The immunological profile of mycosis fungoides.

The immune reactivity of 25 patients with mycosis fungoides was studied twice with a 6 month interval using a panel of T lymphocyte surface markers and functional tests. Patients with clinically inactive disease (stage I + II) had normal T lymphocyte biology. Patients with clinically active disease (stage II-IV) had T lymphopenia, alterations in T cell subpopulations (T gamma and T mu) and a reduced lymphocyte reactivity in vitro following mitogen (PHA, Con A, PWM) and antigen (PPD) stimulation. They also had a reduced secretion of immunoglobulin in vitro after PWM stimulation, apparently due to the alterations in their T lymphocyte subpopulations. The observed changes in the peripheral blood T lymphocyte population and the in vitro function of lymphocytes were not shared by lymphocytes from histologically affected lymph nodes. The natural killer cell activity in blood lymphocytes was found to be normal in all patients.