Expression of HSP-65 in jejunal epithelial cells in patients clinically suspected of coeliac disease

Background Coeliac disease (CD) can be classified both clinically and biolo gically an autoimmune disease. A close relationship obtains between heat sh ock proteins (HSPs) and numerous autoimmune diseases. HSPs are overexpresse d when protecting the host against environmental insult. We sought here to establish whether dietary gluten is such a stress stimulus in patients clin ically suspected of CD, and whether the expression of HSP-65 associates wit h densities of intraepithelial gamma delta(+) T cells and/or with expressio n of mucosal HLA-DR. Methods Seventy-eight children with clinical suspicion of CD underwent a je junal biopsy, Monoclonal antibodies were used to stain jejunal epithelial H SP-65, intraepithelial lymphocytes and mucosal HLA-DR, Serum IgA-class endo mysial autoantibodies (EMA) were measured by an indirect immunofluorescence method, CD susceptibility HLA DQA1*0501 and DQB1*0201 alleles (HLA DQ2) we re determined. Results Enhanced expression of epithelial cell mitochondrial HSP-65 was fou nd in 80% (16/20) of coeliacs and in 24% (14/58) of children excluded for t he disease, but in only 7% (2/28) of control subjects (p < 0.001, p = 0.049 , respectively). Children with enhanced expression of HSP-65 had significan tly higher gamma delta(+) T cell densities than those with normal HSP-65 ex pression. A clear association between HSP-65 and serum IgA-class EMA were a lso ascertained in patients with normal jejunal mucosal morphology, HLA DQ2 positivity did not correlate with the HSP-65 expression, Conclusions Gluten might be an environmental insult not only in CD patients but also in some patients excluded for the disease on biopsy. Enhanced exp ression of epithelial cell stress proteins might be an indicator of such an insult.