Interrelations between ankylosing spondylarthritis and HLA-B27 in some ethnic groups in Russia

Aim. To characterize relationship between prevalence of ankylosing spondyla rthritis (ASA) and incidence rate of HLA-B27 in genotypically different eth nic groups of Russia with interpolation of the results to other populations . Material and methods. 2287 individuals from genotypically different ethnic groups were examined in overall one-stage epidemiological trial. Results. Prevalence of ASA in ethnic groups ranged from 0.2 to 2.0% while o ccurrence of HLA0B27 - from 15 to 40%. Rate of correlation between the dise ase prevalence and incidence of B27 was 0.82. The equation for calculation of ASA incidence rate by HLA-B27 incidence was devised: AC(%) = -0.40+0.06x . Conclusion. In most world populations prevalence of ASA correlates with pop ulation frequency HLA-B27 though in some ethnic groups this correlation is absent. Consequently, ASA is genetically heterogenous.