title: Expression of apoptosis-associated protein RCAS1 in macrophages of histiocytic necrotizing lymphadenitis.
abstract: Receptor-binding cancer antigen expressed on SiSo cells (RCAS1), which is recognized by the 22-1-1 monoclonal antibody (MoAb) against human uterine adenocarcinoma cell line SiSo, has been identified on various kinds of cancer cells. RCAS1 appears to be an apoptosis-associated protein that induces apoptosis in activated T-cells and erythroid progenitor cells. We previously demonstrated that monocytes/macrophages express RCAS1. In the present study, we investigated RCAS1 expression by 22-1-1 MoAb in histiocytic necrotizing lymphadenitis (HNL), which is characterized by necrotic lesions consisting of T-cells undergoing apoptosis and macrophages in proliferation. Expression of RCAS1 was analyzed by immunohistochemical staining in 9 cases of HNL and in 9 cases of reactive lymphadenitis used as a control. The ratio of RCAS1+ cells to CD68+ cells (monocytes/macrophages) was significantly higher in the patients with HNL than in the patients with reactive lymphadenitis (P = .0002; paired t test). Our findings suggest that RCAS1 expressed on macrophages may play an important role in the induction of activated T-cell apoptosis in cases of HNL.
authors.affiliation: Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan. abey@intmed3.med.kyushu-u.ac.jp
authors.forename: Yasunobu
authors.initials: Y
authors.lastname: Abe
authors.forename: Koichi
authors.initials: K
authors.lastname: Ohshima
authors.forename: Manabu
authors.initials: M
authors.lastname: Nakashima
authors.forename: Keiichi
authors.initials: K
authors.lastname: Hara
authors.forename: Takamitsu
authors.initials: T
authors.lastname: Matsushima
authors.forename: Ilseung
authors.initials: I
authors.lastname: Choi
authors.forename: Junji
authors.initials: J
authors.lastname: Nishimura
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kikuchi
authors.forename: Hajime
authors.initials: H
authors.lastname: Nawata
authors.forename: Takeshi
authors.initials: T
authors.lastname: Watanabe
authors.forename: Koichiro
authors.initials: K
authors.lastname: Muta
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm / Q000096:biosynthesis / Q000502:physiology*; D016022:Case-Control Studies; D005260:Female; D020042:Histiocytic Necrotizing Lymphadenitis / Q000209:etiology / Q000276:immunology / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D008199:Lymphadenitis; D008213:Lymphocyte Activation; D008264:Macrophages / Q000737:chemistry / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D013601:T-Lymphocytes / Q000473:pathology
chemical_list: D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm; C120762:EBAG9 protein, human