How the reference values for serum parathyroid hormone concentration are (or should be) established?

Area of Science:

• Endocrinology
• Clinical Chemistry
• Biochemistry

Background:

• Accurate interpretation of serum parathyroid hormone (PTH) concentrations relies on well-validated reference values.
• Establishing these values necessitates large reference populations and clear exclusion criteria to avoid PTH level alterations.

Purpose of the Study:

• To outline the requirements for establishing reliable serum PTH reference values.
• To emphasize the need for consensus on analytical and pre-analytical factors in PTH measurement.

Main Methods:

• Defining criteria for reference population selection, including vitamin D sufficiency, normal renal function, and stratification by factors like age, gender, and BMI.
• Highlighting the importance of analytical and pre-analytical standardization, including sample type (serum preferred), timing, and fasting status.
• Proposing international multicenter collaboration for large-scale data collection.

Main Results:

• Serum PTH reference values should be determined in vitamin D-replete individuals with normal renal function.
• Standardized sample collection, preferably morning serum after overnight fasting, is recommended.
• Inter-method variability necessitates obtaining sufficient sample volume for multiple assay measurements.

Conclusions:

• Consensus on PTH measurement methodology and reference population characteristics is essential.
• International collaborative efforts are needed to establish robust PTH normative data.
• Standardized protocols will improve the accuracy and clinical utility of serum PTH testing.