[Lipoprotein X (LP-X) in the differential diagnosis of cholestasis in children, with special reference to biliary atresia].

Lipoprotein-X (LP-X) in the serum of infants with persistent jaundice is indicative of cholestasis. In early infancy biliary atresia and biliary agenesis are the most common cause of cholestasis, whereas neonatal hepatitis is a less frequent cause of cholestasis. The authors introduced and described the qualitative and quantitative methods of LP-X determination for diagnostic purposes. LP-X estimations were carried out in 9 children with persistent jaundice. LP-X was found to be present in 4 infants-in 2 with complete absence of extrahepatic biliary tracts, in 1 with extrahepatic biliary atresia and in 1 with hypoplastic extrahepatic biliary tract. LP-X was also found in a 5 year old boy with mechanical occlusion of bile ducts caused by a malignant tumor ( rhabdomyoblastoma ), and in 3 year old girl with inborn enzymatic liver dysfunction. In this case LP-X concentration was estimated before and after 3 week course of cholestyramine, after which there was a 35% decrease in the LP-X concentration. In a 4 month old child LP-X was not found in spite of the absence of extra and intrahepatic biliary tracts. This finding may be explained by the far advanced hepatic cirrhosis. The authors stress the importance of introducing of LP-X estimation in the differential diagnosis of jaundice in early infancy.