TEST CATALOG ORDERING & RESULTS SPECIMEN HANDLING CUSTOMER SERVICE EDUCATION & INSIGHTS
Test Catalog

Test ID: 9INHT    
Factor IX Inhibitor Profile Technical Interpretation

Useful For Suggests clinical disorders or settings where the test may be helpful

Technical interpretation of coagulation inhibitor testing to the specific factor requested, primarily factor IX in patients with hemophilia B

Testing Algorithm Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

If the factor IX activity assay is normal or elevated, then a computer-generated interpretive comment will be provided indicating inhibitor testing is not indicated and will not be performed.

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Factor IX inhibitors arise in patients with severe hemophilia B after factor IX transfusion. Patients with factor IX inhibitors may also develop anaphylactic reactions in response to factor IX infusions. Acquired factor IX inhibitors, occurring in previously healthy people, are exceedingly rare.

Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

Only orderable as part of a profile. For more information see 9INHE / Factor IX Inhibitor Evaluation, Plasma.

 

An interpretive report will be provided.

Interpretation Provides information to assist in interpretation of the test results

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Occasionally, a potent lupus-like anticoagulant may cause false-positive testing for a specific factor inhibitor (eg, factor VIII or IX).

Clinical Reference Recommendations for in-depth reading of a clinical nature

1. Hematology: Basic Principles and Practice. Seventh edition. Edited by R Hoffman, EJ Benz Jr, LE Silberstein, et al. Elsevier, 2018

2. Chitlur M, Warrier I, Rajpurkar M, et al: Inhibitors in factor IX deficiency a report of the ISTH-SSC international FIX inhibitor registry (1997-2006). Haemophilia 2009;15(5):1027-1031