Immunological study on the expression of HLA-DR antigen in tonsillar epithelium]

Because of the efficacy of tonsillectomy, palmoplantar pustulosis (PPP) has been regarded as a tonsillar focal infection. The immune mechanism underlying focal infection has been considered to be one of the autoimmune diseases mediated mainly by immunoglobulins, but this remains to be clarified. The present study demonstrates the expression of HLA-DR antigen in tonsillar epithelium. An HLA-DR positive area in the epithelium was computed by an image-analyzing program, and evaluated by means of comparisons among hypertrophic tonsil, recurrent tonsillitis, and tonsils with PPP. HLA-DR antigen appeared at high intensities in hypertrophic tonsils and with PPP. The positive areas were mutually related to aging in hypertrophic tonsil and recurrent tonsillitis. Then, the infiltrating lymphocytes in tonsillar epithelium were counted and compared with the intensity of HLA-DR expression. A close correlation was found between the appearance of HLA-DR antigens and activation of infiltrating T-lymphocytes, but no clear relationship was found between HLA-DR antigen intensity and the number of B-lymphocytes. From these findings, it seemed that, in the tonsils with PPP, high HLA-DR intensity was observed in the epithelium and T-lymphocyte infiltration and activation were prominent. Moreover, the pustules on the soles of PPP patients were investigated. T lymphocytic infiltration was already observable in the upper dermis and epidermis in the early stage. Generally speaking, CD4 positive cells were present in substantially greater number than CD8 positive cells. Many CD25 positive cells were also observed around the basement membrane. But there were few cells adjacent to the pustules. These findings indicate that cellular immunity may influence the formation of pustules in the early stage.