Lot numbers traced 52 of 54 heparin reactions to one contaminant

Investigators at the Centers for Disease Control and Prevention began a nationwide search. They found 152 reactions in 113 patients across 13 states, with a common thread in the heparin used.

Where the administered lot number was recorded, 52 of 54 reactions followed heparin from lots containing oversulfated chondroitin sulfate, a contaminant that traditional screening tests could not distinguish. Every facility with cases had used the same manufacturer's heparin, against 4.3 percent of control facilities.

Nine lots were recalled in January and all of that manufacturer's heparin by late February, by which time new reports had stopped. A companion study showed the contaminant activated a blood pathway that produces bradykinin. The tracing was possible because vials carried lot numbers that could be matched to cases.

The lot number made the contaminant findable.