Investigation of the genetic regulation in allergic rhinitis.

Human leukocyte antigen (HLA) population and family studies were performed to determine whether a specific HLA type is associated with allergic rhinitis. We analyzed hereditary characteristics of allergic rhinitis using 27 nuclear families. According to the results of HLA typing, we concluded that allergic rhinitis is certainly regulated by HLA haplotype linked autosomal recessive inheritance. In addition, the frequency of HLA DQw3 antigen, one of the HLA class II antigens, was higher in the patients allergic to Dermatophagoides farinae, Japanese cedar pollen and/or orchard grass pollen than in non-allergic controls. Secondly, the HLA DQw3 antigen was analyzed in detail by means of HLA DNA typing. Regardless of the type of cDNA probes or restriction enzyme, the serologically defined HLA DQw3 region was highly polymorphic at the DNA level. Furthermore, when we used DQ beta as a probe and BamHI as a restriction enzyme, the 8.1 and 6.3 kb restricted fragments were detected in lower frequency and 3.5 kb fragment in higher frequency in the patients of allergic rhinitis than in non-allergic controls. Further studies by the cloning of these fragments in the patients and the controls to clarify their function may be necessary to define molecular mechanism of the onset of allergic rhinitis.