Austin Pathology

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Copeptin

Alternate Names
ADH, DDAVP, Vasopressin, AVP, anti-diuretic hormone
Ordering Information

Copeptin has now replaced the measurement of ADH (anti-diruretic hormone).

Copeptin is the C-terminal glycoprotein moiety of pre-provassopressin and is released in the same amount as AVP.

 

Morning samples after 8 hour fast (without water restriction) are recommended unless otherwise stated by clinician.

 

Please note that this is a NON-MEDICARE REBATABLE test. The cost is $50 (but may be subject to change by the testing laboratory).

More details may be found HERE.

Laboratory
Referred Test
Specimen
Blood
Container
Serum tube (gold top)
Collection Instruction
Collect at room temperature
Additional Collection Instructions

Lithium heaprin plasma is also a suitable sample type.

Minimum Adult Volume
1mL
Minimum Paediatric Volume
1mL
Frequency
Once a week
Reference Interval

This is a referred test. The following interpretative advice is offered by the testing laboratory and may be found HERE.

 

Reference Values

Non-water deprived, non-fasting adults                            < 16.3 pmol/L

Non-water deprived, fasting ( >8hrs) adults                     < 15.2 pmol/L

Non-water deprived, non- fasting paediatric subjects         < 14.5 pmol/L

For the investigation of diabetes insipidus (DI) and primary polydipsia (PP) in patients with confirmed polyuria (>40 mL/kg/d)*:

  • A baseline Copeptin level >21.4 pmol/L is 100% sensitive and specific for nephrogenic diabetes insipidus 
  • A baseline Copeptin level < 2.6 pmol/L with prior fluid deprivation (> 8hrs) will indicate complete central DI likely 
  • A stimulated Copeptin** > 4.9 pmol/L PP likely and < 4.9 pmol/L partial central DI likely (94.0% specificity and a 94.4% sensitivity)

[Notes: * Without concurrent diabetes mellitus, hypercalcemia, pregnancy, uncorrected thyroid or adrenal insufficiency, and heart failure; ** at sodium levels >147 mmol/L following water deprivation]