[Study on the collagen constitution of hyperplastic scar in different ages and its influencing factors]

To investigate the collagen constitution of hyperplastic scar (HS) in different ages and the change of relative factors.

Thirty cases with HS were divided into two groups according to patients' age: group 1 (1 - 19 years, A) and group 2 (20 - 50 years, B). The normal skin (NS) from corresponding age of volunteers was employed as control group. The changes in TGFbeta1, collagenase (MMP-1) and tissue inhibitor of metalloproteinase (TIMP-1beta) and the collagen ratio were observed by means of in situ hybridization technique and SABC (Strept-Avidin-Biotin complex) immunohistochemistry and image analysis.

The ratio of type I to type III collagen in A group was 6.48 in average and 3.76 in B group, but there was no evident difference in the ratio during the disease process in both groups. The expression of TGFbeta1 in A group was much higher than that in B group (P < 0.01). The TIMP-1 mRNA expression showed no difference among all age groups in HS patients, but it was much higher than that in NS group. The MMP-1 expression was evidently lower than TIMP-1 expression, and there was no difference in MMP-1 expression compared with NS group.

(1) The TGFbeta1 expression in HS patients was negatively correlated with age, and the increased expression of TGFbeta1 produced an increase ratio of type I to type III collagen. (2) High level expression of TIMP-1 led to the formation of HS by inhibiting MMP-1 expression, and the expression was not related to age.