title: Therapeutic targeting of alpha 4-integrins in chronic inflammatory diseases: tipping the scales of risk towards benefit?
abstract: Inhibition of leukocyte trafficking via alpha4-integrin antibody blockade has recently become a validated therapeutic approach for several inflammatory diseases, including multiple sclerosis, ulcerative colitis and Crohn's disease. In the midst of this recent success, 3 patients receiving chronic treatment with the anti-alpha4 antagonist natalizumab (Tysabri) for the treatment of multiple sclerosis or Crohn's disease, developed JC-virus related progressive multifocal leukoencephalopathy (PML). These unforeseen consequences suggest that long term blockade of alpha4-integrins might prevent trafficking of non-pathogenic lymphocytes that are essential for viral immunosurveillance. In the current issue of the European Journal of Immunology Bjursten and colleagues report that long term treatment with anti-alpha4-integrin antibodies results in exacerbation of the murine model of colitis induced by the targeted deletion of the heterotrimeric G protein subunit Galphai2. In order to properly evaluate the efficacy and safety of anti-alpha4-integrin therapy, the relationship between these observations in an immunologically altered animal model and human clinical disease needs to be carefully measured.
authors.affiliation: Theodor Kocher Institute, University of Bern, CH-3012 Bern, Switzerland. bengel@tki.unibe.ch
authors.forename: Britta
authors.initials: B
authors.lastname: Engelhardt
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Briskin
mesh_terms: D000818:Animals; D002908:Chronic Disease; D004195:Disease Models, Animal; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000235:genetics / Q000276:immunology* / Q000378:metabolism / Q000628:therapy*; D039441:Integrin alpha4 / Q000378:metabolism*
chemical_list: D039441:Integrin alpha4