Elevated Factor IX Activity Is Associated With an Increased Odds Ratio for Both Arterial and Venous Thrombotic Events

• Published in: American journal of clinical pathology Vol. 140; no. 5; pp. 680 - 685
• Main Authors: Heikal, Nahla M., Murphy, Karla K., Crist, Ronda A., Wilson, Andrew R., Rodgers, George M., Smock, Kristi J.
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 01.11.2013
• Subjects: Adult; Cerebral Arteries - metabolism; Cerebral Arteries - pathology; Factor IX - metabolism; Female; Humans; Ischemic Attack, Transient - epidemiology; Ischemic Attack, Transient - metabolism; Ischemic Attack, Transient - pathology; Male; Middle Aged; Odds Ratio; Retrospective Studies; Risk Factors; Utah - epidemiology; Venous Thromboembolism - epidemiology; Venous Thromboembolism - metabolism; Venous Thromboembolism - pathology; Young Adult; Utah; Arterial thrombosis; Stroke; Venous thrombosis; Factor IX
• ISSN: 0002-9173; 1943-7722; 1943-7722
• DOI: 10.1309/AJCPAGOR4Q2IIKUG

Elevations of factor IX (FIX) are thought to contribute to thrombotic risk, but this has not been well characterized. We retrospectively sought to determine whether elevated FIX levels are a risk factor for thrombosis in 81 adult subjects younger than 65 years (mean, 47 years) who were referred for evaluation of a hypercoagulable state. Patients were classified by arterial transient ischemic attack/stroke (TIA/stroke, n = 62) or venous thromboembolism (VTE, n = 19) events. FIX activity testing was performed on all 81 subjects and a reference group of 40 healthy individuals. Thirteen (21%) of 62 subjects with TIA/stroke and 5 (26%) of 19 subjects with VTE had elevated FIX activity. Odds ratios for TIA/stroke and VTE in subjects with elevated FIX activity were 3.7 (95% confidence interval [CI], 0.76-17.65) and 6.8 (95% CI, 1.18-39.07), respectively. Our findings suggest an association between elevated FIX levels and both arterial and venous thrombotic events.