The National Hemophilia Foundation estimates that more than 11 million Americans have bleeding and clotting disorders. Some are so mild they require no ongoing treatment. Others, such as hemophilia and heparin-induced thrombocytopenia (HIT), can be life threatening and often require immediate interventions.

Other disorders are so rare that physicians have a difficult time arriving at a diagnosis and the root cause of clinical issues. Examples of key diagnoses requiring expert testing include von Willebrand disease, venous thrombotic risk and ADAMTS13 deficiency, or thrombotic thrombocytopenic purpura (TTP). They may also include adverse drug effects (such as HIT and drug-associated thrombocytopenia), congenital thrombocytopenia and immunologic thrombocytopenia.

Three Categories of Special Coagulation

Special coagulation laboratories divide testing into three primary categories: thrombosis-, bleeding- and fibrin-related testing. Thrombotic disorders are varied and have different causes. Some thrombotic diseases are acquired or autoimmune disorders, while others are caused by molecular mutations. One key set of thrombotic assays is ADAMTS13 Evaluation, which helps with confirmation and prognosis of thrombotic thrombocytopenic purpura (TTP). TTP is a rare life-threatening disorder that causes extensive platelet microthrombi to form in small blood vessels. TTP often occurs due to the inhibition of the ADAMTS13 enzyme. TTP is treatable, however, and with proper diagnosis patients can receive plasmapheresis to achieve clinical remission.

Hypercoaguability also is an important area of coagulation testing; the esoteric coagulation testing menu includes assays for evaluation of HIT . HIT occurs when platelet counts drop abnormally due to the administration of heparin. Specialized tests for HIT antibodies can confirm HIT, resulting in more effective short- and long-term patient care.

Bleeding disorders addressed by special coagulation laboratories include hemophilia A, hemophilia B and von Willebrand disease, the most common hereditary bleeding disorder (though it rarely may be acquired as a result of other medical conditions). The disease presents in several forms.

Fibrinolysis, the destruction of blood clots, represents another distinctive area of special coagulation testing. Excessive fibrin generation may lead to thrombosis, while a lack of fibrin may lead to hemorrhage. An array of testing for fibrinolytic disorders is generally found in special coagulation laboratories.

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