Turnaround times
The quoted turnaround time is from sample receipt in the laboratory, to results authorisation in the Laboratory Information Management system. The times do not include transport of specimen to the laboratory or the administrative process to print and post/email reports. Service users must allow for transport and reporting time when ordering tests.
Clinical background:
Type III procollagen has propeptide extensions at both ends of the molecule. Some of the amino-terminal propeptides are released during the synthesis and deposition of type III collagen. N-terminal propeptide of type III collagen (P3NP) can therefore be found in the serum due to its production during synthesis of new type III collagen or degradation of existing type III collagen fibrils.Increased serum concentrations of P3NP are found in a number of conditions where accumulation and/or degradation of connective tissue take place. Liver fibrosis and cirrhosis of various aetiologies increase serum concentrations of P3NP. The principal clinical use of P3NP is currently as a non-invasive means of monitoring patients treated with methotrexate, thereby reducing the necessity of liver biopsy. Elevations in P3NP are not specific for liver fibrosis and can also be due to fibrotic conditions of the lungs, myeloproliferative disease and healing of damage to cardiac tissue for example.
Specimen container paediatric:
Serum
Specimen container adult:
Serum
Minimum volume paediatric:
2 mL
Minimum volume adult:
2 mL
Sample stability:
Unseparated: Same day
Separated: 5 days at 4 to 8°C
Transport requirements:
Ambient
Interpretation :
Indications for considering liver biopsy:
Pre-treatment P3NP >8.0 µg/L
P3NP above 4.2 µg/L in at least 3 samples over 12-month period
P3NP >8.0 µg/L in two consecutive samples
Indications for considering withdrawal of methotrexate:
P3NP >10.0 µg/L in at least 3 samples in a 12-month period
Reference ranges:
Adults (20-65yrs): 1.7-4.2 ug/L
Other info:
Lithium heparin and EDTA plasma samples also acceptable