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.