Surface markers and mitogen response of cells harvested from cutaneous infiltrates in mycosis fungoides and Sézary's syndrome.

It was the purpose of this study to characterize the proliferating cells in skin lesion of Sézary's syndrome and of mycosis fungoides by means of their surface markers and their response to Phytohemagglutinine mitogen stimulation. Viable infiltrating cells were freed from skin biopsy specimens by means of a disaggregating homogenizer and the cells yielded were tested with heterologius polyvalent anti-human Ig and with anti-human T-cell globulin, as well as for spontaneous rosette formation with sheep red blood cells (SRBC) and for their response to stimulation with Phytohemagglutinine. Most of the infiltrating cells in skin lesions of mycosis fungoides and Sézary's syndrome lack receptors for anti-human Ig but form spontaneous rosettes with SRBC and have receptors for anti-T-cell globulin, indicating the T-lymphocyte nature of the infiltrating cells; however, their response to Phytohemagglutinine is weak. The results indicate the atypical, presumably neoplastic, nature of T-lymphocytes proliferating in skin lesions of mycosis fungoides and Sézary's syndrome.