In Situ Cytokine Expression and Morphometric Evaluation of Total Collagen and Collagens Type I and Type III in Keloid Scars

Keloids are characterized by excessive collagen deposition and growth beyond the edges of the initial injury, and cytokines may be related to their formation. The objective of this study was to evaluate the collagen fibers, analyze in situ expression of cytokines in keloid lesions, and compare to the control group. Results showed that there was a predominance of women and nonwhite and direct black ancestry. Keloid showed a significant increase in total and type III collagen. Significantly, the expression of mRNA for TGF-beta in keloid was increased, the expressions of IFN-gamma, IFN-gamma R1, and IL-10 were lower, and IFN-gamma R1 and TNF-alpha had no statistical difference. Correlations between collagen type III and TGF-beta mRNA expression were positive and significant, IFN-gamma, IFN-gamma R1, and IL-10 were negative and significant, and TNF-alpha showed no statistical difference. We conclude that there was a significant increase of total collagen in keloid and predominance of collagen type III compared to the controls, showing keloid as an immature lesion. There is a significant increase in TGF-beta mRNA in keloid lesions, and a significant decrease in IFN-gamma and IL-10, suggesting that these cytokines are related to keloid lesions.