Antibodies against C1q Are a Valuable Serological Marker for Identification of Systemic Lupus Erythematosus Patients with Active Lupus Nephritis.

Shuhong Chi,Juan Shi,Yunxia Yu,Lijuan Yang,Yurong Zhang,Jijuan Yang,Xiaoming Liu

doi:10.1155/2015/450351

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. Conclusion. 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.

Highlights

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease with unknown etiology which can be characterized by producing various autoantibodies against self-antigens [1]
This study in 95 SLE patients confirms previous findings of the correlation of anti-C1q antibodies with SLE disease activity and renal flares
Anti-C1q antibodies showed a stronger association with renal disease activity in SLE patients than anti-doublestranded DNA (dsDNA) antibodies and reduction of C3 and C4 in terms of diagnostic specificity

Summary

Introduction

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease with unknown etiology which can be characterized by producing various autoantibodies against self-antigens (autoantigens) [1]. SLE can affect multiple systems and major organs, among which lupus nephritis (LN) is a common major organ manifestation and a main cause of the morbidity and mortality of the disease [2]. In this regard, LN affects 40– 80% of SLE patients, and an immunosuppressive treatment for LN may have an adverse effect on kidney and result in chronic renal failure, which sequentially increases the morbidity and mortality in SLE patients [1]. An evaluation of clinical relevance of the autoantibody profile and disease parameters will aid in identifying SLE patients at risk for specific complications at an early stage and enable clinicians to initiate an effective therapeutic strategy that possibly decreases the morbidity and mortality for patients with SLE [5]

Methods

Results

Discussion

Conclusion