Abstract: Objective The aim of this study was to investigate the implication of liver tissue matrix metalloproteinase-2 (MMP-2) and transforming growth factor-β1 (TGF-β1) expression in children with biliary atresia (BA). Methods 49 children with BA and 44 children with choledochal cyst (CCC) were admitted to our hospital between April 2017 and April 2020, and all the children with BA or with CCC underwent Kasai surgery. All the children were followed-up for 2 years. The hepatic MMP-2 and TGF-β1 expression was detected by SP immunohistochemical staining. The Kaplan-Meier was applied to compare the prognosis of children with BA. Results The relative hepatic expression of MMP-2 and TGF-β1 in children with BA were (0.3±0.1) and (3.3±0.5), significantly stronger than [(0.1±0.0) and (1.1±0.2),respectively, P<0.05] in children with CCC; the strong positive rate of hepatic MMP-2 in 8 children with liver fibrosis stage Ⅳ was 62.5% and in another 8 children with stage Ⅲ was also 62.5%, both significantly higher than 14.3% in children with stage Ⅰ or 15.8%(P＜0.05) in children with stage Ⅱ; the strong positive rate of hepatic TGF-β1 in children with stage Ⅳ was 87.5%, and in children with stage Ⅲ was 62.5%, both much higher than 0.0% in with stage Ⅰ or 0.0%(P＜0.05) in with stage Ⅱ; 4 children lost visit at the end of two year follow-up, and 19 children (42.2%)survived in our series; the survival rate in children with weak hepatic MMP-2 positive was 75.0%(9/12), in children with moderate MMP-2 positive was 47.4%(9/19), and in with strong MMP-2 positive was 7.1%(1/14); the survival in children with weak hepatic TGF-β1 positive was 86.7%(13/15), in with moderate TGF-β1 positive was 22.2%(4/18), and in with strong TGF-β1 positive was 16.7%(2/12), suggesting that the survival in child with weak hepatic MMP-2 and TGF-β1 expression was significantly higher than in those with strong expression (Kaplan-Meier analysis, x²=15.357, P=0.000; x²=14.704, P=0.001). Conclusion The expression of MMP-2 and TGF-β1 in liver tissues of children with BA is highly correlated to liver fibrosis, and the children with strong MMP-2 and TGF-β1 expression might have a poor prognosis, which warrants further investigation.

Key words: Biliary atresia, Kasai surgery, Matrix metalloproteinase-2, Transforming growth factor-β1, Liver fibrosis, Prognosis, Children