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。     

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。     

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。     

系统性红斑狼疮血清抗核小体抗体水平及意义的探讨

目的 研究抗核小体抗体(AnuA)在系统性红斑狼疮(systemic lupus erythematosus，SLE)患者血清中的水平及其相关影响因素，探讨AnuA在SLE诊治中的作用和意义。方法 采用酶联免疫吸附法(EUSA)测定120例初诊SLE患者、55例其他风湿性疾病和30名健康对照血清中AnuA水平。同时记录各种临床表现，检测并分析其治疗前的其他自身抗体和实验室指标。结果 自身抗体在SLE及其他风湿病对照组的阳性率分别为AnuA56％和7％，抗dsDNA抗体35％和1％，抗Sm抗体24％和0。AnuA与SLE患者性别、年龄、病程无相关性，对sLE的诊断敏感性和特异性分别为55．8％、9513％，对狼疮肾炎(1upus nephritis，LN)的诊断敏感性和特异性分别为77．％、64．5%。AnuA与肝脏损害和疾病活动呈线性相关(t=3．152，2．171，P＜O．05)。AnuA分别与抗dsDNA、抗Sm联合检测对SLE诊断敏感性提高27％、40％（X^2值分别为38．930、18．161，P＜O．01)。结论AnuA在SLE血清中水平显著增高，AnuA测定是SLE诊断和治疗监测中有价值的新的实验室检测指标之一，与抗dsDNA抗体联合检测可提高诊断SLE、LN的敏感性和特异性。     

抗核小体抗体测定在系统性红斑狼疮诊断中的意义

目的　评价抗核小体抗体 (AnuA)对系统性红斑狼疮 (SLE)诊断的敏感性和特异性 ,并了解其与SLE活动性的关系及与其他自身抗体的关系。方法　用酶联免疫吸附 (ELISA)测定方法检测SLE患者、疾病对照组 (包括原发性干燥综合征、多发性肌炎、皮肌炎、系统性硬化症 )和正常对照组血清中的AnuA ,并记录SLE患者的各种临床表现及实验室指标 ,分析其与AnuA的关系。结果　 10 3例SLE患者中 6 9 9%血清AnuA阳性 ,6 6例疾病对照组仅 3 0 %阳性 ,30名正常对照组全部阴性 ;SLE组患者AnuA阳性率显著高于疾病对照组和正常对照组 (P <0 0 1) ,AnuA在SLE中检测的敏感性和特异性分别为 6 9 9%和 97 9%。AnuA阳性组的SLE患者肾损害、皮肤损害的发生率(6 1 1%、70 8% )明显高于AnuA阴性组 (2 9 0 %、32 3% ) (P <0 0 5 ) ;AnuA阳性组与AnuA阴性组相比 ,在年龄、性别、病程上差异无显著性 (P >0 0 5 )。AnuA滴度的高低与SLE患者的SLEDAI评分有明显相关性 (r=0 2 82 ,P <0 0 5 )。抗dsDNA抗体、抗Sm抗体、快速狼疮因子 (DNP)、抗组蛋白抗体 (AHA)阴性的SLE患者AnuA的阳性率分别为 6 5 6 %、6 8 0 %、6 3 9%、6 4 1%。结论　AnuA对SLE诊断的敏感性高、特异性强 ;它与SLE疾病活动性密切相关 ,对抗dsDNA抗体、Sm、DNP及AHA     

自身抗体联合检测在系统性红斑狼疮诊断中的意义

目的研究抗细胞膜DNA(cmDNA)抗体、抗核小体抗体(AnuA)、抗脱氧核糖核蛋白(DNP)抗体及抗双链DNA(dsDNA)抗体等特异性抗体在系统性红斑狼疮(SLE)诊断中的意义,并与抗核抗体(ANA)的敏感性和特异性进行比较。了解特异性自身抗体联合检测在SLE的诊断及临床应用中的意义。方法测定了125例SLE及118例疾病对照组(包括原发性干燥综合征、多发肌炎、系统性硬化症、未分化结缔组织病、类风湿关节炎、骨关节炎、强直性脊柱炎及银屑病关节炎)患者血清中的自身抗体。利用间接免疫荧光法测定抗cmDNA抗体和ANA,酶联免疫吸附试验(ELISA)测定AnuA、乳凝法检测抗DNP抗体、金标法测定抗dsDNA抗体。结果AnuA、抗cmDNA抗体、抗DNP抗体、抗dsDNA抗体和ANA在SLE患者中的阳性率分别为68%、38.4%、51.2%、49.6%和95.2%,均明显高于疾病对照组(3.4%、4.2%、1.7%、0.8%和25.4%),差异有统计学意义(P<0.001)。ANA与AnuA的敏感性显著高于其他三种抗体,差异有统计学意义(P<0.05);AnuA、抗cmDNA抗体、抗DNP抗体、抗dsDNA抗体和ANA的特异性分别为95.8%、96.6%、98.3%、99.2%和74.6%;AnuA在抗DNP抗体、抗dsDNA抗体阴性的SLE中的阳性率明显高于其他抗体(P<0.05);自身抗体的联合检测可提高SLE诊断的敏感性,但特异性无明显改变。结论抗cmDNA抗     

抗核小体抗体、抗双链DNA抗体和抗超敏双链DNA抗体与系统性红斑狼疮的相关性研究

目的 通过检测系统性红斑狼疮(SLE)患者血清中抗核小体抗体(AnuA)、抗双链DNA (dsDNA)抗体和抗超敏双链DNA (dsDNA-NcX)抗体的水平,分析其在SLE患者中的敏感性、特异性及与其他实验室指标的相关性.方法 采用酶联免疫吸附试验(ELISA)法分别检测91例SLE患者、45例非SLE疾病对照和46例健康对照组血清中AnuA、抗dsDNA抗体和抗dsDNA-NcX抗体的水平,比较3种抗体对SLE诊断的敏感性和特异性,评价其与其他实验室指标的关系.结果 SLE患者AnuA、抗dsDNA抗体和抗dsDNA-NcX抗体的阳性率分别为49.45％、56.04％和61.54％;特异性分别为94.51％、94.51％和100.00％.AnuA、抗dsDNA抗体和抗dsDNA-NcX抗体均与SLEDAI评分呈正相关(r=0.50,P=0.00;r =0.49,P=0.00;r =0.42,P=0.00).ANA的滴度与AnuA的浓度呈正相关(r=0.30,P=0.00),与抗dsDNA抗体的滴度无相关性(r=0.19,P=0.08),与抗dsDNA-NcX抗体的浓度呈正相关(r=0.50,P=0.00).红细胞沉降率在抗dsDNA-NcX抗体、抗dsDNA抗体阴性和阳性组间比较差异无统计学意义(x2=0.76,P=0.38;x2=0.13,P=0.18),而在AnuA阴性与阳性组间比较差异有统计学意义(x2 =20.31,P=0.00).CRP及24小时尿蛋白定量在三者阴性与阳性组间比较差异无统计学意义.补体C3、C4在AnuA、抗dsDNA抗体和抗dsDNA-NcX抗体的阴性与阳性组间比较差异有统计学意义(x2=9.84,P=0.00;x2=16.53,P=0.00;x2 =10.33,P=0.00;x2 =11.61,P=0.00;x2 =12.69,P=0.00;x2=8.77,P=0.00).胱抑素在抗dsDNA抗体和AnuA的阴性与阳性组间比较差异无统计学意义,而在抗dsDNA-NcX抗体阴性与阳性组间比较差异有统计学意义(x2 =4.04,P=0.04).结论 抗dsDNA-NcX抗体可作为SLE的特异性抗体之一,其敏感性和特异性均高于抗dsDNA抗体和AnuA,三者均与SLE的疾病活动相关,联合检测有助于评估病情.     

抗细胞膜DNA抗体的测定及其在系统性红斑狼疮诊断中的意义

目的建立抗细胞膜DNA(mDNA)抗体测定的方法,研究其在系统性红斑狼疮(SLE)诊断中的敏感性和特异性,以及与SLE临床特点及免疫学异常的关系.方法检测SLE患者、疾病对照组和正常对照组血清中的抗mDNA抗体,并分析SLE患者的各种临床表现及实验室指标与抗mDNA抗体的关系.同时研究细胞膜DNA分子在不同细胞表面的表达,用DNA酶、RNA酶及胰酶鉴定抗原性质.结果抗mDNA抗体在SLE中检测敏感性73.3%(152/207),特异性96.4%,疾病对照组阳性率5.4%(9/167),82名正常对照组均为阴性,抗mDNA抗体阳性率在SLE组明显高于疾病对照组和正常对照组(P＜0.01).抗mDNA抗体在其他自身抗体阴性的SLE患者中有较高的检出率,在抗双链DNA(dsDNA)抗体、抗Sm抗体、快速狼疮因子(DNP)、抗组蛋白抗体(AHA)、抗核小体抗体(AnuA)阴性的SLE患者中抗mDNA抗体的阳性率分别是73.8%、62.7%、65.3%、57.8%和51.6%.该抗体阳性组SLE患者皮疹,脱发,关节痛,白细胞和C3、C4减低及IgG、IgA、IgM升高较为常见,但与SLE患者病情活动指数无关.本文还证实细胞膜DNA在人B细胞、T细胞上均有表达,以Raji细胞株表达较好.用DNA酶预处理的细胞涂片再行检测后膜荧光图形消失,而用RNA酶、胰酶预处理后并不消失,证实其为膜DNA抗原.结论抗mDNA抗体是一种诊断敏感性高、特异性强的SLE血清学指标之一,尤其对抗dsDNA、抗Sm、抗DNP、AHA、AnuA阴性的SLE的诊断有参考意义.     

儿童系统性红斑狼疮患者血清抗核小体抗体检测

目的探讨抗核小体抗体(anti-nucleosome antibodies,AnuA)对儿童系统性红斑狼疮(systemic lupus erythematosus,SLE)诊断的意义,并与成人SLE进行比较。方法选取87例儿童SLE患者,30例非SLE儿童疾病对照组(包括幼年类风湿关节炎、脊柱关节病、皮肌炎、干燥综合征和血管炎),122例成人SLE和55例其他结缔组织病患者,采用酶联免疫吸附试验(enzyme-linked immunosorbent assay,ELISA)检测血清AnuA。结果 87例儿童SLE中67例AnuA阳性,30例儿童疾病对照组中2例AnuA阳性,AnuA对儿童SLE诊断的敏感性和特异性分别为77.01%和93.33%,ROC曲线下面积为0.852;阳性预测值和阴性预测值分别为97.10%和58.33%。AnuA对成人SLE患者诊断的敏感度和特异度分别为68.85%和90.91%。AnuA对儿童SLE诊断的敏感度高于成人SLE,对儿童SLE诊断的特异度与成人比较无明显差异(P0.05)。在抗dsDNA抗体和抗Sm抗体阴性的儿童SLE患者中AnuA的阳性率分别为56.52%(26/46)和76.71%(56/73)。结论 AnuA对儿童SLE的诊断具有较高的敏感度和特异度,有助于抗dsDNA抗体和抗Sm抗体阴性儿童SLE的诊断。     

抗核小体抗体诊断系统性红斑狼疮的价值

280份血清,取自健康体检者50例，类风湿关节炎（RA）74例，系统性红斑狼疮（SLE）106例．其他结缔组织病50例．分别检测其抗核抗体（ANA），抗双链DNA（dsDNA），抗史密斯（Sm），抗组蛋白（His）及抗核小体抗体（AnuA）抗体。结果5种抗体诊断SLE的敏感性和特异性为；ANA96．2%、31％，AnuA80．1％、93％，dsDNA56．6%、92％，Sm49．7％、90％，His54．7％、85%。ANA、AnuA敏感性明显高于其他3种抗体（P〈0．001）．AnuA、dsDNA、HiS、Sm的特异性明显高于ANA（P〈0．001）。AnuA是SLE的又一种特异性抗体，其与ANA、dsDNA抗体及Sm抗体、His抗体联合检测对SLE的诊断有重要意义。     

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.     

血清抗C1q抗体与狼疮肾炎活动性及病理改变的相关性

目的 探讨血清抗C1q抗体与狼疮肾炎(LN)肾组织病理改变的相关性,以及对LN的活动性的评价.方法 用酶联免疫吸附法(ELISA)检测活动期LN患者60例和非LN患者60例血清中的抗C1q抗体,分析这一抗体与LN肾组织病理改变、活动指数及其他实验室参数的相关性.结果 LN患者血清抗C1q抗体水平(89±26)U/ml较非LN患者(57±23)U/ml高(P＜0.01);60例LN患者有同期肾活检病理资料,按世界卫生组织(WHO)分型,Ⅱ型12例,Ⅲ型14例,Ⅳ型18例,Ⅴ型16例.经方差分析显示,各病理类型问抗C1q抗体水平差异有统计学意义,其中以Ⅳ型LN的抗C1q抗体水平显著高于其他病理类型(P＜0.01);C1q在肾组织的沉积与血清抗C1q抗体水平相关;血清抗C1q抗体水平与肾脏病变的活动指数(AI)及尿蛋白含量呈正相关(P＜0.01),与补体C3、C4水平呈负相关(P＜0.01);抗双链DNA(dsDNA)抗体阳性的SLE患者,血清抗C1q抗体水平高于抗dsDNA抗体阴性者(P＜0.01).结论 血清抗C1q抗体水平在一定程度上反映LN肾脏的病理改变,并与肾脏病变活动指数有相关性,检测血清抗C1q抗体对评价LN病情及指导治疗有临床实用价值.     

Anti-C1q antibodies are associated with systemic lupus erythematosus disease activity and lupus nephritis in northeast of China

This study aimed to investigate the associations of anti-C1q antibodies with systemic lupus erythematosus (SLE) disease activity and lupus nephritis (LN) in northeast of China. Ninety patients with SLE, 37 patients with other autoimmune diseases, and 40 healthy donors in northeast of China were enrolled. Serum anti-C1q antibodies were measured by ELISA with 20 RU/ml as the threshold of positive results. The prevalence and levels of anti-C1q antibodies in SLE group (50%, 20.54 ± 34.67 RU/ml) were significantly higher than those in autoimmune disease and healthy control groups (P < 0.05), yet no significant difference between LN patients and non-LN lupus patients (57.14% vs 41.46%, P > 0.05; 25.92 ± 39.94 vs 13.07 ± 27.39 RU/ml, P > 0.05). Anti-C1q antibody levels were positively correlated with levels of Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) scores, anti-dsDNA, and anti-cardiolipin and negatively correlated with serum C3 and C4 (P < 0.05). The prevalence of anti-Sm and anti-nucleosome increased in anti-C1q-positive lupus patients (P < 0.05). Compared with anti-C1q-negative lupus patients, patients with 20–40 RU/ml anti-C1q antibodies had comparable disease activity (P > 0.05); patients with 40–80 RU/ml anti-C1q antibodies had significantly lower levels of serum complement (P < 0.05); patients with above 80 RU/ml anti-C1q antibodies had much more severe hypocomplementemia, increased SLEDAI scores, and higher incidence of hematuria and proteinuria (P < 0.05). Furthermore, the specificity and positive predictive value of 80 RU/ml anti-C1q antibodies for LN was 97.56% and 87.50%, respectively. In conclusion, anti-C1q antibodies are associated with SLE and LN disease activity, and the contribution hinges on the titers. Moreover, high-level anti-C1q antibodies are valuable for diagnosing LN.     

Nonrenal and renal activity of systemic lupus erythematosus: a comparison of two anti-C1q and five anti-dsDNA assays and complement C3 and C4

Associations of different assays for antibodies to C1q (anti-C1q) and to dsDNA (anti-dsDNA) and of complements C3 and C4 with disease activity in patients with systemic lupus erythematosus (SLE) were studied. The clinical manifestations of 223 SLE patients were recorded, and the disease activity was assessed by the SLEDAI score. Anti-C1q were determined by two enzyme-linked immunosorbent assays (ELISA) and anti-dsDNA by a radioimmunoassay (RIA), a Crithidia immunofluorescence (IF) assay and three ELISA assays using human telomere DNA, plasmid DNA circles, or calf thymus DNA as antigens, respectively. Complement C3 and C4 were determined by nephelometry. Control sera were obtained from 98 blood donors. In patients with SLE, the prevalence of anti-C1q was 17–18% and that of anti-dsDNA was 36–69%. Anti-C1q, anti-dsDNA, and complement C3 and C4 correlated well with the overall activity of SLE (r?=?0.323–0.351, 0.353–0.566, and ?0.372–0.444, respectively; P?<?0.001). Sensitivity, specificity, positive predictive value, and negative predictive value for active lupus nephritis among SLE patients were 40–44, 92, 29, and 91–92% for anti-C1q and 48–68, 29–66, 11–16, and 86–91% for anti-dsDNA, respectively. Patients with active nephritis had higher levels of anti-C1q and lower levels of C3 and C4 than patients with inactive nephritis (P?=?0.003–0.018). The corresponding associations of anti-dsDNA were somewhat weaker (P?=?0.023–0.198). Hematological parameters reflecting disease activity correlated clearly better with anti-dsDNA and complement C3 and C4 than with anti-C1q. Anti-C1q is inferior to anti-dsDNA as a diagnostic test in SLE and in the evaluation of overall clinical activity of the disease. Anti-C1q together with complement C3 and C4 may offer useful additional information to monitor lupus nephritis activity. There are no practical differences between different assays for anti-C1q and anti-dsDNA.     

Simultaneous detection of anti-C1q and anti-double stranded DNA autoantibodies in lupus nephritis: predictive value for renal flares

Clinical difficulties in predicting systemic lupus erythematosus (SLE) renal flares are still encountered. Biological markers such as autoantibodies (aAbs) may be of major interest for clinicians in the follow-up of SLE patients. The aim of our study was to investigate the clinical utility of one of these biological markers, anti-C1q aAbs, in predicting renal flares of SLE nephritis in comparison with the 'gold standard' anti-double stranded DNA (anti-dsDNA) aAbs. Anti-C1q aAbs and anti-dsDNA aAbs were analysed through a longitudinal retrospective study of 23 SLE patients presenting with one or more renal flares. Anti-C1q and/or anti-dsDNA aAbs were found in 20 (87%) of 23 patients, of whom 16 (69%) displayed both. Thirty-three renal flares occurred during the course of the study, and anti-C1q aAbs and anti-dsDNA aAbs were positive in 25 (76%) and 24 (73%) of these flares respectively. The sensitivity of anti-C1q and/or anti-dsDNA aAbs in predicting renal flares reached 85%. The specificity of anti-C1q aAbs was 84%, of anti-dsDNA aAbs 77% and of both aAbs 97%. Positive and negative predictive values were as follows: 56% and 70% for anti-C1q aAbs, 53% and 72% for anti-dsDNA aAbs. The combination of both aAbs had the highest positive predictive value (69%), whereas absence of both aAbs was associated with the highest negative predictive value (74%). In conclusion, our results confirm that anti-C1q aAbs are present in a significant percentage of SLE patients with active renal involvement, suggesting that these aAbs could be a useful additional marker. The presence of anti-C1q and anti-dsDNA aAbs was associated with a high risk of renal flare, whereas the absence of both aAbs excluded such an event. These data confirm that systematic detection of anti-C1q and anti-dsDNA aAbs is of interest for the follow-up in SLE patients with renal involvement.     

Anti-C1q antibody in patients with lupus nephritic flare: 18-month follow-up and a nested case-control study

Objectives: A prospective cohort was conducted to investigate the association of anti-C1q antibody and lupus/lupus nephritis (LN) flare.

Methods: Sixty-nine consecutive patients with systemic lupus erythematosus were enrolled and followed up for 18 months. Anti-C1q was recorded at the first visit and at the time of flare. For patients with flare, age and sex matched SLE patients were considered as the control group (nested case-control study). The predictability of anti-C1q and other laboratory indices for LN flare during the 18-month follow-up was calculated.

Results: Fourteen out of sixty-nine (20%) had lupus flare. Fourteen patients were chosen as controls. Nine cases and three controls had positive anti-C1q at the first visit (p?=?0.0001). Twenty-six (38%) and 43 (62%) patients had positive and negative anti-C1q antibody at the first visit, respectively, of whom 9 (34.5%) and 3 (7%) patients developed LN flare in the next 18 months (p?=?0.003). Anti-C1q and 24-hour urine protein were found as the main predictors of LN flare. The positive and negative predictive values of anti-C1q for LN flare were 35% and 93%, respectively. Predictive values of positive anti-C1q/low C3 together were 60% and 96%, respectively.

Conclusion: The combination of positive anti-C1q/low C3 had the highest reasonable predictive values for LN flare.