Diagnosis of hemophilia

Laboratory diagnostics of hemophilia

• Diagnose by prolonging the coagulation time of whole blood and activated partial thromboplastin time (APTT); The time of bleeding and prothrombin time is not changed.
• The type and severity of hemophilia is determined by reducing the coagulant activity of antihemophilic globulins in plasma (factors VIII and IX).
• Since the activity of factor VIII can be reduced even in von Willebrand disease, in patients with newly diagnosed hemophilia A it is necessary to determine the content of the antigen of von Willebrand factor (in hemophilia A, the antigen content remains normal).
• Screening of patients for the presence of inhibitors to factors VIII and / or IX is especially necessary before routine surgical interventions.
• Prenatal diagnosis and detection of carriers.

Plan for examination for suspected haemophilia

• blood test: the number of erythrocytes, reticulocytes and hemoglobin; color index, leukocyte formula, ESR; diameter of erythrocytes (on a stained smear);
• coagulogram: the number of platelets; time of bleeding and clotting time; activated partial thromboplastin and prothrombin time; the content of IX and VIII factor and antibodies to factor VIII;
• biochemistry of blood: bilirubin direct and indirect; transaminases ALT and ACT; urea; creatinine; electrolytes (K, Na, Ca, P);
• general urine analysis (exclusion of hematuria);
• analysis of feces for occult blood (Gregersen's test);
• markers of hepatitis (A, B, C, D, E);
• blood group and Rh- factor;
• functional diagnostics: ECG; in the presence of indications - ultrasound of the abdominal cavity and affected joints and their radiography;
• consultations: hematologist, genetics, neuropathologist, ENT doctor; dentist.

Laboratory characteristics of hemophilia:

• increase in several times the duration of coagulation of venous blood according to Lee-White;
• increase in plasma recalcification time;
• increased partial thromboplastin time;
• decreased consumption of prothrombin;
• low level of factor VIII or IX in the blood.

Assessment of the degree of severity of hemophilia is determined by the severity of hemorrhagic and anemic syndromes, the level of coagulation activity and the content of antihemophilic globulins, and the presence of complications.

Complications of hemophilia: hemarthrosis are the most common complications that lead to early disability of patients; renal bleeding with partial or complete obstruction of the urinary tract and the development of acute renal failure; hemorrhage in the brain or spinal cord.

Differential diagnosis of hemophilia in the postnatal period is carried out with hemorrhagic diseases of newborns, coagulopathies, DIC syndrome. Hemorrhagic syndrome with hemophilia A and B has no characteristic differences and differential diagnosis is performed by laboratory and medical genetic methods.

Hemophilia A is diagnosed by analyzing the factor VIII gene, and hemophilia B is the factor IX gene. Two methods are used: "polymerase chain reaction - restriction fragment length polymorphism" and "polymerase chain reaction with reverse transcription". For each method, a small amount of blood or a biopsy sample of the villus of the chorion is necessary, which makes it possible to diagnose hemophilia prenatally at an early stage of pregnancy (8-12 weeks).

[1], [2], [3], [4], [5], [6], [7]