Methotrexate is a commonly used antipsoriatic agent. However, it can cause hepatic fibrosis with long-term use. Whilst the conventional liver biopsy is valuable in diagnosis and in assessment of the current stage of liver damage and fibrosis, it gives a static picture of previously accumulated damage, is associated with significant morbidity, is painful to the patient, and is costly to the health-care economy.
The PIIINP assay can be used to detect changes in the metabolism of connective tissue. One of its most widely used applications is in monitoring the degree of liver damage in psoriasis patients treated with the cytostatic drug methotrexate1,2.
PIIINP overcomes the shortcomings of liver biopsy and has been shown to be a very useful non-invasive marker of liver fibrosis1,2. According to the European S3 Guidelines concerning the systemic treatment of psoriasis vulgaris, PIIINP measurement should be performed prior to commencement of methotrexate treatment and every three months thereafter. Patients whose PIIINP levels are consistently normal are very unlikely to have significant liver damage, and liver biopsies may be restricted to the small minority in whom PIIINP levels are repeatedly elevated3.
1. Chalmers RJG et al. Replacement of routine liver biopsy by procollagen III aminopeptide for monitoring patients with psoriasis receiving long-term methotrexate: a multicenter audit and health economic analysis. Br J Dermatol 2005;152:444-450.
2. Maurice PDL et al. Monitoring patients on methotrexate: hepatic fi brosis not seen in patients with normal serum assays of aminoterminal peptide of type III procollagen. Br J Dermatol 2005;152:451-458.
3. Pathirana D et al. European S3-guidelines on the systemic treatment of psoriasis vulgaris. J Eur Acad Dermatol Venereol. 2009;23 Suppl 2:1-70.
Published November 24, 2016