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Calatroni M, Moroni G, Conte E, Stella M, Reggiani F, Ponticelli C. Anti-C1q antibodies: a biomarker for diagnosis and management of lupus nephritis. A narrative review. Front Immunol 2024; 15:1410032. [PMID: 38938561 PMCID: PMC11208682 DOI: 10.3389/fimmu.2024.1410032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2024] [Accepted: 05/22/2024] [Indexed: 06/29/2024] Open
Abstract
Nephritis is a frequent and severe complication of Systemic Lupus Erythematous (SLE). The clinical course of lupus nephritis (LN) is usually characterized by alternating phases of remission and exacerbation. Flares of LN can lead to deterioration of kidney function, necessitating timely diagnosis and therapy. The presence of autoantibodies against C1q (anti-C1qAb) in the sera of SLE patients has been reported in various studies. Some research suggests that the presence and changes in the titer of anti-C1qAb may be associated with the development of LN, as well as with LN activity and renal flares. However, the exact role of anti-C1qAb in LN remains a subject of debate. Despite variability in the results of published studies, anti-C1qAb hold promise as noninvasive markers for assessing LN activity in SLE patients. Measuring anti-C1qAb levels could aid in diagnosing and managing LN during periods of both inactive disease and renal flares. Nevertheless, larger controlled trials with standardized laboratory assays are necessary to further establish the utility of anti-C1qAb in predicting the reactivation and remission of LN and guiding treatment strategies.
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Affiliation(s)
- Marta Calatroni
- Department of Biomedical Sciences, Humanitas University, Milan, Italy
- Nephrology and Dialysis Division, Humanitas Research Hospital, Institute for Research, Hospitalization and Health Care (IRCCS), Milan, Italy
| | - Gabriella Moroni
- Department of Biomedical Sciences, Humanitas University, Milan, Italy
- Nephrology and Dialysis Division, Humanitas Research Hospital, Institute for Research, Hospitalization and Health Care (IRCCS), Milan, Italy
| | - Emanuele Conte
- Nephrology and Dialysis Division, Humanitas Research Hospital, Institute for Research, Hospitalization and Health Care (IRCCS), Milan, Italy
- Department of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy
| | - Matteo Stella
- Department of Biomedical Sciences, Humanitas University, Milan, Italy
- Nephrology and Dialysis Division, Humanitas Research Hospital, Institute for Research, Hospitalization and Health Care (IRCCS), Milan, Italy
| | - Francesco Reggiani
- Department of Biomedical Sciences, Humanitas University, Milan, Italy
- Nephrology and Dialysis Division, Humanitas Research Hospital, Institute for Research, Hospitalization and Health Care (IRCCS), Milan, Italy
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Zhang P, Yang X, Fang X, Xu C, Gao C, Xia Z. Anti-C1q antibodies in lupus nephritis children with glomerular microthrombosis. Nephrology (Carlton) 2023. [PMID: 37485575 DOI: 10.1111/nep.14194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Revised: 05/22/2023] [Accepted: 05/31/2023] [Indexed: 07/25/2023]
Abstract
AIM Glomerular microthrombosis (GMT) was a common vascular lesion in patients with lupus nephritis (LN). The objective of this study was to investigate the relationship between serum anti-beta2-glycoprotein I antibodies (a-β2GP1) and anti-complement 1q antibodies (a-C1q) antibodies and to investigate the possible mechanism of GMT in children with LN. METHODS The subjects were 191 children with LN diagnosed by renal biopsy in our hospital from January 2017 to January 2020. The patients were divided into GMT group and non-GMT group. The clinical manifestations, laboratory tests, renal pathology, prognosis of the two groups and the relationship between a-β2GP1 and a-C1q antibodies were observed. RESULTS In 191 children with LN, 52 cases (27.23%) presented with GMT. The value of C3, haemoglobin (Hb), estimate glomerular filtration rate (eGFR) and anticardiolipin antibody (ACA) in GMT group were lower than that of non-GMT group (p < .05, p < .01). The value of serum creatinine (Scr), 24 h proteinuria (PRO), urine red blood cells (RBC), N-acetyl-β-d-glucosidase (NAG) and retinol-binding protein (RBP), a-C1q, a-β2GP1, Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) and renal histopathological activity index (AI) score in GMT group were higher than that of non-GMT group (p < .05, p < .01). The positive proportions of serum a-C1q and a-β2GP1 in GMT group were higher than those in non-GMT group (p < .05). According to Spearman correlation analysis, a-C1q was positively correlated with AI score, SLEDAI, a-β2GP1, GMT, LN-III and LN-IV. Hb, eGFR and a-C1q Ab were associated with the formation of GMT in children with LN. The complete proteinuria remission and renal survival in GMT group were significantly lower than those in non-GMT group (p < .05, p < .01). CONCLUSION LN children with GMT had more severe clinical manifestations and renal pathologic damages, and poor outcome. Serum a-C1q level was positively correlated with a-β2GP1, and a-β2GP1 may be involved in the formation of GMT in children with LN, which might involve in the activation of complement classical pathway.
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Affiliation(s)
- Pei Zhang
- Department of Paediatrics, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, People's Republic of China
| | - Xiao Yang
- Department of Paediatrics, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, People's Republic of China
| | - Xiang Fang
- Department of Paediatrics, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, People's Republic of China
| | - Chao Xu
- Department of Paediatrics, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, People's Republic of China
| | - Chunlin Gao
- Department of Paediatrics, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, People's Republic of China
| | - Zhengkun Xia
- Department of Paediatrics, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, People's Republic of China
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Wada Y, Kamata M, Miyasaka R, Abe T, Kawamura S, Takeuchi K, Aoyama T, Oda T, Takeuchi Y. Clinico-Pathogenic Similarities and Differences between Infection-Related Glomerulonephritis and C3 Glomerulopathy. Int J Mol Sci 2023; 24:ijms24098432. [PMID: 37176142 PMCID: PMC10179079 DOI: 10.3390/ijms24098432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 04/26/2023] [Accepted: 05/01/2023] [Indexed: 05/15/2023] Open
Abstract
Recently, the comprehensive concept of "infection-related glomerulonephritis (IRGN)" has replaced that of postinfectious glomerulonephritis (PIGN) because of the diverse infection patterns, epidemiology, clinical features, and pathogenesis. In addition to evidence of infection, hypocomplementemia particularly depresses serum complement 3 (C3), with endocapillary proliferative and exudative GN developing into membranoproliferative glomerulonephritis (MPGN); also, C3-dominant or co-dominant glomerular immunofluorescence staining is central for diagnosing IRGN. Moreover, nephritis-associated plasmin receptor (NAPlr), originally isolated from the cytoplasmic fraction of group A Streptococci, is vital as an essential inducer of C3-dominant glomerular injury and is a key diagnostic biomarker for IRGN. Meanwhile, "C3 glomerulopathy (C3G)", also showing a histological pattern of MPGN due to acquired or genetic dysregulation of the complement alternative pathway (AP), mimics C3-dominant IRGN. Initially, C3G was characterized by intensive "isolated C3" deposition on glomeruli. However, updated definitions allow for glomerular deposition of other complement factors or immunoglobulins if C3 positivity is dominant and at least two orders of magnitude greater than any other immunoreactant, which makes it challenging to quickly distinguish pathomorphological findings between IRGN and C3G. As for NAPlr, it was demonstrated to induce complement AP activation directly in vitro, and it aggravates glomerular injury in the development of IRGN. A recent report identified anti-factor B autoantibodies as a contributing factor for complement AP activation in pediatric patients with PIGN. Moreover, C3G with glomerular NAPlr deposition without evidence of infection was reported. Taken together, the clinico-pathogenic features of IRGN overlap considerably with those of C3G. In this review, similarities and differences between the two diseases are highlighted.
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Affiliation(s)
- Yukihiro Wada
- Department of Nephrology, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara 252-0374, Kanagawa, Japan
| | - Mariko Kamata
- Department of Nephrology, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara 252-0374, Kanagawa, Japan
| | - Ryoma Miyasaka
- Department of Nephrology, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara 252-0374, Kanagawa, Japan
| | - Tetsuya Abe
- Department of Nephrology, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara 252-0374, Kanagawa, Japan
| | - Sayumi Kawamura
- Department of Nephrology, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara 252-0374, Kanagawa, Japan
| | - Kazuhiro Takeuchi
- Department of Nephrology, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara 252-0374, Kanagawa, Japan
| | - Togo Aoyama
- Department of Nephrology, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara 252-0374, Kanagawa, Japan
| | - Takashi Oda
- Department of Nephrology and Blood Purification, Kidney Disease Center, Tokyo Medical University Hachioji Medical Center, Hachioji 193-0998, Tokyo, Japan
| | - Yasuo Takeuchi
- Department of Nephrology, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara 252-0374, Kanagawa, Japan
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Trendelenburg M. Autoantibodies against complement component C1q in systemic lupus erythematosus. Clin Transl Immunology 2021; 10:e1279. [PMID: 33968409 PMCID: PMC8082710 DOI: 10.1002/cti2.1279] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 03/30/2021] [Accepted: 04/01/2021] [Indexed: 12/19/2022] Open
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.
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Affiliation(s)
- Marten Trendelenburg
- Division of Internal Medicine University Hospital Basel Basel Switzerland.,Clinical Immunology Department of Biomedicine University of Basel Basel Switzerland
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Rodriguez-Iturbe B. Autoimmunity in Acute Poststreptococcal GN: A Neglected Aspect of the Disease. J Am Soc Nephrol 2021; 32:534-542. [PMID: 33531351 PMCID: PMC7920173 DOI: 10.1681/asn.2020081228] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Acute poststreptococcal GN (APSGN) is the prototype of immune complex GN and is associated with manifestations of autoimmune reactivity that have been neglected as epiphenomena. Recently, studies have demonstrated transient antifactor B autoantibodies that activate the alternative complement pathway, bringing self-immunity to a central position in the pathogenesis of APSGN. Therefore, examining other manifestations of autoimmunity that have been reported in association with poststreptococcal GN is of interest. This article reviews the renal and extrarenal manifestations of autoimmune reactivity in APSGN and considers their potential relevance in modifying the usually benign clinical course of the disease. It also discusses related aspects of the nephritogenic antigens, complement activation, and genetic elements associated with immune reactivity and their potential relevance to the familial incidence of the disease.
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Affiliation(s)
- Bernardo Rodriguez-Iturbe
- Department of Nephrology, Instituto Nacional de Nutrición y Ciencias Médicas "Salvador Zubirán" and Instituto Nacional de Cardiología "Ignacio Chávez," Mexico City, Mexico
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6
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Abstract
Autoantibodies against complement C1q (anti-C1q) are an excellent marker for active nephritis in SLE patients. Here, we describe a typical protocol for the quantification of anti-C1q using immobilized C1q (important for the presentation of relevant cryptic epitopes) and a high salt buffer for the incubation steps (to prevent immune-complex binding to intact C1q). More recently, a linear epitope on the C1q A chain, that is targeted by anti-C1q, has been described (A08). The assay using this peptide seems to be more specific and more sensitive for the detection of active nephritis in SLE patients than the conventional anti-C1q assay, but further studies are required to establish the role of anti-A08 of C1q in the clinical routine.
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Yang CA, Chiang BL. Inflammasomes and Childhood Autoimmune Diseases: A Review of Current Knowledge. Clin Rev Allergy Immunol 2020; 61:156-170. [PMID: 33236284 PMCID: PMC7685913 DOI: 10.1007/s12016-020-08825-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/09/2020] [Indexed: 02/08/2023]
Abstract
Inflammasomes are multiprotein complexes capable of sensing pathogen-associated molecular patterns (PAMPs), danger-associated molecular patterns (DAMPs), and cellular perturbations. Upon stimulation, the inflammasomes activate the production of the pro-inflammatory cytokines IL-1β and IL-18 and induce gasdermin D-mediated pyroptosis. Dysregulated inflammasome signaling could lead to hyperinflammation in response to environmental triggers, thus contributing to the pathogenesis of childhood autoimmune/autoinflammatory diseases. In this review, we group childhood rheumatic diseases into the autoinflammation to autoimmunity spectrum and discuss about the involvement of inflammasomes in disease mechanisms. Genetic mutations in inflammasome components cause monogenic autoinflammatory diseases, while inflammasome-related genetic variants have been implicated in polygenic childhood rheumatic diseases. We highlight the reported associations of inflammasome signaling-related genetic polymorphisms/protein levels with pediatric autoimmune disease susceptibility and disease course. Furthermore, we discuss about the use of IL-1 receptor antagonist as an adjunctive therapy in several childhood autoimmune diseases, including macrophage activation syndrome (MAS) and multisystem inflammatory syndrome in children (MIS-C) related to COVID-19. A comprehensive multi-cohort comparison on inflammasome gene expression profile in different pediatric rheumatic diseases is needed to identify patient subsets that might benefit from the adjunctive therapy of IL-1β inhibitors.
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Affiliation(s)
- Chin-An Yang
- Division of Laboratory Medicine and Division of Pediatrics, China Medical University Hsinchu Hospital, Jubei, Hsinchu, Taiwan
- College of Medicine, China Medical University, Taichung, Taiwan
| | - Bor-Luen Chiang
- Department of Pediatrics, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan.
- Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan.
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8
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Mosquera J, Pedreañez A. Acute post-streptococcal glomerulonephritis: analysis of the pathogenesis. Int Rev Immunol 2020; 40:381-400. [PMID: 33030969 DOI: 10.1080/08830185.2020.1830083] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Increasing evidence supports a central role of the immune system in acute post streptococcal glomerulonephritis (APSGN), but the current view of how streptococcal biology affects immunity, and vice versa, remains to be clarified. Renal glomerular immune complex deposition is critical in the initiation of APSGN; however, mechanisms previous to immune complex formation could modulate the initiation and the progression of the disease. Initial and late renal events involved in the nephritis can also be related to host factors and streptococcal factors. In this review we describe the mechanisms reported for the APSGN pathogenesis, the interactions of streptococcal products with renal cells and leukocytes, the possible effects of different nephritogenic antigens in the renal environment and the possibility that APSGN is not just due to a single streptococcal antigen and its antibody; instead, kidney damage may be the result of different factors acting at the same time related to both streptococcus and host factors. Addressing these points should help us to better understand APSGN physiopathology.
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Affiliation(s)
- Jesús Mosquera
- Facultad de Medicina, Instituto de Investigaciones Clínicas "Dr. Américo Negrette", Universidad del Zulia, Maracaibo, Venezuela
| | - Adriana Pedreañez
- Facultad de Medicina, Cátedra de Inmunología, Escuela de Bioanálisis, Universidad del Zulia, Maracaibo, Venezuela
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9
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Picard C, Lega JC, Ranchin B, Cochat P, Cabrera N, Fabien N, Belot A. Anti-C1q autoantibodies as markers of renal involvement in childhood-onset systemic lupus erythematosus. Pediatr Nephrol 2017; 32:1537-1545. [PMID: 28343355 DOI: 10.1007/s00467-017-3646-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Revised: 03/05/2017] [Accepted: 03/07/2017] [Indexed: 12/25/2022]
Abstract
BACKGROUND Childhood-onset systemic lupus erythematosus (cSLE) is rare, and considered more severe than its adult-onset counterpart. Lupus nephritis (LN) occurs more frequently in children, accounting for higher long-term morbidity and mortality compared with adults. Thus, reliable biological markers are needed to predict disease course. This study aimed to investigate the capacity of anti-C1q autoantibodies (Abs) to predict renal flare and global disease activity in cSLE patients, and association with disease activity and kidney involvement. METHODS Twenty-eight patients with cSLE including 19 patients (68%) with a history of LN were included retrospectively. Anti-C1q Abs were analysed by ELISA at renal flare-up or in the quiescent phase of disease and compared with Farr dsDNA assay. RESULTS Thirty-one flares occurred during follow-up: anti-C1q Abs were positive in 26 (84%), strongly associated with active disease status (p < 0.0001), and correlated with global disease activity score (p < 0.0001) and anti-dsDNA Abs presence (p < 0.0001). The specificity of anti-C1q Abs was higher than anti-dsDNA (73% vs 19%) in discriminating LN patients, whereas the receiver operating characteristic curves were not statistically different (0.83 ± 0.06 vs 0.78 ± 0.08 respectively), similar to C3 dosage. The presence of anti-C1q Abs at diagnosis was not predictive for global or renal flare. Introduction of a modified SLEDAI score excluding dsDNA Abs, demonstrated a stronger correlation of anti-C1q Abs titres with SLEDAI score in comparison with the Farr test. CONCLUSION Anti-C1q Abs seem very specific to flares, including LN in children, and their role in daily practice compared with the Farr dsDNA assay needs to be defined.
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Affiliation(s)
- Cécile Picard
- Department of Pathology, Hôpital Femme-Mère-Enfant, Hospices Civils de Lyon, 59 boulevard Pinel, 69500, Bron, France. .,Université Claude Bernard Lyon 1, Lyon, France.
| | - Jean-Christophe Lega
- Université Claude Bernard Lyon 1, Lyon, France.,UMR 5558, Laboratoire de Biométrie et Biologie Evolutive, CNRS, Claude Bernard University Lyon 1, University of Lyon, Lyon, France.,Department of Internal and Vascular Medicine, Centre Hospitalier Lyon-Sud, Pierre-Benite, CHU de Lyon, Lyon, France
| | - Bruno Ranchin
- Université Claude Bernard Lyon 1, Lyon, France.,Department of Pediatric Nephrology, Rheumatology and Dermatology, Hospices civils de Lyon, Lyon, France
| | - Pierre Cochat
- Université Claude Bernard Lyon 1, Lyon, France.,Department of Pediatric Nephrology, Rheumatology and Dermatology, Hospices civils de Lyon, Lyon, France
| | - Natalia Cabrera
- Université Claude Bernard Lyon 1, Lyon, France.,Department of Pediatric Nephrology, Rheumatology and Dermatology, Hospices civils de Lyon, Lyon, France
| | - Nicole Fabien
- Université Claude Bernard Lyon 1, Lyon, France.,Department of Immunology, Centre Hospitalier Lyon-Sud, Pierre-Benite, CHU de Lyon, Lyon, France
| | - Alexandre Belot
- Université Claude Bernard Lyon 1, Lyon, France.,Department of Pediatric Nephrology, Rheumatology and Dermatology, Hospices civils de Lyon, Lyon, France
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Koutsonikoli A, Trachana M, Farmaki E, Tzimouli V, Pratsidou-Gertsi P, Printza N, Garyphallos A, Galanopoulou V, Kanakoudi-Tsakalidou F, Papachristou F. Novel biomarkers for the assessment of paediatric systemic lupus erythematosus nephritis. Clin Exp Immunol 2017; 188:79-85. [PMID: 27936517 DOI: 10.1111/cei.12913] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 11/29/2016] [Accepted: 11/30/2016] [Indexed: 12/25/2022] Open
Abstract
The discovery of serum biomarkers specific for paediatric lupus nephritis (pLN) will facilitate the non-invasive diagnosis, follow-up and more appropriate use of treatment. The aim of this study was to explore the role of serum high-mobility group box 1 (HMGB1) protein, antibodies against nucleosomes (anti-NCS), complement factor C1q (anti-C1q) and glomerular basement membrane (anti-GBM) in pLN. Serum samples of 42 patients with paediatric systemic lupus erythematosus (pSLE) (22 with pLN and 20 without renal involvement), 15 patients with other autoimmune nephritis (AN) and 26 healthy controls (HCs) were examined using enzyme-linked immunosorbent assay (ELISA). The activity of both pSLE and pLN was assessed by the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) tool. The levels of all four biomarkers were significantly higher in pLN compared to AN and to HCs. The anti-NCS, anti-GBM and HMGB1 serum levels were significantly higher in pLN than in pSLE without renal involvement. The anti-C1q and the HMGB1 serum levels were correlated positively with pSLE activity. The HMGB1 serum levels were also correlated positively with pLN activity. These findings suggest that serum anti-NCS, anti-GBM and HMGB1 may serve as biomarkers specific for the presence of nephritis in pSLE. HMGB1 emerged as a useful biomarker for the assessment of pLN and pSLE activity, whereas anti-C1q only of pSLE activity.
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Affiliation(s)
- A Koutsonikoli
- 1st Department of Pediatrics, Aristotle University, 'Hippokration' General Hospital, Thessaloniki, Greece
| | - M Trachana
- 1st Department of Pediatrics, Aristotle University, 'Hippokration' General Hospital, Thessaloniki, Greece
| | - E Farmaki
- 1st Department of Pediatrics, Aristotle University, 'Hippokration' General Hospital, Thessaloniki, Greece
| | - V Tzimouli
- 1st Department of Pediatrics, Aristotle University, 'Hippokration' General Hospital, Thessaloniki, Greece
| | - P Pratsidou-Gertsi
- 1st Department of Pediatrics, Aristotle University, 'Hippokration' General Hospital, Thessaloniki, Greece
| | - N Printza
- 1st Department of Pediatrics, Aristotle University, 'Hippokration' General Hospital, Thessaloniki, Greece
| | - A Garyphallos
- 4th Department of Internal Medicine, Aristotle University, 'Hippokration' General Hospital, Thessaloniki, Greece
| | - V Galanopoulou
- Department of Rheumatology, 'Papageorgiou' General Hospital, Thessaloniki, Greece
| | - F Kanakoudi-Tsakalidou
- 1st Department of Pediatrics, Aristotle University, 'Hippokration' General Hospital, Thessaloniki, Greece
| | - F Papachristou
- 1st Department of Pediatrics, Aristotle University, 'Hippokration' General Hospital, Thessaloniki, Greece
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Haddon DJ, Diep VK, Price JV, Limb C, Utz PJ, Balboni I. Autoantigen microarrays reveal autoantibodies associated with proliferative nephritis and active disease in pediatric systemic lupus erythematosus. Arthritis Res Ther 2015; 17:162. [PMID: 26081107 PMCID: PMC4493823 DOI: 10.1186/s13075-015-0682-6] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2015] [Accepted: 06/11/2015] [Indexed: 12/31/2022] Open
Abstract
Introduction Pediatric systemic lupus erythematosus (pSLE) patients often initially present with more active and severe disease than adults, including a higher frequency of lupus nephritis. Specific autoantibodies, including anti-C1q, anti-DNA and anti-alpha-actinin, have been associated with kidney involvement in SLE, and DNA antibodies are capable of initiating early-stage lupus nephritis in severe combined immunodeficiency (SCID) mice. Over 100 different autoantibodies have been described in SLE patients, highlighting the need for comprehensive autoantibody profiling. Knowledge of the antibodies associated with pSLE and proliferative nephritis will increase the understanding of SLE pathogenesis, and may aid in monitoring patients for renal flare. Methods We used autoantigen microarrays composed of 140 recombinant or purified antigens to compare the serum autoantibody profiles of new-onset pSLE patients (n = 45) to healthy controls (n = 17). We also compared pSLE patients with biopsy-confirmed class III or IV proliferative nephritis (n = 23) and without significant renal involvement (n = 18). We performed ELISA with selected autoantigens to validate the microarray findings. We created a multiple logistic regression model, based on the ELISA and clinical information, to predict whether a patient had proliferative nephritis, and used a validation cohort (n = 23) and longitudinal samples (88 patient visits) to test its accuracy. Results Fifty autoantibodies were at significantly higher levels in the sera of pSLE patients compared to healthy controls, including anti-B cell-activating factor (BAFF). High levels of anti-BAFF were associated with active disease. Thirteen serum autoantibodies were present at significantly higher levels in pSLE patients with proliferative nephritis than those without, and we confirmed five autoantigens (dsDNA, C1q, collagens IV and X and aggrecan) by ELISA. Our model, based on ELISA measurements and clinical variables, correctly identified patients with proliferative nephritis with 91 % accuracy. Conclusions Autoantigen microarrays are an ideal platform for identifying autoantibodies associated with both pSLE and specific clinical manifestations of pSLE. Using multiple regression analysis to integrate autoantibody and clinical data permits accurate prediction of clinical manifestations with complex etiologies in pSLE. Electronic supplementary material The online version of this article (doi:10.1186/s13075-015-0682-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- D James Haddon
- Department of Medicine, Division of Immunology and Rheumatology, Stanford University School of Medicine, 291 Campus Drive, Stanford, CA, 94305, USA.
| | - Vivian K Diep
- Department of Medicine, Division of Immunology and Rheumatology, Stanford University School of Medicine, 291 Campus Drive, Stanford, CA, 94305, USA.
| | - Jordan V Price
- Department of Molecular and Cell Biology, Division of Immunology and Pathogenesis, University of California at Berkeley, 142 Life Sciences Addition #3200, Berkeley, CA, 94720, USA.
| | - Cindy Limb
- Department of Medicine, Division of Immunology and Rheumatology, Stanford University School of Medicine, 291 Campus Drive, Stanford, CA, 94305, USA.
| | - Paul J Utz
- Department of Medicine, Division of Immunology and Rheumatology, Stanford University School of Medicine, 291 Campus Drive, Stanford, CA, 94305, USA.
| | - Imelda Balboni
- Department of Pediatrics, Division of Allergy, Immunology and Rheumatology, Stanford University School of Medicine, 291 Campus Drive, Stanford, CA, 94305, USA.
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Bock M, Heijnen I, Trendelenburg M. Anti-C1q antibodies as a follow-up marker in SLE patients. PLoS One 2015; 10:e0123572. [PMID: 25881125 PMCID: PMC4400137 DOI: 10.1371/journal.pone.0123572] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 03/05/2015] [Indexed: 11/18/2022] Open
Abstract
In cross-sectional studies autoantibodies against complement C1q (anti-C1q) were found to be highly associated with active lupus nephritis. The aim of this retrospective study was to determine the value of anti-C1q as follow-up marker of disease activity and renal involvement in patients with systemic lupus erythematosus (SLE). Fifty-two patients with SLE and a minimum of three anti-C1q measurements during follow-up were analyzed. Anti-C1q levels correlated with global disease activity scores. In subgroup analyses, patients without renal involvement did not show a significant correlation between anti-C1q levels and disease activity. In contrast, in patients with renal involvement, anti-C1q levels correlated well with global disease activity. In addition, a positive correlation with the urine protein-to-creatinine ratio and anti-dsDNA antibody levels as well as a negative correlation with complement levels was observed. Anti-C1q antibodies were found to strongly correlate with parameters of SLE disease activity during follow-up, in particular with regard to renal involvement.
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Affiliation(s)
- Merete Bock
- Division of Internal Medicine, University Hospital Basel, Basel, Switzerland
- * E-mail:
| | - Ingmar Heijnen
- Division of Medical Immunology, Department of Laboratory Medicine, University Hospital Basel, Basel, Switzerland
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Eggleton P, Ukoumunne OC, Cottrell I, Khan A, Maqsood S, Thornes J, Perry E, Isenberg D. Autoantibodies against C1q as a Diagnostic Measure of Lupus Nephritis: Systematic Review and Meta-analysis. ACTA ACUST UNITED AC 2014; 5:210. [PMID: 24955287 PMCID: PMC4062947 DOI: 10.4172/2155-9899.1000210] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVES To evaluate the diagnostic accuracy of C1q autoantibodies in identifying lupus nephritis (LN) in patients with systemic lupus erythematosus (SLE). DATA SOURCES AND METHODS Citation indexes were searched and 370 articles published from 1977 to 2013 were evaluated. The 31 selected studies included in the meta-analysis were cross-sectional in design. Among the 31 studies, 28 compared anti-C1q antibodies in 2769 SLE patients with (n=1442) and without a history of LN (n=1327). Nine studies examined anti-C1q in 517 SLE patients with active (n=249) and inactive LN (n=268). Hierarchical summary receiver operating characteristic (HSROC) random effects models were fitted to pool estimates of accuracy across the studies. RESULTS Anti-C1q antibodies discriminated between patients with and without a history of LN, with a median specificity of 73.5%. The HSROC model estimated the corresponding sensitivity to be 70.4%. A hypothetical patient with a 55% prior probability of having a history of LN as opposed to no history (the median prevalence across 28 eligible studies) would have a post-test probability of 76.4% following a positive test result (positive predictive value) or 33.0% following a negative test result (negative predictive value). For discriminating active from inactive LN the median specificity of anti-C1q antibodies was 80%, with a corresponding estimated sensitivity value 75.7% based on the HSROC model. A hypothetical patient with a 56% prior probability of active as opposed to inactive LN (the median prevalence across the 9 eligible studies) would have a post-test probability of 82.8% following a positive test result or 27.9% following a negative test result. CONCLUSIONS Although C1q antibodies are associated with lupus nephritis the post-test probabilities are not sufficiently convincing to provide reasonable certainty of the presence or absence of history of disease/active disease.
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Affiliation(s)
- Paul Eggleton
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, University of Exeter, Exeter, UK
| | - Obioha C Ukoumunne
- NIHR CLAHRC South West Peninsula (PenCLAHRC),University of Exeter Medical School, University of Exeter, Exeter, UK
| | - Isabel Cottrell
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, University of Exeter, Exeter, UK
| | - Asma Khan
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, University of Exeter, Exeter, UK
| | - Sidra Maqsood
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, University of Exeter, Exeter, UK
| | - Jemma Thornes
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, University of Exeter, Exeter, UK
| | - Elizabeth Perry
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, University of Exeter, Exeter, UK
| | - David Isenberg
- Centre for Rheumatology, Department of Medicine University College London, UK
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Abdel Kader MSEM, Abd Elaziz MM, Ahmed DH. Role of serum anti-C1q antibodies as a biomarker for nephritis activity in pediatric and adolescent Egyptian female patients with SLE. ACTA ACUST UNITED AC 2012; 6:489-98. [PMID: 23480832 PMCID: PMC3581052 DOI: 10.1517/17530059.2012.715632] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Objective To evaluate serum anti-C1q antibodies as a biomarker of systemic lupus erythematosus (SLE) flare and as a proposed noninvasive alternative to renal biopsy which is still the “gold standard” to determine renal activity in SLE. Methods Serum anti-C1q antibodies were measured in our patients (all were females), they were followed at the nephrology and pediatric nephrology units at the Faculties of Medicine of Cairo University and Misr University for science and technology (MUST). Our study included 120 patients in the pediatric and adolescent age group and they were categorized into three groups with (mean ± SD of 16.7 ± 3, 16.1 ± 2, 15.9 ± 3) respectively: Group 1 including 40 patients with SLE and active lupus nephritis; Group 2 including 40 patients with SLE and without active lupus nephritis, but with some extra renal activity mainly arthritis; and Group 3 including 40 healthy subjects. Results Anti-C1q antibodies were found to be significantly higher in patients with active lupus nephritis than those without active nephritis than control individuals with a median (range) of [27.5 (14 – 83), 9 (2.5 – 30), 7 (2 – 13)] respectively. In those with active lupus nephritis, anti-C1q was found to correlate significantly with other parameters assessing lupus nephritis activity like C3 (r = -0.33, p < 0.04), C4 (r = -0.32, p < 0.044), daily urinary protein excretion (r = 0.32, p < 0.036), renal SLEDAI (r = 0.64, p < 0.001), and activity index (r = 0.71, p < 0.001). Conclusions Anti-C1q antibodies can be used as a considerable marker for LN activity in that age group with 97.5% sensitivity and 65% specificity with the cutoff level 12 U/l. These levels are clearly higher than those for traditional markers of disease activity such as C3/C4 consumption and anti-dsDNA.
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Affiliation(s)
- Mohamed Salah Eldin Mohamed Abdel Kader
- Misr University for Science and Technology (MUST), Faculty of Medicine, Department of Pediatrics , Villa 1, Queen Zebeada Square, Mohandseen Cairo 12411 , Egypt +00201223100406 ; +0020233044431 ;
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Gilliam BE, Ombrello AK, Burlingame RW, Pepmueller PH, Moore TL. Measurement of autoantibodies in pediatric-onset systemic lupus erythematosus and their relationship with disease-associated manifestations. Semin Arthritis Rheum 2011; 41:840-8. [PMID: 22177108 DOI: 10.1016/j.semarthrit.2011.09.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2011] [Revised: 09/20/2011] [Accepted: 09/27/2011] [Indexed: 12/30/2022]
Abstract
OBJECTIVE To evaluate an autoantibody profile in pediatric-onset systemic lupus erythematosus (SLE) patients to determine clinical and statistical associations with disease-associated manifestations. METHODS Sera from 53 SLE patients and 22 healthy individuals were collected. Antibodies to C1q, histone, chromatin, ribosomal P, dsDNA, and high-avidity dsDNA were measured by enzyme-linked immunosorbent assays. Patient records were evaluated for clinical and laboratory associations. RESULTS The most prevalent autoantibodies found in the SLE cohort were anti-C1q antibodies (n = 32, 60%), which correlated significantly with proteinuria and decreased complement levels (P < 0.05). Anti-C1q and antihistone antibodies were significantly elevated in patients with class III/IV nephritis compared with class I/II/V nephritis (P = 0.041). SLE patients with active nephritis at the time of sample collection demonstrated significantly elevated levels of anti-C1q antibodies compared with those without active nephritis, also exhibiting 100% sensitivity for active nephritis, proteinuria, and urinary casts. Antibodies to C1q, dsDNA, histone, and chromatin were significantly elevated in patients with active disease (P < 0.01). Chart-documented anti-dsDNA antibodies were positive in 28 SLE patients, INOVA anti-dsDNA antibodies in 25 patients, and high-avidity anti-dsDNA antibodies in 8 patients. Antihistone correlated significantly with leukopenia and hemolytic anemia (P < 0.05). CONCLUSIONS This study indicates the importance of measuring anti-C1q antibodies in pediatric-onset SLE patients because elevated anti-C1q antibodies may be more indicative of renal disease activity, showing significant correlation with proteinuria, urinary casts, and active nephritis. Antibodies to C1q, histone, chromatin, and dsDNA exhibited the strongest association with clinical features, indicating the importance of measuring all of these antibodies in pediatric-onset SLE patients.
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Affiliation(s)
- Brooke E Gilliam
- Division of Adult and Pediatric Rheumatology, St. Louis University School of Medicine, St. Louis, MO 63104, USA
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C1q and anti-C1q antibody levels are correlated with disease severity in Chinese pediatric systemic lupus erythematosus. Rheumatol Int 2009; 31:501-5. [PMID: 20033414 DOI: 10.1007/s00296-009-1257-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2009] [Accepted: 11/28/2009] [Indexed: 10/20/2022]
Abstract
The aim of this study was to measure the level of serum complement lq(Clq) and anti-C1q antibodies (ClqAb) in pediatric systemic lupus erythematosus (PSLE), and then analyze the correlation between the levels of serum Clq and ClqAb with disease activity and kidney damage. We investigated 90 PSLE patients, including 43 patients in active stage and 47 patients in remission. Our results showed that the level of serum Clq of PSLE patients was significantly lower than the level of healthy children and children with other rheumatic diseases. In contrast, the level of ClqAb of PSLE patients was significantly higher than the other groups. The level of serum Clq was negatively correlated with systemic lupus erythematosus (SLE) disease active index (SLEDAI) and the level of ClqAb was positively correlated with SLEDAI and kidney damage. The sensitivity of using ClqAb levels to diagnose PSLE was 95.6% and the specificity was 97.5%. 93.0% SLE patients who had high C1qAb levels also showed kidney damage. Therefore, the levels of C1q and C1qAb in serum reflect the disease severity of SLE. Decreased Clq and increased C1qAb is closely correlated with lupus nephritis (LN) in children and may have diagnosis values for child LN.
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Tsirogianni A, Pipi E, Soufleros K. Relevance of anti-C1q autoantibodies to lupus nephritis. Ann N Y Acad Sci 2009; 1173:243-51. [PMID: 19758158 DOI: 10.1111/j.1749-6632.2009.04750.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The first component of the classical pathway of the complement system (C1q) is considered to have a crucial role in the clearance of immune complexes (ICs) as well as in the removal of waste material originating from apoptotic cells. A prolonged exposure of C1q epitopes to the immune system could eventually lead to an autoimmune response against itself. Although autoantibodies against C1q are found in several diseases, their clinical interest originates from their strong association to active lupus nephritis (LN). Several studies indicate that anti-C1q autoantibodies could serve as a reliable serologic marker in the assessment of LN activity compared to other immunological tests. Additionally, it was suggested that anti-C1q autoantibodies could play a role in LN pathogenesis. Their potential pathogenic actions likely depend on genetic background, titers, Ig classes and subclasses, and specific epitopes of anti-C1q autoantibodies as well as C1q availability and allocation. It is still unclear which different types of anti-C1q autoantibodies dominate in each case and if their upregulation is pathogenic, an epiphenomenon of aberrant tissue damage, or compensatory to an uncontrolled immune response.
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Affiliation(s)
- Alexandra Tsirogianni
- Department of Immunology-Histocompatibility, Evangelismos General Hospital, Athens, Greece.
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Sinico RA, Rimoldi L, Radice A, Bianchi L, Gallelli B, Moroni G. Anti-C1q autoantibodies in lupus nephritis. Ann N Y Acad Sci 2009; 1173:47-51. [PMID: 19758131 DOI: 10.1111/j.1749-6632.2009.04746.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Anti-C1q antibodies are found in a variety of diseases, in addition to systemic lupus erythematosus (SLE), and in 3-5% of normal individuals. In particular, anti-C1q antibodies are detected at a high titer in 100% of patients with hypocomplementemic urticarial vasculitis and in 30-48% of SLE patients. Their titer correlates with active renal disease with a sensitivity of 44-100% and a specificity of 70-92%. An increase in anti-C1q antibody titer has been suggested to be able to predict renal flares in lupus nephritis so that monitoring anti-C1q might be valuable for the clinical management of SLE patients as a noninvasive biological marker. Recently our group studied 228 patients affected by lupus nephritis and found that the association of anti-C1q, C3, and C4, in a multivariate analysis, provided the best prediction of renal flares, particularly in patients with focal and diffuse proliferative lupus nephritis and in the absence of antiphospholipid antibodies.
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Affiliation(s)
- Renato Alberto Sinico
- Clinical Immunology Unit, Azienda Ospedaliera, Ospedale San Carlo Borromeo, Milano, Italy.
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Jesus A, Silva C, Carneiro-Sampaio M, Sheinberg M, Mangueira C, Marie S, Liphaus B. Anti-C1q Antibodies in Juvenile-Onset Systemic Lupus Erythematosus. Ann N Y Acad Sci 2009; 1173:235-8. [DOI: 10.1111/j.1749-6632.2009.04675.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Payne D, Houtman P, Browning M. Acute post-streptococcal glomerulonephritis associated with prolonged hypocomplementaemia. J Clin Pathol 2008; 61:1133-5. [PMID: 18820103 DOI: 10.1136/jcp.2008.056705] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
The case of a 6-year-old boy who presented with acute post-streptococcal glomerulonephritis is reported. C3 levels and complement alternative pathway activity remained low for at least 10 months after presentation, before returning to normal. There was no evidence of other renal disease. This case highlights that hypocomplementaemia in acute post-streptococcal glomerulonephritis may persist for several months, and that prolonged hypocomplementaemia does not exclude this diagnosis.
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Affiliation(s)
- D Payne
- Department of Immunology, Leicester Royal Infirmary, Leicester, UK.
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Kozyro I, Korosteleva L, Chernoshej D, Danner D, Sukalo A, Trendelenburg M. Autoantibodies against complement C1q in acute post-streptococcal glomerulonephritis. Clin Immunol 2008; 128:409-14. [DOI: 10.1016/j.clim.2008.04.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2008] [Revised: 04/18/2008] [Accepted: 04/18/2008] [Indexed: 10/22/2022]
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Potlukova E, Jiskra J, Limanova Z, Kralikova P, Smutek D, Mareckova H, Antosova M, Trendelenburg M. Autoantibodies against complement C1q correlate with the thyroid function in patients with autoimmune thyroid disease. Clin Exp Immunol 2008; 153:96-101. [PMID: 18505435 DOI: 10.1111/j.1365-2249.2008.03670.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Autoantibodies against complement C1q (anti-C1q) have been well described in patients with systemic lupus erythematosus, where they correlate with the occurrence of severe lupus nephritis. However, data on anti-C1q in organ-specific autoimmune diseases are scarce. In order to determine the prevalence of anti-C1q in patients with autoimmune thyroid disorders (AITD) and a possible association with thyroid function, we measured prospectively anti-C1q in 23 patients with Graves' disease (GD) and 52 patients with Hashimoto's thyroiditis (HT). Anti-C1q levels were correlated with parameters of thyroid function and autoantibodies against thyroperoxidase, thyroglobulin and thyroid stimulating hormone (TSH) receptor. Twenty-one patients with multi-nodular goitre and 72 normal blood donors served as controls. We found elevated concentrations of anti-C1q more frequently in patients with AITD than in controls: seven of 23 (30%) patients with GD and 11 of 52 (21%) patients with HT, compared with one of 21 (5%) patients with multi-nodular goitre and six of 72 (8%) normal controls. Anti-C1q levels did not correlate with thyroid autoantibodies. However, in GD absolute levels of anti-C1q correlated negatively with TSH and positively with free thyroxine (FT4) and triiodothyronine (FT3). In contrast, in HT, anti-C1q correlated positively with TSH levels. No correlation between TSH and thyroid autoantibodies was found. In conclusion, we found an increased prevalence of anti-C1q in patients with AITD and their levels correlated with the thyroid function in both GD and HT. This correlation seems to be independent of thyroid autoantibodies. Therefore, anti-C1q might point to a pathogenic mechanism involved in the development of AITD that is independent of classical thyroid autoantibodies.
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Affiliation(s)
- E Potlukova
- 3rd Clinic of Medicine, General Teaching Hospital and 1st Faculty of Medicine, Charles University, Prague, Czech Republic.
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Potlukova E, Kralikova P. Complement component c1q and anti-c1q antibodies in theory and in clinical practice. Scand J Immunol 2008; 67:423-30. [PMID: 18363591 DOI: 10.1111/j.1365-3083.2008.02089.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The complement system is a major part of the innate immunity. The first component of the classical pathway of complement activation, C1q, plays a crucial role in the clearance of immune complexes and apoptotic bodies from the organism. Autoantibodies against C1q (anti-C1q) have been found in a number of autoimmune and infectious diseases. They have been best described in patients with systemic lupus erythematosus, where they are thought to play a pathogenic role in lupus nephritis (LN). Their high negative predictive value for the occurrence of active proliferative LN, as well as their possible ability to indicate a renal flare as soon as 6 months in advance, have rendered anti-C1q antibodies a novel non-invasive tool in the detection of active LN.
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Affiliation(s)
- E Potlukova
- Third Clinic of Medicine, General Teaching Hospital, First Faculty of Medicine, Charles University, Prague, Czech Republic.
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