Abstract Background and Aims Patient and kidney outcome in ANCA glomerulonephritis (GN) remains unsatisfactory. Rituximab use failed to reduce the rate of infectious complications and demonstrates a significant rate of hypogammaglobulinaemia in ANCA vasculitis. Adjusting the rituximab dosage to the individual patient's need promises a reduction in treatment toxicity. Method Retrospective analysis of a single centre cohort of ANCA GN patients with disease flares between 2019 – 2022 using a stratified induction immunosuppression with rituximab and cyclophosphamide. Treatment intensity was adjusted to resolution of systemic inflammation and microscopic haematuria, peripheral CD19 cell count depletion and immunoglobulin G (IgG) levels. Results 45 patients (median age 57 years, 55.7% female, median eGFR 27 mls/min) were treated with a median dose of 1.5 grams Rituximab during induction (interquartile range, IQR 1 – 2 grams). 18 patients received concomitant intravenous cyclophosphamide pulses to control the acute inflammation (median cumulative dose of 2 grams, IQR 1.65 – 3 grams). Peripheral B cell depletion was 91.4% at 3 months and 90.3% at 6 months (<3 CD19 cells/ul). During the initial 12 months treatment, IgG level fell below 7g/l in 20 patients, below 5g/l in nine patients and below 3g/l in one patient. Seven patients required renal replacement therapy at diagnosis (15.6%). Five patients recovered kidney function and three patients developed end stage kidney disease (6.7%). Twelve infections were reported requiring antibiotic treatment (26.7%), seven severe infections were documented requiring hospitalisation (13.3%) and one patient died (2.2%). Conclusion An early assessment of treatment response assists adjusting vasculitis therapy. Adjusting management to the patient's individual immunological and treatment response may result in better outcome with less treatment toxicity.