Clinical Epidemiology Unit (T2), Department of Medicine, Karolinska Institutet, Stockholm SE-171 76, Sweden.
Ann Rheum Dis. 2012 Nov;71(11):1865-7. doi: 10.1136/annrheumdis-2012-201638. Epub 2012 Jun 27.
Cases of progressive multifocal leukoencephalopathy (PML), a rare but serious disease, have been reported in patients with rheumatoid arthritis (RA) in association with biological therapy, but little is known about the incidence of PML in patients with RA in the absence of treatment exposure.
To estimate the incidence rate of PML in patients with RA compared with the general population, with and without exposure to biological agents.
Patients with adult onset RA, exposure to biological agents and a diagnosis of PML from 1999 through 2009 were identified from national registries and linked using each Swedish resident's unique personal identification number. General population comparators matched on age, sex and county were also identified. Crude and age- and sex-standardised incidence rates (cases per 100 000 person-years) were calculated with 95% CI.
66 278 patients with RA and 286 949 general population comparators were included in the study. The incidence rate of PML in the overall RA population was 1.0 (95% CI 0.3 to 2.5) compared with 0.3 (95% CI 0.1 to 0.6) in the general population. The difference in incidence rate was 0.7 (95% CI -0.3 to 17). Among all patients exposed to biological agents, only one patient was diagnosed with PML.
Data from this national population-based cohort study suggest that patients with RA may have an increased rate of PML compared with the general population.
进行性多灶性白质脑病（PML）是一种罕见但严重的疾病，在接受生物治疗的类风湿关节炎（RA）患者中已有报道，但在未接受治疗的 RA 患者中，PML 的发病率知之甚少。
估计 RA 患者 PML 的发病率与普通人群相比，以及在有和没有暴露于生物制剂的情况下。
从国家登记处确定了 1999 年至 2009 年期间患有成人发病 RA、暴露于生物制剂和 PML 诊断的患者，并使用每位瑞典居民的独特个人识别号码进行链接。还确定了与年龄、性别和县相匹配的普通人群对照者。使用 95%CI 计算了未经年龄和性别调整的粗发病率（每 100000 人年的病例数）和年龄和性别标准化发病率（每 100000 人年的病例数）。
研究纳入了 66278 例 RA 患者和 286949 例普通人群对照者。整体 RA 人群的 PML 发病率为 1.0（95%CI 0.3 至 2.5），而普通人群为 0.3（95%CI 0.1 至 0.6）。发病率差异为 0.7（95%CI -0.3 至 17）。在所有暴露于生物制剂的患者中，仅有 1 例患者被诊断为 PML。
这项基于全国人群的队列研究数据表明，RA 患者的 PML 发生率可能高于普通人群。
