Psst. Have you heard the latest China story? Remember the poisonous dog food and the lethal toothpaste? Here is another one: Physicians in the U.S. and Germany noticed an unusual rise in mortality in patients receiving heparin.
What is heparin? And who needs it?
Heparin belongs to a group of molecules called glycosaminoglycans (GAG) or sometimes referred to by the old name of mucopolysaccharides (MPS). Basically, GAGs are long chains of sugar molecules linked to each other, and carrying on each sugar unit is an amino group and one or more sulfates.
Not very exciting, except that these molecules perform important biological and medical functions. For instance, heparin is an anti-coagulant. It inhibits clot formation and is used extensively in treatment of heart conditions (atrial fibrillation, acute coronary syndrome, myocardial infarction), as well as other conditions that require anticoagulation, such as deep vein thrombosis and kidney dialysis.
Another molecule belonging to the GAG group is chondroitin sulfate. It, too, is made up of a long chain of linked sugar molecules, each containing an amino group and two sulfates. The difference between heparin and chondroitin sulfate is primarily in their configuration; otherwise, they are very similar.
Where does heparin come from?
From China, where else?
Heparin comes from pigs’ guts. After slaughter, the inside wall of the gut is scraped and dried. The powder is then shipped to a factory where heparin is extracted and purified. Not very kosher, but also, as the cliché says: If you like sausage, don’t watch how it’s made. How they manage to get a drug out of this mess is a marvel.
The mortality wave
When the reports of increased mortality started circulating, the first suspicion was that the culprit is a contaminant in the heparin drug. Not an unreasonable assumption, given the source of heparin and the way it is prepared.
The FDA and some academic institutions jumped into action, and, using standard analytical methods for GAG, discovered the perpetrator: A molecule called over-sulfated chondroitin sulfate.
The plot thickens
Chondroitin sulfate is present in joint cartilage, but not in the gut. So how did it get into the heparin drug? If that’s not enough of a mystery, over-sulfated chondroitin sulfate is not a biological molecule at all; it is produced chemically from chondroitin sulfate. I am not given to conspiracy theories, but consider the facts:
- The stuff is man-made.
- It has anticoagulant activity, just like heparin.
- It is cheaper to produce than heparin.
- There is currently a shortage of pigs in China, and the raw material is now obtained from small, unregulated farms in remote villages.
I have to admit—I admire the practical chemistry knowledge of the Chinese, even the most uneducated villagers. How did they discover the fact that over-sulfated chondroitin sulfate can mimic heparin action? This molecule has been barely studied in the West. But then, remember the Chinese discovery of adding melamine to dog food? Here are the facts of that episode:
- The stuff is man-made.
- It mimics proteins in its nitrogen content.
- It is much cheaper than protein.
Is there a pattern here?
I always thought that crass capitalism is endemic to the U.S. Alas, even in this sphere, the “capitalist dogs” are being overtaken by the Chinese commies. Where is the world coming to?
How are we going to react?
Watch our politicians pounce. There will be patriotic China-baiting speeches on both sides of the aisle. There will be a hearing grilling some poor underpaid FDA official about the inadequacies of the agency. Congress will probably mandate the FDA, for the umpteenth time, to better police the products that pour across the border. But don’t look for any allocation of funds to carry out the mandate. That doesn’t work politically as well as blowing hot air at a hearing. And the administration? They will probably cut the FDA budget; regulation is ideologically impure. In fact, the Wall Street Journal editorial page advocates the abolition of the FDA. Nuts!
P.S. This article was written yesterday, Wednesday, March 19, 2008. Today, the New York Times published this article: “Heparin Discovery May Point to Chinese Counterfeiting.”
Did we score a scoop, or what!