摘要目的:探讨NOD样受体热蛋白结构域相关蛋白3(NLRP3)炎症小体及其下游白细胞介素(IL)-1β、IL-6及IL-18在儿童抗中性粒细胞胞质抗体相关性血管炎(AAV)发病中的作用。方法:回顾性研究。采用免疫组织化学法检测中山大学附属第一医院小儿肾脏风湿病中心2003年9月至2020年9月诊断并行肾活检的22例原发性AAV患儿肾组织中NLRP3炎症小体的定位及表达。采用酶联免疫吸附试验检测血、尿IL-1β、IL-6、IL-18水平。正态分布计量资料两组间比较采用 t检验；多组间比较采用单因素 ANOVA检验；非正态分布计量资料比较采用 Wilcoxon符号秩和检验；分类变量采用 χ2检验；采用 Pearson相关系数或 Spearman秩相关系数分析变量间相关性。 结果:NLRP3广泛表达于肾小管间质，且活动组的表达强度高于对照组，活动组肾小管和肾小球NLRP3半定量评分均高于对照组( F＝0.859、8.320，均 P<0.05)；活动组肾小管NLRP3半定量评分高于肾小球半定量评分( F＝3.517， P<0.05)。活动组肾小管NLRP3半定量评分与肾活检时儿童血管炎活动度评分呈正相关( r＝0.471， P＝0.027)，与肾活检时估算肾小球滤过率呈负相关( r＝－0.548， P＝0.008)。活动组血IL-1β、IL-18及尿IL-6水平均高于缓解组和对照组( F＝16.449、16.449、0.637、29.891、27.612、7.464，均 P<0.05)，缓解组血IL-18水平高于对照组( F＝18.671， P<0.05)。活动组血IL-1β水平与肾小管NLRP3半定量评分呈正相关( r＝0.805， P＝0.002)。活动组血IL-6水平与肾活检时C反应蛋白呈正相关( r＝0.728， P＝0.017)，尿IL-6水平与肾活检新月体比例呈正相关( r＝0.677， P＝0.032)。活动组血IL-18水平与肾小管NLRP3半定量评分、肾活检时儿童血管炎活动度评分及球性硬化比例呈正相关，与肾活检时估算肾小球滤过率值呈负相关( r＝0.644、0.612、0.695、－0.577，均 P<0.05)，尿IL-18水平与肾活检时补体C 4水平呈正相关( r＝0.855， P<0.05)。 结论:NLRP3炎症小体及其下游IL-1β、IL-6、IL-18可能参与AAV的发病和进展，可作为疾病活动评估的参考指标之一。

abstractsObjective:To investigate the role of the NOD-like receptor thermal protein domain associated protein 3(NLRP3)inflammasome and its downstream interleukin(IL)-1β, IL-6, and IL-18 in the pathogenesis of antineutrophil cytoplasmic antibody-associated vasculitis(AAV) in children.Methods:A retrospective study was conducted.Specifically, the localization and expression of the NLRP3 inflammasome in renal tissues of 22 children who were diagnosed with primary AAV and underwent renal biopsy in the Department of Pediatric Nephrology and Rheumatology, the First Affiliated Hospital of Sun Yat-Sen University from September 2003 to September 2020 were detected by the immunohistochemical method.The IL-1β, IL-6 and IL-18 levels in serum and urine were measured by enzyme-linked immunosorbent assay.The measurement data conforming to normal distribution were compared by the t test between two groups and by the single factor ANOVA test among multiple groups.The measurement data that did not conform to normal distribution were compared by the Wilcoxon signed rank sum test.Classification variables were examined by the χ2 test. Pearson correlation coefficient or Spearman rank correlation coefficient were used to analyze the correlation among variables. Results:NLRP3 was widely expressed in the tubulointerstitium, and the expression level in the active group was higher than that in the control group, the semi-quantitative scores of NLRP3 in the renal tubule and glomeruli in the active group were higher than those in the control group ( F=0.859, 8.320, all P<0.05). In the active group, the semi-quantitative score of NLRP3 in the renal tubule was higher than that in the glomeruli( F=3.517, P<0.05). The semi-quantitative score of NLRP3 in the renal tubule was positively correlated with the pediatric vasculitis activity score at renal biopsy ( r=0.471, P=0.027)and negatively correlated with the estimated glomerular filtration rate at renal biopsy ( r=-0.548, P=0.008)in the active group.The serum IL-1β, serum IL-18 and urinary IL-6 levels in the active group were higher than those in the remission group and the control group ( F=16.449, 16.449, 0.637, 29.891, 27.612, 7.464, all P<0.05). The serum IL-18 level in the remission group was higher than that in the control group( F=18.671, P<0.05). In the active group, a positive correlation was found between the serum IL-1β level and the semi-quantitative score of NLRP3 in the renal tubule( r=0.805, P=0.002), between the serum IL-6 level and the C-reactive protein level at renal biopsy ( r=0.728, P=0.017), and between the urinary IL-6 level and the crescent proportion at renal biopsy ( r=0.677, P=0.032). The serum IL-18 level in the active group was positively correlated with the semi-quantitative score of NLRP3 in the renal tubule, pediatric vasculitis activity score and glomerular sclerosis proportion at renal biopsy, and negatively correlated with the estimated glomerular filtration rate at renal biopsy ( r=0.644, 0.612, 0.695, -0.577, all P<0.05). The urinary IL-18 level was positively correlated with the complement C 4 level at renal biopsy ( r=0.855, P<0.05). Conclusions:The NLRP3 inflammasome and its downstream IL-1β, IL-6, and IL-18 may be involved in the pathogenesis and progression of AAV, and can be used as one of the reference indicators for disease activity assessment.