The aim of this study was to examine the relation between levels of salivary mutans streptococci and HLA gene polymorphisms in dental caries-resistant and caries-susceptible human subjects. We analyzed HLA alleles at the HLA loci (DRB1, DQA1, and DQB1) in 89 subjects. Thirty-two subjects had high caries susceptibility, and 57 subjects were caries free. Salivary levels of mutans streptococci were measured with a strip mutans test. Comparisons of salivary mutans streptococci levels between certain allele positive and negative and between caries-resistant and caries-susceptible subjects were tested by means of Mann-Whitney U-test. In caries-resistant or caries-susceptible subjects there were significant differences of salivary mutans streptococci levels between positive allele and negative allele in HLA-DQB1*05 (p = 0.01), DRB1*01 (p = 0.02), DRB1*14 (p = 0.04), DQA1*01 (p = 0.007), and DQA1*04 cluster (p = 0.01), respectively. Moreover, we found significant difference of salivary mutans streptococci levels in HLA-DRB1*04, *08, *09, and *12 alleles between two dental caries statuses, respectively. On the other hand, we did not find such difference in HLA-DRB1*01, *13, *14, and *15 alleles.
- Dental caries
- Mutans streptococci