Fig. 5.

Avidity of immunoglobulin (Ig)A versus IgG autoantibodies. (a) The avidity of IgG transglutaminase-2 (TG2) antibodies (TGA) (left) and gliadin (GA) (right) between IgA-deficient (IgA^−/−) and sufficient (IgA^+/+) coeliac disease patients was compared. No significant differences were observed between these groups. Also for IgG the avidity of GA was higher than of TGA; n = 10 IgA^−/− and 10 IgA^+/+. (b) In the 10 IgA-sufficient patients of Fig. 5a, the avidity of both IgG and IgA antibodies was determined by using different conjugates in a similar enzyme-linked immunosorbent assay (ELISA). For both TGA and GA, IgG antibodies had comparable avidity to IgA antibodies within the same patient. Paired t-testing did not reveal any significant differences between these groups.