Serum concentration of amino-terminal propeptide of type III procollagen (PIIINP) as a prognostic marker for skin fibrosis after scar correction in burned patients.

The amino-terminal propeptide of procollagen type III (PIIINP) has been proposed as a marker for fibrogenesis in patients with different fibroproliferative disorders, e.g. liver and lung fibrosis. In this study, serum concentrations of PIIINP were measured by ELISA as a marker for excessive cicatrization in burned patients before and after scar correction. All patients were followed 6 months to determine a new fibrotic reaction during the wound healing process using the Burn Scar Index and to correlate pre- and post-operative concentrations of PIIINP in their sera with the risk to develop a new severe tissue fibrosis leading to pathological scar formation. Furthermore, PIIINP was determined in the excised scar tissue by immunohistochemistry. The study included 38 patients. Nineteen patients (8 female, 11 male, average age 48.3+/-18.9 years) had hypertrophic scars after major burn injury (TBSA, 21+/-12%; Burn Scar Index, 10.4+/-3.7 points) and underwent scar correction. Nineteen patients (12 female, 7 male, average age 42.3+/-25.5 years) who underwent elective plastic-surgical operations served as the control group. Blood samples were drawn immediately before operation, at the 1st, 3rd, 7th, and 14th post-operative days, as well as 1st, 3rd, and 6th months after operation.Pre-operatively, PIIINP was significantly elevated (P<0.05) in burned patients who underwent scar correction. There was a significant increase (P<0.05) of PIIINP in burned patients from 9.8+/-3.7ng/ml pre-operatively to 13.9+/-4.2ng/ml at the 7th post-operation day. Up to 3 months after operation, the 6 months after scar correction concentration remained at a significantly elevated level compared to pre-operative values. The burned patients had a Burn Scar Index of 7.8+/-3.6 points. Pre-operative PIIINP serum concentrations correlated with the Burn Scar Index (r(2)=0.7 and 0.68; P<0.05). Scar tissue stained intensively positive for PIIINP. There was a significant correlation between pre-operative serum values and degree of immunostaining (r(2)=0.45; P<0.05). The increased concentration of PIIINP seen in our burned patients' sera might serve as a marker for the extent of skin fibrosis and for the risk of developing new severe fibrotic reactions after scar correction.