Department of Clinical Biochemistry, 54M1, Herlev Hospital, Copenhagen University Hospital, Herlev Ringvej 75, DK-2730 Herlev, Denmark.
BMJ. 2012 Sep 6;345:e5244. doi: 10.1136/bmj.e5244.
To test whether elevated concentration of rheumatoid factor is associated with long term development of rheumatoid arthritis.
A prospective cohort study, the Copenhagen City Heart Study. Blood was drawn in 1981-83, and participants were followed until 10 August 2010.
Copenhagen general population.
9712 white Danish individuals from the general population aged 20-100 years without rheumatoid arthritis at study entry.
Rheumatoid arthritis according to baseline plasma IgM rheumatoid factor level categories of 25-50, 50.1-100, and >100, versus <25 IU/mL.
Rheumatoid factor levels were similar from age 20 to 100 years. During 187,659 person years, 183 individuals developed rheumatoid arthritis. In healthy individuals, a doubling in levels of rheumatoid factor was associated with a 3.3-fold (95% confidence interval 2.7 to 4.0) increased risk of developing rheumatoid arthritis, with a similar trend for most other autoimmune rheumatic diseases. The cumulative incidence of rheumatoid arthritis increased with increasing rheumatoid factor category (P(trend)<0.0001). Multivariable adjusted hazard ratios for rheumatoid arthritis were 3.6 (95% confidence interval 1.7 to 7.3) for rheumatoid factor levels of 25-50 IU/mL, 6.0 (3.4 to 10) for 50.1-100 IU/mL, and 26 (15 to 46) for >100 IU/mL, compared with <25 IU/mL (P(trend)<0.0001). The highest absolute 10 year risk of rheumatoid arthritis of 32% was observed in 50-69 years old women who smoked with rheumatoid factor levels >100 IU/mL.
Individuals in the general population with elevated rheumatoid factor have up to 26-fold greater long term risk of rheumatoid arthritis, and up to 32% 10 year absolute risk of rheumatoid arthritis. These novel findings may lead to revision of guidelines for early referral to a rheumatologist and early arthritis clinics based on rheumatoid factor testing.
检测类风湿因子浓度升高是否与类风湿关节炎的长期发展相关。
前瞻性队列研究，哥本哈根城市心脏研究。1981-1983 年采集血液，参与者随访至 2010 年 8 月 10 日。
哥本哈根普通人群。
9712 名丹麦白种人，年龄 20-100 岁，入组时无类风湿关节炎。
根据基线时 IgM 类风湿因子水平，将参与者分为 25-50、50.1-100、>100 与<25IU/ml 四组，分析各组间类风湿关节炎的发生情况。
参与者在 20-100 岁时类风湿因子水平相似。在 187659 人年中，有 183 人发生类风湿关节炎。在健康个体中，类风湿因子水平翻倍与类风湿关节炎发病风险增加 3.3 倍（95%置信区间 2.7 至 4.0）相关，且这种趋势见于大多数其他自身免疫性风湿病。类风湿关节炎的累积发病率随类风湿因子分类增加而升高（趋势检验 P<0.0001）。多变量调整后，类风湿因子水平为 25-50IU/ml、50.1-100IU/ml 和>100IU/ml 时类风湿关节炎的风险比分别为 3.6（95%置信区间 1.7 至 7.3）、6.0（3.4 至 10.0）和 26.0（15.0 至 46.0），与<25IU/ml 相比（趋势检验 P<0.0001）。50-69 岁吸烟女性类风湿因子>100IU/ml 时，类风湿关节炎 10 年的绝对风险最高可达 32%。
普通人群中类风湿因子升高的个体，其长期患类风湿关节炎的风险最高可达 26 倍，10 年的绝对类风湿关节炎风险最高可达 32%。这些新发现可能导致根据类风湿因子检测结果修订指南，以便更早期将患者转至风湿病专家处或更早进入关节炎门诊就诊。
