Procollagen III

 Referred to Berkshire & Surrey Pathology Services, Frimley Park Hospital NHS Foundation Trust, Portsmouth Road, Frimley, Surrey GU16 7UJ

Alternative names, keywords

Procollagen-3 N-terminal peptide, P3NP

Samples required

Clotted blood (gold cap, 5 mL tube).

Test indications

Detection of liver fibrosis for dermatology patients on methotrexate.

The British Society of Rheumatology do not recommend P3NP monitoring in rheumatology patients on methotrexate.

Testing in children is not recommended - ranges are wide due to collagen deposition in normal growth.

Reference range

2.0 - 7.0 µg/L (adults ≥18 years old)

> 7.0 μg/L

First occasion: repeat in 3 months.

> 13.0 μg/L on two occasions; or

> 7.0 μg/L but < 13.0 μg/L on three occasions within 12 months; or

> 17 μg/L on one occasion.

Results may indicate liver fibrosis - suggest onward referral for specialist advice.
Note new reference ranges from 12 March 2018 due to change at referral laboratory.


Turnaround time

Referral lab quotes turnaround time of 9 days, however additional time must be allowed for packing, dispatch and delivery of sample, and return and processing of results.


Biochemistry (Referrals)