Hemophilia A

Hemophilia A

Definition

Hemophilia is a disease that causes the body lacks the protein needed for blood clotting process when there is bleeding. This protein is commonly called a clotting factor or coagulation factors.

Acquired hemophilia is a rare but potentially life-threatening bleeding disorder caused by the development of autoantibodies (inhibitors) directed against plasma coagulation factors, most frequently factor VIII (FVIII), which may be inherited or arise from spontaneous mutation. The development of inhibitory antibodies to FVIII can result in acquired hemophilia A or can complicate the treatment of genetic cases.

Signs and symptoms

Depending on the level of FVIII activity, patients with hemophilia may present with easy bruising, inadequate clotting of traumatic injury or—in the case of severe hemophilia—spontaneous hemorrhage.

Signs of hemorrhage include the following:

• General: Orthostasis, Weakness , Tachypnea ,Tachycardia
• Genitourinary: Hematuria, renal colic, and post circumcision bleeding
• CNS: Headache, stiff neck, vomiting, lethargy, irritability, and spinal cord syndromes
• Gastrointestinal: Hematemesis, melena, frank red blood per rectum, and abdominal pain
• Musculoskeletal (joints): Tingling, cracking, warmth, pain, stiffness, and refusal to use joint (children)
• Other: Epistaxis, oral mucosal hemorrhage, hemoptysis, dyspnea (hematoma leading to airway obstruction), compartment syndrome symptoms, and contusions; excessive bleeding with routine dental procedures

Diagnosis

Laboratory studies for suspected hemophilia include the following:

• Complete blood cell count
• Coagulation studies
• FVIII assay

Expected laboratory values:

• Platelet count: Normal
• Hemoglobin/hematocrit: Normal or low
• Bleeding time and prothrombin time: Normal
• Activated partial thromboplastin time (aPTT): Significantly prolonged in severe hemophilia, but may be normal in mild or even moderate hemophilia

Normal values for FVIII assays are 50-150%.Values in hemophilia are as follows:

• Mild: >5%
• Moderate: 1-5%
• Severe: <1%

Imaging studies for acute bleeds are chosen on the basis of clinical suspicion and anatomic location of involvement, as follows:

• Head computed tomography scans without contrast are used to assess for spontaneous or traumatic intracranial hemorrhage
• MRI scans of the head and spinal column are used for further assessment of spontaneous or traumatic hemorrhage
• MRI is also useful in the evaluation of the cartilage, synovium, and joint space
• Ultrasonography is useful in the evaluation of joints affected by acute or chronic effusions

Testing for inhibitors is indicated when bleeding is not controlled after adequate amounts of factor concentrate are infused during a bleeding episode. Inhibitor concentration is titrated using the Bethesda method, as follows:

• Positive result: Over 0.6 Bethesda units (BU)
• Low-titer inhibitor: Up to 5 BU
• High-titer inhibitor: Over 5 BU

See Also

Hemophilia A 

Hemophilia B 

Hemophilia C
Key Differences Between Hemophilia C and Hemophilia A and B 

Source :

http://emedicine.medscape.com/article/779322-overview

http://www.alodokter.com/hemofilia