Humoral immunity in stage I mycosis fungoides: an increased incidence of lymphocytotoxic antibodies

Thirteen patients with stage I mycosis fungoides (MF) were studied for the presence of circulating autoantibodies including cold-reactive lymphocytotoxic antibodies (LCA), antinuc-lear antibodies and rheumatoid factor antibodies to common food antigens, bovine gamma globulin and casein; and immune complexes as measured by cryoglobulins and I¹²⁵ Clq binding. A significantly increased incidence (11/13) of LCA was found in the MF patients, and this may be related to the alterations in subpopulations of T cells seen in these patients. No significant increase in any other test was noted. There was no evidence of a diffuse hyperactivity of the humoral immune system as seen in systemic lupus erythematosus, which has a similar imbalance of T cell subpopulations.