目的 探讨抗类瓜氨酸化抗体(anti-carbamylated fibrinogen antibodies, 抗CarP抗体)在系统性红斑狼疮(systemic lupus erythematosus,SLE)中的意义,SLE是否与类风湿关节炎(rheumatoid arthritis, RA)一样,存在大量针对类瓜氨酸的自身抗体,抗CarP抗体与关节损伤及疾病活动度高度相关。方法 利用酶联免疫吸附法(enzyme-linked immunosorbent assay,ELISA)检测105例确诊的SLE患者和73例健康对照者血清中抗CarP抗体水平,收集其他SLE相关临床和实验室数据,采用SPSS 24.0软件进行相应统计学分析。结果 SLE中存在抗CarP抗体,且明显高于健康对照组(P<0.05)。抗CarP抗体阳性组与阴性组SLE患者相比,在以下临床及实验室指标方面差异有统计学意义:病程、血沉(erythrocyte sedimentation rate,ESR)、C-反应蛋白(C-reactive protein,CRP)、类风湿因子(rheumatoid factor,RF)、抗心磷脂抗体、抗dsDNA抗体、D-二聚体、IgA、IgG、补体C3、补体C4、外周血红细胞计数和血红蛋白水平(P<0.05)。与SLE其他自身抗体相比,抗CarP抗体的阳性率(21.9%)高于抗Sm抗体(15.24%),与抗核糖体P蛋白抗体(22.86%)阳性率相似;在SLE特异性抗体阴性的患者中可检测到抗CarP抗体,其阳性率分别为: 抗Sm(-)组20.2%(18/89),抗dsDNA(-)组9.3%(4/43),抗核小体抗体(-)组12.5%(6/48)和抗核糖体P蛋白抗体(-)组20.9%(17/81)。而且,抗CarP抗体水平与病程、补体C3、补体C4、红细胞及血红蛋白呈明显负相关(P<0.05),与ESR、CRP、IgA、IgG、RF、抗心磷脂抗体、抗dsDNA抗体及D-二聚体呈明显正相关(P<0.05)。结论 SLE患者血清中抗CarP抗体水平升高,抗CarP抗体与SLE患者临床及实验室指标具有相关性。

Objective: Antibodies against carbamylated protein (anti-CarP) were found to be a promising marker to evaluate joint damage and disease activity in patients with rheumatoid arthritis (RA). However, whether anti-CarP antibodies were present in systemic lupus erythematosus (SLE) remained ambiguity. We have therefore undertaken this study to assess the levels of serum anti-CarP antibodies and to evaluate their clinical value in SLE.Methods: Serum levels of antibodies against carbamylated-fibrinogen (anti-CarP) were measured by enzyme-linked immunosorbent assay (ELISA) in 105 SLE patients and 73 healthy controls. Other clinical and laboratory measurements of the SLE patients were collected from medical records. Data analyses between anti-CarP antibodies and other laboratory measurements were performed using SPSS software for Windows 24.0.Results: The levels of serum anti-CarP antibodies in the patients with SLE were significantly higher than those in the healthy controls (P<0.05). There were significant differences between the anti-CarP-positive group and anti-CarP-negative group in many clinical features. The disease duration, values of ESR, CRP, RF, anti-cardiolipin, anti-dsDNA, D-dipolymer, IgA and IgG were significantly higher in the anti-CarP-positive group compared with the negative group (P<0.05). Conversely, the values of complement 3, complement 4, peripheral blood RBC, and hemoglobin were significantly lower in anti-CarP-positive group than in the negative group(P<0.05). Moreover, the incidence of increase of erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), rheumatoid factor (RF), D-dipolymer, decrease of peripheral blood RBC, hemoglobin, complement 3, complement 4, and positive rate of anti-dsDNA were significant different between the two groups(P<0.05). The positive rate of anti-CarP (21.9%) was higher than that of anti-Sm (15.24%), and close to anti-ribosomal P protein (22.86%) in our SLE patients. In addition, anti-CarP antibody was present in the SLE patients lacking the disease specific antibodies, including anti-Sm (anti-CarP positive rate 20.2%, 18/89), anti-dsDNA (anti-CarP positive rate 9.3%, 4/43), anti-nucleosome (anti-CarP positive rate 12.5%, 6/48), and anti-ribosomal P protein antibody (anti-CarP positive rate 20.9%, 17/81). Moreover, the high levels of anti-CarP antibodies were correlated with short disease duration, low C3, C4, RBC, and hemoglobin (P<0.05), high ESR, CRP, IgA, IgG, RF, anti-cardiolipin, anti-dsDNA, and D-dipolymer (P<0.05).Conclusion: The level of anti-CarP antibody was increased in the serum of patients with SLE. There were correlations between anti-CarP antibodies and clinical and laboratory indicators of SLE patients.