Clinical Significance
PTH, Intact and Calcium - The assay is useful in making the diagnosis of primary hyperparathyroidism, secondary hyperparathyroidism, and a differential diagnosis of hypercalcemia. The assay helps in distinguishing hypercalcemia cause by either primary hyperparathyroidism or malignant disease.

Preferred Specimen(s)
1.5 mL plasma collected in EDTA (lavender-top) tube for the PTH, Intact and 1 mL serum for the Calcium

Alternative Specimen(s)
2 mL (1 mL minimum) frozen serum for PTH, Intact

Minimum Volume
1 mL EDTA plasma for PTH, Intact • 0.5 mL serum for Calcium

Transport Container
Transport tube

Reject Criteria
Gross hemolysis • Grossly lipemic • Plasma submitted in sodium heparin (green-top) tube or lithium heparin (green-top) tube

Methodology
PTH: Immunoassay (IA) • Calcium: Spectrophotometry (SP)

Reference Range(s)
Calcium
Age    Male (mg/dL)    Female (mg/dL)
<1 Month    8.4-10.6    8.4-10.6
1-11 Months    8.7-10.5    8.7-10.5
1-3 Years    8.5-10.6    8.5-10.6
4-19 Years    8.9-10.4    8.9-10.4
20-49 Years    8.6-10.3    8.6-10.2
>49 Years    8.6-10.3    8.6-10.4
Parathyroid Hormone, Intact
<1 Year     8-70 pg/mL
1-7 Years    14-66 pg/mL
8-18 Years    14-85 pg/mL
≥19 Years    16-77 pg/mL
Interpretive Guide
     Intact PTH    Calcium
Normal Parathyroid    Normal    Normal
Hypoparathyroidism    Low or Low Normal    Low
Hyperparathyroidism           
  Primary    Normal or High    High
  Secondary    High    Normal or Low
  Tertiary    High    High
Non-Parathyroid          
  Hypercalcemia    Low or Low Normal    High

Alternative Name(s)
Immunoreactive PTH,Sandwich PTH Assay,PTH Whole Molecule,Intact Hormone,Monogram