Therapy modifies HLA-G secretion differently in Crohn's disease and ulcerative colitis patients.

In our previous paper we have documented a different expression of soluble HLA (Human leukocyte antigen)-G molecules between Ulcerative Colitis (UC) and Crohn’s Disease (CD) patients confirming the presence of different biological characteristics. We have observed a spontaneous secretion in peripheral blood mononuclear cell (PBMC) cultures of CD patients but not in those of UC patients. Moreover, a lack of sHLA-G antigens has been reported in UC patient cultures after lipopolysaccharide (LPS) activation. Our new results suggest that the therapy is able to normalize the production of HLA-G molecules in both CD and UC patients but in a different way: immunosuppressant therapy decreases the hyper-production of HLA-G in CD patients while it starts the release of HLA-G in UC patients. These data confirm the diversity in the behaviour of these two pathologies and propose the analysis of sHLA-G levels in CD and UC patients during the therapeutic follow-up with the goal to distinguish between UC and CD patients and to monitor the therapy. If these results are confirmed in a prospective study, HLA-G could be considered a plasmatic biomarker to establish an individualized treatment to control inflammation, to reduce symptoms and to maintain remissions in inflammatory bowel diseases.