The purpose of this study was to determine the possible role of serum levels of tissue inhibitors of metalloproteinase-1 (TIMP-1) in the pathogenesis of the progressive inflammation and fibrosis in biliary atresia (BA). Serum concentrations of TIMP-1 were measured in 57 BA patients and 15 healthy controls using commercially available enzyme-linked immunosorbent assays. The mean ages of the BA patients and the controls were 6.1 +/- 0.6 and 6.7 +/- 1.1 years, respectively. The patients were categorized into two groups according to their clinical outcomes: patients with jaundice (total bilirubin > or = 2 mg/dl) and patients without jaundice (total bilirubin < 2 mg/dl). In our study, serum levels of TIMP-1 were significantly higher in the BA patients than in healthy subjects (4.8 +/- 0.4 vs. 3.5 +/- 0.3 ng/ml, respectively; p < 0.05). Additionally, serum levels of TIMP-1 significantly increased in the BA patients with jaundice in comparison to those without jaundice (6.3 +/- 0.7 vs. 3.1 +/- 0.3 ng/ml, respectively; p = 0.001). Patients with persistent jaundice had lower levels of albumin but had greater levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and gamma glutamyl transpeptidase compared with patients without jaundice. Furthermore, patients with portal hypertension (PH) had higher TIMP-1 levels than those without PH (5.3 +/- 0.4 vs. 1.9 +/- 0.3 ng/ml, respectively; p < 0.001). It is concluded that serum levels of TIMP-1 increased in patients with BA. The significant increase in TIMP-1 levels is related to the presence of PH and the severity of jaundice. The elevated TIMP-1 levels may reflect the degree of hepatic fibrosis and development of PH. The data suggest that TIMP-1 may play a role in the pathophysiology of post-Kasai BA.