ABSENCE OF GLUTEN-SPECIFIC T-LYMPHOCYTES IN THE SKIN OF PATIENTS WITHDERMATITIS-HERPETIFORMIS

Dermatitis Herpetiformis (DH) is an immunobullous skin disease with an associated gluten-sensitive enteropathy. Withdrawal of gluten from th e diet leads to the resolution of both the skin lesions and the entero pathy. A T cell-mediated immune response to gluten has been implicated in the damage to the gut; the possible gluten specificity of the T ce ll infiltrate in DH skin lesions has not, however, been investigated, T cell lines (TCL) were therefore established from the skin lesions of eight patients with DH by culturing skin fragments for 11-17 days wit h a medium supplemented with 20 U/ml of IL-2. In three cases, gliadin (fraction of gluten toxic to the DH gut) and irradiated, autologous pe ripheral blood mononuclear cells were also added. The TCL were stained for CD3, CD4, CD8, TCR alpha beta and gamma delta expression by indir ect immunofluorescence, and their proliferative responses to mitogens and gluten fraction III (a peptic-tryptic digest of gluten) investigat ed. Of the eight CD3(+) TCL, four were predominantly CD4(+) (82.1-98.8 %), three predominantly CD8(+) (92.6-98.6%) and one TCL contained both 87.6% CD4(+) and 95.2% CD8(+) T cells, a substantial proportion of wh ich were presumably double-labelled CD4(+), CD8(+) T cells. All eight TCL, which were almost exclusively TCR alpha beta(+), proliferated in response to PHA whilst six out of the eight were stimulated by Concana valin A. None of the TCL proliferated to gluten fraction III alone; ho wever, two TCL showed increased proliferation to the antigen in the pr esence of exogenous IL-2 or IL-4 (10 U/ml) compared to cytokine alone. All eight TCL proliferated strongly in the presence of IL-2 alone, bu t only two out of seven showed a moderate response to IL-4. These find ings suggest that gluten-specific T cells are absent from DH skin lesi ons.