Antibodies to tissue transglutaminase in serum
The point of division is considered the content of AT to tissue transglutaminase in the serum above 10 IU / ml for the IgA class, and above 10 IU / ml for IgG.
Tissue transglutaminase belongs to the family of calcium-dependent acyltransferases that catalyze the formation of cross-links between proteins. It has now been established that tissue transgluta-minase is the main, if not the only, endomysial Ar in patients with celiac disease. Determination of AT to tissue transglutaminase in serum is a highly specific method for diagnosing gluten enteropathy. To detect AT, indirect immunofluorescence and ELISA are used. AT to tissue transglutaminase can detect more than
in 95% of patients with celiac disease and their serum concentration correlates with the presence or absence of gluten in food. AT class IgA possess 95-100% sensitivity and 90-97% specificity.
ANTIBODIES TO SACCHAROMYCES CEREVISIAE IN THE BLOOD SERUM
The separation point is the AT content of Saccharomyces cerevisiae in the serum above 10 IU / ml for IgA, above 10 IU / ml for IgG.
Saccharomyces cerevisiae are unicellular fungi, commonly known as "baker's yeast."AT to Saccharomyces cerevisiae of class IgG and IgA are directed against the oligomannan epitope of mannan( phosphopeptidomannane) of the yeast cell membrane. AT class IgG and IgA to Saccharomyces cerevisiae are closely related to Crohn's disease and have a specificity of 95-100%.AT class IgG to Saccharomyces cerevisiae is detected only in 5% of patients with ulcerative colitis.and Ig IgA in 7%.The diagnostic sensitivity of the determination of the AT class of IgG for diagnosis of Crohn's disease is 75%, for IgA - 60% [Quinton J. F. et al., 1998].
The joint determination of p-ANCA and AT class IgG and IgA for Saccharomyces cerevisiae in the serum increases the specificity of the differential diagnosis between Crohn's disease and ulcerative colitis to 99%.The presence of any class of AT to Saccharomyces cerevisiae in the serum and the absence of AT to the cytoplasm of neutrophils possess 95-100% specificity and 50% sensitivity for Crohn's disease;the absence of AT to Saccharomyces cerevisiae and the presence of AT to the cytoplasm of neutrophils makes it possible to diagnose ulcerative colitis with 90-100% specificity and 50-60% sensitivity.