Heparin containment confirmed by U.S. researchers

A team of scientists led by MIT professor Ram Sasisekharan has identified the contaminant present in Baxter’s heparin and has also found the mechanism by which it causes the allergic reactions, if injected in the body.

The researchers confirmed the contaminant present in Baxter’s Heparin to be Hyper-sulphated Chondroitin Sulphate. The compound Chondroitin Sulphate occurs naturally and is used as a dietary supplement to treat joint pain.

According to researchers, the contaminant activates two inflammatory pathways, causing severe allergic reactions and low blood pressure.

"These results provide a potential link between the presence of chemical contaminant in heparin and the clinical symptoms observed in affected patients," Sasisekharan said.

The chondroitin contaminant has a structure very similar to that of heparin. It thus cannot be identified with the tests normally used to inspect batches of heparin.

Heparin is commonly used in dialysis to prevent clotting of the blood when it circulates in a dialysis machine. It makes the blood thinner and thus reduces the loss of the blood during dialysis. Anemic patients can’t afford this blood loss as it could prove fatal for them.

Difficulty in breathing, nausea, vomiting, excessive sweating and rapidly falling blood pressure are few reactions that are developed in people who have been injected with contaminated drug.

Dr. Jeremy Berg, director of the National Institute of General Medical Science, said that in addition to being vital for public health, identifying the recent impurity in heparin was a chemical triumph.

The researchers used a unique combination of scientific techniques to accomplish this complex task, which can also be of use to detect other impurities in pharmaceutical materials, he added.

In January, Baxter had voluntarily recalled nine lots of its heparin sodium injection in 1,000-unit vials, after reports of adverse reactions.

From January 2007 through March 2008, the FDA had received 131 reports of deaths associated with heparin made by Baxter and other companies. Of the 131 deaths, 81 have been linked to an allergic reaction.

FDA had traced the source of the active ingredient to be Scientific Protein Laboratories LLC of Waunakee, Wis., which has a facility in China known as Changzhou SPL.

U.S. and China have been locking horns over the issue of malpractices prevalent in China. China had been making claims that the contaminant can’t be the reason behind the allergic reactions. Now, these findings provide a proof in FDA’s hands and it can strongly put its point forward.