The ANA/RF positive BD patients had ESR 15 mm/hr and a high prevalence of cold sensitivity, claudication, and Raynaud’s phenomenon (p 0.05). Conclusion: There is a possibility of a non-specific autoimmune disposition among BD patients. prevalence of cold sensitivity, claudication, and Raynaud’s phenomenon (p 0.05). Conclusion: There is a possibility of a non-specific autoimmune disposition among BD patients. RF and ANA could be considered for predicting disease progression. strong class=”kwd-title” Key Words: Antibodies, Autoimmunity, Buerger’s Disease, KRCA-0008 Immune System Introduction Thromboangiitis obliterans, also known as Buerger’s disease, is a type of vascular obstructive syndrome that is usually associated with the use of tobacco derivatives and cigarettes (1, 2). The reason of this obstruction is frequent and progressive inflammation, and a blood clotting in the vessels (1, 3, 4). The clinical signs of BD are intermittent pain KRCA-0008 in the fingers, and pain at the tip of the fingers and toes. This disease seems to have no definitive treatment, and the only way to prevent its rapid progression is a cessation of cigarette and tobacco products (3, 5, 6). Buerger’s disease is included in the list of differential diagnoses of all younger patients, who are referred with lower extremity ischemia. This diagnosis is strengthened in case of some KRCA-0008 clinical manifestations, such as rest pain, wounds, and gangrene (1-3). The presence of certain factors in the patient’s records also makes this diagnosis more probable. Compared to patients with atherosclerosis, Cd19 claudication is one of the rare manifestations of BD. Ischemic pain is also observed during rest or ulceration (3, 7). Multi organs are typically involved in BD, with Raynaud’s phenomenon and thrombophlebitis occurring in 40% of these patients (7, 8). During the checkup, the positive result in Allen’s test is useful for distinguishing the disease from atherosclerosis (9). Lupus erythematosus, rheumatoid vasculitis, antiphospholipid antibody syndrome, and mixed connective tissue disease are among the relevant differential diagnoses of BD (10, 11). Despite the decreasing trend in BD in North America and Western Europe, its prevalence is on the rise in Central Asia, the Far East, and the Mediterranean (3, 5). So far, the leading causes of the BD have not been identified; however, smoking plays an active role in its development (4, 5). Interestingly, there are some pieces of evidence in the related literature about patients who had no history of smoking (12, 13). With this in mind, other factors may exist that affect the etiology of BD. Some studies have discovered viral and bacterial impacts, narcotics, and environmental and genetic conditions (12, 13). Additionally, there are studies reporting a group of genes, which have contributions to autoimmune diseases and are widely known as the HLA complex (14-16). One of the arguable aspects of the BD etiology is autoimmunity. The probable association between the immune system and BD has been investigated KRCA-0008 to some extent in previous studies (1, 12, 17, 18). The objective of the present study was to assess the presence of possible autoimmune phenomena in BD patients and the potential role of anti-nuclear antibodies (ANA)/IgM rheumatoid factor (RF) in developing the most common clinical symptoms. Materials and Methods em Ethical statement /em This study was approved by the Medical Research Committee of Mashhad University of Medical Sciences (MUMS), Mashhad, Iran. em Patient selection /em This was a cross-sectional study, where 91 participants were initially recruited according to a call from the Vascular and Endovascular Research Center in 2012. They were then examined based on Shionoya’s medical criteria (5, 19). Also, those individuals who have been reluctant to participant or share additional information about their autoimmune diseases, malignancy, viral diseases, and allergies were removed from the study. In total, 80 male individuals were confirmed having a score of 4 and 5 for KRCA-0008 further assessments. em Study protocol /em After sampling, educated consents were from the individuals. Additionally, the participant’s demographic data and medical symptoms were recorded in detail by professionals. For laboratory checks, 10 mL blood samples were collected to detect antibodies to IgM.