Hypercalcemia laboratory findings
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Anmol Pitliya, M.B.B.S. M.D.[2]
Overview
Routine panel is recommended for patients suspected of hypercalcemia to diagnosed the underlying cause.
Laboratory Findings
The following test may be done as a routine panel if a person is suspected of hypercalcemia:
- Complete blood count (CBC)
- Serum and urinary calcium
- Blood urea nitrogen (BUN)/creatinine
- Parathyroid hormone (PTH)
- PTH-related peptide
- Albumin
- Phosphate
- Alkaline phosphatase
- Vitamin D
- Magnesium
Biochemical tests
Serum Calcium
- An elevated serum 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 urinary 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 differentiate between Familial hypercalciuric hypercalcemia (FHH) with primary hyperparathyroidism.[8][9]
- Serum 1,25-dihydroxy vitamin D (calcitriol) concentration are significantly lower in FHH than primary hyperparathyroidism.
References
- ↑ 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.
- ↑ Law WM, Bollman S, Kumar R, Heath H (1984). "Vitamin D metabolism in familial benign hypercalcemia (hypocalciuric hypercalcemia) differs from that in primary hyperparathyroidism". J. Clin. Endocrinol. Metab. 58 (4): 744–7. doi:10.1210/jcem-58-4-744. PMID 6699136.
- ↑ Christensen SE, Nissen PH, Vestergaard P, Heickendorff L, Rejnmark L, Brixen K, Mosekilde L (2008). "Plasma 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, and parathyroid hormone in familial hypocalciuric hypercalcemia and primary hyperparathyroidism" (PDF). Eur. J. Endocrinol. 159 (6): 719–27. doi:10.1530/EJE-08-0440. PMID 18787045.