ORIGINAL ARTICLE A multicenter study of clinical and laboratory findings of palindromic rheumatism in Iran Alireza KHABBAZI, 1 Mehrzad HAJIALILOO, 1 Sousan KOLAHI, 1 Mohsen SOROOSH, 2 Kamal ESALATMANESH 3 and Sakinehkhatoon SHARIF 4 1 Tabriz Rheumatology Research Team, Tabriz University of Medical Sciences, Tabriz, 2 Department of Internal Medicine, Division of Rheumatology, Army University of Medical Sciences, Tehran, 3 Department of Internal Medicine, Division of Rheumatology, Kashan University of Medical Sciences, Kashan, and 4 Department of Internal Medicine, Division of Rheumatology, Tabriz University of Medical Sciences, Tabriz, Iran Abstract Objective: Considering demographic, clinical and laboratory characteristics of palindromic rheumatism and finding out the difference between rheumatoid factor and anti-cyclic citrullinated peptide positive and negative cases of palindromic rheumatism in Iran. Methods: In this cross-sectional and multicenter study, patients with intermittent arthritis were evaluated by a rheumatologist for palindromic rheumatism. Diagnosis of palindromic rheumatism was made after ruling out other causes of recurrent arthritis, and the fulfillment of the Pasero and Barbieri criteria. Then the demographic and clinical characteristics were recorded and compared in rheumatoid factor and anti-cyclic citrullinated peptide positive and negative patients. Results: Of the 69 patients with palindromic rheumatism, 35 were men and 34 were women. The mean ages of the patients at the time of diagnosis were 38.5 ± 14.6 years. The mean attack intervals and duration of the attacks were 66.3 ± 38.4 days and 3.9 ± 3.3 days, respectively. The most commonly involved joints were knees, metacarpophalangeals and proximal interphalangeals. Rheumatoid factor in 46.4% and anti-cyclic citrullinated peptide in 42% of the cases were positive. Palindromic patients with positive anti-cyclic citrullinated peptide had higher age, shorter duration of disease, shorter duration of attacks, more frequent attacks and more meta- carpophalangeal joints involvement. Conclusions: Rheumatoid factor and anti-cyclic citrullinated peptides were found in a high proportion of patients with palindromic rheumatism. The clinical features of the disease in our study were different in rheuma- toid factor and anti-cyclic citrullinated peptide positive and negative patients. Key words: anti-cyclic citrullinated peptides, intermittent arthritis, palindromic rheumatism, rheumatoid factor. INTRODUCTION Palindromic rheumatism has been described as a recur- rent, irregular, temporary and afebrile inflammatory arthritis and periarthritis. It lasts from a few hours to a few days at variable intervals and leaves no permanent articular damage after subsiding. 1 The attacks happen suddenly and they are often monoarticular; however, sometimes more than one joint may be involved. 2 The attacks occur irregularly and without any specific trig- gering factor. Each episode of attack usually lasts <48 h. 3 There is no fever and systemic symptoms dur- ing the attacks and patients are quite well in the inter- vals between the attacks. 3 Most patients’ laboratory tests and X-rays are normal. 3 Palindromic rheumatism may: evolve into other rheumatic diseases (37%), especially Correspondence: Dr Sousan Kolahi, Rheumatology Research Team, Internal Medicine Department, Emam Reza Hospital, Tabriz, Iran. Email: susan.kolahi@gmail.com © 2012 The Authors International Journal of Rheumatic Diseases © 2012 Asia Pacific League of Associations for Rheumatology and Blackwell Publishing Asia Pty Ltd International Journal of Rheumatic Diseases 2012