RT Journal Article SR Electronic T1 In Vivo Evaluation of 111In-Labeled T-Lymphocyte Homing in Experimental Colitis JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 1759 OP 1765 VO 45 IS 10 A1 Catherine van Montfrans A1 Roelof J. Bennink A1 Kora de Bruin A1 Wouter de Jonge A1 Hein J. Verberne A1 Fiebo J.W. ten Kate A1 Sander J.H. van Deventer A1 Anje A. te Velde YR 2004 UL http://jnm.snmjournals.org/content/45/10/1759.abstract AB Blockade of lymphocyte recruitment to the intestinal mucosa is considered a useful therapy for inflammatory bowel disease (IBD) and anti-α4 antibodies have clinical benefit in patients with active Crohn’s disease. The aim of this study was to evaluate a scintigraphic technique to assess lymphocyte homing to the colon in 2,4,6-trinitrobenzenesulfonic acid (TNBS)–induced experimental colitis (TNBS colitis) in vivo. Methods: TNBS-sensitized and nonsensitized murine total lymphocytes or CD4+ lymphocytes were radiolabeled with 111In-oxinate. Cells were injected into control mice (n = 5) or mice with TNBS colitis (n = 5). Specific abdominal radioactive uptake was determined by SPECT using a dedicated pinhole system 48 h after cell transfer. Radioactive colon uptake was correlated with histology and colon weight as parameters of inflammation. Results: The radioactive colon uptake was most evident in mice with TNBS colitis that received sensitized lymphocytes (uptake ratio [mean ± SEM], 0.51 ± 0.03 vs. 0.22 ± 0.04; P = 0.004). The sensitized 111In-labeled lymphocytes exacerbated colitis compared with nonsensitized lymphocytes. The colon uptake correlated well with both colon weight and histologic score (R2 = 0.836 and 0.933, respectively). The use of purified 111In labeled CD4+ lymphocytes resulted in a similar scintigraphic pattern. Administration of an anti-α4 antibody decreased radioactivity colon uptake of the 111In-labeled cells compared with the control antibody in mice with TNBS colitis (uptake ratio, 0.72 ± 0.14 to 0.33 ± 0.03; P = 0.012). Conclusion: Animal pinhole SPECT can be applied for temporal and spatial analysis of the lymphocyte homing process in experimental colitis. This technique makes possible the in vivo evaluation of therapeutic efficacy of new drugs that interfere with lymphocyte migration. Moreover, colon uptake of radioactivity can be used as a parameter of disease activity in experimental colitis.