Toll样受体9在狼疮肾炎患者外周血B淋巴细胞和肾组织中的表达及临床意义

目的 探讨Toll样受体9(TLR9)在狼疮肾炎(LN)患者外周血B淋巴细胞和肾组织的表达及其临床意义.方法 分别采用细胞内流式细胞术和免疫组织化学方法对对照组和LN患者外周血B淋巴细胞及肾组织中TLR9表达情况进行比较,并对TLR9表达与临床指标相关性进行分析.结果 活动期LN患者外周血CD19+B淋巴细胞TLR9的表达率高于非活动期LN患者及对照组(P＜0.01),且其表达率与SLE疾病活动指数(SLEDAI)评分、抗双链DNA(dsDNA)抗体滴度呈正相关(P＜0.01).LN患者肾组织中肾小球、肾小管间质TLR9表达均较健康组织增高(P＜0.01),其中国际肾脏病学会/肾脏病理学会(ISN/RPS)的Ⅳ型LN肾组织TLR9表达水平较Ⅱ、Ⅲ、Ⅴ型升高(P＜0.01),且肾小球TLR9表达水平与肾小球细胞增殖程度、肾脏病理活动指数、尿蛋白定量(24 h)呈正相关(P＜0.01).与估计的肾小球滤过率(eGFR)呈负相关(P＜0.01);肾小管间质TLR9表达水平与肾脏病理活动指数、肾小管问质损害程度、尿蛋白定量(24 h)也呈正相关(P＜0.01),与eGFR呈负相关(P＜0.01).结论 TLR9参与了LN患者B淋巴细胞的异常活化及肾脏病理损伤过程.     

狼疮肾炎281例临床病理分析

目的 探讨狼疮肾炎(LN)临床表现、实验室检查与肾脏病理改变的特点及其相关性.方法 根据LN的最新病理学分类标准,收集整理281例经肾活检确诊的LN患者的临床病理资料,分析其临床表现、实验室检查和肾脏病理改变及其相关性.结果 281例患者中,男:女为1∶9.7.临床表现以蛋白尿合并血尿(35.2%)、肾病综合征(33.8%)为主.病理表现以Ⅳ型(35.9%)、Ⅴ型(15.7%)占多数,Ⅲ+Ⅴ和Ⅳ+Ⅴ型亦较多,Ⅲ、Ⅳ、Ⅴ型共占总数的89.0%.临床表现为.肾病综合征者主要病理改变为Ⅳ型和Ⅴ型,合并肾功能不全者主要为Ⅵ型和Ⅳ型,单纯血尿者病理改变较轻.47例尿蛋白定量(24 h)少于1.0 g且肾功能正常者中Ⅳ、Ⅴ型合计占40.4%.尿蛋白定量(24 h)以Ⅴ型最高,血肌酐和抗双链DNA(dsDNA)抗体水平以Ⅵ型和Ⅳ型较高,血补体C3水平以Ⅳ型最低.尿蛋白定量(24 h)与血C3呈负相关、与血肌酐呈正相关;血C3与抗dsDNA抗体和肌酐呈负相关;血肌酐和抗dsDNA抗体呈正相关.结论 本组LN病理改变以Ⅲ、Ⅳ、Ⅴ型为主.临床表现与肾脏病理改变有一定相关性,但亦可能不符.某些实验室指标之间及与肾脏病理改变之间存在一定相关性.尿蛋白增多、血C3下降、抗dsDNA抗体升高提示LN的严重性和活动性.肾活检对LN的诊断以及病情判断意义重大.     

血清血管内皮生长因子及可溶性血管内皮生长因子受体1在系统性红斑狼疮患者中的表达及其意义

目的 研究血清中血管内皮生长因子(VEGF)及可溶性血管内皮生长因子受体1(sFlt-1)在活动期系统性红斑狼疮(SLE)及不同肾脏病理类型的狼疮肾炎(LN)患者中表达的意义. 方法 采用双抗体夹心酶联免疫吸附法(ELISA)对60例SLE患者及30名健康人血清中VEGF及sFlt-1的水平同时进行检测,结合临床资料及肾脏病理进行相关分析. 结果 活动期SLE患者血清VEGF及sFlt-1水平均明显升高;血清中VEGF/sFlt-1的比值健康对照组较活动期SLE、非活动期SLE及LN组患者降低(P＜0.01),Ⅴ型LN组该比值较Ⅱ、Ⅲ、Ⅳ型LN组升高(P＜0.05);血清sFlt-1的浓度与尿蛋白呈正相关(rs=0.6244,P＜0.01),血清VEGF的浓度与尿蛋白无明显相关(rs=0.1807,P＞0.05);血清sFlt-1的浓度与ESR正相关(rs=0.4235,P＜0.01),血清VEGF的浓度与ESR无明显相关(rs=0.0532,P＞0.05);血清VEGF及sFlt-1浓度与SLE疾病活动指数(SLEDAI)均呈正相关(rs=0.5046,P＜0.01,rs=0.5152,P＜0.01);血清VEGF浓度与肾组织活动指数(RAI)呈正相父(r=0.3386,P＜0.05),血清sFlt-1浓度与RAI无明显相关(rs=0.0240,P＞0.05);SLE患者中VEGF、sFlt-1水平与血压、血肌酐、尿素氮、C3、C4、C反应蛋白(CRP)无明显相关. 结论 血清VEGF及sFlt-1的水平可作为SLE病情活动评价指标,VEGF的高表达可能与增殖性肾小球病变相关,sFlt-1的表达与蛋白尿关系密切.     

抗核小体抗体与抗C1q抗体在狼疮肾炎血清的表达及其临床意义

目的探讨抗核小体抗体与抗C1q抗体在狼疮肾炎（lupus nephritis，LN）患者血清的表达及其临床意义。方法使用酶联免疫吸附试验（ELISA）对46例LN患者血清进行检测，并与31例无肾炎临床表现的SLE患者作对照。结果LN患者血清中抗核小体抗体与抗C1q抗体浓度及阳性率显著高于SLE对照组（P〈0．01）。抗双链DNA（dsDNA）抗体、抗Sm抗体、抗nRNP抗体、抗心磷脂（aCL）IgG抗体有较高的阳性率，与对照组相比差异有统计学意义（P〈0．05）。将抗核小体抗体、抗C1q抗体、抗dsDNA抗体、抗Sm抗体、抗nRNP抗体和aCLIgG抗体分别引入Logistic回归进行统计分析，结果显示入选的自变量包括抗核小体抗体、抗C1q抗体、抗dsDNA抗体（P〈0．05）。结论在LN患者中，存在着抗核小体抗体、抗C1q抗体的高表达。抗核小体抗体及抗C1q抗体在LN发病中起重要的作用。抗核小体抗体、抗C1q抗体、抗dsDNA抗体是反映SLE患者并发肾脏损害的重要指标，在LN诊断和判定其活动性方面有重要作用。     

狼疮肾炎肾小球微血栓形成及其与抗凝血相关因子抗体抗磷脂抗体的相关性研究

目的 评估肾小球微血栓(GMT)在狼疮肾炎(LN)中的发生率,并探讨针对某些凝血相关因子的抗体和抗磷脂抗体在LN患者GMT形成中的临床意义.方法 连续收集124例LN患者肾活检组织标本和血浆,观察组织标本中GMT的发生率.并分成LN-GMT组和LN-non-GMT组;比较两组患者的疾病活动度、相关实验室检查指标和肾组织活动,慢性指数;测定患者的狼疮抗凝物(LA)、抗心磷脂抗体(ACL)、抗β2糖蛋白I(抗β2GP I)抗体、抗凝血酶抗体、抗纤溶酶抗体、抗组织型纤溶酶原激活物(t-PA)抗体和抗膜联蛋白AⅡ(Annexin A II)抗体.结果 GMT在LN中的发生率约为20.2%;LN-GMT组系统性红斑狼疮疾病活动指数(SLEDAI)、肾组织病变活动指数、肾组织病变慢性指数、尿蛋白定量(24 h)、血清肌酐、血清尿素氮的水平和高血压的发生率都较LN-non-GMT组高(P＜0.01);LN-GMT组LA、IgG型抗B2GP I抗体和抗凝血酶抗体阳性率均显著高于LN-non-GMT组(P＜0.05);两组IgG型ACL抗体、抗纤溶酶抗体、抗t-PA抗体和抗Annexin A II抗体阳性率差异均无统计学意义(P＞0.05);两组各抗体IgM型差异无统计学意义(P＞0.05).结论 LN中伴有GMT形成的患者肾脏病变重于无GMT者;LA、IgG型抗β2GP I抗体和抗凝血酶抗体与LN患者GMT形成相关.     

三种自身抗体联合检测对狼疮疾病活动和狼疮肾炎的价值

目的探讨联合检测抗C1q抗体、抗核小体抗体(AnuA)和抗dsDNA抗体对狼疮活动和狼疮肾炎(LN)的价值。方法 90例系统性红斑狼疮(SLE)分为疾病活动和疾病稳定组、LN和非LN组, 酶联免疫吸附试验(ELISA)检测血清抗C1q抗体和AnuA水平,间接免疫荧光法比较三抗体单个和联合对疾病活动和LN的价值。结果抗C1q抗体、AnuA和抗dsDNA抗体阳性对疾病活动的敏感性分别为 71．4％、75．0％和66．1％,特异性分别为75．5％、70．6％和88．2％;抗dsDNA抗体阴性患者分别有36．7％抗 C1q抗体阳性和26．5％AnuA阳性。疾病活动组三抗体阳性率和抗体水平显著高于疾病稳定组;三抗体与 SLE疾病活动指数(SLEDAI)、血沉(ESR)、IgG、球蛋白水平显著正相关,与C3、C4及白蛋白水平显著负相关。LN组三抗体水平显著高于非LN组。结论三抗体都是狼疮疾病活动的指标,都与LN有关,联合检测可以提高疾病活动检出率。     

儿童狼疮肾炎肾脏组蛋白(核小体)检测意义

目的通过检测狼疮肾炎(LN)患儿肾脏中的组蛋白,探讨核小体在儿童LN肾脏中的沉积及可能的意义。方法用间接免疫荧光法检测27例LN患儿、10例正常对照肾组织冰冻切片中组蛋白和抗IgG抗体的沉积,同时用酶联免疫吸附测定法检测LN患儿血清抗双链DNA(dsDNA)、抗组蛋白及抗核小体抗体。结果 27例LN患儿中,21例肾脏组蛋白染色阳性(病理分类Ⅱ型1例、Ⅲ型3例、Ⅳ型14例、Ⅴ型3例),不同病理类型间组蛋白的染色强度差异无统计学意义(H=8.71,P>0.05),染色部位主要分布于系膜区和基底膜,对照者肾组织组蛋白染色均为阴性。21例肾脏组蛋白染色阳性LN患儿中,1例肾脏抗IgG抗体染色阴性;其余6例肾脏组蛋白染色阴性患儿肾脏抗IgG抗体染色均为阳性。27例LN患儿血清中均存在不同程度的抗dsDNA、抗组蛋白和抗核小体抗体。结论组蛋白(核小体)在肾脏沉积与儿童LN发病有关。但LN的发病机制复杂,组蛋白(核小体)介导的免疫复合物沉积并非唯一的致病机制。     

狼疮肾炎肾组织核转录因子-κB单核细胞趋化因子-1与CD68的表达及相关分析

目的 对狼疮肾炎(LN)肾组织进行核转录因子-κB(NF-κB)、单核细胞趋化因子(MCP-1)及巨噬细胞特异性抗体(CD68)检测,探讨其与LN肾脏病理及临床指标的关系.方法 应用免疫组织化学二步法检测49例LN肾组织NF-κB、MCP-1及CD68,原位杂交法检测49例LN肾组织NF-κB,并与肾脏病理及临床指标进行分析.结果 ①LN肾组织中NF-κB、MCP-1及CD68表达均比对照组显著升高(P＜0.01);其中Ⅳ型LN肾组织中NF-κB、MCP-1及CD68的表达比非Ⅳ型LN及对照组明显增加(P＜0.01,P＜0.05).原位杂交与免疫组织化学法检测NF-κB差异无统计学意义(P＞0.05).②LN肾组织中,NF-κB的表达与肾组织活动性指数、尿蛋白定量(24 h)及血清肌酐均高于对照组,且三者之间差异有统计学意义(P＜0.01,P＜0.01,P＜0.05);MCP-1与CD68的表达在肾小球和肾小管中仅与肾组织活动性指数(r=0.447,0.532,P＜0.05)、尿蛋白定量(24 h)(r=0.357,0.368,P＜0.05)呈正相关,而与血肌酐之间差异无统计学意义(P＞0.05).结论 NF-κB通过活化MCP-1进一步诱导巨噬细胞可能是LN肾脏损害的原因之一,NF-κB信号途径有望成为抑制巨噬细胞在肾脏局部浸润和增生的一个新的治疗靶点.     

系统性红斑狼疮患者磷脂酶C-γ1与磷脂酶C-γ2表达的研究

目的 探讨系统性红斑狼疮(SLE)患者外周血单个核细胞(PBMCs)中磷脂酶C-γ1、磷脂酶C -γ2的表达水平及其与SLE疾病活动性的相关性.方法 运用半定量聚合酶链反应(RT-PCR)法,检测30例SLE患者与25名健康对照人的磷脂酶C-γ1与磷脂酶C-γ2 mRNA表达水平,并采用Pearson相关性检验分析它们与补体C3、C4、抗双链DNA (dsDNA)抗体及SLE疾病活动指数(SLEDAI)积分的相关性.结果 ①SLE组与健康对照组相比,磷脂酶C-γ1与磷脂酶C-γ2 mRNA表达显著增高(分别为P＜0.01);②磷脂酶C-γ1与磷脂酶C-γ2 mRNA表达水平之间呈正相关(r=0.726,P＜0.01);③SLE组磷脂酶C-γ1 mRNA表达水平与补体C3、C4、抗dsDNA抗体均无相关性,而与SLEDAI积分呈正相关(r=0.002,P＜0.05).磷脂酶C-γ2与补体C3、C4呈显著负相关(r=-0.914,P＜0.01;r=-0.829,P＜0.05),与抗dsDNA抗体正相关(r=0.171,P＜0.05),与SLEDAI积分相关性不明显.结论 本研究发现SLE患者磷脂酶C-γ1与磷脂酶C-γ2的表达水平在SLE患者中增高,磷脂酶C-γ1与SLEDAI积分呈正相关,磷脂酶C-γ2与补体C3、C4呈负相关,与抗dsDNA抗体正相关,可能对SLE患者的诊断和病情评估有较大价值.     

血清C1q抗体水平与系统性红斑狼疮活动性和狼疮肾炎的关系

目的分析探讨血清C1q抗体水平与系统性红斑狼疮（SLE）活动性以及狼疮肾炎之间的关系。方法采用ELISA方法检测92例SLE患者C1q抗体水平。并与其他SLE活动性指标进行相关分析。结果SLE患者C1q抗体阳性率为67.4%。活动性狼疮组的C1q抗体阳性率及C1q抗体水平显著高于非活动性狼疮组（P〈0.001）。活动性狼疮肾炎组C1q抗体阳性率（P〈0.05）和C1q抗体水平（P〈0.01）显著高于非活动性狼疮肾炎组。联合抗dsDNA抗体检测,没有1例活动性狼疮肾炎患者的C1q抗体和抗dsDNA抗体同时阴性。结论血清C1q抗体与狼疮活动以及活动性狼疮肾炎关系密切,C1q抗体的检测有助于活动性狼疮的诊断,联合抗dsDNA抗体的检测是活动性狼疮肾炎的特异性检测指标。     

Anti-C1q antibodies and antiendothelial cell antibodies in systemic lupus erythematosus – relationship with disease activity and renal involvement

The aim of this study was to investigate the relationship between the presence and titre of antibodies against C1q (anti-C1q Ab) and disease activity and renal involvement in patients with systemic lupus erythematosus (SLE). Anti-C1q Ab were measured in 79 patients with SLE (70 women and 9 men; mean age 41.7 years; mean disease duration 8.4 years): 19 patients had active disease with lupus nephritis, 8 active disease without nephritis, 26 inactive disease with nephritis and 26 inactive disease without nephritis. Anti-dsDNA antibodies (EIA and immunofluorescence), antiendothelial cell antibodies (AECA) and complement levels (C3, C4, total haemolytic complement activity) were determined in parallel. Anti-C1q Ab were positive in 49%, anti-dsDNA Ab in 61% and AECA in 19% of the patients, respectively. Significantly higher titres of anti-C1q Ab were found in patients with active disease compared with those with inactive SLE (P < 0.01). Serum levels of anti-C1q Ab showed a positive correlation with anti-dsDNA Ab and SLEDAI score (P < 0.01) and a negative correlation with C3 (P < 0.05), C4 (P < 0.01) and CH50U (P < 0.01). The presence of anti-C1q Ab was not different between patients with or without nephritis. In patients with (P < 0.05) and without nephritis (P < 0.01) the frequency of anti-C1q Ab was significantly higher in active patients compared with inactive patients. Both anti-C1q and anti-ds-DNA Ab were detectable in 74% of patients with active nephritis but only in 30% of all other patients (P=0.001). None of the patients with active nephritis was negative for anti-C1q and anti-dsDNA Ab, whereas 37% of the patients without active nephritis were negative for both antibodies (P < 0.01). Sensitivity, specificity, positive and negative predictive values for active lupus nephritis among SLE patients were 100%, 50%, 51.9% and 100% for anti-dsDNA Ab (EIA) and 74%, 70%, 57% and 89.4% for positive findings of both anti-dsDNA and anti-C1q Ab. The presence and titre of anti-C1q-Ab in SLE are related to disease activity. Absence of anti-dsDNA Ab excludes active nephritis; positive findings of both anti-dsDNA Ab and anti-C1q Ab are of relatively high specificity for active nephritis.     

抗C1q抗体与系统性红斑狼疮疾病活动及狼疮肾炎的关系

目的研究抗C1q抗体与系统性红斑狼疮（systemic lupus erythematosus,SLE）疾病活动及肾损害的相关性。方法使用ELISA法测定93例初诊SLE患者和69例其他风湿性疾病患者及32名健康对照者血清中抗C1q抗体的浓度。同时记录SLE疾病活动指数（systemic lupus erythematosus Disease Activity Index,SLEDAI）、自身抗体和相关实验室指标。结果血清抗C1q抗体、抗dsDNA抗体、抗核小体抗体（anti-nucleosome antibodies,AnuA）,SLE组的阳性率分别为40.9%、62.4%和62.8%。血清抗C1q抗体阳性组患者的肾损害发生率（84.2%）明显高于阴性组（23.6%）。狼疮肾炎（lupus nephritis,LN）患者血清抗C1q抗体浓度（55.36±51.96）RU/ml及阳性率（71.1%）显著高于无肾炎表现的狼疮对照组（12.09±14.46）RU/ml,12.5%。无论患者有无肾损害,狼疮疾病活动患者抗C1q抗体浓度（62.46±50.29）RU/ml及阳性率（85.7%）显著高于疾病稳定的狼疮对照组（8.79±6.42）RU/ml,3.9%。而AnuA和抗dsDNA抗体只在伴有狼疮肾损害的疾病活动组即活动LN的阳性率（87.9%与50.0%）显著高于非活动LN对照组（66.7%与33.3%）。LN组抗C1q抗体、AnuA、抗dsDNA和抗Sm（Smith）抗体阳性率显著高于非LN组（71.1%与12.5%）,（77.8%与47.9%）,（57.8%与25.0%）,（31.1%与10.4%）。SLE疾病活动组抗C1q抗体、AnuA、抗dsDNA阳性率显著高于疾病稳定组（85.7%与3.9%）,（88.1%与41.2%）,（61.9%与17.6%）。活动LN抗C1q抗体、AnuA、抗dsDNA阳性率显著高于非活动LN（93.9%与8.3%）,（87.9%与50.0%）,（66.7%与33.3%）。活动LN组抗C1q抗体、AnuA、抗dsDNA及抗中性粒细胞胞质抗体（ANCA）阳性率显著高于其他SLE组（93.9%与13.1%）,（87.9%与48.3%）,（66.7%与26.7%）,（43.5%与8.5%）。结论血清抗C1q抗体能够反映SLE的疾病活动,并与SLE肾损害相关,是对活动性LN敏感的自身抗体。     

Association between ongoing anti-C1q antibody production in peripheral blood and proliferative nephritis in patients with active systemic lupus erythematosus

The aim of this study was to compare ongoing production of anti-C1q antibodies (anti-C1q) in peripheral blood with serum anti-C1q levels in patients with systemic lupus erythematosus (SLE), especially in patients with nephritis. Using the ELISPOT technique for the detection of IgG and IgA anti-C1q production, 21 patients with active SLE were investigated. ELISAs for IgG and IgA anti-C1q were compared with the ELISPOT results. Six of the patients were found to have proliferative nephritis (WHO grade III/IV) confirmed by renal biopsy. High numbers of IgG anti-C1q spot-forming cells (SFC), defined as > 20/10(5) plated peripheral blood mononuclear cells (PBMC), were exclusively observed in patients with proliferative nephritis (P < 0.0001). Serum levels of IgG anti-C1q were significantly increased in patients with proliferative nephritis (P = 0.039). High ongoing IgG anti-C1q production was observed in all patients with proliferative nephritis, which may be a contributory factor in the pathogenesis of this disorder. The detection of IgG anti-C1q production may be valuable in the clinical investigation of patients with suspected SLE nephritis.      

Anti-C1q antibodies in nephritis: correlation between titres and renal disease activity and positive predictive value in systemic lupus erythematosus

OBJECTIVE: To investigate antibodies to complement 1q (anti-C1q) and investigate the correlation between anti-C1q titres and renal disease in systemic lupus erythematosus (SLE). METHODS: 151 SLE patients were studied. In patients with biopsy proven lupus nephritis (n = 77), activity of renal disease was categorised according to the BILAG renal score. Sera were tested for anti-C1q by enzyme immunoassay. Serum samples were randomly selected from 83 SLE patients who had no history of renal disease, and the positive and negative predictive value of the antibodies was studied. RESULTS: Patients with active lupus nephritis (BILAG A or B) had a higher prevalence of anti-C1q than those with no renal disease (74% v 32%; relative risk (RR) = 2.3 (95% confidence interval, 1.6 to 3.3)) (p<0.0001). There was no significant difference in anti-C1q prevalence between SLE without nephritis and SLE with non-active nephritis (BILAG C or D) (32% v 53%, p = 0.06) or between active and non-active nephritis (74% v 53%, p = 0.06). Patients with nephritis had higher anti-C1q levels than those without nephritis (36.0 U/ml (range 4.9 to 401.0) v 7.3 U/ml (4.9 to 401.0)) (p<0.001). Anti-C1q were found in 33 of 83 patients (39%) without history of renal disease. Nine of the 33 patients with anti-C1q developed lupus nephritis. The median renal disease-free interval was nine months. One patient with positive anti-C1q was diagnosed as having hypocomplementaemic urticarial vasculitis syndrome during follow up. CONCLUSIONS: Anti-C1q in SLE are associated with renal involvement. Monitoring anti-C1q and their titres in SLE patients could be important for predicting renal flares.     

血中透明质酸浓度变化对狼疮肾炎活动的评价意义

目的　探讨血中透明质酸 (HA)变化对狼疮肾炎活动度的评价。方法　对 30例狼疮肾炎患者作肾活检并按病理组织学分析计算狼疮活动积分 ,用放射免疫分析法测定血中HA浓度 ,分析狼疮肾炎组HA浓度变化与肾脏狼疮活动积分高低的相关性 ,并对比研究 5 4例慢性肾小球肾炎病人的血清HA变化。结果　狼疮肾炎患者血中HA浓度与狼疮活动度呈明显正相关 (P <0 0 0 1) ,狼疮活动控制后血中HA明显下降 (P <0 0 1) ,狼疮性肾炎组HA浓度明显高于慢性肾炎组。结论　测定血中HA浓度可作为评估狼疮活动的指标之一。     

补体C1q及抗C1q抗体与系统性红斑狼疮及狼疮肾炎相关性的研究

目的 检测系统性红斑狼疮（SLE）患者血清补体C1q及抗C1q抗体（C1qAb）水平，比较血清C1q与C1qAb之间的相关性；分析血清C1q及C1qAb水平与SLE、狼疮肾炎（LN）以及SLE病情活动的相关性。方法 采用单向免疫扩散法（SRID）检测血清C1q，酶联免疫吸附法（ELISA）检测血清C1qAb。结果 SLE患者的血清C1q水平显著低于其他对照组，而血清C1qAb水平显著高于其他对照组。其中LN患者的血清C1q水平显著低于非LN的SLE患者、血清C1qAb水平显著高于非LN的SLE患者。SLE患者血清C1qAb与C1q之间呈显著负相关。病情活动期的SLE患者血清C1q水平显著低于稳定期患者；血清C1qAb水平显著高于稳定期患者。结论 血清C1q的降低及血清C1qAb的升高与SLE相关。血清C1qAb的升高，可能是导致血清C1q降低的主要原因之一。血清C1q、C1qAb水平与SLE患者肾脏损害显著相关。血清C1q、C1qAb水平与病情活动显著相关。     

Relationship of Circulating Anti-C3b and Anti-C1q IgG to Lupus Nephritis and Its Flare

Background and objectives

Autoantibodies to complement C1q (anti-C1q) are associated with the diagnosis of lupus nephritis. In this study, we compare anti-C1q IgG with another complement autoantibody, anti-C3b IgG, as a biomarker of lupus nephritis and lupus nephritis flare.

Design, setting, participants, & measurements

Our investigation involved the Ohio SLE Study, a prospective observational cohort of patients with recurrently active lupus who were followed bimonthly. Serum anti-C1q and anti-C3b IgG levels were assessed cross-sectionally by ELISA in 40 normal controls and 114 patients in the Ohio SLE Study (41 nonrenal and 73 lupus nephritis) at study entry, and longitudinally in a subset of patients in the Ohio SLE Study with anti-C1q–positive lupus nephritis in samples collected every 2 months for 8 months leading up to lupus nephritis flare (n=16 patients).

Results

In the cross-sectional analysis, compared with anti-C1q IgG, anti-C3b IgG was less sensitive (36% versus 63%) but more specific (98% versus 71%) for lupus nephritis. Only anti-C3b IgG was associated with patients with lupus nephritis who experienced at least one lupus nephritis flare during the Ohio SLE Study period (P<0.01). In the longitudinal analysis, circulating levels of anti-C1q IgG increased at the time of lupus nephritis flare only in patients who were anti-C3b positive (P=0.02), with significant increases occurring from 6 (38% increase) and 4 months (41% increase) before flare. Anti-C3b IgG levels also trended up at lupus nephritis flare, although the change did not reach statistical significance (P=0.07). Neither autoantibody increased 2 months before flare.

Conclusions

Although not as prevalent as anti-C1q IgG, anti-C3b IgG showed nearly complete specificity for lupus nephritis. The presence of anti-C3b IgG identified patients with lupus nephritis who were prone to flare and in whom serial measurements of markers associated with complement, such as anti-C1q IgG, may be useful to monitor lupus nephritis activity.