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The intestinal T cell infiltrate in IBD patients with active endoscopic disease is composed of increased percentages of CD4+ T cells, Tregs, and TCM, with lower percentages of CD8+ T cells and CD103+ T cells, compared with HC and endoscopic inactive IBD. Baseline percentages of CD3, CD4, and Tregs were associated with disease outcome. Further research is needed to demonstrate the predictive value of these lymphocyte subsets.

PurposeThe purpose of this study was to evaluate the diagnostic value of 18F-fluorodeoxyglucose (FDG) positron emission tomography and computed tomography (PET/CT scan) and magnetic resonance imaging (MRI) in diagnosing spondylodiscitis and its complications, such as epidural and paraspinal abscesses.MethodsFrom January 2006 to August 2013 patients with a clinical suspicion of spondylodiscitis, with an infection, or with fever of unknown origin were retrospectively included if 18F-FDG-PET/CT and MRI of the spine were performed within a 2-week time span. Imaging results were compared to the final clinical diagnosis and follow-up data were collected.ResultsSixty-eight patients were included of whom 49 patients were diagnosed with spondylodiscitis. MRI showed an overall sensitivity of 67 % and specificity of 84 %. Diagnostic accuracy was 58 %, when MRI was performed within 2 weeks after the start of symptoms and improved to 82 %, when performed more than 2 weeks after onset of symptoms. 18F-FDG-PET/CT showed a sensitivity of 96 % and a specificity of 95 %, with no relation to the interval between the scan and the start of symptoms.ConclusionsAs compared to MRI, 18F-FDG-PET/CT has superior diagnostic value for detecting early spondylodiscitis. After 2 weeks both techniques perform similarly.

Background The integrin CD103 is proposed to be a potential therapeutical target in inflammatory bowel disease (IBD), as it can form a heterodimeric integrin with β7 (Etrolizumab, anti-β7 integrin) on epithelial T cells. Therefore, we aimed to study the frequencies of different intestinal CD103+T-cell subsets, both CD4+ and CD8+, in newly diagnosed, untreated IBD patients at baseline and during follow-up, compared with healthy controls. Methods Intestinal biopsies from inflamed segments during colonoscopy and peripheral blood samples were prospectively taken from IBD patients at diagnosis and during follow-up. Blood and single cell suspensions from biopsies were analyzed for CD103+ T-cell subpopulations by flow cytometry and expressed as median percentages of the total T-cell population. Results In total, 75 Crohn’s disease (CD) patients, 49 ulcerative colitis (UC) patients, and 16 healthy controls were included. At presentation, IBD patients displayed lower percentages of CD103+T-cell subsets in inflamed biopsies: 3% (1 to 5) CD103+CD4+ in IBD vs 5% (5 to 7) in healthy controls (P = 0.007) and 9% (4 to 15) CD103+CD8+ compared with 42% (23 to 57) in healthy controls (P = 0.001). The majority of intestinal T cells was composed of CD103-CD4+ T cells (65% [52 to 74]) in IBD compared with 30% (21 to 50) in healthy controls (P = 0.001). In patients with endoscopic remission during follow-up (n = 27), frequencies of CD103+ and CD103-T-cell subsets were comparable with healthy controls. Conclusion At diagnosis, active inflammation in IBD was associated with decreased percentages of both CD103+CD4+ and CD103+CD8+T-cell subsets in colon and ileum biopsies. In active disease during follow-up, these T-cell populations remained low but increased in remission to values comparable with healthy controls. A shift toward more CD103-T cells was observed during active inflammation.

Monoclonal antibodies targeting integrins are emerging as new treatment option in inflammatory bowel diseases. Integrins are molecules involved in cell adhesion and signalling. After the successful introduction of anti-α4β7, currently anti-β7 is under evaluation in a phase three trial. Anti-β7 blocks both α4β7/MAdCAM-1 and αEβ7/E-cadherin interaction, targeting both the homing to and the retention in the gut of potential pathological T cells. Since the physiological and potential pathological roles of immune cells expressing αEβ7 are less distinct than of those expressing α4β7, an overview of the current state of knowledge on αEβ7 in mice and humans in both health and inflammatory bowel diseases is presented here, also addressing the potential consequences of anti-β7 treatment.