BackgroundThe term seronegative spondyloarthropathies (SpA) is used to define a specific group of disorders with certain common features, an increased incidence of HLA-B27, as well as negative rheumatoid factor and ANA being among them. The association of HLA-B27 within the group of SpA varies significantly, ranging from <50% in psoriatic, enteropathic, and inflammatory bowel disease-associated SpA, to 80% in reactive arthritis, to $><$ 50% in psoriatic, enteropathic and inflammatory bowel disease-associated SpA, to >95% in ankylosing spondilitis. The frequency of the HLA-B27 allele also varies widely across populations. The North-South and the East-West gradients are known with HLA-B27 high prevalence in Northern Eurasia and North America (10–16% of Scandinavians, 25–50% of Indigenous Northern Americans), and lower (2–6%) in Mediterranean regions, and decreasing prevalence from Southeast Asia (>12%) to China (1-6%) [1].ObjectivesTo determine the prevalence of HLA-B27 in Yakut children with SpA and in the population of healthy YakutsMethodsThe prevalence of HLA-B27 was studied among 75 unrelated Yakut children with SpA (mean age 10.2±0,5 years, 41 boys and 34 girls, otherwise healthy) and among unrelated healthy adult Yakuts (mean age 39.5±1,2, 56 men and 36 women) reflecting the general population of Yakutia. HLA typing was performed by means of a standard single specific primer - polymerase chain reaction (Amplikit-27, Russia).ResultsIn children association of SpA with HLA-B27 was revealed (p=0,022), 46,67% of them being HLA-B27 positive (OR =2, 22, CIOR: 1,17-4,22). Prevalence of HLA-B27 in total Yakut population was found to be 28.26%.ConclusionsOur results show low prevalence of HLA-B27 haplotype in Yakut children with SpA and rather high prevalence in the total population of Yakuts, being at the level of prevalence in Koriaks and Cukchi [2,3]. HLA-B27 is known to encompass many different alleles while SpA has thus far been documented in subjects possessing any one of the first several subtypes. Low prevalence of HLA-B27 in children with SpA makes it important to investigate which of them are specific for Yakut populationReferencesKhan MA: HLA-B27 and its subtypes in world populations. Curr Opin Rheumatol 1995, 7:263–269.Pereverzeva VV. Prevalence of HLA-antigenes, genes and haplotypes in alien and native population of North-Eastern Russia. Diss. PhD. Tomsk, 2002: 191 pp. (in Russian)Krylov M., Erdesz S., Alexeeva L., Benevolenskaya L., Arnett F.C., J.D.Reveille. HLA Class II and HLA-B27 oligotyping in two native Siberian population groups. Tissue Antigens, 1995;46(5):382-6Disclosure of InterestNone declared
