Hemophilia A & B

Hemophilia A (factor VIII deficiency) and hemophilia B (factor IX deficiency) are X-linked bleeding disorders. Severity depends on residual factor activity. Modern prophylaxis and gene therapy substantially reduce bleeding and improve life expectancy.

Classification

• Severe: <1% factor activity
• Moderate: 1–5%
• Mild: >5–40%

Symptoms

• Spontaneous joint/muscle bleeds (ankles, knees, elbows)
• Prolonged bleeding after injury/surgery
• Easy bruising, mucosal bleeding (less common than in von Willebrand disease)
• Intracranial hemorrhage in severe cases
• Chronic hemarthroses leading to arthropathy

Diagnosis

• Prolonged activated partial thromboplastin time (aPTT) with normal PT
• Specific factor assays to quantify FVIII or FIX activity
• Genetic testing for carrier detection and prenatal counseling

Treatment & Management

Factor Replacement Therapy

• Recombinant factor VIII or IX concentrates (standard or extended half-life)
• Prophylaxis schedules individualized based on pharmacokinetics
• On-demand dosing for mild cases or breakthrough bleeds
• Desmopressin (DDAVP) for mild hemophilia A to boost endogenous FVIII

Non-Factor Therapies

• Emicizumab (bispecific antibody) for hemophilia A with or without inhibitors
• Investigational agents (concizumab, marstacimab) targeting TFPI or antithrombin to rebalance hemostasis

Inhibitor Management

• Immune tolerance induction (ITI) with high-dose factor
• Bypassing agents (activated prothrombin complex concentrate, recombinant factor VIIa)
• Emicizumab for inhibitor patients

Gene Therapy

• AAV-mediated FVIII or FIX gene transfer provides long-lasting factor expression in many adults; durability and monitoring continue to evolve

Supportive Care

• RICE (rest, ice, compression, elevation) for bleeds
• Physical therapy to maintain joint function/flexibility
• Dental prophylaxis (antifibrinolytics) before procedures
• Vaccinations (HBV, HAV) due to previous reliance on plasma products

Living with Hemophilia

• Track bleeds, infusions, factor levels, inhibitor testing, joint symptoms
• Store factor products properly, maintain infusion supplies (needles, ports)
• Wear medical alert ID; educate school/work contacts
• Encourage safe physical activity (swimming, cycling) to strengthen muscles around joints
• Address mental health—chronic pain and treatment burden can be stressful

Complications

• Chronic joint disease (hemophilic arthropathy)
• Inhibitor development (antibodies against infused factor)
• Viral transmission historically (HIV/HCV) – now extremely rare but part of long-term care
• Thrombosis risk when using non-factor therapies in combination

Research & Future Directions

Refinements in gene therapy, RNA interference, and gene editing aim for durable cures with lower vectors doses. Long-acting non-factor prophylaxis and personalized PK dosing continue to improve outcomes.

Experimental & Emerging Treatments

• Next-Gen AAV Vectors: Liver-targeted capsids with lower immunogenicity.
• Liver-Directed Gene Editing (CRISPR): Corrects FVIII/FIX gene directly.
• siRNA/Antisense Oligonucleotides: Rebalance coagulation by silencing anticoagulant pathways.
• Oral Hemostatic Agents: Early-stage research for convenient prophylaxis.

Track Hemophilia with Diagnoza.care

Stay Ahead of Bleeds – Log infusions, product lots, trough levels, inhibitor screens, joint scores, bleeds, imaging, PT sessions, and clinic visits; capture side effects; and let the AI companion identify patterns needing dose adjustments or further evaluation.

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Medical Disclaimer: Informational only. Follow your hematologist/hemophilia treatment center for individualized prophylaxis, inhibitor management, and gene therapy eligibility. Sources: World Federation of Hemophilia, National Hemophilia Foundation, American Society of Hematology