ANTIPOLYSACCHARIDE ANTIBODIES IN 450 CHILDREN WITH OTITIS-MEDIA

We have measured antibodies to pneumococcal and Haemophilus polysaccha rides in a prospective study of 450 children aged 2-16 years with otit is media requiring grommets (ear tubes). Pneumococcal antibody levels were significantly higher in the 2-6 year (P < 0.004) and 7-10 year (P < 0.04) study groups in comparison with age-matched controls. There w as no difference in Haemophilus antibody levels between the study and control group children for the age groups 2-6 years and 11-16 years. H aemophilus antibody levels were significantly lower in the 7-10 year ( P < 0.003) group in comparison with age-matched controls. Eighty-eight out of 450 (19.6%) children had pneumococcal antibody levels below th e 25th percentile. Nineteen out of 88 (21.6%) children with pneumococc al antibody levels below the 25th centile were test immunized with 23 valent Pneumococcal polysaccharide and unconjugated Haemophilus type b capsular polysaccharide. Of these 19 children (aged 4-11 years), five mounted suboptimal responses to both polysaccharide antigens, whilst one child failed to respond to Haemophilus polysaccharide alone. There was no significant difference in the prevalence of IgG subclass defic iency between the normal responders and poor responders to immunizatio n (P = 0.12). We found no evidence of specific polysaccharide antibody deficiency in the vast majority of the 450 children studied. However, the significance of poor antibody responses to test immunization in a small minority of children with otitis media is unclear. Long-term fo llow up of these children is required to determine whether poor immuni zation responses herald the development of frank antibody deficiency.