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Int J Clin Exp Pathol 2013;6(4):561-570

Original Article
Identification of CD68+ neutrophil granulocytes in in vitro model of acute inflammation
and inflammatory bowel disease

Ahmad Amanzada, Ihtzaz Ahmed Malik, Martina Blaschke, Sajjad Khan, Hazir Rahman, Giuliano Ramadori, Federico Moriconi

Division of Gastroenterology and Endocrinology, Department of Internal Medicine, University Medical Center, Georg-August-University
Göttingen, Germany; Department of Clinical Chemistry, University Medical Center, Georg-August-University Göttingen, Germany. The first two
authors contributed equally to the present work.

Received January 5, 2013; Accepted February 26, 2013; Epub March 15, 2013; Published April 1, 2013

Abstract: CD-68 is widely regarded as a selective marker for human monocytes and macrophages and is commonly used in human pathology
studies. The purpose of this study was to investigate the expression of CD-68 in human peripheral blood mononuclear cells (PBMCs),
neutrophil granulocytes (NGs) and in inflamed intestinal tissue samples for comparison. PBMCs and NGs were isolated from heparinized
human blood samples. Intestinal biopsies were obtained during routine endoscopic procedures from patients with inflammatory bowel
disease (IBD), e.g. ulcerative colitis and Crohn’s disease. Gene and protein expression was analyzed by real-time RT-PCR, Western blot and
immunohistochemistry. Both PBMCs and NGs preparations contained cells that were positive for CD-68 and either neutrophil elastase (NE), or
myeloperoxidase (MPO). CD-68+/NE-/MPO- cells were regarded as monocytes. CD-68 mRNA expression was detected in PBMCs and NGs
preparations. With Western blot and by performing immunoprecipitation of cell lysate, we could clearly detect CD-68 in NGs, U-937, THP-1,
Hep-G2, Jurkat cells and PBMCs. Identification of inflammatory cells in acutely inflamed colonic mucosa obtained from patients with IBD
revealed a strong accumulation of CD-68+/MPO+ cells compared to normal colonic mucosa. The uptake of the marker by phagocytosis was
excluded by performing a double staining with CD-163/NE and CD-163/MPO in PBMCs, NGs cultures and in inflamed colonic mucosa. These
results identify CD-68+ NGs in peripheral blood and inflamed colonic mucosa. CD-68 is not only a marker for the macrophag-es-monocytes
but also for NGs. (IJCEP1301008).

Keywords: CD-68, inflammatory bowel disease, monocytes, neutrophil granulocytes, peripheral blood mononuclear cells

Address correspondence to: Dr. Federico Moriconi, Division of Gastroenterology and Endocrinology, University Medical Center, Göttingen,
Germany, Robert-Koch-Straße 40, 37075 Göttingen, Germany. Tel: + 49-551-397474; Fax: + 49-551-398596; E-mail: fmoriconi@med.uni-
goettingen.de