title: Some characteristics of immunofluorescence tests for antibodies against gluten, using wheat grain sections or gliadin coated sepharose beads.
abstract: Antibodies against gluten and gliadin were determined by the indirect immunofluorescence technique, using frozen wheat grain sections or gliadin-coated Sepharose beads. The methodological characteristics and diagnostic usefulness of the two techniques were evaluated. The reproducibility of both was improved by introducing a fluorometric reading-off procedure. Antibody quantitations were preferably performed as end-point titrations. The two techniques had different dose-response relationships. The grain section technique was more discriminative for small variations in antibody concentration than the bead technique. The latter was, however, more reproducible. Besides antibodies against gliadin, a number of patients with gluten enteropathy had antibodies against the main septa of wheat grains. Fluorescence intensity was preferably expressed in multiples of background intensity. A reaction was visually perceived when the fluorometrically-measured fluorescence intensity reached 2.5 times the background intensity. Using this value as the limit for positive reactions, antibodies were demonstrated in 81% of the cases with verified gluten intolerance, compared with 28% in cases with other intestinal allergies and 8% in normals. The diagnostic specificity of both the grain section and Sepharose bead technique for gluten enteropathy increased with increasing antibody concentration and was apparently 100% when the fluorescence intensity produced by a 1/10 serum dilution reached a value 7 to 8 times that of the background. Antibodies against reticulin were demonstrated in 1/4 of the cases having anti-gluten antibodies but in none of those with non-gluten-induced gastro-intestinal symptoms. Antibodies of the IgG class against cow's milk were demonstrated more often and in higher titre in cases with anti-gluten antibodies than in those without them.
mesh_terms: D000293:Adolescent; D000328:Adult; D000906:Antibodies / Q000032:analysis*; D002446:Celiac Disease / Q000175:diagnosis* / Q000276:immunology; D002648:Child; D004306:Dose-Response Relationship, Immunologic; D005260:Female; D005455:Fluorescent Antibody Technique; D005903:Gliadin / Q000276:immunology*; D005983:Glutens / Q000276:immunology*; D006801:Humans; D008297:Male; D008863:Microspheres; D010940:Plant Proteins / Q000276:immunology*; D012155:Reticulin / Q000276:immunology; D012685:Sepharose
chemical_list: D000906:Antibodies; D010940:Plant Proteins; D012155:Reticulin; D005983:Glutens; D005903:Gliadin; D012685:Sepharose