Expression of HSP-65 in Jejunal Epithelial Cells in Patients Clinically Suspected of Coeliac Disease

Abstract

Background Coeliac disease (CD) can be classified both clinically and biologically an autoimmune disease. A close relationship obtains between heat shock proteins (HSPs) and numerous autoimmune diseases. HSPs are overexpressed when protecting the host against environmental insult. We sought here to establish whether dietary gluten is such a stress stimulus in patients clinically suspected of CD, and whether the expression of HSP-65 associates with densities of intraepithelial γδ⁺ T cells and/or with expression of mucosal HLA-DR.

Methods Seventy-eight children with clinical suspicion of CD underwent a jejunal biopsy. Monoclonal antibodies were used to stain jejunal epithelial HSP-65, intraepithelial lymphocytes and mucosal HLA-DR. Serum IgA-class endomysial autoantibodies (EMA) were measured by an indirect immunofluorescence method. CD susceptibility HLA DQA1*0501 and DQB1* 0201 alleles (HLA DQ2) were determined.

Results Enhanced expression of epithelial cell mitochondrial HSP-65 was found in 80% (16/20) of coeliacs and in 24% (14/58) of children excluded for the 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 significantly higher γδ⁺ T cell densities than those with normal HSP-65 expression. A clear association between HSP-65 and serum IgA-class EMA were also 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 expression of epithelial cell stress proteins might be an indicator of such an insult.

Key Words:

• Autoimmune
• Coeliac disease
• Heat shock proteins
• γδ T cells
• Endomysial autoantibodies