目的 探讨IgA血管炎肾炎（immunoglobulin A vasculitis with nephritis, IgAVN）患儿不同比例新月体形成对临床表现和病理特征的影响。 方法 按新月体的比例分组并比较，无新月体组75例、≤25%新月体组156例、>25%新月体组33例。 结果 与无新月体组比较，另两组患儿24 h尿蛋白、尿免疫球蛋白（immunoglobulin G, IgG）/肌酐、尿红细胞、纤维蛋白原、中性粒细胞/淋巴细胞比值升高（P<0.05），血清IgG下降，出现低白蛋白状态、高凝状态、病理分级Ⅲ级+Ⅳ级、弥漫性系膜增生占比增高（P<0.05）。与≤25%新月体组相比，>25%新月体组24 h尿蛋白、尿红细胞、纤维蛋白原升高，血清IgG、肾小球滤过率降低，弥漫性系膜增生、肾小管萎缩或间质纤维化占比升高（P<0.05）。>25%新月体组的总胆固醇、甘油三酯、尿素氮、血肌酐水平高于无新月体组（P<0.05）。血清IgG下降、高凝状态、24 h尿蛋白升高、弥漫性系膜增生和肾小管间质慢性病变是新月体比例增多的影响因素（P<0.05）。 结论 IgAVN患儿中新月体比例越多，各项实验室指标异常和肾小管间质慢性病变更重，因此细分新月体比例可以更好地指导临床治疗。

Objective To investigate the impact of the different proportions of crescent formation on clinical manifestations and pathological features in children with immunoglobulin A vasculitis with nephritis (IgAVN). Methods The children with IgAVN were divided into no-crescent group (75 children), ≤25% crescent group (156 children), and >25% crescent group (33 children). Results Compared with the no-crescent group, the other two groups had significant increases in 24-hour urinary protein, urinary immunoglobulin G (IgG)/creatinine ratio, urine red blood cell count, fibrinogen, and neutrophil-lymphocyte ratio, a significant reduction in serum IgG, and a significantly higher proportion of children with low albumin and hypercoagulability, pathological grade III+IV or diffuse mesangial proliferation (P<0.05). Compared with the ≤25% crescent group, the >25% crescent group had significant increases in 24-hour urinary protein, urine red blood cell count, and fibrinogen, significant reductions in serum IgG and glomerular filtration rate, and a significantly higher proportion of children with diffuse mesangial proliferation, tubular atrophy or interstitial fibrosis (P<0.05). Compared with the no-crescent group, the >25% crescent group had significantly higher levels of total cholesterol, triglycerides, urea nitrogen, and serum creatinine (P<0.05). A reduction in serum IgG, hypercoagulability, an increase in 24-hour urinary protein, diffuse mesangial proliferation, and chronic tubulointerstitial lesions were influencing factors for the increase in the proportion of crescent formation (P<0.05). Conclusions For children with IgAVN, the higher proportion of crescent formation is associated with greater abnormalities in laboratory markers and more severe chronic tubulointerstitial lesions, and thus a detailed analysis of the proportion of crescent formation can better guide clinical treatment.