Tu1235 Multicentre Follow-up Study of Phagocyte-Derived S100A12 as a Surrogate Marker of Intestinal Inflammation in Inflammatory Bowel Disease

Abstract

demonstration of MSc markers in granulomas of ITB and evaluate whether the distribution of MSc markers could differentiate between granulomas of CD & ITB. Materials & methods: We retrospectively enrolled 17 patients with confirmed ITB(8)or CD(9) and granulomas on histopathology. The 8 ITB cases were culture +ve for myco.tb and mTB PCR +ve. The 9 CD cases were identified according to WHO criteria for definite CD. Paraffinembedded tissue blocks were sectioned to determineMScmarkers CD29, CD90 and CD73 expression by immunofluorescence (Bioimager , BD BioSciences,USA). Conjugated monoclonal antibodies against CD29 (mouse, 313001; BIolegend,USA.), CD73 (mouse, ab54217) & CD90 (rabbit, ab92574) (Abcam) were used for identification of the MScs. Double staining was carried to confirm presence of MScs. Results: CD29 and CD90 positive cells were noted around both ITB and CD granulomas. However CD73, a marker for permeability barrier was expressed around the granulomas of ITB alone and was completely absent in the granulomas of CD (Fig 1). Double staining showed that CD73 Cells were also expressing CD90 & CD29 confirming MSc. Discussion: The differential CD73 expression around ITB granuloma indicates that Mtb evades host immunity by recruiting MScs with high CD73. The study also demonstrates CD73 expression in MScs as a marker for differentiation between granulomas of ITB and CD. These features postulate and support the loss of permeability barrier (reduced CD73 expression) in CD but present in ITB due to presence of the bacterium. MSC therapy has shown benefit in CD2. Conclusion: Granulomas of ITB and CD can be differentiated by CD73 MSc surface marker expression.MSCs with increased CD73 expression could be the future for therapeutic intervention in Crohns. Ref: 1. Raghuvanshi S et al Proc Natl Acad Sci USA. 2010Dec 14; 107(50):21653-8 2. Ciccocioppo R et al Gut 2011; 60:788-98