Association between endogenously activated T cells and immunoglobulin-secreting B cells in patients with active systemic lupus erythematosus.
Systemic lupus erythematosus (SLE) is characterized by increased numbers of circulating B cells activated polyclonally to secrete immunoglobulin. Because T cells secrete, or shed, various factors that are functionally important in regulating immunoglobulin production by B cells, a reverse hemolytic plaque assay was developed to quantitate such activated T cells. In this technique, we used a rabbit antiserum raised to supernatants of concanavalin-A--stimulated human lymphocytes. The relevant antigenic specificity of this antiserum is directed toward the shed surface membrane determinant(s) preferentially expressed on activated T cells. Freshly isolated peripheral blood mononuclear cells from 14 SLE patients contained more than 10 times the number of endogenously activated T cells than cells from normal subjects. Within the SLE group, plaque-forming T cells were particularly increased in patients with active disease. By linear regression analysis, a significant positive correlation was revealed between such activated T cells and immunoglobulin-secreting B cells, also measured by a reverse plaque assay (r = 0.83). It appears that both activated B cells and T cells circulate in increased numbers in SLE. Additional investigation will be required to define the molecular nature of the T cell product(s) being measured and to clarify the relationship of these findings to the immunoregulatory abnormalities in this disorder.
D000818:Animals; D001402:B-Lymphocytes / Q000032:analysis*; D003208:Concanavalin A / Q000494:pharmacology; D006462:Hemolytic Plaque Technique; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D008180:Lupus Erythematosus, Systemic / Q000276:immunology*; D011043:Pokeweed Mitogens / Q000494:pharmacology; D011817:Rabbits; D013601:T-Lymphocytes / Q000032:analysis*
D007074:Immunoglobulin G; D011043:Pokeweed Mitogens; D003208:Concanavalin A