Researchers Identify Contaminant in Tainted Heparin

Armed with information on the chemical structure of the contamination, experts should now be able to distinguish pure heparin from tainted heparin, the study authors stated.

TheNew England Journal of Medicinepaper details a screening test for oversulfated chondroitin sulfate, and also demonstrates that heparin contaminated with OSCS and synthetically-derived OSCS result in side effects in pigs similar to those seen in humans.

Raw heparin is derived from pig intestines, and it's often processed by small, unregistered mom-and-pop workshops in China. Heparin is used for certain types of surgery to prevent blood clots. Kidney patients also take it before undergoing dialysis.

Oversulfated chondroitin sulfate mimics heparin's qualities and is a modified form of chondroitin sulfate. Chondroitin sulfate is a naturally occurring substance made from animal cartilage and is often used in supplements to treat arthritic joints. But, oversulfated chondroitin sulfate is man-made and doesn't occur naturally.

While the reports represent progress, many mysteries still remain, said experts.

"The fact that there's a test available will certainly be helpful and can reassure the public that the heparin being used at their respective hospitals, if a test is being used, is safe. That's good news because heparin is a ubiquitous medication," said Dr. Jack Ansell, a hematologist and chairman of medicine at Lenox Hill Hospital in New York City. "The thing that's still puzzling is is this a natural contaminant or not? We don't know where it's coming from. The nature of the chemical suggests that this is a naturally derived product. If that's the case, it means that it's been inserted or added in some sense, and that still is unclear. We need more information about that."

More information

The U.S. National Library of Medicine has more on heparin.

SOURCES: April 23, 2008,Nature Biotechnology, online; April 24, 2008,New England Journal of Medicine, April 23, 2008, news release, Massachusetts Institute of Technology, Cambridge, Mass.