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

LANG
82349
effects are dizziness, ataxia, blurred or double vision, nausea, or vomiting.
Useful For: Monitoring serum concentration of lamotrigine Assessing compliance Adjusting
lamotrigine dose in patients receiving other anticonvulsant drugs which interact pharmacokinetically
with lamotrigine
Interpretation: The serum concentration should be interpreted in the context of the patient's clinical
response and may provide useful information in patients showing poor response (noncompliance?) or
adverse effects, particularly when lamotrigine is co-administered with other anticonvulsant drugs. While
most patients show response to the drug when the trough concentration is in the range of 2.5 mcg/mL to
15.0 mcg/mL, and show signs of toxicity when the peak serum concentration is >20 mcg/mL, some
patients can tolerate peak concentrations as high as 70 mcg/mL.
Reference Values:
Patients receiving therapeutic doses usually have lamotrigine concentrations of 2.5-15.0 mcg/mL.
Clinical References: 1. Johannessen SI, Battino D, Berry DJ, et al: Therapeutic drug monitoring
of the newer antiepileptic drugs. Ther Drug Monit 2003;25(3):347-363 2. Johannessen SI, Landmark
CJ: Value of therapeutic drug monitoring in epilepsy. Expert Rev Neurother 2008;8(6):929-939 3.
Johannessen SI, Tomson T: Pharmacokinetic variability of newer antiepileptic drugs: when is
monitoring needed? Clin Pharmacokinet 2006;45(11):1061-1075 4. Physician's Desk Reference. 61th
Edition. Montvale, NJ: Thomson PDR, 2007 5. Goodman & Gilman's: The Pharmacological Basis of
Therapeutics. 10th Edition. New York. McGraw-Hill Book Company 2001
Langust (Lobster), 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
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
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