• 1
    Botto M, Walport MJ. C1q, autoimmunity and apoptosis. Immunobiology 2002; 205: 395406.
  • 2
    Pickering MC, Botto M, Taylor PR, Lachmann PJ, Walport MJ. Systemic lupus erythematosus, complement deficiency, and apoptosis. Adv Immunol 2000; 76: 227324.
  • 3
    Schejbel L, Skattum L, Hagelberg S, Ahlin A, Schiller B, Berg S, et al. Molecular basis of hereditary C1q deficiency—revisited: identification of several novel disease-causing mutations. Genes Immun 2011; 12: 62634.
  • 4
    Fremeaux-Bacchi V, Weiss L, Demouchy C, Blouin J, Kazatchkine MD. Autoantibodies to the collagen-like region of C1q are strongly associated with classical pathway-mediated hypocomplementemia in systemic lupus erythematosus. Lupus 1996; 5: 21620.
  • 5
    Trouw LA, Seelen MA, Duijs JM, Benediktsson H, Van Kooten C, Daha MR. Glomerular deposition of C1q and anti-C1q antibodies in mice following injection of antimouse C1q antibodies. Clin Exp Immunol 2003; 132: 329.
  • 6
    Coremans IE, Spronk PE, Bootsma H, Daha MR, van der Voort EA, Kater L, et al. Changes in antibodies to C1q predict renal relapses in systemic lupus erythematosus. Am J Kidney Dis 1995; 26: 595601.
  • 7
    Moroni G, Trendelenburg M, Del Papa N, Quaglini S, Raschi E, Panzeri P, et al. Anti-C1q antibodies may help in diagnosing a renal flare in lupus nephritis. Am J Kidney Dis 2001; 37: 4908.
  • 8
    Trendelenburg M, Marfurt J, Gerber I, Tyndall A, Schifferli JA. Lack of occurrence of severe lupus nephritis among anti-C1q autoantibody–negative patients. Arthritis Rheum 1999; 42: 1878.
  • 9
    Fremeaux-Bacchi V, Noel LH, Schifferli JA. No lupus nephritis in the absence of antiC1q autoantibodies? Nephrol Dial Transplant 2002; 17: 20413.
  • 10
    Wener MH, Uwatoko S, Mannik M. Antibodies to the collagen-like region of C1q in sera of patients with autoimmune rheumatic diseases. Arthritis Rheum 1989; 32: 54451.
  • 11
    Siegert C, Daha M, Westedt ML, van der Voort E, Breedveld F. IgG autoantibodies against C1q are correlated with nephritis, hypocomplementemia, and dsDNA antibodies in systemic lupus erythematosus. J Rheumatol 1991; 18: 2304.
  • 12
    Seelen MA, Trouw LA, Daha MR. Diagnostic and prognostic significance of anti-C1q antibodies in systemic lupus erythematosus. Curr Opin Nephrol Hypertens 2003; 12: 61924.
  • 13
    Trendelenburg M, Lopez-Trascasa M, Potlukova E, Moll S, Regenass S, Frémeaux-Bacchi V, et al. High prevalence of anti-C1q antibodies in biopsy-proven active lupus nephritis. Nephrol Dial Transplant 2006; 21: 311521.
  • 14
    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: 4751.
  • 15
    Akhter E, Burlingame RW, Seaman AL, Magder L, Petri M. Anti-C1q antibodies have higher correlation with flares of lupus nephritis than other serum markers. Lupus 2011; 20: 126774.
  • 16
    Katsumata Y, Miyake K, Kawaguchi Y, Okamoto Y, Kawamoto M, Gono T, et al. Anti-C1q antibodies are associated with systemic lupus erythematosus global activity but not specifically with nephritis: a controlled study of 126 consecutive patients. Arthritis Rheum 2011; 63: 243644.
  • 17
    Kohro-Kawata J, Wener MH, Mannik M. The effect of high salt concentration on detection of serum immune complexes and autoantibodies to C1q in patients with systemic lupus erythematosus. J Rheumatol 2002; 29: 849.
  • 18
    Sellar GC, Blake DJ, Reid KB. Characterization and organization of the genes encoding the A-, B- and C-chains of human complement subcomponent C1q: the complete derived amino acid sequence of human C1q. Biochem J 1991; 274: 48190.
  • 19
    Schaller M, Bigler C, Danner D, Ditzel HJ, Trendelenburg M. Autoantibodies against C1q in systemic lupus erythematosus are antigen-driven. J Immunol 2009; 183: 822531.
  • 20
    Hochberg MC, for the Diagnostic and Therapeutic Criteria Committee of the American College of Rheumatology. Updating the American College of Rheumatology revised criteria for the classification of systemic lupus erythematosus [letter]. Arthritis Rheum 1997; 40: 1725.
  • 21
    Bigler C, Schaller M, Perahud I, Osthoff M, Trendelenburg M. Autoantibodies against complement C1q specifically target C1q bound on early apoptotic cells. J Immunol 2009; 183: 351221.
  • 22
    Mannik M, Wener MH. Deposition of antibodies to the collagen-like region of C1q in renal glomeruli of patients with proliferative lupus glomerulonephritis. Arthritis Rheum 1997; 40: 150411.
  • 23
    Tsacheva I, Radanova M, Todorova N, Argirova T, Kishore U. Detection of autoantibodies against the globular domain of human C1q in the sera of systemic lupus erythematosus patients. Mol Immunol 2007; 44: 214751.
  • 24
    Wellmann U, Letz M, Herrmann M, Angermuller S, Kalden JR, Winkler TH. The evolution of human anti-double-stranded DNA autoantibodies. Proc Natl Acad Sci U S A 2005; 102: 925863.
  • 25
    Jiang H, Cooper B, Robey FA, Gewurz H. DNA binds and activates complement via residues 14-26 of the human C1q A chain. J Biol Chem 1992; 267: 25597601.
  • 26
    Jiang H, Robey FA, Gewurz H. Localization of sites through which C-reactive protein binds and activates complement to residues 14-26 and 76-92 of the human C1q A chain. J Exp Med 1992; 175: 13739.
  • 27
    Ying SC, Gewurz AT, Jiang H, Gewurz H. Human serum amyloid P component oligomers bind and activate the classical complement pathway via residues 14-26 and 76-92 of the A chain collagen-like region of C1q. J Immunol 1993; 150: 16976.
  • 28
    Roumenina LT, Ruseva MM, Zlatarova A, Ghai R, Kolev M, Olova N, et al. Interaction of C1q with IgG1, C-reactive protein and pentraxin 3: mutational studies using recombinant globular head modules of human C1q A, B, and C chains. Biochemistry 2006; 45: 4093104.
  • 29
    McGrath FD, Brouwer MC, Arlaud GJ, Daha MR, Hack CE, Roos A. Evidence that complement protein C1q interacts with C-reactive protein through its globular head region. J Immunol 2006; 176: 29507.
  • 30
    Garlatti V, Chouquet A, Lunardi T, Vives R, Paidassi H, Lortat-Jacob H, et al. C1q binds deoxyribose and heparan sulfate through neighboring sites of its recognition domain. J Immunol 2010; 185: 80812.
  • 31
    Toomayan GA, Chen LE, Jiang HX, Qi WN, Seaber AV, Frank MM, et al. C1-esterase inhibitor and a novel peptide inhibitor improve contractile function in reperfused skeletal muscle. Microsurgery 2003; 23: 5617.
  • 32
    Pflieger D, Przybylski C, Gonnet F, Le Caer JP, Lunardi T, Arlaud GJ, et al. Analysis of human C1q by combined bottom-up and top-down mass spectrometry: detailed mapping of post-translational modifications and insights into the C1r/C1s binding sites. Mol Cell Proteomics 2010; 9: 593610.
  • 33
    Roumenina LT, Sene D, Radanova M, Blouin J, Halbwachs-Mecarelli L, Dragon-Durey MA, et al. Functional complement C1q abnormality leads to impaired immune complexes and apoptotic cell clearance. J Immunol 2011; 187: 436973.
  • 34
    Radanova M, Vasilev V, Deliyska B, Kishore U, Ikonomov V, Ivanova D. Anti-C1q autoantibodies specific against the globular domain of the C1qB-chain from patient with lupus nephritis inhibit C1q binding to IgG and CRP. Immunobiology 2012; 217: 68491.
  • 35
    Schellekens GA, de Jong BA, van den Hoogen FH, van de Putte LB, van Venrooij WJ. Citrulline is an essential constituent of antigenic determinants recognized by rheumatoid arthritis-specific autoantibodies. J Clin Invest 1998; 101: 27381.
  • 36
    Schellekens GA, Visser H, de Jong BA, van den Hoogen FH, Hazes JM, Breedveld FC, et al. The diagnostic properties of rheumatoid arthritis antibodies recognizing a cyclic citrullinated peptide. Arthritis Rheum 2000; 43: 15563.