Children prone to pneumococcal otitis media have weaker antibody response
Kaur R. Pediatr Infect Dis J. 2011;30:645-650.
Children who are prone to acute otitis media treatment failure mount less of an immunoglobulin G serum antibody response to Streptococcus pneumoniae proteins after acute otitis media and nasopharyngeal colonization compared with children with episodic acute otitis media, according to results of a recent study.
A study by Ravinder Kaur, PhD, and colleagues from Rochester, N.Y., focused on the serum antibody response among otitis-prone children compared with non-otitis-prone children to five S. pneumoniae proteins (PhtD, LytB, PcpA, PhtE, and Ply) that are potential vaccine candidates. The researchers, including Infectious Diseases in Children Editorial Board member Michael E. Pichichero, MD, also studied immune responses in children who met the definition of acute otitis media treatment failure (AOMTF).
The investigators compared the serum IgG antibody titers of five S. pneumoniae proteins (PhtD, LytB, PcpA, PhtE, and Ply) in 268 children. Of those, 34 children had episodic AOM, 35 children were otitis-prone and 25 children had AOMTF caused by S. pneumoniae. The children in the study groups ranged in age from 6 months to 36 months.
The results related to the antigen-specific immune responses are somewhat contradictory to previous studies because this study revealed that serum antibody responses occurred to S. pneumoniae proteins in children who are otitis-prone and who have AOMTF.
Based on these findings, the researchers said a parenteral vaccine composed of at least one or more of PhtD, PhtE, PcpA, LytB, and detoxified Ply derivative may elicit the immunologic hyporesponsiveness seen after natural exposure to S. pneumoniae.
Otitis-prone children were defined as having three or more episodes in 12 months. Children in the AOMTF group failed to clear bacterial infection and continued to have symptoms after at least 48 hours of appropriate antibiotic therapy and/or had return of AOM symptoms within 14 days of treatment. The children in the non-otitis-prone group had only one or two documented episodes of AOM.
Disclosure: The study was supported by Sanofi-Pasteur and NIH. The researchers report no relevant financial disclosures.
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