title: Antibodies against C1q Are a Valuable Serological Marker for Identification of Systemic Lupus Erythematosus Patients with Active Lupus Nephritis.
abstract: OBJECTIVE
  An early diagnosis of lupus nephritis (LN) has an important clinical implication in guiding treatments of systemic lupus erythematosus (SLE) in clinical settings. In this study, the diagnostic values of circulating autoantibodies to C1q alone or in combination with other markers for accessing active SLE and LN were evaluated.
  
  
  METHODS
  The diagnostic value of anti-C1q autoantibodies for identification of patients with active SLE disease and LN was evaluated by analyzing the level of anti-C1q antibodies in sera from 95 SLE patients, 40 non-SLE patients, and 34 healthy cohorts.
  
  
  RESULTS
  The prevalence of anti-C1q antibodies was significantly higher in patients with SLE (50/95, 52.6%), active SLE (40/51, 78.4%), and LN (30/35, 85.7%) in comparison with non-SLE patient controls, patients with inactive SLE, and non-LN, respectively. A combination of anti-C1q with anti-dsDNA and/or levels of complements C3 and C4 exhibited an increased specificity but a decreased sensitivity for identification of patients with active SLE and LN diseases relative to each of these markers alone.
  
  
  CONCLUSIONS
  Anti-C1q antibodies were strongly associated with disease activity and LN in SLE patients, suggesting that it may be a reliable serological marker for identification of SLE patients with active LN and active SLE disease.
authors.affiliation: Department of Rheumatology, The General Hospital of Ningxia Medical University, Yinchuan 750004, China.
authors.forename: Shuhong
authors.initials: S
authors.lastname: Chi
authors.affiliation: Department of Rheumatology, The General Hospital of Ningxia Medical University, Yinchuan 750004, China.
authors.forename: Yunxia
authors.initials: Y
authors.lastname: Yu
authors.affiliation: Center of Laboratory Medicine, The General Hospital of Ningxia Medical University, Yinchuan 750004, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Shi
authors.affiliation: Department of Rheumatology, The General Hospital of Ningxia Medical University, Yinchuan 750004, China.
authors.forename: Yurong
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Rheumatology, The General Hospital of Ningxia Medical University, Yinchuan 750004, China.
authors.forename: Jijuan
authors.initials: J
authors.lastname: Yang
authors.affiliation: Department of Rheumatology, The General Hospital of Ningxia Medical University, Yinchuan 750004, China.
authors.forename: Lijuan
authors.initials: L
authors.lastname: Yang
authors.affiliation: Institute of Human Stem Cell Research, The General Hospital of Ningxia Medical University, Yinchuan, Ningxia 750004, China.
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Liu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001323:Autoantibodies / Q000097:blood; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D015922:Complement C1q / Q000276:immunology*; D005260:Female; D006801:Humans; D008181:Lupus Nephritis / Q000097:blood*; D008297:Male; D008875:Middle Aged; D012698:Serologic Tests
chemical_list: D001323:Autoantibodies; D015415:Biomarkers; D015922:Complement C1q