Ramos-Casals M, Campoamor M T, Chamorro A, Salvador G, Segura S, Botero J C, Yagüe J, Cervera R, Ingelmo M, Font J
Department of Autoimmune Diseases, Institut d'Investigacions Biomèdiques August Pi i Sunyer, Hospital Clinic, School of Medicine, University of Barcelona, Barcelona, Spain.
Lupus. 2004;13(10):777-83. doi: 10.1191/0961203304lu1080oa.
The objective of the study was to analyse the prevalence and clinical significance of hypocomplementemia in a large series of patients diagnosed either with systemic lupus erythematosus (SLE) or with primary antiphospholipid syndrome (APS) and its association with the main clinical, hematological and immunological features of these diseases. Between 1992 and 2003, complement determinations (C3 and C4 levels, CH50 activity) were performed in 597 consecutive patients diagnosed with SLE (530 women and 67 men, mean age 32.6 years) and 70 with primary APS (57 women and 13 men, mean age 38.7) visited in our department. Complement determinations are routinely made at the first visit of patients and yearly during the follow-up. SLE and primary APS were diagnosed according to current classification criteria. Hypocomplementemia was detected in 371 (62%) of SLE patients. Compared with patients with normal complement values, those with hypocomplementemia showed a higher prevalence of female gender (P < 0.001), fever (P = 0.021), nephropathy (P < 0.001), cutaneous vasculitis (P = 0.023), positive anti-dsDNA antibodies (P = 0.012) and cryoglobulinemia (P < 0.001). In addition, patients with hypocomplementemia showed a higher prevalence of APS-related features such as hemolytic anemia (P = 0.001) and antiphospholipid antibodies (P < 0.001). Hypocomplementemia was prospectively related to accumulated hospitalization in SLE patients but not with the accumulated number of lupus flares or with the survival after follow-up of five years. In contrast, 33 (47%) patients with primary APS presented low complement values, which were associated with a higher prevalence of livedo reticularis (P = 0.022), thrombocytopenia (P = 0.004), lupus anticoagulant (P = 0.013), positive IgM-aCL (P = 0.039), positive ANA (P = 0.002) and anti-dsDNA (P = 0.046). The diagnostic value of hypocomplementemia in patients with SLE is based on the association with disease activity, immune-complex mediated manifestations (glomerulonephritis, cryoglobulinemia) and APS-related features (livedo reticularis, hemolytic anemia and aPL). Hypocomplementemia was found in nearly half of patients with primary APS, and was associated with some APS features (livedo reticularis, thrombocytopenia, aPL) but also with SLE-related immunological markers (ANA and anti-dsDNA), identifying a subset of patients with primary APS with a higher risk of evolving to SLE. These results clearly support the routine determination of complement factors in the clinical follow-up of patients with SLE and primary APS.
本研究的目的是分析大量诊断为系统性红斑狼疮（SLE）或原发性抗磷脂综合征（APS）患者中低补体血症的患病率、临床意义及其与这些疾病主要临床、血液学和免疫学特征的关联。1992年至2003年期间，对我科诊治的597例连续诊断为SLE的患者（530例女性和67例男性，平均年龄32.6岁）和70例原发性APS患者（57例女性和13例男性，平均年龄38.7岁）进行了补体测定（C3和C4水平、CH50活性）。患者首次就诊时常规进行补体测定，随访期间每年测定一次。SLE和原发性APS根据现行分类标准进行诊断。371例（62%）SLE患者检测到低补体血症。与补体值正常的患者相比，低补体血症患者女性患病率更高（P<0.001）、发热（P = 0.021）、肾病（P<0.001）、皮肤血管炎（P = 0.023）、抗双链DNA抗体阳性（P = 0.012）和冷球蛋白血症（P<0.001）。此外，低补体血症患者APS相关特征如溶血性贫血（P = 0.001）和抗磷脂抗体（P<0.001）的患病率更高。低补体血症与SLE患者的累计住院率呈前瞻性相关，但与狼疮发作的累计次数或五年随访后的生存率无关。相比之下，33例（47%）原发性APS患者补体值较低，这与网状青斑（P = 0.022）、血小板减少症（P = 0.004）、狼疮抗凝物（P = 0.013）、IgM-aCL阳性（P = 0.039）、ANA阳性（P = 0.002）和抗双链DNA阳性（P = 0.046）的患病率较高有关。低补体血症在SLE患者中的诊断价值基于其与疾病活动、免疫复合物介导的表现（肾小球肾炎、冷球蛋白血症）和APS相关特征（网状青斑、溶血性贫血和抗磷脂抗体）的关联。近一半的原发性APS患者存在低补体血症，其与一些APS特征（网状青斑、血小板减少症、抗磷脂抗体）以及SLE相关的免疫标志物（ANA和抗双链DNA）有关，确定了一部分原发性APS患者发展为SLE的风险较高。这些结果明确支持在SLE和原发性APS患者的临床随访中常规测定补体因子。
