Hemophilia – Factor VIII or IX Deficiency

Hemophilia A and hemophilia B are bleeding disorders caused by genetic variants in the F8 or F9 gene that result in deficiencies of factor VIII (FVIII) or factor IX (FIX), respectively. These disorders are clinically indistinguishable and present with bleeding symptoms ranging from mild to severe, depending on the underlying defect.

Tabs Content

Clinical Overview

Diagnosis

Indications for Testing

Spontaneous or prolonged bleeding suggestive of coagulation disorder
Family history of hemophilia
Acute or recent onset bleeding accompanied by prolonged partial thromboplastin time (PTT)

Laboratory Testing for Coagulation Disorders

CBC with platelet count – normal in hemophilia A and B
Prothrombin time (PT) – normal in hemophilia A and B
- PTT – prolonged in moderate and severe hemophilia
- Often normal in mild cases or in female carriers
- PTT that corrects with mixing study suggests factor deficiency
- PTT that does not correct with mixing study suggests an inhibitor
Mixing study – incubated mixing studies are often necessary to identify presence of inhibitors (eg, acquired versus inherited hemophilia)
Thrombin clotting time and plasma concentration of fibrinogen – normal in hemophilia A and B

Laboratory Testing for Hemophilia

FVIII activity level – decreased in hemophilia A and acquired hemophilia A
FIX activity level – decreased in hemophilia B and acquired hemophilia B
- Not reliable for carrier status detection in females
- Measurement in neonate may need to be repeated when family history of mild disease exists
von Willebrand factor (VWF) level – normal
- Because VWF is a carrier for FVIII, von Willebrand disease (VWD) should be ruled out in patients with decreased FVIII levels
- A rare subtype of VWD (type 2N) has isolated low FVIII activity with normal VWF level and mimics hemophilia A
  - Specialized coagulation or genetic testing can be used to distinguish these disorders
Bethesda assay – used as reflex test to detect presence of inhibitors versus factor deficiency and to monitor treated hemophilia patients for the development of an inhibitor
Genetic testing
- Patient risk should be calculated by a clinical geneticist using laboratory results and family history
- Indications
  - Confirm the causative F8 or F9 gene variant in affected individuals
  - Determine carrier status in at-risk females
At-risk fetus
- Third trimester amniocentesis should be considered for confirmation of affected male fetus
- Uncontaminated cord blood should be used at birth to establish diagnosis if not done previously
- Order FVIII and FIX assays in addition to activated PTT; FIX assays are difficult to interpret in neonates

Prognosis

Improved prognosis with the advent of FVIII and FIX replacement
Major disability from bleeding – joint disease
Leading cause of death from bleeding – intracranial hemorrhage

Differential Diagnosis

VWD
Rare coagulation factor deficiencies
- FII, FV, FVII, FX, FXI, FXII, FXIII
- Fibrinogen
- Deficiencies of FXII, prekallikrein, and high molecular weight kininogen prolong the PTT but do not result in a bleeding tendency
Fibrinolytic disorders
Qualitative platelet function disorders

Monitoring

Individuals receiving treatment for hemophilia are at risk for development of inhibitors
- Development of inhibitors not necessarily accompanied by clinical signs, so monitoring is required
Indications for testing
- Prior to elective invasive procedures
- Suboptimal response to factor concentrate replacement
- Before and after switching factor products
- 2-3 weeks after intensive treatment or surgery
- Severe hemophilia A and B
  - Every third exposure day or every 3 months until 20 exposure days have been reached
- Hemophilia A
  - Once or twice annually throughout a patient’s life
- Hemophilia B
  - Testing unnecessary after 150 exposure days unless presence of inhibitor clinically suspected
Laboratory testing
- Factor assays
  - Consider confirmation of low factor activity using a chromogenic assay since a number of interfering substances (eg, heparin, lupus anticoagulants) can interfere with the first-line clot-based factor assays, and some forms of hemophilia have clinically significant discrepancies between clot-based and chromogenic assay results
  - Note that some of the newer extended half-life factor replacement products are not accurately measured in some types of factor assays (depends on the combination of product and assay methodology)
    - If these products are being used, need to confirm which type of factor assay is appropriate for the product
- Bethesda assay or Nijmegen-Bethesda assay
- Activated partial thromboplastin time – initial test but not appropriate for specific diagnostic testing
- Barriers to testing
  - Cost
  - Availability

Background

Epidemiology

Incidence
- Hemophilia A – 1/4,000-5,000 male births worldwide; rare in females
- Hemophilia B – 1/25,000 male births worldwide; rare in females
- Acquired hemophilia – 1-2/million worldwide
  - <1/million in children
Age
- Severe disease – usually detected in first year of life
- Moderate disease – detected before age 5
- Mild disease – detected later in life
- Acquired disease – bimodal peaks at 20-40 years and 60-90 years
Types
- Hemophilia A – FVIII deficiency
- Hemophilia B – FIX deficiency
- Acquired hemophilia – autoimmune disorder caused by antibodies to FVIII or, rarely, FIX

Inheritance

Hemophilia A

X-linked recessive F8 gene variants
- Penetrance – 100% in males, 10% in females
- Female offspring of affected males are obligate carriers
  - 10% of female carriers are symptomatic, typically with mild disease
- >2,900 F8 sequence variants reported to date
Genotype/phenotype correlations
- Molecular causes for severe disease
  - Intron 22A inversion – 48%
  - Point variants – 43%
  - Large gene deletions – 6%
  - Intron 1 inversion – 3%
- Molecular causes for moderate to mild disease
  - Point variants or small insertions/deletions – 98%
  - Large gene deletions – <1%
- In probands with no apparent family history of hemophilia
  - >80% of mothers are identified as carriers
  - 10-15% show de novo F8 gene variants

Hemophilia B

X-linked recessive F9 gene variants
- Penetrance – 100% in males, 10% in females
- Female offspring of affected males are obligate carriers
  - 10% of female carriers are symptomatic, typically with mild disease
- ~33-50% show de novo F9 gene variants
- ~900 F9 sequence variants reported to date

Clinical Presentation

Hemophilia A is clinically indistinguishable from hemophilia B
Excessive bleeding – occurs spontaneously or from trivial injury
- Common bleeding manifestations – hemarthrosis, hematomas, gastrointestinal bleeding, genitourinary bleeding
Frequency and severity of excessive bleeding based on FVIII or FIX activity
- Mild disease (6-40% factor activity) – bleeding may occur with major trauma or surgery; no spontaneous bleeding
  - Often not diagnosed until adulthood
  - Carrier females – 10% have mild disease (<40% factor activity) and are at risk for excessive bleeding
- Moderate disease (1-5% factor activity) – bleeding may occur with minimal trauma or minor surgery; spontaneous bleeding rare
  - Typically diagnosed by 5 years
- Severe disease (<1% factor activity) – high risk of severe, spontaneous bleeding
  - Usually diagnosed in first year of life due to spontaneous muscle and joint bleeding
Acquired disease occurs rarely in children and the bleeding patterns can be different than in inherited disease (greater frequency of mucocutaneous bleeding)
- 50% have no known risk factor (Mulliez, 2014)
- Associated conditions
  - Autoimmune – systemic lupus erythematosus, rheumatoid arthritis, multiple sclerosis, Sjögren syndrome, antiglomerular basement membrane disease, myasthenia gravis, inflammatory bowel disease
  - Cancer – lymphomas, plasma cell dyscrasia, myelodysplastic syndrome, pemphigus
  - Hepatitis B or C viral infection (chronic)
  - Drugs (eg, sulfonamides, penicillin, phenytoin)
  - Pregnancy/postpartum

ARUP Lab Tests

Tests generally appear in the order most useful for common clinical situations. Click on number for test-specific information in the ARUP Laboratory Test Directory.

CBC with Platelet Count and Automated Differential 0040003
Method: Automated Cell Count/Differential

Recommended Use

Initial test for suspected bleeding disorder

Prothrombin Time 0030215
Method: Electromagnetic Mechanical Clot Detection

Recommended Use

Initial test for suspected bleeding disorder

Partial Thromboplastin Time 0030235
Method: Electromagnetic Mechanical Clot Detection

Recommended Use

Initial test for suspected bleeding disorder

Fibrinogen 0030130
Method: Electromagnetic Mechanical Clot Detection

Recommended Use

Determine if fibrinogen deficiency is a potential cause of bleeding

Thrombin Time with Reflex to Thrombin Time 1:1 Mix 0030260
Method: Electromagnetic Mechanical Clot Detection

Recommended Use

Assist in diagnosing dysfibrinogenemia or abnormalities with fibrin polymerization

Screen samples for the presence of heparin or direct thrombin inhibitors

Reflex – if thrombin time is elevated, then thrombin time 1:1 mix will be added

Factor VIII, Activity 0030095
Method: Electromagnetic Mechanical Clot Detection

Recommended Use

Diagnose hemophilia A or acquired factor VIII (FVIII) deficiency

Part of diagnostic workup for von Willebrand disease (VWD)

Not recommended when screening for thrombophilia

Factor VIII Activity with Reflex to Bethesda Quantitative, Factor VIII 0030026
Method: Electromagnetic Mechanical Clot Detection

Recommended Use

Diagnose FVIII deficiency

Detect FVIII inhibitors

Monitor FVIII replacement therapy

Reflex – if FVIII activity is ≤20%, Bethesda quantitative (FVIII) will be added

von Willebrand Panel 0030125
Method: Electromagnetic Mechanical Clot Detection/Platelet Agglutination/Microlatex Particle-Mediated Immunoassay

Recommended Use

Recommended panel for the initial workup of suspected VWD

Panel includes von Willebrand factor (VWF) antigen, ristocetin cofactor activity, and FVIII activity

Factor IX, Activity 0030100
Method: Electromagnetic Mechanical Clot Detection

Recommended Use

Diagnose factor IX (FIX) deficiency (hemophilia B)

Monitor FIX replacement therapy

Factor IX Activity with Reflex to Bethesda Quantitative, Factor IX 0030032
Method: Electromagnetic Mechanical Clot Detection

Recommended Use

Diagnose FIX deficiency

Detect FIX inhibitors

Monitor FIX replacement therapy

Reflex – if FIX activity is ≤20%, Bethesda quantitative (FIX) will be added

Hemophilia A (F8) 2 Inversions with Reflex to Sequencing and Reflex to Deletion/Duplication 2001614
Method: Inverse Polymerase Chain Reaction/Sequencing/Multiplex Ligation-dependent Probe Amplification

Recommended Use

Detect the causal F8 variant in established cases of hemophilia A

Determine carrier status in at-risk females with severely affected male relatives

For mild to moderate hemophilia A, hemophilia A (F8) sequencing is preferred

Reflex – if inversion testing does not explain clinical scenario, F8 gene sequencing will be added; if gene sequencing does not explain clinical scenario, deletion/duplication testing will added

Clinical sensitivity – 98%

Limitations

Diagnostic errors can occur due to rare sequence variations

Regulatory region and deep intronic variants, other than the F8 intron 22-A and intron 1 inversions, will not be detected

Deletions/duplications in exon 23 will not be detected.

Hemophilia B (F9) Sequencing and Deletion/Duplication 2010494
Method: Polymerase Chain Reaction/Sequencing/Multiplex Ligation-dependent Probe Amplification

Recommended Use

Most comprehensive test to confirm diagnosis or determine carrier status for F9 gene variants

Limitations

Diagnostic errors can occur due to rare sequence variations

Regulatory region variants and deep intronic variants will not be detected

The breakpoints of large deletions/duplications will not be determined

Large deletions/duplications in exon 1 may not be detected

Variants in genes other than F9 will not be detected

Medical Reviewers

Heikal, Nahla, MD, MS, Assistant Medical Director, Immunology and Hemostasis/Thrombosis at ARUP Laboratories; Assistant Professor of Clinical Pathology, University of Utah

Lyon, Elaine, PhD, FACMG, Medical Director, Molecular Genetics and Genomics, Medical Director, Pharmacogenomics at ARUP Laboratories; Professor of Clinical Pathology, University of Utah

Miller, Christine E., MS, LCGC, Genetic Counselor, Molecular Genetics at ARUP Laboratories; Faculty, Graduate Program in Genetic Counseling, University of Utah

Rodgers III, George M., MD, PhD, Medical Director, Hemostasis and Thrombosis at ARUP Laboratories; Professor of Internal Medicine and Adjunct Professor of Clinical Pathology, University of Utah

Smock, Kristi J., MD, Medical Director, Hemostasis/Thrombosis at ARUP Laboratories; Associate Professor of Clinical Pathology, University of Utah

Velden, Sara, MS, LCGC, Genetic Counselor, Molecular Genetics and Cytogenetics at ARUP Laboratories

References

Guidelines

Chalmers E, Williams M, Brennand J, Liesner R, Collins P, Richards M, Paediatric Working Party of United Kingdom Haemophilia Doctors' Organization. Guideline on the management of haemophilia in the fetus and neonate. Br J Haematol. 2011; 154(2): 208-15. PubMed

de Moerloose P, Fischer K, Lambert T, Windyga J, Batorova A, Lavigne-Lissalde G, Rocino A, Astermark J, Hermans C. Recommendations for assessment, monitoring and follow-up of patients with haemophilia. Haemophilia. 2012; 18(3): 319-25. PubMed

James AH. Diagnosis and management of women with bleeding disorders--international guidelines and consensus from an international expert panel. Haemophilia. 2011; 17 Suppl 1: 3-5. PubMed

MASAC Recommendations on Standardized Testing and Surveillance for Inhibitors in Patients with Hemophilia A and B. National Hemophilia Foundation. New York , NY [Accessed: May 2017]

MASAC Statement Regarding Use of Various Clotting Factor Assays to Monitor Factor Replacement Therapy. National Hemophilia Foundation. New York , NY [Accessed: May 2017]

WFH Guidelines for the Management of Hemophilia. World Federation of Hemophilia. Montréal, Canada [Updated: Aug 2014; Accessed: Feb 2016]

General References

Boylan B, Rice AS, Neff AT, Manco-Johnson MJ, Kempton CL, Miller CH, Hemophilia Inhibitor Research Study Investigators. Survey of the anti-factor IX immunoglobulin profiles in patients with hemophilia B using a fluorescence-based immunoassay. J Thromb Haemost. 2016; 14(10): 1931-1940. PubMed

Coppola A, Favaloro EJ, Tufano A, Di Minno MN, Cerbone AM, Franchini M. Acquired inhibitors of coagulation factors: part I-acquired hemophilia A. Semin Thromb Hemost. 2012; 38(5): 433-46. PubMed

de Brasi C, El-Maarri O, Perry DJ, Oldenburg J, Pezeshkpoor B, Goodeve A. Genetic testing in bleeding disorders. Haemophilia. 2014; 20 Suppl 4: 54-8. PubMed

Fijnvandraat K, Cnossen MH, Leebeek FW, Peters M. Diagnosis and management of haemophilia. BMJ. 2012; 344: e2707. PubMed

Franchini M, Favaloro EJ, Lippi G. Mild hemophilia A. J Thromb Haemost. 2010; 8(3): 421-32. PubMed

Franchini M, Zaffanello M, Lippi G. Acquired hemophilia in pediatrics: a systematic review. Pediatr Blood Cancer. 2010; 55(4): 606-11. PubMed

Hemophilia - Bleeding and Clotting Disorders Surveillance. Centers for Disease Control and Prevention. Atlanta, GA [Last updated: Jul 2014; Accessed: Jan 2017]

Mulliez SM, Vantilborgh A, Devreese KM. Acquired hemophilia: a case report and review of the literature. Int J Lab Hematol. 2014; 36(3): 398-407. PubMed

Verbruggen B, Meijer P, Novákova I, Van Heerde W. Diagnosis of factor VIII deficiency. Haemophilia. 2008; 14 Suppl 3: 76-82. PubMed

Wagenman BL, Townsend KT, Mathew P, Crookston KP. The laboratory approach to inherited and acquired coagulation factor deficiencies. Clin Lab Med. 2009; 29(2): 229-52. PubMed

References from the ARUP Institute for Clinical and Experimental Pathology^®

Flanders MM, Crist RA, Roberts WL, Rodgers GM. Pediatric reference intervals for seven common coagulation assays. Clin Chem. 2005; 51(9): 1738-42. PubMed

Heikal NM, Murphy KK, Crist RA, Wilson AR, Rodgers GM, Smock KJ. Elevated factor IX activity is associated with an increased odds ratio for both arterial and venous thrombotic events. Am J Clin Pathol. 2013; 140(5): 680-5. PubMed

Miranda GG, Rodgers GM. Treatment of an acquired factor VIII inhibitor with sequential recombinant factor VIIa and FEIBA. Haemophilia. 2009; 15(1): 383-5. PubMed

Nance D, Rodgers GM. Switching haemophilia products and inhibitor risk: a United States' perspective Eur J Haematol. 2015; 94(4): 283. PubMed

Peerschke EI, Castellone DD, Ledford-Kraemer M, Van Cott EM, Meijer P, NASCOLA Proficiency Testing Committee. Laboratory assessment of factor VIII inhibitor titer: the North American Specialized Coagulation Laboratory Association experience. Am J Clin Pathol. 2009; 131(4): 552-8. PubMed

Rodgers GM. Prothrombin complex concentrates in emergency bleeding disorders. Am J Hematol. 2012; 87(9): 898-902. PubMed

Sborov DW, Rodgers GM. How I manage patients with acquired haemophilia A. Br J Haematol. 2013; 161(2): 157-65. PubMed

Yaish H, Rodgers GM. A haemophilia B patient with severe burn injury: increased requirement for factor IX replacement therapy associated with venous thromboembolism. Haemophilia. 2008; 14(3): 607-9. PubMed

Last Update: March 2018


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	Hemophilia – Factor VIII or IX Deficiency. ARUP Consult^©. Retrieved April 18, 2018, from: https://arupconsult.com/content/hemophilia

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Hemophilia – Factor VIII or IX Deficiency

Tabs Content

Diagnosis

Indications for Testing

Laboratory Testing for Coagulation Disorders

Laboratory Testing for Hemophilia

Prognosis

Differential Diagnosis

Monitoring

Background

Epidemiology

Inheritance

Clinical Presentation

ARUP Lab Tests

Medical Reviewers

References

Guidelines

General References

References from the ARUP Institute for Clinical and Experimental Pathology®

References from the ARUP Institute for Clinical and Experimental Pathology^®