Hyperparathyroidism laboratory findings
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief:
Overview
An elevated/reduced concentration of serum/blood/urinary/CSF/other [lab test] is diagnostic of [disease name].
OR
Laboratory findings consistent with the diagnosis of [disease name] include [abnormal test 1], [abnormal test 2], and [abnormal test 3].
OR
[Test] is usually normal among patients with [disease name].
OR
Some patients with [disease name] may have elevated/reduced concentration of [test], which is usually suggestive of [progression/complication].
OR
There are no diagnostic laboratory findings associated with [disease name].
Laboratory Findings
Primary hyperparathyroidism
- An elevated serum calcium on routine biochemical screening in a asymptomatic patient should raise the suspicion of primary hyperparathyroidism.[1]
- An elevated/ concentration of serum ionized calcium with elevated parathyroid level is diagnostic of primary hyperparathyoidism.
- 25-Hydroxy vitamin D is usually normal among patients with primary hyperparathyroidism.
- Laboratory findings consistent with the diagnosis of primary hyperparathyroidism include
- Elevated concentration of serum calcium
- Elevated serum parathyroid level
- Low normal serum phosphorous concentration
- Elevated 1,25-dihydroxy vitamin D (calcitriol) may be found in around half of patients.
- There is a mild elevation in bone turnover indices including serum alkaline phosphate activity, osteocalcin, and urinary hydroxypiridinium collagen crosslinks.
Secondary hyperparathyroidism
- Laboratory findings consistent with the diagnosis of secondary hyperparathyroidism include:
- Elevated serum parathyroid hormone level
- Low to normal serum calcium
- Low serum vitamin D (25-hydroxy vitamin D) may be found if vitamin D deficiency is the cause of secondary hyperparathyroidism.
Tertiary hyperparathyroidism
- An elevated concentration of serum calcium with elevated parathyroid level in post renal transplant patients is diagnostic of tertiary hyperparathyoidism.
Biochemical Tests
Serum Calcium
- An elevated serum ionized calcium on routine biochemical screening in a asymptomatic patient should raise the suspicion of primary hyperparathyroidism.[1]
- Measurement of total serum calcium with automatic techniques has similar or even more reliability than serum ionized calcium measurement.
- An elevated serum calcium should be confirmed by repeat measurement.
- 20% of patients with proven primary hyperparathyroidism have normal total calcium and elevated parathyroid hormone. Serum ionized concentration measurement is helpful in such cases.[2]
- Some patients with primary hyperparathyroidism may have elevated concentration of serum parathyroid hormone with normal serum calcium, which is usually suggestive of normocalcemic primary hyperparathyroidism.[3] Causes of secondary hyperparathyroidism should be rules out for making the diagnosis of normocalcemic primary hyperparathyroidism. Normocalcemic primary hyperparathyroidism might represent the first symptomatic stage of primary hyperparathyroidism.[4]
Serum Parathyroid hormone
- Method of choice for measuring intact parathyroid hormone include Immunoradiometric assay(IMRA) or Immunochemiluminescent assay(ICMA).[5]
24-Hour urinary calcium
- 24-Hour urinary calcium excretion is indicated by the calcium:creatinine clearance ratio.[6][7]
- It is used to seperate the patients with familial hypocalciuric hypercalcemia and typical primary hyperparathyroidism.
Serum 1,25-dihydroxy vitamin D
- May be used to f=differentiate between Familial hypecalciuric hypercalcemia (FHH) with primary hyperparathyroidism.
- Serum 1,25-dihydroxy vitamin D (calcitriol) concentration are significantly lower in FHH than primary hyperparathyroidism.
References
- ↑ 1.0 1.1 Silverberg SJ, Bilezikian JP (1996). "Evaluation and management of primary hyperparathyroidism". J. Clin. Endocrinol. Metab. 81 (6): 2036–40. doi:10.1210/jcem.81.6.8964825. PMID 8964825.
- ↑ Glendenning P, Gutteridge DH, Retallack RW, Stuckey BG, Kermode DG, Kent GN (1998). "High prevalence of normal total calcium and intact PTH in 60 patients with proven primary hyperparathyroidism: a challenge to current diagnostic criteria". Aust N Z J Med. 28 (2): 173–8. PMID 9612524.
- ↑ Silverberg SJ, Lewiecki EM, Mosekilde L, Peacock M, Rubin MR (2009). "Presentation of asymptomatic primary hyperparathyroidism: proceedings of the third international workshop". J. Clin. Endocrinol. Metab. 94 (2): 351–65. doi:10.1210/jc.2008-1760. PMC 5393372. PMID 19193910.
- ↑ Lowe H, McMahon DJ, Rubin MR, Bilezikian JP, Silverberg SJ (2007). "Normocalcemic primary hyperparathyroidism: further characterization of a new clinical phenotype". J. Clin. Endocrinol. Metab. 92 (8): 3001–5. doi:10.1210/jc.2006-2802. PMID 17536001.
- ↑ Endres DB, Villanueva R, Sharp CF, Singer FR (1991). "Immunochemiluminometric and immunoradiometric determinations of intact and total immunoreactive parathyrin: performance in the differential diagnosis of hypercalcemia and hypoparathyroidism" (PDF). Clin. Chem. 37 (2): 162–8. PMID 1993319.
- ↑ Marx SJ, Stock JL, Attie MF, Downs RW, Gardner DG, Brown EM, Spiegel AM, Doppman JL, Brennan MF (1980). "Familial hypocalciuric hypercalcemia: recognition among patients referred after unsuccessful parathyroid exploration". Ann. Intern. Med. 92 (3): 351–6. PMID 7356229.
- ↑ Marx SJ, Spiegel AM, Brown EM, Koehler JO, Gardner DG, Brennan MF, Aurbach GD (1978). "Divalent cation metabolism. Familial hypocalciuric hypercalcemia versus typical primary hyperparathyroidism". Am. J. Med. 6http://www.sciencedirect.com/science/article/pii/0002934378908148?via%3Dihub5 (2): 235–42. doi:10.1016/0002-9343(78)90814-8. PMID 686009.