Altered gastrointestinal immune response in sarcoidosis.

Abstract

SUMMARY Because of the possible clinical association between coeliac disease and sarcoidosis, the incidence of humoral sensitivity to dietary proteins was examined in patients with sarcoidosis. Raised concentrations of circulating IgG antibodies to alpha gliadin were found in 41/99 sarcoid patients whereas antibody levels to casein, beta lactaglobulin and ovalbumen were similar to normal controls. Subsequently, a group of 26 sarcoid patients were selected for small intestinal biopsy; 11 had raised and 15 normal alpha gliadin antibody (AGA) levels. One AGA positive patient had villous atrophy consistent with coeliac disease. Intraepithelial lymphocyte (IEL) counts were raised in AGA positive (median 30; 95% confidence limits 22-46) and AGA negative (median 24; 95% confidence limits 19-32) sarcoid patients when compared with a control group (median 13.5; 95% confidence limits 10-18) p<001. Serum IgG concentrations were raised in 11/52 patients tested but there was no correlation between IgG levels and the presence ofIgG antigliadin antibodies. HLA Dr typing was done in 21 of the 26 biopsied patients. The coeliac disease associated antigen Dr3 was present in eight of 21 (38%) which is very similar to the prevalence in unselected blood donors (34%). There was no significant difference in IEL counts between Dr3 positive and Dr3 negative sarcoid patients. These findings suggest that in patients with sarcoidosis, there is an altered gastrointestinal mucosal immune response, accompanied in about 40% of patients by specific sensitisation to wheat protein.

Immune-mediated and chronic inflammatory disease in people with sarcoidosis: disease associations in a large UK database

“…However, it is higher than would be expected from any population estimates of the prevalence of coeliac disease, notwithstanding the fact that coeliac disease is common in the West of Ireland. In another study of 99 patients with sarcoidosis, positive α-gliadin IgG antibodies were detected in 41%, compared with 5% of normal controls and 93% of patients with coeliac disease 17. No data are available in this study on endomysial or tissue transglutaminase antibody serology.…”

Identification of HLA-DR–bound peptides presented by human bronchoalveolar lavage cells in sarcoidosis

“…Interestingly, in a study of immune reactivity in serum, it was found that nearly 40% of sarcoidosis patients had antibodies to ATP synthase (24%) or to gliadin (15%) (29). Similarly, another study found that approximately 40% of sarcoidosis patients were sensitized to gluten (30). One explanation behind a shared immune reactivity between sarcoidosis and celiac disease could be shared HLA alleles, since DQ2 and DRB1*0301 are strongly linked (31).…”

Sarcoidosis in Patients with Celiac Disease

“…In contrast, a Swedish study by Papadopoulos et al in 1999 found an increased frequency of gliadin antibodies but no actual increase in the diagnosis of celiac disease in patients with sarcoidosis [8]. Similarly, in 1988, McCormick et al discovered elevated levels of gliadin antibodies in Irish patients with sarcoidosis but were not able to diagnose celiac disease by biopsy in a significant number of patients [10]. Despite these studies, there have been several case reports of patients with both diagnoses [16][17][18].…”

“…Certain class II haplotypes [8] and gastric autoimmunity [9,10] have been implicated as linking factors. However, there has been no recent literature examining the converse relationship; thus, this study was done to determine the prevalence of sarcoidosis in patients with known celiac disease.…”