目的: 探讨链球菌(Streptococcus)感染是否有可能加重过敏性紫癜肾炎患儿的肾损害及可能机制。方法: 回顾性分析2015年7月至2019年12月在安徽医科大学第一附属医院确诊为过敏性紫癜肾炎的485例儿童的临床资料。根据出院诊断是否合并链球菌感染分为两组, 合并链球菌感染组(实验组)91例患儿, 对照组394例患儿。通过人工神经网络初步挑选合适的测试项目, 再采用SPSS 23.0统计软件进行数据分析。结果: 两组患儿在尿蛋白、肝肾功能、免疫球蛋白和补体的检测项目上的差异均有统计学意义, 其中抗链球菌溶血素O与IgG(Spearman r=-0.328)、纤维蛋白降解产物(Spearman r=-0.207)、总蛋白(Spearman r=-0.202)和球蛋白(Spearman r=-0.223)均呈轻度相关性。两组患儿在平均年龄(P=0.001)、IgG(P＜0.001)、纤维蛋白降解产物(P=0.019)、血清总蛋白(P＜0.001)、球蛋白(P＜0.001)、IgA(P＜0.001)、IgM(P=0.003)、补体C3(P=0.016)、补体C4(P=0.002)、白蛋白/球蛋白比例(P=0.007)、血清碱性磷酸酶(P=0.036)和估计肾小球滤过率(estimated glomerular filtration rate, eGFR, P=0.039)的平均水平上差异均有统计学意义。为研究过敏性紫癜肾炎患儿肾损伤的危险因素, 将抗链球菌溶血素O、年龄、免疫球蛋白和补体作为自变量, 尿蛋白检测参数和肝肾功能作为因变量做Logistic回归分析, 年龄≤10岁和低补体血症可能是过敏性紫癜肾炎患儿加重肾损害的危险因素。结论: 链球菌感染可能会加重过敏性紫癜肾炎患儿的肾损害, 其中低补体血症、炎症、纤维蛋白溶解和凝血异常可能起重要作用。合并链球菌感染的患儿临床上应及时进行抗感染治疗, 出院后应定期随访。

Objective: To explore whether streptococcal infection may aggravate renal damage in children with Henoch-Schönlein purpura nephritis and its possible mechanism. Methods: In the study, 485 children diagnosed with Henoch-Schönlein purpura nephritis from July 2015 to December 2019 were selected to analyze their clinical data retrospectively. According to the diagnosis of discharge, whether it was combined with streptococcal infection, the children were divided into two groups. The experimental group contained 91 children with Henoch-Schönlein purpura nephritis combined with streptococcal infection, and there were 394 children who were not infected with Streptococcus in the control group. Suitable test items were preliminarily selected through artificial neural network, and then data analysis was performed through SPSS 23.0. Results: The children with Henoch-Schönlein purpura nephritis infected with streptococcus had statistically significant differences compared with the uninfected children in the test items of urine protein, liver and kidney function, immunoglobulin and complement. Anti-streptolysin O had mild correlation with IgG (Spearman r=-0.328), fibrin degradation products (Spearman r=-0.207), total protein (Spearman r=-0.202) and globulin (Spearman r=-0.223). Compared with the children who were not infected with streptococcus, the differences of the average levels of age (P=0.001), IgG (P < 0.001), fibrin degradation products (P=0.019), total protein (P < 0.001), globulin (P < 0.001), IgA (P < 0.001), IgM (P=0.003), complement 3 (P=0.016), complement 4 (P=0.002), albumin/globulin ratio (P=0.007), alkaline phosphatase (P=0.036), and estimated glomerular filtration rate (P=0.039) in the infected children were statistically significant. In order to explore the risk factors of kidney damage in the children with Henoch-Schönlein purpura nephritis, Logistic regression was performed using anti-streptolysin O, age, immunoglobulin and complement as independent variables, urine protein detection parameters, liver and kidney functions as dependent variables. Age ≤10 years old and hypocomplementemia might be risk factors for aggravating renal damage in the children with Henoch-Schönlein purpura nephritis. Conclusion: Streptococcal infections may aggravate renal damage in children with Henoch-Schönlein purpura nephritis, in which hypocomplementemia, inflammation, fibrinolysis and disorders of coagulation perhaps play an important role. Children with streptococcal infection should be treated with anti-infective treatment in time and necessarily, and followed up after discharge regularly.