Rheumatology unit, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden.
Clinical Epidemiology Unit, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden.
Ann Rheum Dis. 2017 Nov;76(11):1803-1808. doi: 10.1136/annrheumdis-2017-211174. Epub 2017 Aug 30.
To investigate the association between infection or respiratory tract disease and future risk of developing idiopathic inflammatory myopathy (IIM).
A case-control study was performed using Swedish nationwide registers. Adults with newly diagnosed IIM were identified (2002-2011) from the National Patient Register (NPR) and the Swedish Rheumatology Register (n=957). Controls were matched by age, sex and place of residence (n=9476). Outpatient visits and hospitalisations preceding IIM diagnosis indicating infection or respiratory disease were identified from NPR. Conditional logistic regression models were used to calculate OR and 95% CI. Sensitivity analyses were performed by varying the exposure definition, adjusting for previous healthcare consumption and excluding individuals with connective tissue disease, IIM lung phenotype or IIM-associated cancer.
Preceding infections were more common in IIM cases compared with controls (13% vs 9%) and were associated with an increased risk of IIM (OR 1.5, 95% CI 1.2 to 1.9). Gastrointestinal and respiratory tract infections were associated with an increased risk of IIM while cutaneous infections were not.Preceding respiratory tract disease was present in 10% of IIM cases and 4% of controls (OR 2.3, 95% CI 1.8 to 3.0). Both upper and lower respiratory tract diseases were associated with an increased risk of IIM.Variations in exposure and outcome definitions did not greatly affect the results.
Infections and respiratory tract diseases are associated with an increased risk of IIM which suggests that the triggering of the immune system may take place outside the skeletal muscle.
探讨感染或呼吸道疾病与特发性炎性肌病（IIM）未来发病风险之间的关联。
采用瑞典全国性登记处进行病例对照研究。从国家患者登记处（NPR）和瑞典风湿病登记处（n=957）中确定新诊断为 IIM 的成年患者（2002-2011 年），并通过年龄、性别和居住地与对照组（n=9476）相匹配。从 NPR 中确定出在 IIM 诊断前预示感染或呼吸道疾病的门诊就诊和住院情况。采用条件逻辑回归模型计算比值比（OR）和 95%置信区间（CI）。通过改变暴露定义、调整先前医疗保健的使用情况以及排除患有结缔组织疾病、IIM 肺部表型或 IIM 相关癌症的个体，进行敏感性分析。
与对照组相比，在 IIM 病例中，先前的感染更为常见（13% vs 9%），且与 IIM 的发病风险增加相关（OR 1.5，95%CI 1.2-1.9）。胃肠道和呼吸道感染与 IIM 的发病风险增加相关，而皮肤感染则没有。在 IIM 病例中有 10%存在先前的呼吸道疾病，而对照组中有 4%（OR 2.3，95%CI 1.8-3.0）。上呼吸道和下呼吸道疾病均与 IIM 的发病风险增加相关。暴露和结局定义的变化并没有很大程度上影响结果。
感染和呼吸道疾病与 IIM 的发病风险增加相关，这表明免疫系统的触发可能发生在骨骼肌之外。
