Objectives.  The aim of the present study was to explore the frequency of clinical and serological manifestations of gastrointestinal immune reactivity in a large group of Swedish patients with sarcoidosis.

Design.  In patients with documented sarcoidosis, the presence of pernicious anaemia and coeliac disease was examined. Antibodies to H⁺/K⁺ ATPase, gliadin (AGA‐IgA/IgG) and endomysium (IgA‐EMA) were analysed. In H⁺/K⁺ ATPase antibody‐positive patients, serum gastrin levels were measured and, when elevated, gastrointestinal biopsy was offered (biopsy performed in 6/9 patients); biopsy was also offered to those with positive EMA or AGA of either class (biopsy performed in 8/12 patients). Subjects from national and local studies were used as controls.

Setting.  The patients were recruited at the Department of Pulmonary Medicine, and the study was conducted at the Department of Endocrinology, University of Lund, Malmö University Hospital, Malmö, Sweden.

Subjects.  Of all patients (n = 89) with documented sarcoidosis attending the Department of Pulmonary Medicine between January 1980 and December 1991, 78 [34 females and 44 males; median age at the time of the study, 48 (range 22–81) years; median observation time since the diagnosis of sarcoidosis, 120 (range 1–468) months] were examined.

Results.  Twenty‐nine patients (37.2%) had signs of gastrointestinal immune reactivity. H⁺/K⁺ ATPase antibodies were detected in 19 patients (24.4 vs. 4% in controls, P = 0.00015). Serum gastrin levels (median 45, range 22–720 pmol L^–1) in those patients correlated with antibody titre (r² = 0.882). Gliadin antibodies were detected in 12 patients (15.4 vs. 8.1% in controls, P = 0.042), of whom 11 (14.1 vs. 4.5% in controls, P = 0.00114) had AGA‐IgA alone. One patient had pernicious anaemia and another coeliac disease (EMA‐positive).

Conclusion.  We have demonstrated a high frequency of gastric autoimmunity and gluten‐associated immune reactivity in patients with sarcoidosis, occurring in almost 40% of the cases, the former being the most frequent gastrointestinal immune manifestation. Despite a high frequency of humoral autoimmunity, the frequencies of clinical disease, pernicious anaemia and coeliac disease were not increased as compared with the control population.