Relative deficiency in IgA production by duodenal explants from German shepherd dogs with small intestinal disease

Matched samples of serum, saliva and tears were collected from four groups of dogs; two of the groups were German shepherd dogs (GSDs) either with (Gr oup 1) or without (Group 4) a variety of small intestinal disorders; the re maining two groups were dogs of other breeds, again with (Group 2) or witho ut (Group 3) small intestinal disease. Capture ELISAs were used to measure IgG, IgM, IgA and albumin concentrations within these samples; intestinal h umoral immune status of clinical cases was assessed by quantifying immunogl obulin production from duodenal explant cultures. There were no significant differences in IgG, IgM or IgA concentrations in serum, saliva or tears between the different groups of dog. Moreover, no si gnificant differences were noted between groups for IgG, IgM and IgA saliva ry and tear secretory indices. IgA production by 24-h explant cultures was significantly lower in GSDs compared with non-GSDs with small intestinal di sease (groups 1 and 2, respectively), but the numbers of lamina propria IgA (+) plasma cells in duodenal biopsies were not different between groups. Th ese results suggest that there may be a relative deficiency in local IgA se cretion in GSDs with small intestinal enteropathies, which is not reflected in either serum IgA concentrations, or in secretion at unaffected mucosal sites. It remains to be determined whether such a deficiency is a breed-rel ated primary defect, or whether it arises secondary to the pathological pro cesses within the intestinal mucosa. (C) 2000 Elsevier Science B.V. All rig hts reserved.