Heparin contamination in coagulation testing and a protocol to avoid it and the risk of inappropriate FFP transfusion.

Artifactual heparin contamination of blood samples drawn for coagulation testing is an ongoing problem. A retrospective analysis of activated partial thromboplastin times (APTTs) greater than 45 seconds from patients on neither heparin nor Coumadin (Dupont, Wilmington, DE) therapy shows complete correction of the APTT to normal in 39% of such samples after treatment with heparinase. Recheck of samples with significantly prolonged APTTs after treatment with heparinase is proposed as the best method to avoid inappropriate transfusion of fresh frozen plasma.

Trials of commercial reagents in anion-exchange coagulation procedures: ortho diagnostics.

The suitability of Ortho Diagnostics one-stage prothrombin time (PT) reagent (Ortho Brain Thromboplastin) and activated partial thromboplastin (aPTT) reagent (Activated Thrombofax) has been evaluated for use in conjunction with the anion-exchange heparin removal maneuver. The PT/HR and aPTT/HR are tests used to follow the anticoagulant influence of coumarins when heparin also is being administered. After establishing a coumarin therapeutic range for Activated Thrombofax, a parallel trial was conducted with Ortho Brain Thromboplastin on coumarin-treated patient plasmas. Determinations also were made after heparin (0.2 mu/mL) was added and then removed by ECTEOLA microchromatography columns. Ortho Brain Thromboplastin was found to induce a shortening bias associated with a spurious improvement in the precision of tests run on anion-exchange treated plasmas that potentially could result in coumarin overdosage. The systematic error did not appear to result either from protracted incubation or the activation of prekallikrein, high molecular weight kininogen, Factor XI or XII. This reagent was found to perform appropriately with plasma not exposed to ECTEOLA. Activated Thrombofax gave reliable and reproducible results before and after heparin removal. This aPTT reagent could be used in the aPTT/HR anticoagulant surveillance scheme.

Heritable alpha 2-macroglobulin deficiency in a patient with arterial thrombosis: alpha 2-macroglobulin deficiency Irvine.

A heritable deficiency in α(2)-macroglobulin (α(2)M) was identified in a 61-year-old man with arterial thrombosis. Plasma α(2)M levels among the patient's symptom-free relatives consistently ranged from 43 to 55 percent of laboratory mean-normal values. The new α(2)M variant displayed retarded anodal immunoelectrophoretic mobility when studied in plasma and serum. The affected members of this lineage showed no evidence of acquired or inherited thrombotic or consumptive derangements involving other plasma proteins. The significance of a possible causal association between α(2)M deficiency and the predisposition to arterial thrombosis is considered. The uncomplicated use of streptokinase and urokinase to treat the reference patient's arterial thrombosis is described. Recommendations are made for the adoption of a descriptive nomenclature. The new familial deficiency is tentatively designated α(2) (+)-macroglobulin deficiency Irvine.