心脏直视手术患儿补体4基因多态性对体外循环中补体激活程度的影响

目的：研究补体4基因多态性与体外循环中补体系统激活程度和肺功能障碍之间的关系。方法：选择武汉市及周边地区在体外循环（CPB）下进行心脏直视手术的患儿156例，于术前抽血用交叉免疫电泳法进行补体4基因型分析。分别于CPB开始前，CPB结束时以及鱼精蛋白中和肝素后10min抽取动脉血样，以放免法对补体3和4活化产物C3a和C4a进行测定。同时记录肺顺应性。结果：补体4基因型AABB，AOBB，OOBB，AABO及AAOO出现频率分别为51．28%,17.95%,4.49%,19.87%及6．41％，CPB结束时C4a水平无明显升高，C3a水平显著升高。鱼精蛋白中和肝素后10min时C4a和C3a水平显著升高，以OOBB组升高最显著，其次为AOBB组；同时OOBB组肺顺应性下降最显著，其次为AOBB组，结论：体外循环由替代途径激活补体系统，鱼精蛋白－肝素复合物由经典途径激活补体系统，国人补体4基因型中，OOBB型出现的频率较白种人高，该基因型在体外循环中补体系统被激活及肺功能受损程度最严重。

Effect of complement 4 genetic polymorphism on complement activation during cardiopulmonary bypass in open heart surgery among children

Objective To evaluate the relation between complement 4 genetic pol ymorphism and complement activation during extracorporeal circulation in open he art surgery among children. Methods One hundred and fifty-six children to und e rgo open heart surgery with cardiopulmonary bypass in Wuhan and surrounding area s were investigated. Blood samples were obtained before the operation to analyze the C4 phenotypes by crossed immunoelectrophoresis. Before the initiation of CP B, at the end of CPB, and 10 minutes after protamine infusion, arterial blood sa mples were drawn to test the C4a and C3a with radioimmunoassay and lung complian ce was recorded. Results The frequencies of C4 genetic phenotypes AABB, AOBB, OOBB, AABO, and AAOO were 51.28%, 17.95%, 4.49%, and 19.80% respectively among t he investigated children. At the end of CPB, The C4a levels remained almost the same, and C3a levels increased significantly. Ten minutes after the protamine in fusion, significant increase was seen in the levels of both C4a and C3a, especia lly in the OOBB phenotype group followed by AOBB phenotype group. The lung compl iance began to decrease by the end of CPB, most significantly in the OOBB phenot ype group, followed by the AOBB group, along with the increase of C4a level. Conclusion The complement system is activated by the alternative pathway during C PB and by the classic way during the formation of protamine-heparin complexes. T he complement system is activated and the lung function is damaged the most seri ously during CPB among the persons with OOBB phenotype. The frequency of OOBB ph enotype is higher among Chinese than among Caucasians.