Increased interleukin-6 levels, interleukin-6 receptor and gp130 expression in peripheral lymphocytes of patients with inflammatory bowel disease

Interleukin-6 is one of the most well-characterized cytokines with pleiotro pic properties. Besides its B-lymphocyte activation role in hematopoiesis, interleukin-6 plays a central role in regulation of systemic nflammation. I nterleukin-6 binds to receptors on target cells (such as hepatocytes and ly mphocytes), consisting of an 80 kDa binding chain and gp130, a polypeptide responsible for signal transduction. In addition to the detection of elevat ed amounts of interleukin-6 in the blood, gene expression (mRNA) of subunit s of the interleukin-6 receptor complex have also been studied by examining the reverse transcriptase polymerase chain reaction on peripheral lymphocy tes from patients with characteristic radiological symptoms suffering from Crohn's disease. Our data show significantly elevated gene expression both of the 80 kDa interleukin-6 binding chain and gp130. These results suggest that enhancement of the expression of the constituents of interleukin-6 and the interleukin-6 receptor system plays a relevant role in systemic inflam mation in inflammatory bowel disease.