Oral Presentation Australian Society for Microbiology Annual Scientific Meeting 2014

Protein specific antibody responses to conserved antigens of nontypeable Haemophilus influenzae and Streptococcus pneumoniae differ between Indigenous and non-Indigenous Australian children with otitis media - implications for vaccination? (#88)

Ruth Thornton 1 2 , Jessica Hillwood 2 , Sophie Toster 2 , Phillipa Edminston 2 , Guicheng Zhang 2 , Shyan Vijayasekaran 2 3 , Karli Corscadden 1 2 , Harvey Coates 2 3 , Peter Richmond 1 2
  1. Vaccine Trials Group, Telethon Kids Institute, Subiaco, Western Australia, Australia
  2. University Of Western Australia, SUBIACO, WA, Australia
  3. Otorhinolaryngology, Princess Margaret Hospital for Children, Subiaco, WA, Australia

Background and aims: Some children are prone to recurrent and severe otitis media (OM) particularly Indigenous Australian children. The aim of this study was to investigate differences in naturally acquired serum antibody responses to nontypeable Haemophilus influenzae (NTHi) and Streptococcus pneumoniae proteins in Indigenous and non-Indigenous otitis prone children.

Methods: Serum samples from 32 healthy non-indigenous children, 64 Caucasian children and 55 Indigenous children undergoing surgery for OM were for specific IgG and IgA antibody against pneumococcal proteins Ply, CbpA, PspA1 and 2 and NTHi proteins PD, P6 and P4, using a multiplex bead based assay.

Results: Indigenous children had higher levels of IgA than their non-Indigenous counterparts with OM (PspA1, CbpA, Ply and P6). No differences were observed for most IgG (Ply, CbpA, PspA 1 and 2, P6 and P4) between healthy controls, Indigenous OM children and non-Indigenous OM children. Despite high levels of NTHi exposure, Indigenous children had the lowest geometric mean concentration of PD IgA and IgG (10927AU and 92967AU respectively), when compared to both non-Indigenous otitis prone children (16399AU, 168384AU) and healthy non-Indigenous controls (11464AU, 335709AU).

Conclusions: Despite increased susceptibility to severe recurrent OM Indigenous children mount similar or increased antibody responses to most conserved NTHi and pneumococcal antigens tested when compared to their non-Indigenous OM prone children and healthy controls. Indigenous children with OM and their non-Indigenous counterparts, appear to have deficient PD IgA and IgG responses. This could have major implications when considering vaccination with the new PD containing pneumococcal conjugate vaccine.