title: Intravenous immunoglobulin therapy for severe Clostridium difficile colitis.
abstract: BACKGROUND
  Many individuals have serum antibodies against Clostridium difficile toxins. Those with an impaired antitoxin response may be susceptible to recurrent, prolonged, or severe C difficile diarrhoea and colitis.
  
  
  OBJECTIVE
  To examine whether treatment with intravenous immunoglobulin might be effective in patients with severe pseudomembranous colitis unresponsive to standard antimicrobial therapy.
  
  
  METHODS
  Two patients with pseudomembranous colitis not responding to metronidazole and vancomycin were given normal pooled human immunoglobulin intravenously (200-300 mg/kg).
  
  
  METHODS
  Antibodies against C difficile toxins were measured in nine immunoglobulin preparations by ELISA and by cytotoxin neutralisation assay.
  
  
  RESULTS
  Both patients responded quickly as shown by resolution of diarrhoea, abdominal tenderness, and distension. All immunoglobulin preparations tested contained IgG against C difficile toxins A and B by ELISA and neutralised the cytotoxic activity of C difficile toxins in vitro at IgG concentrations of 0.4-1.6 mg/ml.
  
  
  CONCLUSIONS
  Passive immunotherapy with intravenous immunoglobulin may be a useful addition to antibiotic therapy for severe, refractory C difficile colitis. IgG antitoxin is present in standard immunoglobulin preparations and C difficile toxin neutralising activity is evident at IgG concentrations which are readily achieved in the serum by intravenous immunoglobulin administration.
authors.affiliation: Section of Gastroenterology, Boston University School of Medicine, Massachusetts, USA.
authors.forename: J
authors.initials: J
authors.lastname: Salcedo
authors.forename: S
authors.initials: S
authors.lastname: Keates
authors.forename: C
authors.initials: C
authors.lastname: Pothoulakis
authors.forename: M
authors.initials: M
authors.lastname: Warny
authors.forename: I
authors.initials: I
authors.lastname: Castagliuolo
authors.forename: J T
authors.initials: JT
authors.lastname: LaMont
authors.forename: C P
authors.initials: CP
authors.lastname: Kelly
mesh_terms: D000906:Antibodies / Q000032:analysis; D001426:Bacterial Proteins; D001427:Bacterial Toxins / Q000276:immunology; D016360:Clostridioides difficile; D004761:Enterocolitis, Pseudomembranous / Q000628:therapy*; D004768:Enterotoxins / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D016756:Immunoglobulins, Intravenous / Q000737:chemistry; D008297:Male; D008875:Middle Aged
chemical_list: D000906:Antibodies; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004768:Enterotoxins; D007074:Immunoglobulin G; D016756:Immunoglobulins, Intravenous; C041348:tcdA protein, Clostridium difficile; C031815:toxB protein, Clostridium difficile