Factor X assays using chromogenic substrate S-2222.

Abstract

Factor X was assayed using chromogenic substrate S-2222 for four patients with severe factor X deficiency and for nine patients with homozygous or heterozygous factor X Friuli disorder. Factor X Friuli disorder is characterized by the presence of an abnormal factor X that is normally activated by Russell's viper venom, but is not activated by tissue thromboplastins. The levels of factor X found in factor X deficiency varied between 2 and 10% of normal and therefore were higher than those found in the same plasmas using "clotting" methods (1% or less than 1% of normal). The levels of factor X found in homozygous factor X Friuli patients varied between 4 and 11% of normal, and therefore were practically identical to those found by means of clotting methods that employed tissue thromboplastins (7-9% of normal). These values were definitely lower than those obtained using a Russell's viper venom and cephalin mixture as thromboplastin (82-92%). A similar pattern was observed for patients heterozygous for the abnormality. These findings indicate that "amidolytic" methods are not necessarily identical to clotting methods. Furthermore, they indicate that substrate S-2222 is not specific for factor X.

• Authors: A Girolami, L Saggin, G Boeri
• Journal: American journal of clinical pathology (Am J Clin Pathol) Vol. 73 Issue 3 Pg. 400-2 (Mar 1980) ISSN: 0002-9173 [Print] England
• PMID: 7361721 (Publication Type: Journal Article)

Chemical References

• Oligopeptides
• benzoyl-Ile-Glu-Gly-Arg-p-nitroanilide
• Factor X

Topics

• Blood Coagulation Tests
• Factor X (analysis)
• Factor X Deficiency (blood, congenital, diagnosis)
• Humans
• Hypoprothrombinemias (blood)
• Oligopeptides
• Prothrombin Time