Lymphocytes obtained after enzymatic digestion of intestinal biopsies from patients with coeliac disease were examined for the presence of gliadin specific antibody secreting cells by means of the ELISPOT technique. This technique permits enumeration of gliadin antibody secreting immunocytes, differentiated with regard to immunoglobulin class. Patients with coeliac disease were found to have high (834/10(6) cells) numbers of antigliadin spot forming cells (SFC) in gut mucosa. IgG and IgM antigliadin antibody secreting cells were infrequently shown whereas IgA antigliadin SFC predominated in all patients tested (average 68% of total SFC). Ten control patients were investigated in parallel with the coeliac patients and showed only low numbers of gliadin antibody secreting cells in gut mucosa (49/10(6) isolated cells). Antigliadin antibody secretion by peripheral blood mononuclear cells was shown in only two of six coeliac patients tested and in none of the control patients. The findings suggest that the intestinal mucosa is a major site for antigliadin antibody production and that IgA is the dominating Ig-class of these antibodies. The high sensitivity and accuracy of the ELISPOT technique may provide a useful instrument for future studies of antibody production and regulation of the gut immune response to gluten and other alimentary antigens in coeliac and other intestinal diseases.