Immunological in situ identification of the lymphoid cells in the skin infiltrate of lichen planus

A specific rabbit anti‐human T‐lymphocyte antiserum has been used in an indirect immunofluorescence technique to identify T lymphocytes in situ in tissue sections from lichen planus skin lesions. T lymphocytes were also identifiedin situ by means of aminoethylisothiouronium bromide‐treated sheep red blood cells, using an immune adherence technique. Various types of coated sheep red blood cells were utilized to detect cells with receptors for FcIgG and complement factor C3b. The results demonstrated the presence of predominantly T lymphocytes, and probably some macrophages and few B lymphocytes in the skin infiltrate of lichen planus. Total and differential white count as well as relative and absolute numbers of B and T lymphocytes in peripheral blood were also determined, and found to be within the normal range.