Autoantibodies in celiac disease: Importance of fibroblasts

Background: Serum reticulin and endomysium autoantibodies are highly celiac disease-specific, and the autoantigens have been shown to be derived from human fibroblasts. Among human tissues, the umbilical cord also expresses these antigens. This study was conducted to compare different autoantibody tests and especially to elucidate whether human umbilical cord is a suitable substrate in tests and whether the cord jelly-derived fibroblasts express the antigens. Methods: The indirect immunofluorescence method was used to detect the tissue and Wharton's jelly-derived fibroblast antibodies in 334 celiac disease and control sera samples. Affinity chromatography studies were used to show the correlation between human fibroblast-derived autoantigens and tissue and gliadin antibodies. The jelly-derived fibroblasts were used as antigen in a whole-cell enzyme-linked immunosorbent assay. Results: Celiac disease patient sera showed IgA-class human umbilical cord antibody with high sensitivity (100%) and specificity (99%). All celiac disease patient sera tested showed in indirect immunofluorescence the molecules expressed by Wharton's jelly-derived fibroblasts. The whole-cell fibroblast autoantibody enzyme-linked immunosorbent assay had a sensitivity of 100% and a specificity of 81%. Human fibroblast-derived celiac disease autoantigens absorbed most of the IgA responsible for human umbilical cord antibodies but not the IgA responsible for gliadin antibodies in the same sera. Conclusions: Wharton's jelly-derived fibroblast autoantibodies tested in a novel whole-cell enzyme-linked immunosorbent assay correlated well with the human umbilical cord but not with gliadin antibodies.