Microarray analysis of leukocytapheresis-induced changes in gene expression patterns of peripheral blood mononuclear cells in patients with ulcerative colitis

Caudal type homeobox 2 expression induced by leukocytapheresis might be associated with mucosal healing in ulcerative colitis

BACKGROUND AND AIM

Ulcerative colitis (UC) is a chronic inflammatory disease of the colon with an intractable, recurrent course. Although the goal of UC therapy has recently been to target mucosal healing, the molecular mechanism of mucosal healing remains unknown. In this study, we aimed to elucidate the molecular dynamics related to the proliferation and differentiation of intestinal epithelial cells during cytapheresis therapy in a short duration.

METHODS

Endoscopy was performed in 26 patients with UC in multicentre hospitals, and biopsy specimens were collected from the rectum before and within two weeks after leukocytapheresis (LCAP). The expression of representative proteins in intestinal epithelial cells and pathological findings was compared before and after LCAP.

RESULTS

The expression of caudal type homeobox 2 (CDX2) and a hes family bHLH transcription factor 1(HES1) markedly increased after LCAP. Patients with endoscopic improvement after LCAP showed the expression of CDX2 before LCAP. Moreover, the number of goblet cells significantly increased after LCAP. Patients without endoscopic improvement after LCAP did not show the expression of CDX2 before LCAP. However, the expression of CDX2 markedly increased after LCAP.

CONCLUSION

This study suggests that cytapheresis might induce CDX2 expression without affecting the cell proliferation, thus resulting in mucosal healing with goblet cell restoration.

Therapeutic leukocytapheresis in inflammatory bowel disease: clinical efficacy and mechanisms of action

Intense infiltration of the intestinal mucosa by activated leukocytes is a hallmark of inflammatory bowel disease (IBD). Therefore, removal of circulating leukocytes may be an attractive approach for treating IBD. Leukocytapheresis with Cellsorba, a column of polyethylenephtarate fibers that captures monocytes, granulocytes and lymphocytes, has been used to treat IBD, particularly ulcerative colitis, in Japan and Europe. This article reviews the clinical efficacy and safety data and the mechanisms of action of leukocytapheresis in IBD. Although the majority of clinical studies enrolled only small numbers of patients and had open-labeled designs, leukocytapheresis showed clinical efficacy with an excellent safety profile. Leukocytapheresis depletes granulocytes, monocytes, lymphocytes and platelets, alters cell population profiles, modulates cytokine production, and induces bone marrow-derived cells. In conclusion, leukocytapheresis exerts anti-inflammatory and tissue-repairing effects on the intestinal mucosa in IBD. Further studies are needed to explain the exact mechanism of action and to determine the true efficacy of this approach.

Granulocyte/monocyte apheresis as immunotherapic tool: cellular adsorption and immune modulation

Cellular apheresis is now established as a rational therapeutic procedure in certain inflammatory and autoimmune diseases, particularly in inflammatory bowel diseases, but the efficacy of this procedure can not be fully explained solely on the basis of removal of granulocytes and monocytes. It is suggested that a selective modulator increase of regulatory T cells contributes to beneficial effect of adsorptive leukocytapheresis in patients with these pathologies. Though currently applied as second-line medication, it could be considered in the future as an effective alternative to the use of immune suppressive regimens or biological agents and taken into account to establish a tailor's patient therapy in inflammatory and autoimmune conditions.

Research progress in susceptibility genes of inflammatory bowel disease

Inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, is a group of non-specific chronic inflammatory conditions of the gastrointestinal tract with unknown complex etiology. Epidemiologic data indicate genetic contribution to IBD pathogenesis, which include familial aggregation, twin studies, racial and ethnic differences in disease prevalence. The most widely adopted approaches to identifying susceptibility genes in IBD include linkage studies, genome-wide association (GWA) studies and microarray. The first two technologies have confirmed NOD2, IL23R and other genes implicated in IBD pathogenesis and advances in microarray technology makes it possible to diagnose IBD at gene expression level. This article reviewed IBD related genes and introduced application of microarray to IBD research.