title: Absence of pseudomembranes in Clostridium difficile-associated diarrhea in patients using immunosuppression agents.
abstract: OBJECTIVE
  Clostridium difficile is a major cause of diarrhea in hospitalized patients. Although pseudomembranes are crucial evidence for diagnosis of C. difficile-associated diarrhea (CDAD), some cases do not show any pseudomembranes. The aim of this study was to verify the hypothesis that pseudomembranes are not generated in immunosuppressed patients because of the absence of immunoreactions.
  
  
  METHODS
  We investigated the endoscopic findings of patients with ulcerative colitis (UC) or who had received hematopoietic stem cell transplantation, and who presented with C. difficile toxin A and had undergone colonoscopy between April 2002 and July 2007 at our institutes. Results. In 4 patients the diagnosis was UC and C. difficile infection, and in another 4 patients the diagnosis was CDAD after hematopoietic stem cell transplantation. None of these cases showed pseudomembranes. Shallow ulcers were found in all four cases with UC. Only non-specific findings were obtained for the CDAD patients after hematopoietic stem cell transplantation.
  
  
  CONCLUSIONS
  Pseudomembranes, the typical evidence for CDAD, were not detected in any patients using immunosuppressive agents. Additional bacterial examination is therefore essential when UC becomes exacerbated and when patients present with diarrhea after hematopoietic stem cell transplantation, even in the absence of pseudomembranes.
authors.affiliation: Department of Molecular Hematology and Oncology, Kyoto Prefectural University of Medicine Graduate School of Medical Science, Kyoto, Japan. nomuken@koto.kpu-m.ac.jp
authors.forename: Kenichi
authors.initials: K
authors.lastname: Nomura
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Fujimoto
authors.forename: Mihoko
authors.initials: M
authors.lastname: Yamashita
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Morimoto
authors.forename: Muneo
authors.initials: M
authors.lastname: Ohshiro
authors.forename: Kazumi
authors.initials: K
authors.lastname: Sato
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Oyake
authors.forename: Shugo
authors.initials: S
authors.lastname: Kowata
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Konishi
authors.forename: Toshikazu
authors.initials: T
authors.lastname: Yoshikawa
authors.forename: Yoji
authors.initials: Y
authors.lastname: Ishida
authors.forename: Masafumi
authors.initials: M
authors.lastname: Taniwaki
mesh_terms: D000293:Adolescent; D000328:Adult; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D000890:Anti-Infective Agents / Q000627:therapeutic use; D001427:Bacterial Toxins / Q000032:analysis; D016360:Clostridioides difficile / Q000302:isolation & purification; D003093:Colitis, Ulcerative / Q000188:drug therapy / Q000382:microbiology / Q000473:pathology*; D003113:Colonoscopy; D003967:Diarrhea / Q000382:microbiology*; D004359:Drug Therapy, Combination; D004761:Enterocolitis, Pseudomembranous / Q000188:drug therapy / Q000382:microbiology / Q000473:pathology*; D004768:Enterotoxins / Q000032:analysis; D005243:Feces / Q000737:chemistry / Q000382:microbiology; D018380:Hematopoietic Stem Cell Transplantation / Q000379:methods; D006801:Humans; D016867:Immunocompromised Host; D007166:Immunosuppressive Agents / Q000008:administration & dosage*; D008297:Male; D008795:Metronidazole / Q000627:therapeutic use; D008875:Middle Aged; D012189:Retrospective Studies; D016896:Treatment Outcome; D014640:Vancomycin / Q000627:therapeutic use
chemical_list: D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D001427:Bacterial Toxins; D004768:Enterotoxins; D007166:Immunosuppressive Agents; C041348:tcdA protein, Clostridium difficile; D008795:Metronidazole; D014640:Vancomycin