Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 13 3 2014 06 15 147 156 EN Yadollah Shakiba Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. Susan Koopah Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. Ahmad Reza Jamshidi Rheumatology Research Centre, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran. Ali Akbar Amirzargar Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. Ahmad Massoud Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. Amir Kiani Molecular Diagnostic Research Center, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran. Mohammad Hossein Nicknam Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. Bahareh Nazari Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. Behrouz Nikbin Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran AND Molecular Immunology Research Center, Tehran University of Medical Sciences, Tehran, Iran. 2015 10 16 In  this  study  we  determined  the  frequency,  sensitivity  and  specificity  of  anti  cyclic citrullinated peptides (anti-CCP) IgG antibody, total rheumatoid factor (RF-T), and RF isotypes in Iranian patients with rheumatoid arthritis (RA) and their association with age, clinical and serological parameters. Anti-CCP and RF-T and RF isotypes level were measured in 418 patients and 399 healthy controls by enzyme-linked immunosurbant assay (ELISA). Additionally, serum C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), visual analog scale (VAS) and disease activity score (DAS28) were evaluated in RA patients. The anti-CCP was positive in 53.1% of RA patients and 4.7% of controls. The frequency of RF-T was 61.87% and 17.66% in RA patients and controls respectively. The prevalence of RF isotypes in RA patients was 46.52% for RF-IgM, 23.47% for RF-IgA and 21.74% for RF-IgG. 31.39% of RA patients were RF-IgM positive without RF-IgA and RF-IgG and 21.9% were positive for all three RF classes. The anti-CCP positive patients showed increased number of swollen joints. On the other hand, RF-T positive patients exhibited a longer disease duration, lower age of onset and also higher ESR, CRP level and increased swollen joints. RF-T titer was significantly higher in RA patients with active disease compared to remission, low and moderate active groups. The sensitivity and specificity were 53.1, 95.3 for anti-CCP antibody and 61.8, 82.3 for RF-T. Our results support that anti-CCP and RF titer maybe valuable in estimation of disease activity and other inflammatory parameters in RA patients. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/462 https://ijaai.tums.ac.ir/index.php/ijaai/article/download/462/375