反复呼吸道感染患儿锌治疗前后红细胞CD35分子表达和血清炎性因子的变化

目的检测反复呼吸道感染（recurrent respiratory tract infection，RRTI）患儿红细胞表面CD。分子的表达，研究循环免疫复合物（CIC）和血清炎性因子在感染反复发生中的机制，并观察锌治疗的临床效果。方法将116例RRTI患儿根据不同感染部位分为上呼吸道感染组和下呼吸道感染组，随机选择同期发病的急性呼吸道感染患儿40例和50名健康儿童作为对照，检测红细胞膜CD35分子表达、CIC阳性率，以及IL-6、IL-8和TNF-α的含量。从116例RRTI患儿中选取68例患儿，随机分成锌治疗组（38例）和对照组（30例），治疗结束时和结束后12周再次检测上述指标。结果RRTI患儿（上呼吸道感染组和下呼吸道感染组）红细胞膜CD35分子表达明显低于健康对照组（t值分别为6．17和6．46，P值均〈0．01），而CIC阳性率及其他炎性因子则较健康对照组明显升高，且这些指标在下呼吸道感染中变化更为明显。感染缓解期的RRTI患儿较急性呼吸道感染患儿红细胞CD35表达明显降低（t=20．307，P〈0．01）。经过锌治疗后，RRTI患儿的各项指标明显改善。结论红细胞膜CD，，分子表达低下和CIC等血清炎性因子的过量产生可能是RRTI患儿反复呼吸道感染的重要免疫病理机制之一。锌治疗对上述指标的改善有一定的作用。

Expression of CD35 on erythrocyte membrane and changes of serum inflammatory cytokines in children with recurrent respiratory tract infection before and after zinc treatment

Objective To investigate the expression of CD35 on erytbrocyte membrane and the changes of serum inflammatory cytokines in children with recurrent respiratory tract infection （RRTI） and their relation to zinc therapy. Methods One hundred and sixteen RRTI children including 82 cases of upper respiratory tract infection and 34 cases of lower respiratory tract infection were enrolled in the study; 40 children with acute respiratory infection and 50 healthy children were randomly selected as the controls. The expression of CD35 on erythrocyte membrane, positive rate of circulating immune complex （ CIC）, IL-6, IL-8 and TNF-α were detected. Sixty-eight RRTI children with hypozincemia were randomly divided into zinc treatment group （ n = 38） and control group （ n = 30）. The above parameters were detected at the end of the treatment and 12 weeks after the treatment. Results The expression of CD35 on erythrocyte membrane was significantly lower in RRTI children （ upper respiratory group and lower respiratory group ） than that in healthy controls （t =6.17 and 6.46, P 〈0.01 ）. CIC-positive rate and the contents of IL-6, IL-8 and TNF-α were increased in RRTI children, especially in those with lower respiratory tract infections. Compared with the children of acute respiratory infections, the expression of CD35 on erythrocyte membrane was much lower in RRTI children in the remission stage （t = 20. 307, P 〈 0.01 ）. The above parameters were improved in RRTI children who received zinc treatment. Conclusions Down-regulation of CDz5, insufficient elimination of CIC, excessive production of serum IL-6, IL-8 and TNF-α were observed in RRTI children, which might be the immunopathologic mechanism of the repeated infection. These indexes can be improved after zinc treatment.