血清IgA/C3对IgA肾病诊断及治疗预后的意义

Significance of serum IgA/C3 ratio in the diagnosis and prognosis of IgA nephropathy

目的研究血清IgA/C3比值对IgA肾病(IgAN)的诊断与其他肾小球疾病鉴别诊断的意义,以及IgAN患者治疗前后IgA/C3的变化情况。方法收集汕头大学附属第二医院和中山大学附属第六医院2013年1月至2017年12月间初治的肾脏病理诊断结果为IgAN、原发非IgA肾小球疾病(原发非IgAN)及继发肾小球疾病的IgA、C3及相关实验室检查结果,分析IgAN与其他相关肾小球疾病IgA/C3的差异性以及IgAN治疗前后IgA/C3的变化情况。结果(1)IgAN的IgA/C3为3.0±1.3,原发非IgAN的IgA/C3为1.9±0.8,LN的IgA/C3为6.9±4.9,IgANvs原发非IgAN(P<0.01),IgANvsLN(P<0.01),差异有统计学意义。(2)原发非IgAN亚类疾病的IgA/C3,微小病变性肾病为1.9±0.8,膜性肾病为1.9±0.8,局灶节段性肾小球硬化为2.1±0.5,3组疾病与IgAN的IgA/C3比较,IgANvs微小病变性肾病(P<0.01),IgANvs膜性肾病(P<0.01),IgANvs局灶节段性肾小球硬化(P<0.01),差异有统计学意义。(3)多因素回归分析得出IgA/C3是IgAN在原发肾小球疾病组中发病的重要危险因素(OR=2.509,95%CI1.196~5.262,P=0.015)。(4)IgAN透析患者IgA/C3vs原发非IgAN透析患者IgA/C3[(3.7±1.8)vs(1.8±0.6),t=2.855,P=0.011],IgAN透析患者IgA/C3vs原发非IgAN非透析患者IgA/C3[(3.7±1.8)vs(1.9±0.8),t=3.412,P=0.005],差异有统计学意义。(5)IgAN组与原发非IgAN组IgA/C3的ROC曲线诊断分析中,IgA/C3≥2.106时可诊断为IgAN,曲线下面积为0.775(P<0.01)。(6)随访的43例IgAN患者中有37例经治疗后24h尿蛋白定量缓解,治疗前(尿蛋白未缓解)IgA/C3vs治疗后(尿蛋白缓解)IgA/C3为(3.1±1.1)vs(2.3±0.9),差异有统计学意义(t=3.506,P=0.001)。结论IgA/C3比值在原发肾小球疾病中对IgAN具有诊断及鉴别诊断意义,且治疗后IgA/C3比值降低是IgAN患者病情好转的预测因子。

Objective To study the significance of serum IgA/C3 ratio in the diagnosis of IgA nephropathy (IgAN) and differential diagnosis of other non-IgAN glomerular diseases,and the changes of IgA/C3 ratio in patients with IgAN before and after treatment.Methods The results of serum IgA,C3 and related laboratory tests from patients treated preliminarily in the Second Affiliated Hospital of Shantou University and the Sixth Affiliated Hospital of Sun Yat-sen University from January.2013 to December.2017,whose were diagnosed with IgAN or primary non-IgAN or secondary glomerular diseases,were collected.The differences of the serum IgA/C3 ratio between IgAN and other related glomerular diseases and the IgA/C3 changes before and after treatment were analyzed.Results (1)The serum IgA/C3 ratio for IgAN,primary non-IgANand LN were 3.0±1.3,1.9±0.8 and 6.9±4.9,respectively,with statistical significance of the differences of IgAN vs primary non-IgAN(P<0.01)and vs LN (P<0.01).(2) The serum IgA/C3 ratios for the primary non-IgAN subgroups minimal change nephritis(MCD),membranous nephropathy(MN) and focal segmental glomerulosclerosis(FSGS) were 1.9 ±0.8,1.9 ± 0.8 and 2.1±0.5,respectively.There was statistically significant difference of IgAN vs MCD(P<0.01),vs MN (P<0.01) and vs FSGS IgAN (P<0.01).(3)By multivariate regression analysis,IgA/C3 ratio ( OR =2.509,95% CI 1.196~5.262,P = 0.015 ) could be regard as an important risk factor for patients to suffer IgA Ninthe primary glomerular disease group.(4) The serum IgA/C3 ratio sexhibited statistically significant difference of IgAN + dialysis vs non-IgAN +dialysis[(3.7±1.8 vs (1.8±0.6),P =0.011] and vs non-IgAN + non-dialysis[(3.7±1.8) vs (1.9±0.8),P =0.005].(5) In the ROC curve diagnosis for IgAN and primary non-IgAN diseases,the cut point of the serum IgA/C3 ratio was equal to or greater than 2.106 or greater with the area under the curve of 0.775 (P<0.01),which assisted to distinguish IgAN with other primary glomerular disease.(6) Among 43 IgAN patients who were followed up,37 ones acquired remission in proteinuria 24 hours after treatment.The serum IgA/C3 ratios before treatment(with proteinuria remission) and after treatment (without proteinuria remission) were (3.1± 1.1 ) vs (2.3±0.9),with difference of statistical significance( t =3.506,P =0.001).Conclusions The serum IgA/C3 ratio is of significance in the diagnosis and differential diagnosis of IgAN among primary glomerular diseases,and the decrease of the ratio maybe a positive factor for prognosis of IgAN.