Flow cytometric measurement of intracellular migration inhibition factor and tumour necrosis factor alpha in the mucosa of patients with coeliac disease

There is increasing evidence that proinflammatory cytokines contribute to m any of the small intestinal features in coeliac disease. The aim of the stu dy was to investigate the expression of two proinflammatory cytokines, migr ation inhibition factor (MIF) and tumour necrosis factor alpha (TNF-alpha) in duodenal biopsy specimens from patients with coeliac disease on a gluten -free diet and normal control subjects. A flow cytometric system was used t o analyse intracellular protein levels of MIF and TNF-alpha in freshly isol ated cells from duodenal biopsies taken from 12 patients with treated coeli ac disease and 10 healthy control subjects. From the biopsy specimens, sing le cell suspensions of the epithelium and lamina propria were prepared usin g EDTA/DTT and enzymes. Intracellular cytokine expression was studied in in traepithelial lymphocytes (IELs), lamina propria T cells (LP T) and intesti nal epithelial cells using different surface labelling antibodies. MIF prot ein was constitutively expressed in IELs, LP T cells and epithelial cells f rom normal intestinal mucosa. In contrast, although TNF-alpha was found in LP T cells, this cytokine was virtually undetectable in either IELs or epit helial cells. In coeliac disease, intracellular levels of MIF were signific antly higher in epithelial cells compared with control subjects (P = 0.005) . Raised levels of TNF-alpha were found in epithelial cells (P = 0.03) as w ell as IELs (P = 0.045) from coeliac patients compared with controls. The f indings from this study show up-regulated expression of MIF and TNF-alpha i n IELs and epithelial cells of histologically normal mucosa in patients wit h coeliac disease. Increased expression of proinflammatory cytokines in cel ls occupying the epithelial layer could help explain the rapidity with whic h the coeliac mucosa may respond to gluten challenge.