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Tests and Services

Coagulation and Thrombosis Testing

The Coagulation and Thrombosis Laboratory at Children’s National Medical Center provides comprehensive coagulation and thrombosis testing to diagnosis benign and malignant hematopoietic (blood formation) disorders in patients treated in Children’s Comprehensive Hemophilia and Thrombosis Center and throughout the hospital

Hematological testing
Hematology is the study of blood and its main components – red blood cells, white blood cells, and platelets. The most frequently-ordered tests are:
  • Complete blood count (CBC), which is a comprehensive evaluation and classification of cell types, useful in the evaluation of anemia, infection, inflammatory conditions, and malignancies. Using immature granulocyte counts as part of the CBC allows rapid detection of early septic states.
  • Sickle cell prep.
  • Reticulocyte enumeration, which assesses the body’s ability to generate red blood cells and assists in classifying the type of anemia along with the complete blood count.
Coagulation testing
Coagulation testing helps evaluate whether the body is able to control bleeding adequately or to determine if there is increased risk of clotting. Frequently-ordered tests include:
  • Prothrombin time (PT), which tests the extrinsic pathway of the coagulation system
  • Activated partial thromboplastin time (aPTT), which tests the intrinsic pathway of the coagulation system
  • Fibrinogen, which is the main constituent of a clot. Decreased levels pose a risk of bleeding
Other specific coagulation tests include:
  • Hemophilia A evaluation for Factor VIII and inhibitors
  • Hemophilia B evaluation for Factor IX and inhibitors
  • Platelet functional defects
  • von Willebrand disease evaluation for von Willebrand factor antigen, Ristocetin cofactor activity, Factor VIII, and Platelet function screen (PFA-100)
  • Measurement of all coagulation factors, D-dimer and test for heparin induced thrombocytopenia (HIT)
Hemoglobinopathy evaluation specialized testing
A comprehensive hemoglobinopathy evaluation for thalassemias and sickle and non-sickle hemoglobinopathies is provided with review of pertinent clinical and laboratory data as well as peripheral smear review. Specialized testing includes:
  • Hemoglobin A2 and F quantitation
  • Isoelectric focusing gel electrophoresis
  • Heinz body preparation
  • Capillary zone electrophoresis
  • Acid/alkaline agarose gel electrophoresis
Coagulation evaluation specialized testing
The laboratory physicians provide a comprehensive review of clinical and laboratory data for a variety of coagulation disorders:
  • Hemophilia A and B
  • von Willebrand disease
  • Platelet function defects
  • Thrombophilia states, such as protein S, protein C and antithrombin III deficiency
Thrombophilia testing
DNA testing is provided for other risk factors for thrombophilia including:
  • Prothrombin G20210A mutation
  • Factor V Leiden mutation
  • Methylene-Tetra-Hydro-Folate-Reductase (MTHFR) mutations
Special analysis of small sample volume for newborns is provided.

Children’s Coagulation and Thrombosis Program works closely with the Sickle Cell Disease program. Both programs are funded by the Centers for Disease Control and Prevention and the Maternal and Child Health Bureau.

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Coagulation and Thrombosis Testing - Departments & Programs - Children's National Medical Center