Urinary markers of the alternative and lectin complement pathway are increased in IgA vasculitis nephritis.

"CONFLICT OF INTEREST STATEMENT L.O. has previously undertaken expert advisory work for Omeros Corporation, Biocryst Pharmaceuticals Inc., and Novartis AG, who are developing drugs to target the complement system. All other authors declare no conflicts of interest."

"FUNDING This is a summary of independent research funded by a FAIR project grant (166185) (Funding Autoimmune Research Charity; registered UK Charity; number: 1176388) and carried out at the National Institute for Health Research (NIHR), Alder Hey Children's Research Facility. The views expressed are those of the author(s) and not those of the funders, NHS, the NIHR, or the Department of Health. This work was further supported by the UK's Experimental Arthritis Treatment Centre for Children (supported by Versus Arthritis, Alder Hey Children's NHS Foundation Trust, the Alder Hey Charity and the University of Liverpool) and partially carried out at the NIHR Alder Hey Clinical Research Facility. Kidney Research UK (Paed_RP_008_20 190 926) and the Wellcome Trust Institutional Strategic Support Fund (30158) have also financially supported some of the authors in this work."