Measurement of serum TNF-alpha as an accurate marker in diagnosing extrahepatic biliary atresia

ABSTRACT

Most diagnostic tests for biliary atresia [BA] are invasive. This study evaluates the sensitivity and specificity of serum tumor necrosis factor-alpha [TNF-alpha] 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-alpha levels measured by ELISA. We compared the mean TNF-alpha level between the two groups, in addition to the sensitivity and specificity of serum TNF-alpha 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-alpha level in the EHBA group [220 pg/ml] compared to the non-EHBA group [79.8 pg/ml, p=0.023]. Serum TNF-alpha cut off point for determining EHBA from non-EHBA was calculated as 80 pg/ml. Mean serum TNF-alpha in males [171.28 pg/ml] was more than females [90.80 pg/ml]. There was a significantly higher mean serum TNF-alpha level in the EHBA group than the non-EHBA group. Serum TNF-alpha could be a proper test that has comparatively good sensitivity, specificity, positive predictive value and negative predictive value for predicting EHBA