Sorted By Test Name - Mayo Medical Laboratories

BPG2
81425
TXBU
83335
1,25-dihydroxy vitamin D) Differential diagnosis of hypercalcemia
Interpretation: 1,25-Dihydroxy vitamin D concentrations are low in chronic renal failure and
hypoparathyroidism. 1,25-Dihydroxy vitamin D concentrations are high in sarcoidosis and other
granulomatous diseases, some malignancies, primary hyperparathyroidism, and physiologic
hyperparathyroidism. 1,25-dihydroxy vitamin D concentrations are not a reliable indicator of vitamin D
toxicity; normal (or even low) results may be seen in such cases.
Reference Values:
Males
or =16 years: 18-64 pg/mL
Females
or =16 years: 18-78 pg/mL
Clinical References: 1. Endres DB, Rude RK: Vitamin D and its metabolites. In Tietz Textbook of
Clinical Chemisty. 3rd edition. Edited by CA Burtis, ER Ashwood. Philadelphia, WB Saunders Company,
1999, pp 1417-1423 2. Bringhurst FR, Demay MB, Kronenberg HM: Vitamin D (calciferols): metabolism
of vitamin D. In Williams Textbook of Endocrinology. 9th edition. Edited by JD Wilson, DW Foster, HM
Kronenberg, PR Larsen. Philadelphia, WB Saunders Company, 1998, pp 1166-1169
11 Beta-Prostaglandin F2 Alpha, Urine
Clinical Information: Prostaglandin D(2) (PGD[2]) is generated by human mast cells after they are
activated via the IgE receptor or by calcium ionophore. In addition to mast cells, activated alveolar
macrophages and platelets also produce and secrete PGD(2). There are a large number of metabolic
products of PGD(2), the most abundant is 11 beta-prostaglandin F2 alpha.(1) While the most definitive
test for systemic mast-cell disease is bone marrow examination, measurement of mast-cell mediators in
blood or urine is less invasive and is advised for the initial evaluation of suspected cases. Elevated levels
of tryptase, N-methylhistamine or 11 beta-prostaglandin F2 alpha are consistent with the diagnosis of
systemic mast cell disease.(2)
Useful For: Measurement of 11 beta-prostaglandin F2 alpha in urine is useful in the evaluation of
patients suspected of having systemic mast-cell disease
Interpretation: Levels of 11 beta-prostaglandin F2 alpha >1,000 ng/24 hours are consistent with the
diagnosis of systemic mast-cell disease.
Reference Values:
>1,000 ng/24 hours is considered elevated.
Clinical References: 1. Roberts LJ, Sweetman BJ, Lewis RA, et al: Increased production of
prostaglandin D2 in patients with systemic mastocytosis. N Engl J Med 1980;303:1400-1404 2. Metcalfe
DD: Mastocytosis syndromes. In Allergy Principles and Practice. Vol. II. 4th Edition. Edited by E
Middleton Jr, CE Reed, EF Ellis, et al. St. Louis, Mosby Yearbook, Inc. 1993, pp 1537-1551
11-Dehydro-Thromboxane B2, Urine
Clinical Information: Thromboxane A2 is produced by the enzyme cyclo-oxygenase-1 (COX1) of
activated platelets and stimulates further platelet activation, platelet aggregation, and vasoconstriction.
11-Dehydro-thromboxane B2 (11-dTXB2) is the stable, inactive metabolite of thromboxane A2. Urinary
11-dTXB2 has been shown to reflect in vivo platelet activation.(1) Elevated values have been seen in up
to 85% of patients with acute ischemic stroke.(2,3) This marker also has been shown to have potential use
as an aid in the diagnosis of myocardial infarction.(4) Aspirin therapy has been reported to reduce
cardiovascular events in men and women by 15% to as much as 40%. However, aspirin use is not without
risk, and is associated with higher frequencies of gastrointestinal bleeding and hemorrhagic stroke.
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