Measurement of Serum TNF-α as an Accurate Marker in Diagnosing Extrahepatic Biliary Atresia

Most diagnostic tests for biliary atresia (BA) are invasive. This study evaluates the sensitivity and specificity of serum tumor necrosis factor-α (TNF-α) for diagnosing extra hepatic biliary duct atresia (EHBA) in infants. Infants with cholestasis who were admitted to Children′s Medical Center Hospital were evaluated. A total of 50 infants (20 with EHBA and 30 non-EHBA) were included in this study. We evaluated the definite cause of cholestasis. Intra-operative cholangiography and, if possible, Kasai portoenterostomy were performed in infants with high suspicion for EHBA. Upon admission and prior to surgical intervention, infants had their serum TNF-α levels measured by ELISA. We compared the mean TNF-α level between the two groups, in addition to the sensitivity and specificity of serum TNF-α for diagnosis of EHBA. This study enrolled 28 (56%) male and 22 (44%) female infants. Infants'' mean age was 2.87 months in the EHBA group and 2.6 months in the non-EHBA group. Sensitivity of serum TNF was 60% and its specificity was 76.66% for predicting EHBA. The positive predictive value was calculated as 63.1%, the negative predictive value was 74.1%, and accuracy was 70%. There was a significantly higher mean serum TNF-α level in the EHBA group (220 pg/ml) compared to the non-EHBA group (79.8 pg/ml; p=0.023). Serum TNF-α cut off point for determining EHBA from non-EHBA was calculated as 80 pg/ml. Mean serum TNF-α in males (171.28 pg/ml) was more than females (90.80 pg/ml). There was a significantly higher mean serum TNF-α level in the EHBA group than the non-EHBA group. Serum TNF-α could be a proper test that has comparatively good sensitivity, specificity, positive predictive value and negative predictive value for predicting EHBA.