Sorted By Test Name - Mayo Medical Laboratories

VITC
60296
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
responsible for eliciting signs and symptoms. The level of IgE antibodies in serum varies directly with the
concentration of IgE antibodies expressed as a class score or kU/L.
Reference Values:
Class IgE kU/L Interpretation
0 Negative
1 0.35-0.69 Equivocal
2 0.70-3.49 Positive
3 3.50-17.4 Positive
4 17.5-49.9 Strongly positive
5 50.0-99.9 Strongly positive
6 > or =100 Strongly positive Reference values
apply to all ages.
Clinical References: Homburger HA: Allergic diseases. In Clinical Diagnosis and Management by
Laboratory Methods. 21st edition. Edited by McPherson RA, Pincus MR. WB Saunders, Publ, New York,
Chapter 53, Part VI, pp. 961-971, 2007
Ascorbic Acid, Plasma
Clinical Information: Ascorbic acid (vitamin C) is essential for the enzymatic amidation of
neuropeptides, production of adrenal cortical steroid hormones, promotion of the conversion of
tropocollagen to collagen, and metabolism of tyrosine and folate. It also plays a role in lipid and vitamin
metabolism and is a powerful reducing agent or antioxidant. Specific actions include: activation of
detoxifying enzymes in the liver, antioxidation, interception and destruction of free radicals, preservation
and restoration of the antioxidant potential of vitamin E, and blockage of the formation of carcinogenic
nitrosamines. In addition, vitamin C appears to function in a variety of other metabolic processes in which
its role has not been well characterized. Prolonged deficiency of vitamin C leads to the development of
scurvy, a disease characterized by an inability to form adequate intercellular substance in connective
tissues. This results in the formation of swollen, ulcerative lesions in the gums, mouth, and other tissues
that are structurally weakened. Early symptoms may include weakness, easy fatigue and listlessness, as
well as shortness of breath and aching joints, bones, and muscles. The need for vitamin C can be increased
by the use of aspirin, oral contraceptives, tetracycline, and a variety of other medications. Psychological
stress and advancing age also tend to increase the need for vitamin C. Among the elderly, lack of fresh
fruit and vegetables often adds vitamin C depletion to the inherently increased need, with development of
near-scurvy status.
Useful For: Diagnosing vitamin C deficiency As an aid to deter excessive intake
Interpretation: Values 0.6 mg/dL indicate
adequate supply. The actual level at which vitamin C is excessive has not been defined. Values >3.0
mg/dL are suggestive of excess intake. Whether vitamin C in excess is indeed toxic continues to be
uncertain. However, limited observations suggest that this condition may induce uricosuria and, in
individuals with glucose-6-phosphate dehydrogenase deficiency, may induce increased red blood cell
fragility.
Reference Values:
0.6-2.0 mg/dL
Current as of January 4, 2013 7:15 pm CST 800-533-1710 or 507-266-5700 or MayoMedicalLaboratories.com Page 187