Mayo Test Catalog, (Sorted By Test Name) - Mayo Medical ...

WRF
8760
9943
WSPV
82659
Mol Genet 2005;14:1745-1751 3. Sconce E, Khan T, Wynne H, et al: The impact of CYP2C9 and
VKORC1 genetic polymorphism and patient characteristics upon warfarin dose requirements proposal for
a new dosing regimen. Blood 2005;106:2329-2333
Warfarin, Serum
Clinical Information: Warfarin (Coumadin) is an anticoagulant that acts by antagonizing the action
of vitamin K resulting in the same coagulation abnormalities produced by vitamin K deficiency.
Warfarin reduces the levels of prothrombin and factors VII, IX, and X, thereby prolonging the
prothrombin and partial thromboplastin times. Warfarin produces its anticoagulant effect within 36 to
72 hours of initiating therapy, and the duration of action may persist for 4 to 5 days following
withdrawal of drug. Warfarin circulates almost completely bound to albumin (>98%), and its half-life
ranges from 20 to 60 hours. Abnormal bleeding is the chief complication of overdose.
Useful For: Monitoring patients whose prothrombin time is inconsistent with the prescribed warfarin
dose, particularly when failure to comply or surreptitious drug use is suspected. Note: This test is not
useful for evaluation of the patient with prolonged bleeding time suspected of exposure to rat poisons.
Interpretation: Therapeutic concentration: 2.0 mcg/mL to 5.0 mcg/mL Toxic concentration: > or
=10.0 mcg/mL
Reference Values:
Therapeutic concentration: 2.0-5.0 mcg/mL
Toxic concentration: > or =10.0 mcg/mL
Clinical References: Gallus A, Jackaman J, Tillett J, et al: Safety and efficacy of warfarin started
early after submassive venous thrombosis or pulmonary embolism. Lancet 1986;2:1293-1296
Warthin-Starry Stain
Useful For: Demonstrating spirochetes and Donovan bodies
Reference Values:
The laboratory will provide a pathology consultation and stained slide.
Wasp Venom, IgE
Clinical Information: Clinical manifestations of immediate hypersensitivity (allergic) diseases are
caused by the release of proinflammatory mediators (histamine, leukotrienes, and prostaglandins) from
immunoglobulin E (IgE)-sensitized effector cells (mast cells and basophils) when cell-bound IgE
antibodies interact with allergen. In vitro serum testing for IgE antibodies provides an indication of the
immune response to allergen(s) that may be associated with allergic disease. The allergens chosen for
testing often depend upon the age of the patient, history of allergen exposure, season of the year, and
clinical manifestations. In individuals predisposed to develop allergic disease(s), the sequence of
sensitization and clinical manifestations proceed as follows: eczema and respiratory disease (rhinitis and
bronchospasm) in infants and children less than 5 years due to food sensitivity (milk, egg, soy, and
wheat proteins) followed by respiratory disease (rhinitis and asthma) in older children and adults due to
sensitivity to inhalant allergens (dust mite, mold, and pollen inhalants).
Useful For: Testing for IgE antibodies may be useful to establish the diagnosis of an allergic disease
and to define the allergens responsible for eliciting signs and symptoms. Testing also may be useful to
identify allergens which may be responsible for allergic disease and/or anaphylactic episode, to confirm
sensitization to particular allergens prior to beginning immunotherapy, and to investigate the specificity
of allergic reactions to insect venom allergens, drugs, or chemical allergens.
Interpretation: Detection of IgE antibodies in serum (Class 1 or greater) indicates an increased
likelihood of allergic disease as opposed to other etiologies and defines the allergens that may be
Current as of January 3, 2013 2:22 pm CST 800-533-1710 or 507-266-5700 or MayoMedicalLaboratories.com Page 1881