In non-severe hemophilia A the risk of inhibitor after intensive factor treatment is greater in older patients: a case-control study

• Type of Material: Article
• Authors: Christine Kempton, Emory University; John M. Soucie, Emory University; C. H. Miller, Centers for Disease Control and Prevention; C. Hooper, Centers for Disease Control and Prevention; M. A. Escobar, University of Texas; A. J. Cohen, Newark Beth Israel Med. Ctr.; N. S. Key, University of North Carolina, Chapel Hill; A. R. Thompson, Puget Sound Blood Center; T. C. Abshire, BloodCenter of Wisconsin
• Language: English
• Date: 2010-10
• Publisher: Wiley: 12 months
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2010 International Society on Thrombosis and Haemostasis
• Final Published Version (URL): http://onlinelibrary.wiley.com/doi/10.1111/j.1538-7836.2010.04013.x/abstract;jsessionid=BFD8E7383414A3700A184DF76B7CBAF4.d04t01?systemMessage=Wiley+Online+Library+will+be+unavailable+for+approximately+4+hours+between+09%3A00+EDT+and+14%3A00+EDT+on+Saturday%2C+28+September+2013+as+we+make+upgrades+to+improve+our+services+to+you.+There+will+also+be+some+delays+to+online+publishing+between+25+to+28+September+2013.+We+apologize+for+the+inconvenience+and+appreciate+your+patience.+Thank+you+for+using+Wiley+Online+Library%21
• Title of Journal or Parent Work: Journal of Thrombosis and Haemostasis
• ISSN: 1538-7933
• Volume: 8
• Issue: 10
• Start Page: 2224
• End Page: 2231
• Grant/Funding Information: The study was supported by a grant from CSL Behring Foundation for Advancement of Patient Health and the Cooperative Agreement Prevention of Bleeding Disorder Complications through Regional Hemophilia Treatment Centers.
• Keywords: inhibitor; hemophilia A
• Research Categories: Health Sciences, Medicine and Surgery; Health Sciences, General

Abstract

Summary Background Twenty-five percent of new anti-factor VIII (FVIII) antibodies (inhibitors) that complicate hemophilia A occur in those with mild and moderate disease. Although intensive FVIII treatment has long been considered a risk factor for inhibitor development in those with non-severe disease, its strength of association and the influence of other factors have remained undefined. Objective To evaluate risk factors for inhibitor development in patients with non-severe hemophilia A. Methods Information on clinical and demographic variables and FVIII genotype was collected on 36 subjects with mild or moderate hemophilia A and an inhibitor and 62 controls also with mild or moderate hemophilia A but without an inhibitor. Results Treatment with FVIII for six or more consecutive days during the prior year was more strongly associated with inhibitor development in those ≥ 30 years of age compared with those < 30 years of age [adjusted odds ratio (OR) 12.62; 95% confidence interval (CI), 2.76–57.81 vs. OR 2.54; 95% CI, 0.61–10.68]. Having previously received < 50 days of FVIII was also not statistically associated with inhibitor development on univariate or multivariate analysis. Conclusions These findings suggest that inhibitor development in mild and moderate hemophilia A varies with age, but does not vary significantly with lifetime FVIII exposure days: two features distinct from severe hemophilia A.