether to ban a chemical that's widely used in the plastics and metal linings of food containers, according to a court settlement reached between the agency and the Natural Resources Defense Council. The NRDC filed a petition in 2008 asking the agency to ban bisphenol A, or BPA, citing a growing body of research that suggests exposure to the chemical might pose serious health risks. The settlement now forces the FDA to take a position on the chemical.
OVERWEIGHT KIDS MAY SEE RISK AT 3
When children are overweight, heart-health risk factors such as dangerous cholesterol levels and artery inflammation can start as early as age 3, said a University of Miami study published in the journal Obesity. "There's clearly a link between weight and cardiovascular risk," said Sarah Messiah, a research assistant professor and lead author. "When a doctor sees an overweight child at age 3, he has to talk to the parents about it. The negative health processes are not 20 years down the road -- they're already starting." The information in the study is culled from health records of 3,644 children ages 3 to 6 from the 1999-2008 National Health and Nutrition Examination Surveys, a nationwide databank.
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