The Association of Stimulated Salivary Flow Rates with HLA Class II Allele Frequencies

Abstract

It has been reported that salivary secretion is highly affected by many systemic diseases, and that genetic polymorphism of HLA (human leukocyte antigen) class II gene influences susceptibility to these systemic diseases. Therefore, this study investigated the association of stimulated salivary flow rates with HLA class II allele frequencies, to determine whether HLA genotypes are related to affect salivary production. The types of HLA-DRB 1, -DQA 1 and -DQB 1 genes were studied in 105 unrelated healthy young Japanese adults (78 male, 27 female), aged 18-28 years (mean 20.5 years), using polymerase chain reaction-sequence specific oligonucleotide probe (PCR-SSOP) analysis. The subjects were placed into three groups I ≦ 0.7 ml/min, 0.7-2.0 ml/min and ≦ 2.0 ml/min of salivary flow rates stimulated with paraffin wax. HLA-DRB 1*0901, -DQA 1 *0301 and -DQB 1*0303 alleles frequencies were significantly higher in the ≦ 0.7ml/min group compared with those in the ≦ 2.0 ml/min group. Contrarily, HLA-DRB 1*0802, HLA-DRB 1*1302, HLA-DRB 1*1501 and HLA-DQA 1*0102 allele frequencies were significantly higher in the ≦ 2.0 ml/min group compared with those in ≦ 0.7 ml/min. The results of the present study indicate that HLA class II alleles, or closely linked loci, may be involved in saliva secretion.