STUDIES OF LYMPHOCYTOTOXINS IN INFECTIOUS MONONUCLEOSIS AND SYSTEMIC LUPUS-ERYTHEMATOSUS - EVIDENCE FOR IMMUNE COMPLEX-MEDIATED CYTO-TOXICITY

  • 1 January 1980
    • journal article
    • research article
    • Vol. 39  (3) , 593-598
Abstract
The hypothesis that serum lymphocytotoxins are antigen-antibody complexes was examined. High MW fractions from the sera of 18 patients with infectious mononucleosis (IM), 13 patients with systemic lupus erythematosus (SLE) and 6 healthy controls were prepared by precipitation with polyethylene glycol 6000 (PEG). The lymphocytotoxic activity (LCA) of these PEG precipitates was significantly greater (P < 0.01) than that of the corresponding sera and a significant correlation (r [correlation coefficient] = 0.66, P < 0.01) was observed between the LCA of sera and the PEG precipitates. In contrast to the concentration of LCA in the PEG precipitates, the heterophil antibody titers of the precipitates from IM sera were significantly less (P < 0.05) than serum titers. Antisera raised against PEG precipitates from sera from 9 patients with IM contained significant LCA. The nature of this LCA differed from that of the LCA in the original sera in temperature dependence and molecular size. Antigen-antibody complexes in 7 sera (4 IM, 3 SLE) were dissociated at low pH (3.0) and fractionated by gel filtration at pH 3.0. The LCA of these fractions was compared with the LCA of equivalent fractions obtained by gel filtration at pH 7.2. The heterophil antibody present in sera from patients with IM and the cytotoxicity of anti-lymphocyte globulin (ALG) were used as antibody controls. The LCA in patient sera but not heterophil antibody or ALG cytotoxicity was significantly reduced (P < 0.001) by low pH gel filtration.