增殖性狼疮肾炎患者血红蛋白与肾功能进展的关系

Correlation between hemoglobin and progression of renal function in patients with proliferative lupus nephritis

目的探究增殖性狼疮肾炎(proliferative lupus nephritis,PLN)患者血红蛋白(hemoglobin,Hb)与肾功能进展之间的关系。方法回顾性分析2010年1月至2019年2月于深圳大学第一附属医院肾内科住院经肾活检明确的PLN患者资料,据随访期间患者是否进展至血肌酐倍增/终末期肾病(end⁃stage renal disease,ESRD)分为肾功能稳定组和肾功能进展组,分别对两组患者的人口学资料、临床病理特点进行比较。采用Cox回归分析及广义相加模型平滑曲线拟合等方式探讨Hb与肾功能进展的相关性。结果纳入PLN患者87例,年龄(34.97±11.95)岁,女性79例(90.80%),中位随访19.0(6.5,43.5)个月,其中15例(17.24%)出现肾功能进展。与肾功能稳定组相比,肾功能进展组患者Hb水平相对较低(t=3.887,P<0.001),基线血肌酐(Z=-2.466,P=0.003)、血尿酸(t=-2.154,P=0.034)水平较高。肾组织病理分型中,肾功能进展组患者狼疮肾炎IV型比例,伴肾小管萎缩、间质纤维化比例均高于肾功能稳定组,但两组间的差异均无统计学意义(均P>0.05)。多因素Cox回归分析提示,高Hb水平是PLN患者出现血肌酐倍增/ESRD的独立保护因素(HR=0.893,95%CI 0.836~0.954,P=0.001),Hb每升高1个单位(g/L),出现血肌酐倍增/ESRD的风险下降10.7%。广义相加模型平滑曲线拟合结果表明Hb水平与血肌酐倍增/ESRD发生风险的变化趋势呈线性相关(对数似然比检验,P=0.100)。受试者工作特征曲线分析提示将Hb水平控制在77 g/L以上,PLN患者中出现血肌酐倍增/ESRD的风险相对较低(曲线下面积为0.788,临界点为77 g/L,敏感度为0.600,特异度为0.903)。结论Hb与PLN患者肾功能进展密切相关,提高对PLN患者Hb水平的关注和处理对改善肾脏预后可能具有重要作用。

Objective To explore the correlation between hemoglobin(Hb)and progression of renal function in patients with proliferative lupus nephritis(PLN).Methods Data of biopsy⁃proven PLN patients from January 2010 to February 2019 in Department of Nephrology,the First Affiliated Hospital of Shenzhen University were retrospectively analyzed.The patients were divided into stable renal function group and renal function progression group according to changes of renal function including serum creatinine doubling/end⁃stage renal disease(ESRD)and the demographic,clinical,and pathological characteristics were compared between the two groups.Cox regression and smooth curve fitting of generalized additive model analysis were used to explore the correlation between Hb and progression of renal function.Results A total of 87 patients were included in this study.The age was(34.97±11.95)years old and 79 cases(90.80%)were females.During follow⁃up of 19.0(6.5,43.5)months,renal function of 15 patients(17.24%)progressed.Compared with stable renal function group,Hb level of patients in renal function progression group were lower(t=3.887,P<0.001),and serum creatinine(Z=-2.466,P=0.003)and uric acid(t=-2.154,P=0.034)were higher.As to the pathological characteristics,the proportion of class lupus nephritis⁃IV,renal tubular atrophy and interstitial fibrosis in renal function progression group were higher than those in stable renal function group,but there was no statistical difference between the two groups(all P>0.05).Multivariate Cox regression analysis indicated that high Hb was an independent protective factor of renal function progression in PLN patients(HR=0.893,95%CI 0.836-0.954,P=0.001).The risk of progression to serum creatinine doubling/ESRD would decrease by 10.7%when Hb increased by 1 unit(g/L).Smooth curve fitting of generalized additive model analysis showed that Hb was linearly correlated with the risk of renal function progression(P=0.100).Receiver operating characteristic curve indicated that the risk of doubling serum creatinine/ESRD in PLN patients would be relatively low when Hb level was above 77 g/L(area under the curve 0.788,best threshold 77 g/L,sensitivity 0.600,specificity 0.903).Conclusions Hb is closely related to progression of renal function in patients with PLN.More attention and management of Hb levels in patients with PLN can play an important role in improving renal prognosis.