Salivary immunoglobulin A and serum antibodies to Streptococcus mutans ribosomal preparations in dental caries-free and caries-susceptible human subjects.

Caries-free subjects or individuals with low caries susceptibility exhibited significantly higher (P less than 0.001) levels of naturally occurring salivary immunoglobulin A (IgA) and serum IgG, IgA, and IgM antibodies to a Streptococcus mutans ribosomal preparation than subjects with high caries susceptibility. Absorption of saliva and serum samples with S. mutans ribosomal preparations, but not with other S. mutans antigens or with Escherichia coli and Neisseria gonorrhoeae ribosomal preparations, removed the antibody activity. Absorption with Streptococcus sanguis ribosomes and NH4Cl-washed S. mutans ribosomes partially removed the anti-S. mutans ribosome antibody activity. These results provide evidence that naturally occurring salivary and serum antibodies to the S. mutans ribosomal preparation correlate with susceptibility to dental caries.