OBJECTIVE: To determine the prevalence, distribution, and clinical manifestations of arthritis in a cohort of patients with idiopathic inflammatory myopathies (IIM). Associations with autoantibody status and HLA genetic background were also explored. METHODS: Consecutive patients with IIM treated in a single center were included in this cross-sectional study (n = 106). History of arthritis, 68-joint and 66-joint tender and swollen joint index, clinical features of IIM, and autoantibody profiles were obtained by clinical examination, personal interview, and review of patient records. High-resolution genotyping in HLA-DRB1 and HLA-DQB1 loci was performed in 71 and 73 patients, respectively. RESULTS: A combination of patients' medical history and cross-sectional physical examination revealed that arthritis at any time during the disease course had occurred in 56 patients (53%). It was present at the beginning of the disease in 39 patients (37%) including 23 cases (22%) with arthritis preceding the onset of muscle weakness. On physical examination, 29% of patients had at least 1 swollen joint. The most frequently affected areas were wrists, and metacarpophalangeal and proximal interphalangeal joints. Twenty-seven out of the 29 anti-Jo1-positive patients had arthritis at any time during the course of their illness; this prevalence was significantly higher compared to patients without the anti-Jo1 autoantibody (p < 0.0001). No association of arthritis with individual HLA alleles was found. CONCLUSION: Our data suggest that arthritis is a common feature of myositis. It is frequently present at the onset of disease and it may even precede muscular manifestations of IIM. The most common presentation is a symmetrical, nonerosive polyarthritis affecting particularly the wrists, shoulders, and small joints of the hands. We have confirmed a strong association of arthritis with the presence of the anti-Jo1 antibody.

From the Institute of Rheumatology and the Department of Rheumatology 1st Faculty of Medicine Charles University Prague Prague Czech Republic; and the Royal National Hospital for Rheumatic Diseases Bath UK M Klein MD; H Mann MD; L Pleštilová MD Institute of Rheumatology and the Department of Rheumatology 1st Faculty of Medicine Charles University Prague; Z Betteridge PhD; N McHugh MD Professor Royal National Hospital for Rheumatic Diseases; M Remáková MSc Institute of Rheumatology and the Department of Rheumatology 1st Faculty of Medicine Charles University Prague; P Novota Dr Institute of Rheumatology; J Vencovský MD Professor Institute of Rheumatology and the Department of Rheumatology 1st Faculty of Medicine Charles University Prague

J Rheumatol. 2015 Jun;42(6):1060. doi: 10.3899/jrheum.141470. PubMed

J Rheumatol. 2015 Jun;42(6):1061. doi: 10.3899/jrheum.150063. PubMed

References provided by Crossref.org

Idiopathic inflammatory myopathies

Arthritis in Idiopathic Inflammatory Myopathies

Frequency, mutual exclusivity and clinical associations of myositis autoantibodies in a combined European cohort of idiopathic inflammatory myopathy patients