Indirect Detection of Sodium, Potassium, and Chloride in Human Serum with Roche ISE

Detection of Intact Parathyroid Hormone in Human Serum with Roche e801

Test Name: Immunoassay for the in vitro quantitative determination of intact parathyroid hormone (PTH) in human serum and plasma for the differential diagnosis of hypercalcemia and hypocalcemia. This assay can be used intraoperatively.
Method Name: The Elecsys assay for determining intact PTH employs a sandwich test principle in which a biotinylated monoclonal antibody reacts with the N terminal fragment (1-37) and a monoclonal antibody labeled with a ruthenium complex reacts with the C terminal fragment (38-84). The antibodies used in this assay are reactive with epitopes in the amino acid regions 26-32 and 37-42.
Results: Technical Range: 1.2-5000 pg/mL
Reportable Range: 1.45-3267 pg/mL
Reference Ranges: <39.6 pg/mL
Clinical Significance: Parathyroid hormone (PTH) is a single-chain 84 amino-acid peptide produced by the parathyroid glands in response to decreased extracellular concentrations of ionized calcium. Its main role is to increase serum calcium levels by stimulating the release of calcium from bone and its renal re-absorption in the distal tubule. In the proximal tubule, PTH stimulates the synthesis of calcitriol which in turn increases intestinal absorption of calcium and exerts an endocrine feed-back on the secretion of PTH at the parathyroid level. PTH also decreases the renal re-absorption of phosphate in the proximal tubule, thereby decreasing serum phosphate.

Parathyroid gland disorders lead to elevated or depressed blood calcium levels (hypercalcemia or hypocalcemia) brought about by a change in the secretion of PTH.

Detection of subfunctioning parathyroid glands (hypoparathyroidism) requires the use of a highly sensitive test in order to be able to measure PTH levels well below normal. Hyperfunctioning of the parathyroid glands results in an increased secretion of PTH (hyperparathyroidism). Primary causes are adenomas of the parathyroid glands. In secondary hyperparathyroidism the blood calcium level is low as a result of other pathological states (e.g. vitamin D deficiency).

The determination of PTH intraoperatively during adenoma resection in the parathyroid glands has been reported for primary hyperparathyroidism, secondary hyperparathyroidism relating to renal failure, and tertiary hyperparathyroidism post renal transplant surgery. Because PTH has a reported half life of 3-5 minutes, a significant drop in PTH levels after resection of the abnormal gland or glands enables the surgeon to assess whether all hyperfunctioning parathyroid tissue has been removed from the patient.

The National Academy of Clinical Biochemistry recommends routine use of intraoperative PTH testing for patients undergoing surgery for primary hyperparathyroidism, both in initial surgeries and in reoperative procedures.

Submission Criteria: For specimen collection and preparation, only use suitable tubes or collection containers.
Only the specimens listed below were tested and found acceptable.
Serum Plasma: Li-heparin and K2-EDTA plasma
Do not use fluoride plasma
The sample types listed were tested with a selection of sample collection tubes that were commercially available at the time of testing, therefore not all available tubes of all manufacturers were tested. Sample collection systems from various manufacturers may contain differing materials which could affect the test results in some cases.  When processing samples in primary tubes (sample collection systems), follow the instructions of the tube manufacturer.
Storage and Stability:
Serum 6 months at -20°C
2 days at 2-8°C
Plasma 6 months at -20°C
3 days at 2-8°C
2 days at 15-25 °C
Rejection Criteria: Rejection criteria include but are not limited to:
1. Specimens containing fibrin or clots.
2. Excessive platelet clumping
3. Leaking specimens
4. Substandard mixing or collection
5. Expired or improperly stored collection tubes.
6. Improperly filled tubes based on collection tube manufacturer’s guidelines.
7. Contaminated specimens (IV fluid, foreign particles, etc.)
8. Specimens not analyzed within the appropriate time frame.
9. Samples not shipped at appropriate temperature.
10.Samples without 2 proper identifiers or samples having identifiers that do not match the electronic or paper lab requisition.
Authorization: Diagnostic testing can only be performed with approval from an authorized provider/agency.
Turn Around Time: 1 day.