en Evaluation of the Pattern of Antinuclear Antibodies (ANA) Profile among Patients Suffering from Three Major Rheumatic Diseases داخلی ( روماتولوژی ) داخلی ( روماتولوژی ) پژوهشی اصیل Original Article <strong>Background and Objective: </strong>Autoimmune diseases (AIDs) are characterized by tissue destruction or organ dysfunction by the body&rsquo;s own immune system. The anti-nuclear antibodies (ANA) test is a helpful test for diagnosing and classifying ANA-associated rheumatic diseases (AARDs). This study aimed to evaluate the frequency and profile of autoantibodies among patients suffering from systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and Sjogren&#39;s syndrome (SS).<br> <strong>Methods: </strong>This cross-sectional study was performed on patients who referred to the Rheumatology Clinic of Birjand University of Medical Sciences. Demographic data and information about risk factors were collected by a questionnaire. In confirmed cases, the presence of autoantibodies was detected by Fluorescent method (FANA). In all positive patients, ANA profiles were identified.<br> <strong>Findings:</strong> Totally, 138 patients were included in this study. Prevalence of the three main diseases including SLE, RA, and SS was 45.5%, 39.0%, and 15.4%, respectively and being overweight was the most common risk factor. The rate of positive FANA test was 71.4%, 43.8%, and 78.9% in SLE, RA, and SS, respectively. In the case of autoantibodies, Ro-52 autoantibody had the highest prevalence. The most common co-incidence of autoantibodies was for DFS70 with PM-Scl100.<br> <strong>Conclusion:</strong> The results of this study showed that the mean titers of ANAs were higher in SS patients. The Ro-52 autoantibody was the most commonly detected autoantibody. There was no specific profile of autoantibodies for none of the studied diseases. Further studies are needed to evaluate the correlation between the presence of particular autoantibodies with the prognosis of the patients.<br> &nbsp; Antinuclear Autoantibodies (ANA), Autoimmune Diseases (AIDs), Rheumatoid Arthritis (RA), Sjogren's Syndrome (SS), Systemic Lupus Erythematosus (SLE) 15 24 http://crms.mubabol.ac.ir/browse.php?a_code=A-10-155-1&slc_lang=en&sid=1 M Fereidouni محمد فریدونی dr.m.fereidouni@gmail.com 10031947532846001524 10031947532846001524 Yes Cellular and Molecular Research Center, Birjand University of Medical Sciences, Birjand, Iran Cellular and Molecular Research Center, Birjand University of Medical Sciences, Birjand, Iran E Atabati الهام عتباتی elham1405@yahoo.com 10031947532846001525 10031947532846001525 No Cellular and Molecular Research Center, Birjand University of Medical Sciences, Birjand, Iran Cellular and Molecular Research Center, Birjand University of Medical Sciences, Birjand, Iran S Khojasteh-Kaffash سروش خجسته کفاش soroushkaffash@gmail.com 10031947532846001526 10031947532846001526 No Student Research Committee, School of Medicine, Birjand University of Medical Sciences, Birjand, Iran کمیته تحقیقات دانشجویی، دانشکده پزشکی، دانشگاه علوم پزشکی و خدمات بهداشتی درمانی بیرجند، بیرجند، ایران A Fanoodi علی فنودی Fanoodi.af@gmail.com 10031947532846001527 10031947532846001527 No Student Research Committee, School of Medicine, Birjand University of Medical Sciences, Birjand, Iran کمیته تحقیقات دانشجویی، دانشکده پزشکی، دانشگاه علوم پزشکی و خدمات بهداشتی درمانی بیرجند، بیرجند، ایران A Bahrami افسانه بهرامی afsbahrami91@yahoo.com 10031947532846001528 10031947532846001528 No Cellular and Molecular Research Center, Birjand University of Medical Sciences, Birjand, Iran Cellular and Molecular Research Center, Birjand University of Medical Sciences, Birjand, Iran M R Mogharrabi محمدرضا مقربی mogharrabi78@gmail.com 10031947532846001529 10031947532846001529 No Student Research Committee, School of Medicine, Birjand University of Medical Sciences, Birjand, Iran کمیته تحقیقات دانشجویی، دانشکده پزشکی، دانشگاه علوم پزشکی و خدمات بهداشتی درمانی بیرجند، بیرجند، ایران M Zardast محمود زردست dr.zardast@yahoo.com 10031947532846001530 10031947532846001530 No Department of Pathology, School of Medicine, Birjand University of Medical Sciences, Birjand, Iran Department of Pathology, School of Medicine, Birjand University of Medical Sciences, Birjand, Iran