Abstract: Objective: To investigate the diagnostic value of interleukin 6 (IL-6) and serum amyloid protein A (SAA) in relapse of primary nephrotic syndrome combined with infection in children. Methods: 78 children with relapse of primary nephrotic syndrome were divided into 3 groups: group A, 42 children with relapse of primary nephrotic syndrome combined bacterial infection; group B, 24 children with relapse of primary nephrotic syndrome combined viral infection; group C,12 children with relapse of primary nephrotic syndrome with non infection. The serum IL-6 level and SAA of children in 3 groups were respectively detected, and ROC curve were established to evaluate the diagnostic value of IL-6 and SAA in relapse of primary nephrotic syndrome combined with bacterial infection. Results: The positive rate of IL-6 and SAA (85.71%, 71.43%) of children in group A were significantly higher than group B (0.00%, 20.83%) and group C (16.67%, 33.33%, P<0.05). The AUC of IL-6 and SAA was respectively 0.899 and 0.56. When the cutoff point of IL-6 was 10.71, the sensitivity, specificity, Youden index, positive likelihood ratio and negative likelihood ratio of IL-6 in diagnosing primary nephrotic syndrome combined with bacterial infection were 85.7%, 91.7%, 0.774, 10.33 and 0.16. Conclusions: Detection of SAA and IL-6 can be used to distinguish primary nephrotic syndrome combined bacterial infection from with viral infection and non infection. Moreover, IL-6 has a higher diagnostic value in primary nephrotic syndrome combined with bacterial infection.

Key words: Interleukin 6, Serum amyloid protein A, Primary nephrotic syndrome, Relapse

摘要： 目的:探讨白介素6（IL-6）和血清淀粉样蛋白A（SAA）对儿童原发性肾病综合征（PNS）复发合并感染的诊断价值。方法:78例PNS复发患儿分为三组,A组：PNS合并细菌感染42例,B组：PNS合并病毒感染24例,C组：非感染PNS复发患儿l2例。分别检测三组患儿的IL-6、SAA水平,并建立受试者工作曲线（ROC）评价IL-6和SAA对PNS合并细菌感染的诊断价值。结果:A组患儿IL-6、SAA阳性率（85.71%、71.43%）明显高于B组（0.00%、20.83%）和C组（16.67%、33.33%）,差异有统计学意义(P<0.05)。IL-6的ROC曲线下面积（AUC）为0.899,SAA的AUC为0.56。IL-6截断点为10.71时,诊断PNS合并细菌感染的敏感度及特异性分别为85.7%和91.7%,Youden指数为0.774,阳性及阴性似然比分别为10.33和0.16。结论:检测SAA和IL-6可用于区分PNS合并细菌感染与PNS合并病毒感染和非感染;其中IL-6在PNS合并细菌感染时有较高的辅助诊断价值。

关键词: 白介素6, 血清淀粉样蛋白A, 原发性肾病综合征, 复发