P15 PREVALENCE OF AUTOANTIBODIES IN CHILDREN WITH PATCHY AND TOTAL ALOPECIA AREATA
Yanovich O, Vorontsova T
Department of Immunoendocrinology, Research Clinical Institute of Radiation Medicine & Endocrinology, Minsk, Belarus

The aim of the study was to estimate the prevalence of autoantibodies in children with alopecia areata (AA) from Belarus. All patients were divided into two groups depending on the clinical forms of alopecia areata (AA): 1 - children with patchy AA (n = 72); 2 - patients with total AA (n = 28). Autoantibodies to thyroidperoxidase (AB-TPO) and thyroglobulin (AB-TG) were measured by radioimmunoassay using Medipan diagnostica kits. Autoantibodies to DNA (AT-DNA) were detected by immunoprecipitation assay. Specific autoantibodies to hair follicles were detected by Western-blotting. Specific autoantibodies to hair follicles were noted significantly often at patchy AA (n = 42) - 62,0±7,5 % in comparison to total AA (n = 24) - 27,0±9,1 % (p < 0,05). Prevalence of AB-TPO was more frequent in patients with patchy AA in comparison to children with total AA but increase was not significant (10,5±3,6 % vs. 3,8±1,8 %). From the other side the frequency of both AB-TPO and AB-DNA were significantly higher in the patients with patchy AA in comparison to the group with total AA (7.7±3.1 % vs. 0 %, p < 0.05). Patients with patchy AA had a significantly increased prevalence of AB-TG than in group with total AA (8.9±3.3% vs. 0%, p<0.05). The frequency of positive AB-DNA in group 1 (11.5%) was almost the same as in the group 2 (9%). Our study showed an increase of frequency of specific and non-specific autoantibodies in children with patchy AA in comparison to group with total AA.