Similarities in intestinal humoral immunity in dermatitis herpetiformis without enteropathy and in coeliac disease.

Intestinal humoral immunity was examined in eight patients with dermatitis herpetiformis and normal jejunal histology (as determined by quantitative morphometry) on a gluten-containing diet. Jejunal aspirate was taken at the time of jejunal biopsy, and levels of total immunoglobulins (IgA, IgM, IgG) and specific antibody to gliadin and two other dietary proteins, betalactoglobulin and ovalbumin, were measured. The pattern of secretory immune responses in the dermatitis herpetiformis patients was similar to that in twenty-six patients with untreated coeliac disease--ie, higher than normal concentrations of IgA, IgM, and IgG and high levels of specific antibodies (IgA and IgM) to the three dietary proteins. Serum levels of IgA antigliadin were similar in the dermatitis herpetiformis and control (twenty-eight patients who underwent jejunal biopsy to exclude coeliac disease) groups, and serum levels of IgG antigliadin were intermediate between those of the control and coeliac disease groups. These findings suggest that investigation of gut humoral immunity may provide a diagnostic index of latent coeliac disease. The definition of coeliac disease as a permanent gluten-sensitive enteropathy may have to be revised if the proposed two-stage model is confirmed.