biostudies-literatureBirmingham DJNIDDK NIH HHSNCRR NIH HHS47-53https://www.ebi.ac.uk/biostudies/studies/S-EPMC4702227biostudies-literatureUnknown11(1)<h4>Background and objectives</h4>Autoantibodies to complement C1q (anti-C1q) are associated with the diagnosis of lupus nephritis. In this study, we compare anti-C1q IgG with another complement autoantibody, anti-C3b IgG, as a biomarker of lupus nephritis and lupus nephritis flare.<h4>Design, setting, participants, & measurements</h4>Our investigation involved the Ohio SLE Study, a prospective observational cohort of patients with recurrently active lupus who were followed bimonthly. Serum anti-C1q and anti-C3b IgG levels were assessed cross-sectionally by ELISA in 40 normal controls and 114 patients in the Ohio SLE Study (41 nonrenal and 73 lupus nephritis) at study entry, and longitudinally in a subset of patients in the Ohio SLE Study with anti-C1q-positive lupus nephritis in samples cClinical journal of the American Society of Nephrology : CJASNRelationship of Circulating Anti-C3b and Anti-C1q IgG to Lupus Nephritis and Its Flare.PMC4702227P01 DK55546UL1 RR025755P01 DK055546Gullo TRNdukwe EGRovin BHBirmingham DJDials SNagaraja HNHebert LABitter JEConroy SfalseRelationship of Circulating Anti-C3b and Anti-C1q IgG to Lupus Nephritis and Its Flare.<h4>Background and objectives</h4>Autoantibodies to complement C1q (anti-C1q) are associated with the diagnosis of lupus nephritis. In this study, we compare anti-C1q IgG with another complement autoantibody, anti-C3b IgG, as a biomarker of lupus nephritis and lupus nephritis flare.<h4>Design, setting, participants, & measurements</h4>Our investigation involved the Ohio SLE Study, a prospective observational cohort of patients with recurrently active lupus who were followed bimonthly. Serum anti-C1q and anti-C3b IgG levels were assessed cross-sectionally by ELISA in 40 normal controls and 114 patients in the Ohio SLE Study (41 nonrenal and 73 lupus nephritis) at study entry, and longitudinally in a subset of patients in the Ohio SLE Study with anti-C1q-positive lupus nephritis in samples c2016-01-01T00:00:00Z2016 Jan2025-04-22T19:50:43.205Z2019-03-27T02:06:20ZS-EPMC47022272670043910.2215/cjn.0399041510.2215/CJN.03990415