title: South-to-north gradient in distribution of the r determinant of hepatitis B surface antigen in Japan.
abstract: A total of 2.305 sera positive for hepatitis B surface antigen were obtained from asymptomatic carriers throughout Japan and subtyped for the d, y, w, and r specificities by the hemagglutination inhibition method. Determinant d prevailed in Japan (d, 99.1%; y, 0.9%), and there was no regional variation in its occurrence. In sharp contrast, there was a marked variation in the distribution of the w and r determinants, forming an apparent south-to-north gradient of r. The percentage of r determinant was highest in Kyushu (92%-94%); it decreased gradually along the axis of Japan to the north and was lowest in Akita (46%), which is located at the north end of Honshu.
mesh_terms: D000483:Alleles; D000818:Animals; D000918:Antibody Specificity; D002353:Carrier State; D000939:Epitopes; D004912:Erythrocytes / Q000276:immunology; D006385:Hemagglutination Inhibition Tests; D006509:Hepatitis B / Q000453:epidemiology*; D006511:Hepatitis B Antigens / Q000032:analysis*; D006801:Humans; D007106:Immune Sera; D005779:Immunodiffusion; D007564:Japan; D012756:Sheep / Q000276:immunology
chemical_list: D000939:Epitopes; D006511:Hepatitis B Antigens; D007106:Immune Sera