狼疮肾炎患者血清补体C3与肾小球微血栓的相关性

Correlation between serum C3 and glomerular microthrombosis in patients with lupus nephritis

目的:探讨狼疮肾炎(lupus nephritis,LN)患者中血清补体C3与肾小球微血栓(glomerular microthrombosis,GMT)的关系。方法:回顾性分析2010年1月至2019年2月于深圳市第二人民医院肾内科住院确诊的LN患者资料,据是否有GMT形成分为GMT组与无GMT组,并分别对两组患者的人口学资料、临床特点、病理及预后指标进行比较;采用Logistic回归分析及广义相加混合模型平滑曲线拟合等方式探讨血清补体C3与GMT的相关性。采用Kaplan-Meier生存曲线比较两组患者的肾脏预后。结果:本研究共纳入116例LN患者,年龄(32.79±11.43)岁,女性108例(93.10%);共37例(31.90%)合并GMT(GMT组),79例未合并GMT(非GMT组)。与非GMT组相比,GMT组患者年龄相对更大(t=-2.876,P=0.002),高血压比例更高(χ^2=7.492,P=0.006),24 h尿蛋白量更多(Z=-2.115,P=0.003),eGFR及血清C3水平更低(Z=3.469,P<0.001;t=1.744,P<0.001),系统性红斑狼疮疾病活动度评分更高(t=-2.758,P=0.007)。病理方面以IV型LN占多数(72.97%),总新月体更多(Z=-1.866,P=0.002),活动性指数更高(t=-5.005,P<0.001),核碎裂、内皮增生和肾小管萎缩更严重(χ^2=14.987,P<0.001;χ^2=15.695,P<0.001;χ^2=4.130,P=0.042)。多因素Logistic回归分析提示血清补体C3是LN患者GMT形成的相关因素(OR=0.966,95%CI 0.938~0.995,P=0.023)。广义相加混合模型平滑曲线拟合结果表明补体C3水平与GMT形成的变化趋势呈线性关系。Kaplan-Meier生存曲线表明两组患者在尿蛋白完全缓解(Log-rankχ^2=5.858,P=0.016)及血肌酐翻倍或进展至终末期肾病(Log-rankχ^2=3.945,P=0.047)方面的差异存在统计学意义。结论:LN患者血清C3水平与GMT形成密切相关,GMT组与非GMT组患者的肾脏预后差异存在统计学意义。

Objective To investigate the correlation between serum C3 and glomerular microthrombosis in patients with lupus nephritis(LN).Methods Patients who were diagnosed as LN by renal biopsy hospitalized in Department of Nephrology,the First Affiliated Hospital of Shenzhen University from January 2010 to February 2019 were retrospectively analyzed and they were divided into glomerular microthrombosis group(GMT group)and non-glomerular microthrombosis group(non-GMT group).The demographic data,clinical characteristics,pathology and prognosis of the two groups were compared.Logistic regression and smooth curve fitting of generalized additive mixed model analysis were used to explore the correlation between serum C3 and glomerular microthrombosis.Renal prognosis of the two groups were compared by the Kaplan-Meier survival curve.Results A total of 116 patients were enrolled,aged(32.79±11.43)years old,in which 108 cases(93.10%)were female.Thirty-seven patients(31.90%)were confirmed to be combined with GMT(GMT group)and 79 cases were not(non-GMT group).Compared with the non-GMT group,patients in the GMT group were relatively older(t=-2.876,P=0.002),with higher proportion of hypertension(χ^2=7.492,P=0.006),higher urine protein quantitation(Z=-2.115,P=0.003),lower levels of eGFR and serum complement C3(Z=3.469,P<0.001;t=1.744,P<0.001),higher systemic lupus erythematosus disease activity index(t=-2.758,P=0.007).As to the pathological characteristics,type IV LN patients were the majority(72.97%).Proportion of crescents and pathological activity indicators of the GMT group were higher(Z=-1.866,P=0.002;t=-5.005,P<0.001),nuclear fragmentation,endothelial hyperplasia and renal tubular atrophy were more serious(χ^2=14.987,P<0.001;χ^2=15.695,P<0.001;χ^2=4.130,P=0.042).Multivariate logistic regression analysis indicated that serum complement C3 was a relational factor of the formation of GMT in LN patients(OR=0.966,95%CI 0.938-0.995,P=0.023).Smooth curve fitting of generalized additive mixed model analysis indicated that level of complement C3 had a linear relationship with the changing trend of GMT.The Kaplan-Meier curve showed that there were statistical differences between the two groups in terms of complete remission of urine protein(Log-rankχ^2=5.858,P=0.016)and doubled serum creatinine/end-stage renal disease(Log-rankχ^2=3.945,P=0.047).Conclusions Serum C3 is closely related to the formation of GMT in LN patients,and statistical differences were demonstrated in the renal prognosis of GMT group and non-GMT group.