Bile acids: Method validation and diagnosis of intrahepatic cholestasis of pregnancy

The intrahepatic cholestasis is the most common of hepatopathies specific to pregnancy. Serum total bile acids concentration (ACIBI) is the most sensitive and specific diagnostic marker of this disease. The objective of this study is to validate the enzymatic quantification method of ACIBI of Randox on Cobas 6000 c501® Roche Diagnostics ™. A retrospective study of 6 months on all patients in the gynecology-obstetric department of the hospital completes the method validation.The repeatability study on ACIBI concentrations at 20 and 40 μmol / L shows coefficients of variation respectively at 1.1% and 0.9%, that of reproducibility at 2.4% and 1.8%. The linearity is 230 μmol / L and the limit of quantification is 3 μmol / L. The measurement uncertainty is 0.52 μmol / L for a concentration of 12 μmol / L.The statistical analysis of 150 folders shows 9 cases of cholestasis of pregnancy without any other associated anomaly; 5 severe cases at a mean level of ACIBI at 56 ± 10 μmol / L with premature delivery and 4 cases of moderate CG with ACIBI at 26 ± 8 μmol / L accompanied by a regression of symptoms following treatment with ursodeoxycholic acid.The enzymatic assay method of bile acids of Randox validated in our laboratory showed good performances. In addition to its diagnostic value, the determination of bile acids has a prognostic and therapeutic value. Elevated fasting level > 40 μmol / L is considered as a risk factor for fetal complications and it is considered in the decision to to premature inducing of labour.