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Procollagen III N-terminal Propeptide (PIIINP)

Published: July 27, 2026Updated: August 25, 2026

Procollagen III N-terminal propeptide (PIIINP) is a biomarker that reflects the synthesis of type III collagen, which is associated with liver fibrosis and hepatic remodeling.

Quick summary

PIIINP is a diagnostic marker for liver fibrosis and hepatic remodeling.

Medically reviewed by WellAlly Editorial TeamLast reviewed August 25, 2026Editorial policy

Key facts at a glance

Units
U/L
Clinical utility
diagnostic
Result kind
quantitative
FDA-cleared
Roche P3NP, UniQ P3NP
interpretation: {"text":"PIIINP levels within the range of 0–12 U/L indicate normal collagen turnover and no significant liver fibrosis.","label":"Normal"}; {"text":"Levels above 12 U/L may indicate active collagen synthesis and potential liver fibrosis, necessitating further diagnostic evaluation.","label":"Elevated"}

Procollagen III N-terminal propeptide (PIIINP) is a peptide cleaved from the procollagen III molecule during the formation of type III collagen. Type III collagen is a crucial component of the extracellular matrix in the liver, particularly during fibrogenesis.

Elevated levels of PIIINP in the blood are indicative of increased collagen synthesis, which is commonly associated with liver fibrosis. This makes PIIINP a valuable diagnostic tool for assessing the extent of liver damage and monitoring disease progression.

The reference range for PIIINP is typically 0–12 U/L. Levels above this range may suggest active fibrotic processes in the liver, prompting further investigation and potential intervention.

Frequently asked questions

What does a high PIIINP level mean?
A high PIIINP level suggests increased collagen synthesis, which is often associated with liver fibrosis and other fibrotic conditions.
How is PIIINP testing used in clinical practice?
PIIINP testing is used to assess the degree of liver fibrosis, monitor disease progression, and evaluate the effectiveness of anti-fibrotic therapies.
  1. 1
    Procollagen III N-terminal propeptide (PIIINP) as a marker of liver fibrosisSource
  2. 2
    Clinical utility of serum PIIINP in liver fibrosisSource

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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

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Medically reviewed by WellAlly Editorial Team Last reviewed August 25, 2026. · Read our editorial policy