INTRAVENOUS IMMUNOGLOBULIN THERAPY FOR SEVERE CLOSTRIDIUM-DIFFICILE COLITIS

Background-Many individuals have serum antibodies against Clostridium difficile toxins. Those with an impaired antitoxin response may be sus ceptible to recurrent, prolonged, or severe C difficile diarrhoea and colitis. Aims-To examine whether treatment with intravenous immunoglob ulin might be effective ire patients wit-h severe pseudomembranous col itis unresponsive to standard antimicrobial therapy. Patients-Two pati ents with pseudomembranous colitis nor responding to metronidazole and vancomycin were given normal pooled human immunoglobulin intravenousl y (200-300 mg/kg). Methods-Antibodies against C difficile toxins were measured in mine immunoglobulin preparations by ELISA and by cytotoxin neutralisation assay, Results-Both patients responded quickly as show n by resolution of diarrhoea, abdominal tenderness, and distension, Al l immunoglobulin preparations tested contained IgG against C difficile toxins A and B by ELISA and neutralised the cytotoxic activity of C d ifficile toxins in vitro at IgG concentrations of 0.4-1.6 mg/ml. Concl usion-Passive immunotherapy with intravenous immunoglobulin may be a u seful addition to antibiotic therapy for severe, refractory C difficil e colitis. IgG antitoxin is present in standard immunoglobulin prepara tions and C difficile toxin neutralising activity is evident at IgG co ncentrations which are readily achieved in the serum by intravenous im munoglobulin administration.