|NATIONAL INSTITUTES OF HEALTH
||National Institute of |
Environmental Health Sciences
|FOR IMMEDIATE RELEASE
Thursday, September 10, 1998
The National Toxicology Program Center and an ICCVAM subcommittee, the latter co-chaired by scientists Denise M. Sailstad of EPA and David G. Hattan at FDA, have organized the review of the alternative test, which is called the Murine Local Lymph Node Assay. The assay, or test, uses mice instead of guinea pigs—and requires half to a third as many, and can be done in a week as opposed to three to four weeks.
In the old test, the product was painted on the body and the guinea pig was then injected with an additional, potentially irritating chemical to help accentuate the test chemical’s effect. In the newer test, the mouse’s ears are painted with the test substance and its immunological response is determined by looking at lymph node tissue. The animal does not have to get challenge-induced contact dermatitis. "If you have a chemical that’s an allergen," according to a scientist who has worked with the test, "it stimulates the immune system so cells divide, and that’s what we’re looking at."
The newer test also costs about half of the old. It was first conceived by Ian Kimber, head of research at the Zeneca Central Toxicology Laboratory in England, and it was submitted as an alternative by three scientists from private industry. Tests from five different laboratories working with FDA were published this year.
The review, which is open to the public, will be from 8:30 a.m. to 5:30 p.m. Sept. 17 at the Gaithersburg Hilton, 620 Perry Parkway, Gaithersburg, Md. Copies of the proposed LLNA Test Method may be obtained by writing the NTP Center for the Evaluation of Alternative Toxicological Methods, MD EC-17 at NIEHS, PO Box 12233, Research Triangle Park, NC 27709, or be telephoning (919) 541-3398 or faxing (919) 541-0947.
Contact dermatitis is a major problem for consumers of many products, including cosmetics and household products. It is also the second most common occupational disease, costing industry and workers as much as $1 billion annually if lost workdays and associated loss of productivity are included. In industry, irritant contact dermatitis is the most common, usually resulting from reactions to chemical irritants such as solvents and cutting fluids. In addition, there is allergic contact dermatitis caused by a variety of substances, from latex to some pesticides, that trigger an allergic, or delayed hypersensitivity, reaction.
Director of NIEHS and NTP Kenneth Olden, Ph.D., said, "As we seek to reduce the numbers of animals used in testing, we realize too that improvements in test methods can translate directly into fewer injuries to the public and in the workplace. Good, accurate tests are an important tool of disease and injury prevention."