Ross S C, Densen P
Medicine (Baltimore). 1984 Sep;63(5):243-73.
Inherited deficiencies of the complement proteins are rare in unselected populations. Examination of patients with the clinical correlates of complement deficiency (autoimmune disease and certain bacterial infections) shows the frequency of inherited complement deficiency to rise enormously (5.9% of patients with systemic lupus erythematosus, 10 to 25% of adults with sporadic meningococcal disease). Autoimmune diseases of all types, but especially systemic lupus erythematosus, discoid lupus and glomerulonephritis, are seen in all categories of complement deficiency, most typically in those of the early classical pathway (C1, C4, C2). Pneumococcal infections are characteristic of deficiencies of the early classical pathway, as well. Deficiencies of C3 are associated with severe disease including autoimmune phenomena, pneumococcal and neisserial infections. C3-deficient patients become ill substantially earlier in life. Infections with N. meningitidis and N. gonorrhoeae are most typical of the late component deficiencies, with over 40% of homozygotes affected. Despite the presence of this deficiency from birth and the peak age-specific incidence of meningococcal disease in the general population at ages 3-8 months, the median age of first infection in the late component-deficient patients is 17 years. Relapse of infection is ten times more common in these patients, and discrete recurrences are seen in 45% of affected individuals. An unusual and unexplained predilection for infection with serogroup Y N. meningitidis exists. Despite an immune deficiency, and problems with ascertainment bias, it appears that persons with late component complement deficiency enjoy less mortality than normals who contract meningococcal disease. Attempts to explain the pathogenesis of neisserial infection in late component deficiencies have focused on the concept that normally non-pathogenic serum-sensitive bacteria are etiologic in the absence of serum bactericidal activity. Data to support this concept remain to be developed and contrary data exist. A separate mechanism may predispose properdin-deficient patients to meningococcal infection, since they appear to develop fulminant infections with high mortality.
在未经筛选的人群中，补体蛋白的遗传性缺陷较为罕见。对具有补体缺陷临床相关表现（自身免疫性疾病和某些细菌感染）的患者进行检查发现，遗传性补体缺陷的发生率大幅上升（系统性红斑狼疮患者中有5.9%，散发性脑膜炎球菌病成年患者中有10%至25%）。各类自身免疫性疾病，尤其是系统性红斑狼疮、盘状红斑狼疮和肾小球肾炎，在所有补体缺陷类型中均有出现，最常见于早期经典途径（C1、C4、C2）的缺陷。肺炎球菌感染也是早期经典途径缺陷的特征。C3缺陷与包括自身免疫现象、肺炎球菌和奈瑟菌感染在内的严重疾病相关。C3缺陷患者在生命早期发病明显更早。脑膜炎奈瑟菌和淋病奈瑟菌感染是晚期成分缺陷最典型的表现，超过40%的纯合子会受到影响。尽管从出生就存在这种缺陷，且一般人群中脑膜炎球菌病的年龄特异性发病率在3至8个月时达到峰值，但晚期成分缺陷患者首次感染的中位年龄为17岁。这些患者感染复发的频率高出十倍，45%的受影响个体出现离散复发。对血清群Y脑膜炎奈瑟菌感染存在一种不寻常且无法解释的偏好。尽管存在免疫缺陷以及确定偏倚问题，但似乎晚期成分补体缺陷患者的死亡率低于患脑膜炎球菌病的正常人。解释晚期成分缺陷中奈瑟菌感染发病机制的尝试主要集中在这样一种概念上，即通常无致病性的血清敏感细菌在缺乏血清杀菌活性时具有致病性。支持这一概念的数据仍有待完善，且存在相反的数据。一种单独的机制可能使备解素缺陷患者易患脑膜炎球菌感染，因为他们似乎会发展为高死亡率的暴发性感染。
