Resumen

VARGAS NATTEZ, Sandra Grisel; GARCIA, Heidy  y  SOSA TORDOYA, Luis Fernando. Indirect immunofluorescence test for diagnosis of autoimmune hepatitis type 1. BIOFARBO [online]. 2012, vol.20, n.1, pp. 22-29. ISSN 1813-5363.

Autoimmune hepatitis (AIH) is a disease characterized by the presence of antibodies directed against actin filaments. The determination of smooth muscle antibodies (SMA) is used to support the diagnosis of type 1 AIH. The aim of this study was to assess an optimized indirect immunofluorescence test (IFI) used for the identification of AML in patients with presumptive diagnosis of type 1 AIH, for which a substrate based on histological sections of mouse stomach was used. The results obtained with respect to the gold standard (IFI-AML commercial kit) for the optimized test showed 100% sensitivity, 95% specificity, 96% efficiency, and positive and negative predictive values ​​of 89.3% and 100%, respectively, the likelihood ratio (LR+) was 18.3 and the LR− was 0.0. Also, the degree of correlation between the results of the two tests compared to the gold standard and the optimized test was determined; for this purpose, we used the Kappa index, showing a value of 0.82 (p<0.005), a very good correlation. The repeatability and reproducibility tests were 100% and 90%, respectively, for the optimized method. The results obtained in this study show that the optimized test can be used as a screening test for diagnosis of type 1 AIH, and the this test must be accompanied by a test of greater specificity and sensitivity such as anti-mitochondrial antibodies (AMA) in order to confirm or rule out type 1 AIH or primary biliary cirrhosis (PBC).

Palabras llave : Type I autoimmune hepatitis; primary biliary cirrhosis; diagnostic test.