RT Journal Article T1 Anti-myeloperoxidase and proteinase 3 antibodies for nephritis flare prediction in anti-neutrophil cytoplasmic antibody-associated vasculitis. A1 Rodríguez, Eva A1 Latzke, Belén A1 Sierra, Milagros A1 Romera, Ana María A1 Siedel, Diego A1 Agraz, Irene A1 Soler, María José A1 García-Carro, Clara A1 Draibe, Juliana A1 de la Prada, Francisco José A1 Villacorta, Javier A1 Buxeda, Anna A1 Sierra-Ochoa, Adriana A1 Lozano, Inés A1 Durán, Xavier A1 Barrios, Clara A1 Pascual, Julio K1 ANCA-associated vasculitides K1 myeloperoxidase antibodies K1 pauci-immune necrotizing glomerulonephritis flare K1 proteinase-3 antibodies AB The value of myeloperoxidase (MPO) and proteinase 3 (PR3) antibody titres in the assessment of renal disease activity and flare prediction in patients with anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) is not well known. We performed a retrospective study including 113 AVV patients with renal biopsy-proven pauci-immune necrotizing glomerulonephritis from seven Spanish hospitals. The main inclusion criteria were assessment of MPO antibodies using multiplex flow immunoassay and PR3 antibody measurements using immunoassay chemiluminescence with an identical range of values for all participating centres. Serum MPO antibodies 3 ± 1.2 months before relapse were higher in patients who relapsed [19.2 ± 12.2 versus 3.2 ± 5.1 antibody index (AI); P  MPO level monitoring using multiplex flow immunoassay and PR3 measurements using immunoassay chemiluminescence are useful and sensitive tools for the prediction of renal relapse in the follow-up of AAV patients with renal disease and relevant surrogate markers of renal disease activity. YR 2022 FD 2022 LK http://hdl.handle.net/10668/19816 UL http://hdl.handle.net/10668/19816 LA en DS RISalud RD Apr 7, 2025