P148 Immunohistochemical staining of plasma cells and eosinophils in Inflammatory Bowel Disease: a preliminary report.
G. Canavese*1, V. Villanacci2, R. Rocca3, M. Daperno3, R. Suriani3, M. Salemme2, G. Bassotti4
1Azienda Ospedaliera Città della Salute e della Scienza di Torino, Pathology Department, Torino, Italy, 2Department of Molecular and Translational Medicine, Spedali Civili and University of Brescia, Pathology Section, Brescia, Italy, 3Ospedale Mauriziano, Gastroenterology Department, Torino, Italy, 4Department of Medicine, University of Perugia School of Medicine, Gastroenterology section, Perugia, Italy
The initial histological diagnosis of inflammatory bowel disease (IBD) is often difficult due to the poorly specific morphological signs of the disease. The early appearance (within 2 weeks) of basal plasmacytosis is the most useful sign in differentiating IBD from non IBD colitis within the first two weeks after symptom onset (1,2,3). Moreover, a recent study demonstrated that the presence of eosinophils intermingled with plasma cells are strictly related to a IBD diagnosis (4). On the other hand, the evaluation of these population of inflammatory elements is often limited by the modification of plasma cell nuclear chromatin, due to tissue processing artifacts or to incorrect staining. Purpose of the study was to evaluate the advantages of immunohistochemical (IHC) staining of eosinophils and plasma cells in colonic biopsies in order to improve the detection of basal plasmacytosis.
44 cases of naïve patients (first diagnosis, no ongoing treatment), 20 cases with histological diagnosis of IBD and 24 cases with non IBD colitis, with complete mapping of ileocolic segments were recruited for the study. Biopsy samples from each site of the endoscopic mappings were stained with a monoclonal antibody against plasma cells (CD138, clone MI15 - Dako, Denmark 1:700) and against eosinophil granulocytes ( CD193 Abcam 1:100)
IHC double staining with the two antibodies demonstrated a basal distribution of plasma cells intermingled with eosinophil granulocytes in 20/20 (100%) of cases of IBD colitis and in 7 out of 24 (29%) cases of non IBD colitis (p < 0.05).
(1) IHC stains allows an easy detection of basal plasmacytosis in all cases of IBD colitis and in a smaller proportion of non IBD cases. The technique demonstrated high sensibility and lower specifity in this preliminary study. (2) the detection of inflammatory cell populations by IHC markers could provide new insights on the value of basal plasmacytosis in the diagnostic process.
(3) more reliable data about the distribution of the above mentioned cells during the natural history of the disease and in non-IBD colitis could open new perspectives in understanding the pathogenesis of the disease and in surveillance and treatment strategies.
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