Pediatr Infect Dis J. 2015 Oct 7. [Epub ahead of print]
Acute otitis media (AOM) is the most common pediatric bacterial infection, and stringently-defined otitis prone (sOP) children have immunologic deficiencies. We recently found that nasopharyngeal (NP) colonization by Streptococcuspneumoniae (Spn) elicits a NP mucosal antibody response to vaccine candidate pneumococcal proteins that correlate with protection from AOM in non-sOP (NOP) children. Here we sought to determine if sOP children experience significantly higher colonization rates with Spnthan NOP children, develop lower naturally acquired NP mucosal antibody responses to those same pneumococcal proteins after colonization by Spn, and suffer greater frequency of AOM as a consequence.
NP samples were collected form 130NOPand 45 sOP children during 270 healthy visits and 201 AOM visits between 6 and 24 months of age. Spn were identified by standard culture. NP mucosal IgG and IgA levels to vaccine candidate proteins pneumococcal histidine triad protein D (PhtD), pneumococcal choline binding protein A (PcpA), and pneumolysin D1 (PlyD1) were measured by quantitative ELISA.
sOP children had significantly higher colonization frequency by Spn (p<0.0001) andsignificantly lower IgGand IgA levels to all three vaccine candidate proteins studied compared to NOP children (all p values <0.05) except IgG to Ply D1 (p=0.31). Spn colonization in NOP children led to 2-5 fold increase in mucosal IgG and IgA levels to all three proteins (all p values <0.01), whereas Spncolonization in sOP children generally failed toelicit antibody responses (all P values > 0.05). PcpA was unique in inducing significant increases in mucosal IgA(p=0.02). When high mucosal IgG levels to all three proteins and IgA to PcpA were measured they correlated with reduced AOM in sOP children.
sOP children experience significantly higher colonization rates with Spn, develop lower naturally acquired NP mucosal antibody responses to pneumococcal vaccine candidate proteins PhtD, PcpA and PlyD1 after colonization by Spn, and suffer greater frequency of AOM if they do not generate high mucosal antibody to the studied proteins.
PMID: 26448450 [PubMed - as supplied by publisher]