Suppression of immunoglobulin synthesis by lymphocyte subpopulations in patients with Crohn's disease.
In previous studies, patients with mild or inactive Crohn's disease were found to have increased suppressor T-cell activity. To further characterize suppressor T cells in Crohn's disease, studies were carried out with the use of monoclonal antibodies. Excessive suppressor activity was eliminated by removal of OKT 8+ lymphocytes by complement-mediated lysis. However, the percentage of OKT 8+ (or Leu 2a+) cells and the ratio of OKT 4+ to OKT 8+ (or Leu 3a+ to Leu 2a+) cells were not significantly different from normal. Although the subgroup of patients with increased suppression of immunoglobulin synthesis had a significantly lower mean Leu 3a to Leu 2a ratio than that of normal subjects, in the whole group of Crohn's patients studied, neither the percentage of Leu 2a+ cells nor the ratio of Leu 3a+ to Leu 2a+ cells correlated with excessive suppression of immunoglobulin synthesis. A subpopulation of Leu 2a+ lymphocytes reactive with the monoclonal antibody HNK-1 (Leu 2a+ HNK-1+) was increased in patients with Crohn's disease. Furthermore, elimination of HNK-1-reactive lymphocytes by complement-mediated lysis diminished the excessive suppressor cell function in patients with Crohn's disease. The percentage of Leu 2a+ HNK-1+ lymphocytes correlated significantly with the suppression of pokeweed mitogen-stimulated immunoglobulin synthesis in vitro. Thus, patients with mild Crohn's disease have an increased suppressor cell activity in vitro which correlates with the presence of a subset of lymphocytes that have an HNK-1+ Leu-2a+ phenotype.
D000293:Adolescent; D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal / Q000276:immunology; D002478:Cells, Cultured; D002648:Child; D003165:Complement System Proteins / Q000276:immunology; D003424:Crohn Disease / Q000276:immunology*; D003601:Cytotoxicity Tests, Immunologic; D005260:Female; D006801:Humans; D007075:Immunoglobulin M / Q000096:biosynthesis*; D008214:Lymphocytes / Q000276:immunology; D008297:Male; D008875:Middle Aged; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*
D000911:Antibodies, Monoclonal; D007075:Immunoglobulin M; D003165:Complement System Proteins