McKay Kyla A, Kwan Vivian, Duggan Thomas, Tremlett Helen
Faculty of Medicine (Neurology), Vancouver Coastal Health Research Institute, Brain Research Centre, University of British Columbia, Vancouver, BC, Canada V6T 2B5.
Biomed Res Int. 2015;2015:817238. doi: 10.1155/2015/817238. Epub 2015 Jan 31.
Multiple sclerosis (MS) is a chronic central nervous system disease with a highly heterogeneous course. The aetiology of MS is not well understood but is likely a combination of both genetic and environmental factors. Approximately 85% of patients present with relapsing-remitting MS (RRMS), while 10-15% present with primary progressive MS (PPMS). PPMS is associated with an older onset age, a different sex ratio, and a considerably more rapid disease progression relative to RRMS. We systematically reviewed the literature to identify modifiable risk factors that may be associated with these different clinical courses. We performed a search of six databases and integrated twenty observational studies into a descriptive review. Exposure to Epstein-Barr virus (EBV) appeared to increase the risk of RRMS, but its association with PPMS was less clear. Other infections, such as human herpesvirus-6 and chlamydia pneumoniae, were not consistently associated with a specific disease course nor was cigarette smoking. Despite the vast literature examining risk factors for the development of MS, relatively few studies reported findings by disease course. This review exposes a gap in our understanding of the risk factors associated with the onset of PPMS, our current knowledge being predominated by relapsing-onset MS.
多发性硬化症（MS）是一种病程高度异质性的慢性中枢神经系统疾病。MS的病因尚不完全清楚，但可能是遗传和环境因素共同作用的结果。约85%的患者表现为复发缓解型多发性硬化症（RRMS），而10 - 15%的患者表现为原发进展型多发性硬化症（PPMS）。与RRMS相比，PPMS发病年龄较大，性别比例不同，疾病进展明显更快。我们系统回顾了文献，以确定可能与这些不同临床病程相关的可改变风险因素。我们检索了六个数据库，并将20项观察性研究纳入描述性综述。感染爱泼斯坦 - 巴尔病毒（EBV）似乎会增加RRMS的风险，但其与PPMS的关联尚不清楚。其他感染，如人类疱疹病毒6型和肺炎衣原体，以及吸烟，均未始终与特定病程相关。尽管有大量关于MS发病风险因素的文献，但相对较少的研究按病程报告结果。本综述揭示了我们对与PPMS发病相关风险因素的理解存在差距，目前我们的认知主要基于复发型MS。
