Autoantibodies against complement component C1q in systemic lupus erythematosus. Issue 4 (29th April 2021)

• Record Type: Journal Article
• Authors: Trendelenburg, Marten
• Is Part Of: Clinical & translational immunology. Volume 10:Issue 4(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-04-29
• Subjects: anti‐C1q antibodies -- C1q -- complement -- SLE -- systemic lupus erythematosus; Immunologic diseases -- Periodicals; Immunology -- Periodicals; Clinical medicine -- Periodicals; Immune System Diseases -- therapy; Immunotherapy; Immunologic Factors -- therapeutic use; Translational Medical Research; Molecular Targeted Therapy; Clinical medicine; Immunologic diseases; Immunology; Periodicals; Periodicals; Fulltext; Internet Resources; Periodicals; 616.079
• DOI: 10.1002/cti2.1279
• Languages: English
• ISSNs: 2050-0068

Abstract

Abstract: Systemic lupus erythematosus (SLE) is the archetype of a systemic autoimmune disease, but the multifaceted pathogenic mechanisms leading to inflammation and organ damage are not fully understood. Homozygous deficiency of complement C1q, the first component of the classical pathway of complement, is strongly associated with the development of SLE, thus pointing at a primarily protective role of C1q. However, while most SLE patients do not have hereditary C1q deficiency, there is indirect evidence for the importance of C1q in the inflammatory processes of the disease, including hypocomplementemia as a result of activation via the classical pathway, deposition of C1q in affected tissues and the occurrence of autoantibodies against C1q (anti‐C1q). The growing body of knowledge on anti‐C1q led to the establishment of a biomarker that is used in the routine clinical care of SLE patients. Exploring the binding characteristics of anti‐C1q allows to understand the mechanisms, that lead to the expression of relevant autoantigenic structures and the role of genetic as well as environmental factors. Lastly, the analysis of the pathophysiological consequences of anti‐C1q is of importance because C1q, the target of anti‐C1q, is a highly functional molecule whose downstream effects are altered by the binding of the autoantibody. This review summarises current study data on anti‐C1q and their implications for the understanding of SLE. Abstract : Autoantibodies against complement C1q (anti‐C1q) are an exciting biomarker of disease activity and for the occurrence of active proliferative nephritis in patients with systemic lupus erythematosus. The exploration of binding characteristics of anti‐C1q and its functional consequences provides important insights into pathogenic mechanisms of the disease involving complement deposition and activation, the clearance mechanisms of apoptotic cell debris, phagocyte function and the role of genetic as well as environmental factors.