Cirrhosis bile acid conjugation

We (K1) attempted to develop a noncompetitive assay based on the anti-idiotype antibodies for a conjugated bile acid metabolite, ursodeoxycholic acid 7-A-acetyl-glucosaminide (UDCA 7-NAG), which is expected to serve as a diagnostic index for an autoimmune disease, primary biliary cirrhosis. In our assay, the hapten UDCA 7-NAG, a /3-type antibody, and a biotin-labeled a-type antibody were simultaneously added to a microtiter plate coated with an F(ab )2 fragment of a specific anti-UDCA 7-NAG antibody, then incubated at room temperature for 8 h. Bound biotin was then detected with HRP-labeled streptavidin, whose enzyme activity was measured using o-phenylenediamine/H202 as a substrate. This noncompetitive assay system provided a subfemtomole-order sensitivity (detection limit 118 amol) that was 7 times lower than the competitive immunoassay using the same anti-hapten antibody (K2), even with a common colorimetric detection (Fig. 13). Somewhat improved specificity was also obtained namely, better... 

More frequently encountered are acquired defects in bUe acid synthesis, which have been noted in Liver diseases such as hepatitis and cirrhosis. In acute hepatitis, alterations of bile acid synthesis and conjugation occur because of hepatic parenchymal cell disease. In cirrhosis, there is a marked reduction in cholic acid synthesis with a low concentration of biliary deoxycholic acid. These abnormalities are due both to decreased synthesis and to portosystemic shunting. The... 

Samuelson, K., Aly, A., Johansson, C., and Norman, A., Serum and urinary bile adds in patients with primary biliary cirrhosis. Scand. J. Gastroentend. 17, 121-128 (1982). Samuelson, K., and Eklund, A., Determination of urinary cholic and chenodeoxycholic acid conjugates with radioimmunoassay. Scand. J. Clin. Lab. Invest. 40,555-561 (1980). 

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