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Diagnosis of hemophilia
Last reviewed: 04.07.2025

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Laboratory diagnostics of hemophilia
- Diagnosis is based on prolongation of whole blood clotting time and activated partial thromboplastin time (APTT); bleeding time and prothrombin time are unchanged.
- The type and severity of hemophilia are determined by a decrease in the coagulant activity of antihemophilic globulins in plasma (factors VIII and IX).
- Since factor VIII activity may also be reduced in von Willebrand disease, von Willebrand factor antigen levels should be determined in patients with newly diagnosed hemophilia A (in hemophilia A, the antigen levels remain normal).
- Screening of patients for the presence of inhibitors to factors VIII and/or IX is especially necessary before elective surgical interventions.
- Prenatal diagnosis and carrier detection.
Examination plan for suspected hemophilia
- blood test: number of erythrocytes, reticulocytes and hemoglobin; color index, leukocyte formula, ESR; diameter of erythrocytes (on a stained smear);
- coagulogram: platelet count; bleeding time and clotting time; activated partial thromboplastin and prothrombin time; content of factors IX and VIII and antibodies to factor VIII;
- blood biochemistry: direct and indirect bilirubin; transaminases ALT and AST; urea; creatinine; electrolytes (K, Na, Ca, P);
- general urine analysis (to exclude hematuria);
- fecal occult blood test (Gregersen test);
- hepatitis markers (A, B, C, D, E);
- blood group andRhfactor;
- functional diagnostics: ECG; if indicated - ultrasound of the abdominal cavity and affected joints and their radiography;
- consultations: hematologist, geneticist, neurologist, ENT specialist; dentist.
Laboratory characteristics of hemophilia:
- a several-fold increase in the duration of venous blood coagulation according to Lee-White;
- increase in plasma recalcification time;
- increase in partial thromboplastin time;
- decreased prothrombin consumption;
- low levels of factor VIII or IX in the blood.
The severity of hemophilia is assessed by the severity of hemorrhagic and anemic syndromes, the level of coagulation activity and the content of antihemophilic globulins, as well as the presence of complications.
Complications of hemophilia: hemarthrosis is the most common complication, which leads 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 diagnostics of hemophilia in the postnatal period is carried out with hemorrhagic diseases of newborns, coagulopathies, and DIC syndrome. Hemorrhagic syndrome in hemophilia A and B has no characteristic differences and differential diagnostics is carried out by laboratory and medical-genetic methods.
Hemophilia A is diagnosed by analyzing the factor VIII gene, and hemophilia B is diagnosed by analyzing the factor IX gene. Two methods are used: "polymerase chain reaction - restriction fragment length polymorphism" and "polymerase chain reaction with reverse transcription". Each method requires a small amount of blood or chorionic villus biopsy, which makes it possible to diagnose hemophilia prenatally at an early stage of pregnancy (8-12 weeks).