IgA Antibodies to SBR of Streptococcus mutans in Young Children

Objective: Studies have shown that Streptococcus mutans is a principal etiological agent of dental caries and immune responses to these bacteria have raised much research interest over the past few decades. However, the role of salivary IgA has not been fully elucidated. The purpose of the present study was to investigate the role of salivary IgA antibody in the protective immunity against the saliva-binding region (SBR) of AgI/II of S. mutans. 

 

Method:  A total of 80, 5-12 year-old children were recruited from the out-patient clinic at School of Dentistry, University of Detroit Mercy. Whole saliva stimulated by paraffin-chewing was collected and children were investigated for decayed, missing, and filled surfaces (DMFS) according to WHO criteria. Oral hygiene was determined according to the simplified Oral Hygiene Index (OHI-S) of Greene and Vermillion. The Dentocult®  SM and Dentocult®  LB Strips were used to estimate S. mutans and Lactobacillus (LB) count in stimulated saliva. The level of salivary IgA antibody against SBR and S. mutans were determined by enzyme-linked immunosorbent assay (ELISA). Data subjected to statistical analysis.

 

Result: The results of our study showed that children with low caries prevalence had a significantly higher amount of salivary IgA antibody against SBR / S. mutans compared to those with high caries prevalence. Furthermore, a significant correlation between salivary Lactobacillus counts, salivary flow rate and caries prevalence were also observed. 

Conclusion: The results of our study suggest that salivary IgA antibodies to SBR and S. mutans may play an important role in developing a protective immunity to dental caries in School-aged children. Our results also demonstrated that salivary S. mutans and Lactobacillus are strongly correlated with caries prevalence and should be considered as risk factors for dental caries.