Autoantibodies to duodenal gastric-inhibitory-peptide (GIP) cells and to secretin (S) cells in patients with coeliac disease, tropical sprue and maturity-onset diabetes.

The presence of autoantibodies detected by immunofluorescence to single endocrine cells, of human duodenum is described in three groups of patients and two control groups. Of 173 coeliac cases, four had GIP cell antibodies, one had secretin cell antibodies and twenty-one reacted with both cell types. Of twelve tropical sprue sera, four reacted with the same two cells. Among fifty elderly diabetics treated with hypoglycaemic drugs, seven sera gave a positive cytoplasmic IFL on duodenal substrate. Four were identified as GIP cells by use of the appropriate hormone antiserum and three reactions were against cells distinct from those stained by anti-GIP, -secretin, -somatostatin, -glucagon and -gastrin. Additional gut hormone antisera will have to be tested to identify these APUD cells. Thirty blood donors and seventy-three sera from autoimmune endocrine patients gave entirely negative results on unfixed cryostat sections of duodenal mucosa. Although impaired GIP and secretin responses have been reported in coeliac disease, and abnormal GIP values were found in Type II diabetes, there is as yet no data to correlate these metabolic dificiencies with the presence of endocrine cell antibodies in the serum. These studies are in progress.