Treatment of Granulomatosis with polyangiitis

assess severity w/ BVAS/GPA score (Arth Rheum Dis 2009;68:1827) same as Microscopic polyangiitis.md

Mild disease

(no end-organ dysfxn; BVAS 0–3): MTX + steroids (Arth Rheum 2012;64:3472)

Severe disease

(end-organ damage incl. pulm hemorrhage, RPGN etc.; BVAS >3):

Induction:

[RTX 375 mg/m2/wk × 4 wk or 1000 mg on d1 + d15 or CYC 2 mg/kg/d × 3–6 mo or pulse 15 mg/kg q2–3 wk] + steroids 1 g IV × 3 d → ~1 mg/kg/d (Ann Rheum Dis 2015;74:1178). RTX preferred as ↓ toxicity (Arth Rheum 2021;73:1366).

Plasma exchange (PLEX)

may ↓ risk of ESRD in those most at risk (NEJM 2020;382:622; Arth Rheum 2021;73:1366).

Adding avacopan

(oral C5a receptor inhibitor) increases remission rate and allows ↓ steroids (NEJM 2021;384:599)

Maintenance

RTX q6mo superior to AZA or observ. (Ann Intern Med 2020;173:179) Relapse: mild → steroids ± MTX or AZA; severe → reinduce w/ steroids + RTX or CYC ↑ ANCA w/o clinical evidence of flare should not prompt Δ Rx (Annals 2007;147:611)