B-1021. Serum Immunoglobulin M as Protection Against Haemophilus influenzae Carriage: A Longitudinal Study in Patients with Agammaglobulinemia or Hyper IgM Syndrome
Session: Poster Session: Innate and Adaptive Immune Responses to Infection
Sunday, October 26, 2008: 12:00 AM
Room: Hall C
Background: Patients with agammaglobulinemia “AG” or hyper IgM syndrome “HIGM” experience infectious complications despite adequate immunoglobulin substitution. The impact of serum IgM on carriage of extracellular bacteria in the upper respiratory tract was addressed. Methods: 101 patients were included (81 with AG and 20 with HIGM). Sputum exams and nasopharyngeal swabs were performed to study bacterial carriage and IgG, IgM and IgA serum levels were assessed at enrollment and every 3 months for 2 years . Serum IgM of 5 patients with AG and 5 patients with HIGM were studied by Western blot to test their immunoreactivity against total protein extract of a pool of Haemophilus influenzae (Hi) strains isolated along this study. Results: Median age was 15.4 years in patients with AG vs. 20.2 in those with HIGM, IgG level 9.0 g/dl vs. 10.8, IgM level < 0.06 g/dl vs. 1.7. Prevalence of Hi (all non-capsulated) carriage was 30.9% (25/81) vs. 5.0% (1/20) (p=0.02). No difference was found for S. pneumonia, P. aeruginosa, M. catarrhalis, S. aureus and N. meningitidis carriages between the two groups.
In univariate analysis, presence of IgM was associated with a lower rate Hi carriage (Log-Rank test, P=0.003).
In multivariate analysis, presence of IgM was a protector factor for Hi carriage (Hazard ratio=0.3; 95%CI=0.1-0.7) independently of antimicrobial prophylaxis and age.
Western blotting analysis demonstrated a strong immunoreactivity of HIGM sera for Hi whole protein extracts, in striking contrast to AG sera. Conclusion: Patients with AG carry significantly more frequently Hi in their upper respiratory tract than patients with HIGM.
Serum IgM may protect against Hi carriage independently of antibiotic prophylaxis and age.
Yasmine Dudoit1, Alain Fischer1, Anne Durandy1, Capucine Picard1, Caroline Thomas2, Felipe Suarez1, Isabelle Pellier2, Julien Beaute1, Kamila Kebaili2, Marc Lecuit, MD PhD3, Marianne Debre1, Nathalie Aladjidi2, Nizar Mahlaoui1, Olivier Lortholary, MD, PhD4, Olivier Lambotte2, Olivier Hermine1, Romain Micol3, Samer Kayal1, Vincent Barlogis2 and  R. Micol, None., (1)CEREDIH, Hopital Necker-Enfants Malades, (2)CEREDIH network, (3)Institut Pasteur, Paris, France, (4)AP-HP; Univ. Paris V