title: Anti-C1q autoantibodies in lupus nephritis.
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.
authors.affiliation: Clinical Immunology Unit, Azienda Ospedaliera, Ospedale San Carlo Borromeo, Milano, Italy. renatoalberto.sinico@fastwebnet.it
authors.forename: Renato Alberto
authors.initials: RA
authors.lastname: Sinico
authors.forename: Laura
authors.initials: L
authors.lastname: Rimoldi
authors.forename: Antonella
authors.initials: A
authors.lastname: Radice
authors.forename: Laura
authors.initials: L
authors.lastname: Bianchi
authors.forename: Beniamina
authors.initials: B
authors.lastname: Gallelli
authors.forename: Gabriella
authors.initials: G
authors.lastname: Moroni
mesh_terms: D001323:Autoantibodies / Q000097:blood*; D015922:Complement C1q / Q000276:immunology*; D003176:Complement C3 / Q000276:immunology; D003181:Complement C4 / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D006801:Humans; D008181:Lupus Nephritis / Q000175:diagnosis*; D015999:Multivariate Analysis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D001323:Autoantibodies; D003176:Complement C3; D003181:Complement C4; D015922:Complement C1q