류마티스관절염의 질병 경과에 영향을 미치는 요인

Abstract

Objectives: Rheumatoid arthritis is a chronic inflammatory disease, which mainly affects the joints and often results in joint damage and physical disability. During the past decade, therapy for rheumatoid arthritis has progressed to early and aggressive treatment including conventional DMARDs and biologics. The objective of our study was to determine whether early diagnosis and treatment have long-term benefit for disease activity and functional disability and identify the effect of tight control of RA on various disease outcomes in a large nation-wide observational RA cohort treated by practicing rheumatologists.

Materials and Methods: RA patients over the age 18 who satisfied the 1987 ACR criteria for RA were recruited as a part of the KORean Observational study Network for Arthritis (KORONA).

1. Effects of early diagnosis on disease activity and functional disability A total of 4540 RA patients completed questionnaire to establish their demographic profile (age, gender, family income and degree of education), medical history, disease specific outcomes and RA-related information. Disease activity was measured with DAS28-ESR, and it was divided by a score of 2.6, that is defined as remission. Functional disability was measured with Korean HAQ-DI, it was divided by score 1. We used chi-squared test and t-test to identify the differences between male and female patients, crude and multi-adjusted model to identify the impact of early diagnosis on disease activity and functional disability.

2. Impact of immediate changes in DMARDs on outcomes in rheumatoid arthritis with moderate-to-severe activity We selected 1900 RA patients with a baseline Disease Activity Score employing 28 joints–erythrocyte sediment rate (DAS28-ESR) of more than 3.2 and who had 1 year of follow-up data. The patients were divided into two groups: (1) disease-modifying antirheumatic drugs (DMARDs)-changed group (patients who changed the types or amounts of their DMARDs) and (2) DMARDs-unchanged group (patients who maintained their DMARDs). We measured various disease outcomes, including the Health Assessment Questionnaire–Disability Index (HAQ-DI), DAS28-ESR, C-reactive protein (CRP), ESR, and global health assessments by both physicians and patients. The t-test was used to identify the effects of tight control of RA on various disease outcomes.

Results 1. Effects of early diagnosis on disease activity and functional disability; cross-sectional study In multivariate analysis, early diagnosis was not associated with higher remission rate. Functional disability was associated with higher DAS28-ESR score, female gender, advanced age, longer disease duration and delayed diagnosis. Subgroup analysis according to disease duration, early diagnosis was independently associated with functional disability in shorter disease duration, whereas it is not associated with functional disability in longer disease duration. Subgroup analysis according to disease activity, early diagnosis was independently associated with functional disability in patients with moderate to severe disease activity.

2. Impact of immediate changes in DMARDs on outcomes in rheumatoid arthritis with moderate-to-severe activity Patients in the DMARDs-changed group were younger, had a shorter disease duration, used less leflunomide, used more biologic agents, and had better outcomes in DAS28-ESR, CRP, and the global health assessment by a physician than those in the DMARDs-unchanged group. HAQ-DI, ESR, and the global health assessment by the patient did not differ between the two groups.

Conclusion: Early diagnosis and early treatment of RA is essential in RA patients. In our study, early diagnosis is associated with functional disability especially with disease duration less than 10 years and moderate to severe disease activity patients. Immediate changes in DMARDs according to disease activity can improve disease outcomes, especially DAS28-ESR, CRP, and the global health assessment by a physician. Additional prospective study design with more detailed information and radiologic progression will be helpful to identify the impact of early diagnosis and disease outcomes.