常见感染和中风之间联系的新证据

哥伦比亚大学的一位教授已经收集到一种常见的细菌感染与中风有关的额外证据

纽约——7月7日,2000年的一项研究发表在7月出版的《中风》杂志上,米切尔博士S.V.艾尔金德发现肺炎衣原体感染者四倍半遭受第一次缺血性中风比那些没有暴露在细菌。这种关联在所有年龄和种族的研究人群中是一致的，在男性和女性中都是一致的。肺炎梭状芽胞杆菌感染呼吸道，也在心脏病患者的血管壁中发现。这种感染很常见，而且通常是轻微的。埃尔金德博士是哥伦比亚大学内外科医学院(Columbia University College of Physicians & Surgeons)的神经学助理教授，同时也是纽约长老会医院(Columbia Presbyterian Medical Center of NewYork Presbyterian Hospital)的助理主治医生。“感觉就像感冒一样。”这种细菌不会引起性传播感染衣原体，但与引起这种疾病的生物体有关。埃尔金德博士和他的同事调查了从曼哈顿北部中风研究中选择的89例中风病例和89例匹配的对照组。他们通过血液测试来检测肺炎梭菌的抗体。他们采用了三种测试方法:一种是免疫球蛋白A抗体，这种抗体在感染肺炎梭状芽胞杆菌后会在血液中持续数日; immunoglobulin G antibodies to the bacterium, which stay in the body for several years; and immunoglobulin M antibodies. Antibodies are molecules the body's immune system makes in response to infection. The researchers used microimmunofluorescence to measure the levels of these antibodies. The team found that the shorter-lived IgA antibodies were strongly associated with the risk of having a first stroke. Having the IgG antibodies also increased stroke risk, but less severely than the IgA antibodies. A person with the IgG antibodies in his or her blood was about two and a half times as likely to have a stroke. None of the patients had elevated levels of IgM antibodies. If C. pneumoniae does increase stroke risk, the association is probably due to inflammation resulting from the infection, according to Dr. Elkind. He points out that researchers have been investigating the role of inflammation in heart disease and stroke since the 1950s. "Atherosclerosis looks like an inflammatory disease," says Dr. Elkind. "Evidence has been accumulating over the years that this is the case." An association between C. pneumoniae and heart disease was first observed by Scandinavian researchers in the late 1980s, he notes, adding, "The general idea is that infection with C. pneumoniae may be another thing, just like cholesterol and homocysteine, that is associated with atherosclerosis." Trials are now underway to investigate whether treating people with antibiotics reduces their risk of heart attacks. Dr. Elkind and his colleagues are also conducting a larger study of C. pneumonia and stroke. The research was supported by the National Institute of Neurological Disorders and Stroke, the General Clinical Research Center, the American Heart Association, and the Centers for Disease Control.