thromboplastin and Blood-Protein-Disorders

Resistance to the anticoagulant effects of activated protein C (APC) is now considered the most prevalent cause of inherited thrombophilia. The great majority of patients with activated protein C resistance (APCR) have a missense mutation in the factor V molecule (factor V Leiden, FVR506Q) resulting in defective inactivation of factor Va due to a loss of an APC cleavage site. The diagnosis of APCR has been based upon the inability of APC to prolong the activated partial thromboplastin (aPTT) clotting time in subjects with APCR. However, this assay has a number of deficiencies which limit its general use. We have evaluated a newly described one-stage tissue factor dependent factor V coagulation assay for APCR in 117 patients and controls and compared the results of this assay in a blinded manner to a polymerase chain reaction (PCR) based assay for the molecular defect of factor V Leiden. 43% (50/117) of the patients studied were receiving coumadin or heparin, or had a lupus anticoagulant. The tissue factor dependent factor V assay had 100% specificity and sensitivity for factor V Leiden and successfully predicted a homozygous state in the three documented homozygotes. The PCR-based assay for factor V Leiden resulted in a single false positive assay due to a silent A to C transition at nucleotide 1692 resulting in the loss of the Mnl restriction endonuclease cleavage site. The single-stage tissue factor dependent factor V assay is a highly sensitive and generally applicable assay for APCR.

Topics: Blood Coagulation Tests; Blood Protein Disorders; Factor V; Humans; Protein C; Sensitivity and Specificity; Thromboplastin

Topics: Blood Cell Count; Blood Coagulation; Blood Platelets; Blood Protein Disorders; Cholestasis; Diagnosis, Differential; Duodenal Neoplasms; Factor VII; Hemorrhage; Heparin; Humans; Liver Neoplasms; Neoplasm Metastasis; Pancreatic Neoplasms; Syndrome; Thromboplastin

Evidence of disseminated intravascular coagulation (DIC) was sought in New Zealand white rabbits infused with autologous, hemolyzed whole blood. Hemoglobinemia was induced in 17 rabbits by rapid intravenous injection of frozenthawed whole blood. Three dose regimens yielded mean peak plasma hemoglobin concentrations of 325, 615 and 860 mg/100 ml respectively (range 260 to 1050 mg/100 ml). Eleven control animals were infused with autologous, nonhemolyzed whole blood in similar doses. Rabbits were killed at either 15, 60, 120 or 180 minutes following infusion and multiple organ biopsies obtained immediately post-mortem. Coagulation studies demonstrated no significant alterations in prothrombin time, partial thromboplastin time, thrombin time or fibrinogen. Fibrin degradation products were not found. Histologic examination of lung, heart, liver, spleen and kidney revealed no fibrin deposition, thrombus formation or other abnormalities. We conclude from our study that induction of brief, experimental hemoglobinemia in New Zealand white rabbits, utilizing moderately large doses of autologous, hemolyzed whole blood, does not result in the development of DIC.

Topics: Animals; Blood Coagulation; Blood Coagulation Tests; Blood Protein Disorders; Blood Transfusion, Autologous; Disseminated Intravascular Coagulation; Fibrinogen; Hemoglobins; Kidney; Liver; Lung; Myocardium; Prothrombin Time; Rabbits; Spleen; Thrombin; Thromboplastin; Urine

Topics: Afibrinogenemia; Aged; Blood Coagulation Tests; Blood Platelets; Blood Protein Disorders; Factor VIII; Female; Fibrin; Hemorrhagic Disorders; Humans; Immunoglobulin G; Japan; Male; Middle Aged; Multiple Myeloma; Thromboplastin; Waldenstrom Macroglobulinemia

Topics: Blood Cell Count; Blood Coagulation Disorders; Blood Coagulation Factors; Blood Coagulation Tests; Blood Platelets; Blood Protein Disorders; Blood Protein Electrophoresis; Hemorrhagic Disorders; Hemostasis; Humans; Immunodiffusion; Immunoglobulin G; Immunoglobulin M; Leukemia, Lymphoid; Multiple Myeloma; Platelet Adhesiveness; Thromboplastin; Waldenstrom Macroglobulinemia

Topics: Aged; Blood Coagulation Disorders; Blood Coagulation Tests; Blood Platelets; Blood Protein Disorders; Calcium; Collagen; Connective Tissue; Fibrin; Fibrinogen; gamma-Globulins; Hemorrhagic Disorders; Humans; Male; Multiple Myeloma; Nitrogen Mustard Compounds; Plasmapheresis; Prothrombin Time; Thromboplastin; Tryptophan

Topics: Beta-Globulins; Blood Coagulation Disorders; Blood Protein Disorders; Genetics, Medical; Humans; Thromboplastin