title: Significance of increased proliferation of immature plasma cells in the appendix of patients with ulcerative colitis.
abstract: The etiology of ulcerative colitis (UC) is not known. Recent studies support a primary role of the appendix in the pathogenesis of UC, however phenotypical studies of proliferating cells in the appendix have not been reported. We report phenotypical studies of lymphocytes and of proliferating subpopulations in the appendix of patients with inflammatory bowel disease and of controls. Surgical samples of the appendix were obtained from 5 patients with colon cancer, 5 with acute appendicitis, 12 with UC and 7 with Crohn's disease (CD). Frozen sections were cut from fixed samples, and immunostained with lymphocyte markers and anti-Ki-67 antibodies. The number of Ki-67(+) proliferating cells, CD19, and CD138 cells was significantly higher in the appendix of patients with UC than in controls, patients with acute appendicitis, and patients with CD. Immunohistological double staining revealed significant proliferation of CD3, CD19, and CD138 cells in the appendix of patients with UC. The proportions of Ki-67(+) cells in CD3, CD19, and CD138 cells were significantly higher in both total UC patients and patients in remission-stage UC, than in controls, patients with acute appendicitis, and patients with CD. Lamina propria cells in the appendix of patients with UC showed augmented proliferation with increased numbers of CD19 and CD138 cells. The number of CD3 cells was not significantly increased, but the proportion of proliferating CD3 cells was increased. An increased proportion of Ki-67(+) cells in CD19 and CD138 cells represents proliferation of immature plasma cells in the appendix of patients with UC, and proliferation of such immature plasma cells was seen in both active- and remission-stage UC. Proliferation of immature plasma cells in the appendix of patients with UC suggests a primary role of humoral immune responses in the pathogenesis of UC.
authors.affiliation: Department of Gastroenterology, Osaka City University Graduate School of Medicine, Abeno-ku, Osaka 545-8585, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Kawachiya
authors.forename: Nobuhide
authors.initials: N
authors.lastname: Oshitani
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Jinno
authors.forename: Kenji
authors.initials: K
authors.lastname: Watanabe
authors.forename: Shiro
authors.initials: S
authors.lastname: Nakamura
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Fujiwara
authors.forename: Kazuhide
authors.initials: K
authors.lastname: Higuchi
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Maeda
authors.forename: Yukio
authors.initials: Y
authors.lastname: Nishiguchi
authors.forename: Kosei
authors.initials: K
authors.lastname: Hirakawa
authors.forename: Takayuki
authors.initials: T
authors.lastname: Matsumoto
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Arakawa
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000378:metabolism; D001065:Appendix / Q000473:pathology*; D002454:Cell Differentiation; D049109:Cell Proliferation; D003093:Colitis, Ulcerative / Q000473:pathology*; D046508:Culture Techniques; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D010950:Plasma Cells / Q000166:cytology* / Q000378:metabolism
chemical_list: D015703:Antigens, CD; D019394:Ki-67 Antigen