IgG-antibody response against Clostridium difficile antigens, PCR-ribotype and relapse of C.difficile-infection
Abstract number: P723
Bauer M.P., Poxton I.R., Adamowicz K., Kuijper E.J., van Dissel J.T.
Objectives: To investigate the IgG antibody response against C. difficile antigens in patients with C. difficile infection (CDI), and establish the correlation with infecting PCR-ribotype and previous episodes as well as future relapse of CDI.
Methods: In sera of patients with toxin assay-positive and culture-proven CDI who had completed 10 days of antibiotic therapy for CDI, IgG titres against EDTA extracts (cell surface molecules), guanidine hydrochloride extracts (surface-layer proteins) and culture supernatant (crude toxin) of ribotypes 001 and 027, and against lipoteichoic acid of ribotype 001, were determined by enzyme-linked immunosorbent assay (optical density [OD]). By multivariate analysis, we correlated the IgG titres with infecting ribotype (027 versus other), prior CDI episodes (first versus >1 prior episodes) and future relapse within a 60-day follow-up period.
Results: Patients suffering CDI caused by ribotype 027 had higher ODs against EDTA extracts and crude toxins of both ribotypes as compared with patients with CDI caused by other ribotypes. IgG antibody titres against antigens from ribotype 001 were higher than those against antigens from ribotype 027. Against EDTA extracts and crude toxins of ribotype 27, the difference in ODs between those infected by O27 versus other ribotypes reached a level of significance. In all patients, ODs in ELISA measuring antibody titres against surface-layer proteins were low. Of note, IgG antibody titres were not influenced by number of prior CDI episodes nor a predictor for future relapse.
Conclusion: Patients infected by C. difficile ribotype 027 have higher ODs, reflecting a higher concentration or higher affinity in the IgG-ELISA, against cell surface molecules and crude toxins as compared with patients infected by other ribotypes. IgG titres were not correlated with number of prior episodes, nor were they a predictor for future relapse.
|Session name:||19th European Congress of Clinical Microbiology and Infectious Diseases|
|Location:||Helsinki, Finland, 16 - 19 May 2009|
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