Polyclonal nature of the intestinal mucosal lymphocyte populations in inflammatory bowel disease. A molecular genetic evaluation of the immunoglobulin and T-cell antigen receptors.

To define the clonality of the intestinal lymphocytes involved in the immune response of inflammatory bowel disease, we performed a molecular genetic analysis of the arrangement of the immunoglobulin and antigen-specific T-cell receptor genes of isolated lamina propria lymphocytes derived from resected intestinal specimens of 12 patients with Crohn's disease, 5 patients with chronic ulcerative colitis, and 7 patients with other gastrointestinal diseases. The sensitivity of this technique is sufficient to detect a monoclonal population when there is as little as 1% clonal expansion in a mixed cell population. In all these groups of patients, deoxyribonucleic acid from the non-T cells demonstrated only a germ-line gene pattern, and no non-germ-line rearrangements of immunoglobulin genes as assessed by an immunoglobulin-joining heavy-chain gene probe. Deoxyribonucleic acid from the lamina propria T cells showed a rearrangement pattern of the antigen-specific T-cell receptor beta- and gamma-chain genes that is characteristic of polyclonal T cells as assessed by T-constant beta- and T-joining gamma-gene probes. These results indicate that the lamina propria non-T and T-lymphocyte populations in inflammatory bowel disease and controls are polyclonal.