Crohn’s disease (CD) patients suffering from peripheral arthritis or ankylosing spondylitis reveal restricted T cell receptor Vβ regions in different temporal phases of disease

Little is known about the mechanisms triggering and controlling both the development and perpetuation of extraintestinal complications in CD. The aim of the present study was to test the hypothesis that the T cell immune response in CD patients with joint complications may be altered when compared with patients without extraintestinal manifestations. We used a semiquantitative polymerase chain reaction assay to analyse the T cell antigen receptor repertoire in peripheral blood T cells from eight CD patients suffering from peripheral arthritis and ankylosing spondylitis, 12 CD patients without extraintestinal manifestations, and from seven non‐CD patients with ankylosing spondylitis showing typical changes on joint radiographs. Being concerned that different patterns may be seen in different phases of the inflammatory disease process, we have also taken care to analyse sequential samples at various time points of the disease. Expression of all 22 Vβ genes was found in each healthy control and in each CD patient without extraintestinal manifestations and showed no major variation over time. Southern hybridization analysis of amplified products revealed a highly restricted Vβ repertoire in all CD patients suffering from peripheral arthritis and ankylosing spondylitis. In contrast, non‐CD patients with ankylosing spondylitis without signs or symptoms of gastrointestinal problems demonstrated the presence of the entire Vβ repertoire. Our longitudinal studies confirmed variable Vβ usage over time, as certain transcripts were found only in distinct temporal phases of disease. Our data are not directly suggestive of a common superantigen model of CD, but instead emphasize a specific decrease in signals throughout the T cell receptor Vβ repertoire in CD patients suffering from joint complications.