[Quantitative determination of LP-X in the differential diagnosis and treatment of direct hyperbilirubinemia in infancy].

Quantitative measurements of serum concentrations of LP-X were performed in 45 newborn and infants. The changes of LP-X concentrations before and after a 2-3 weeks' course of cholestyramine therapy differentiated extrahepatic biliary atresia (n = 6) from other causes of neonatal liver disease with a sensitivity of 100%, a specificity of 78.6 to 84.6% and an efficiency of 81.3 to 86.7%. The efficiency was decreased in children with alcoholic stools (75-80%). Cholestyramine treatment of 3-7 days did not allow to diagnose all children with extrahepatic biliary atresia. However, the test was superior to a combination of single measurements of LP-X and GGT. The changes of LP-X concentrations in serum were influenced by the individual course of the disease but not by the synthetic function of the liver (as indicated by CHE activities) or by parenteral nutrition or bacterial infections. LP-X was a valuable parameter in the management of cholestyramine therapy in infants with liver diseases.