Effect of Heparin Contaminated with Oversulfated Chondroitin Sulfate on the Collection and Analysis of Plasma

Abstract

Oversulfated chrondroitin sulfate (OSCS) was recently identified as a contaminant of heparin and was associ- ated with serious adverse events in patients treated with heparin. Because heparin is a common component of blood col- lection tubes, we tested the effect of OSCS on the laboratory analysis of plasma. Blood from healthy volunteers (N=50) was collected into tubes containing various mixtures of heparin and OSCS. Samples were inspected for microclots and were analyzed for a panel of 28 routine laboratory tests. No microclots were observed in tubes that contained only heparin but were detected in 18%, 88% and 76% of plasma samples containing 5%, 15%, 20% OSCS (%weight relative to hepa- rin), respectively. OSCS at the highest dose (20%) caused a systematic bias for the following 6 tests: Lactate Dehydro- genase: 18% (12% to 24%); Triiodothyronine: -5.7% (-8.1% to -3.3%); Potassium: -2.8% (-4.2% to -1.4%); Total Protein: 2.5% (1.4% to 3.6%); Chloride: -1.4% (-1.8% to -1.0%) and Uric Acid: 1% (0.5% to 1.4%). In summary, OSCS contami- nation of heparin was found to potentially affect the anticoagulation of plasma and the analytical performance of several routine clinical laboratory tests.