T-LYMPHOCYTES BEARING THE GAMMA-DELTA T-CELL RECEPTOR IN CUTANEOUS LESIONS OF LANGERHANS CELL HISTIOCYTOSIS

The aim of this study was to investigate the regional importance of gammadelta T cells in cutaneous lesions of Langerhans' cell histiocytosis. Six cases of Langerhans' cell histiocytosis were investigated by immunohistochemical techniques (alkaline phosphatase-antialkaline phosphatase complex and indirect immunoperoxidase). Increase of gammadelta T cells was observed in 3 cases of Langerhans' cell histiocytosis. In these cases up to 30% of CD3+ cells stained with an anti-TCR gammadelta monoclonal antibodies and in two of them gammadelta T cells showed a marked epidermotropism. In the specimens of the remaining three cases gammadelta T cells were found in an overall percentage of 5% of CD3+ cells, but in two cases a significant increase of epidermal gammadelta T cells was observed. The finding of numerous gammadelta T cells in Langerhans' cell histiocytosis is provocative and supports the suggestion of a functional relationship between gammadelta T cells and LCH cells.