Association of Anergy with an Immunosuppressive Peptide Fraction in the Serum of Patients with Cancer

Abstract
To study the relation between circulating immunosuppressive factors and anergy in patients with cancer, we tested 53 patients with cancer for hypersensitivity to skin-test antigens and 2,4-dinitrochlorobenzene. Of 41 patients with negative skin tests, 27 (66 per cent) had immunosuppressive serum (≥70 per cent inhibition of lymphocyte stimulation by phytohemagglutinin). None of 12 with positive skin tests had immunosuppressive serum. Thus, anergy and serum immunosuppressive activity were correlated (p<0.05). After ion-exchange chromatography, most of the immunosuppressive activity in cancer serum was in the first peak, fraction I. The same fraction from subjects without cancer contained no detectable immunosuppressive activity. Mean total immunosuppressive activity of cancer serum was 166.0 ± 97.5 (S.D.) units, and that of non-cancer serum was 30.4 ± 9.2 units (p<0.05). Diafiltration of fraction I. from cancer serum yielded a fraction (< 10,000 daltons) that was highly immunosuppressive. Thus, anergy in cancer appears correlated with the presence of a circulating immunosuppressive serum component. (N Engl J Med 291: 1263–1267, 1974)