Rabinovitch R A, Koethe S M, Kalbfleisch J H, Preheim L C, Rytel M W
J Clin Microbiol. 1986 Jan;23(1):56-61. doi: 10.1128/jcm.23.1.56-61.1986.
In the absence of specific antibody, opsonization of Streptococcus pneumoniae may be mediated by the alternative complement pathway (AP) or by C-reactive protein (CRP) via C1 binding. To determine the role of these mechanisms in pneumococcal (PNC) disease, we studied 19 patients with differing severities of PNC infection. C4 and CRP levels and zymosan-induced consumption of 50% hemolytic complement (CH50) were measured in specimens obtained acutely and then weekly. In patients with complicated illness, the modified mean CH50 in acute sera was 178 +/- 57 U/ml, significantly lower than the mean CH50 of 331 +/- 80 U/ml in patients with uncomplicated illness (P less than 0.05). The values of the two groups on a given day approximated each other on days 7, 14, and 23. Consumption of complement by zymosan was also lower in acute sera of patients with complicated illness, with a mean value of 19 +/- 18 U/ml compared with 58 +/- 30 U/ml in those with uncomplicated illness (P less than 0.05). This difference was also seen on day 7 (P less than 0.05). Disease involving lower-numbered PNC serotypes (less than 10) correlated with reduced availability of AP factors in acute sera, independent of illness severity. Mean CRP levels were inversely related to zymosan-induced complement activation in patients with complicated illness. These data suggest that in vivo depletion of AP factors is significantly greater in patients with complicated illness and is associated with high CRP levels. CRP may enhance AP activation via C3 convertase generation and function with it as a preantibody host defense mechanism.
在缺乏特异性抗体的情况下，肺炎链球菌的调理作用可能由替代补体途径（AP）介导，或由C反应蛋白（CRP）通过C1结合介导。为了确定这些机制在肺炎球菌（PNC）疾病中的作用，我们研究了19例不同严重程度的PNC感染患者。在急性期及之后每周采集的标本中检测C4和CRP水平以及酵母聚糖诱导的50%溶血补体（CH50）消耗情况。在患有复杂疾病的患者中，急性血清中改良平均CH50为178±57 U/ml，显著低于非复杂疾病患者的平均CH50 331±80 U/ml（P<0.05）。两组在第7天、14天和23天的给定日期的值相互接近。患有复杂疾病患者的急性血清中酵母聚糖介导的补体消耗也较低，平均值为19±18 U/ml，而无复杂疾病患者为58±30 U/ml（P<0.05）。在第7天也观察到了这种差异（P<0.05）。涉及较低编号PNC血清型（少于10种）的疾病与急性血清中AP因子可用性降低相关，与疾病严重程度无关。在患有复杂疾病的患者中，平均CRP水平与酵母聚糖诱导的补体激活呈负相关。这些数据表明，患有复杂疾病的患者体内AP因子的消耗明显更大，且与高CRP水平相关。CRP可能通过生成C3转化酶增强AP激活，并与之共同作为一种前抗体宿主防御机制发挥作用。
