Safety of glucocorticoid dose reduction in microscopic polyangiitis: a multicentre REVEAL cohort study

Area of Science:

• Rheumatology
• Clinical Immunology
• Pharmacology

Background:

• Microscopic polyangiitis (MPA) is a rare autoimmune vasculitis often treated with glucocorticoids (GCs).
• Long-term GC use is associated with significant adverse events.
• Optimizing GC tapering strategies is crucial for improving patient outcomes in MPA.

Purpose of the Study:

• To evaluate the safety and efficacy of reducing glucocorticoids (GCs) in patients diagnosed with microscopic polyangiitis (MPA).
• To determine if a 6-month GC dose target of ≤10 mg/day prednisolone-equivalent is associated with adverse outcomes.

Main Methods:

• Retrospective analysis of 223 MPA patients from the REVEAL cohort (2005-2023).
• Patients were stratified by 6-month GC dose (≤10 vs. >10 mg/day).
• Overlap weighting balanced baseline characteristics; Cox models assessed 10-year outcomes; logistic regression identified predictors of GC dose.

Main Results:

• Reducing GCs to ≤10 mg/day at 6 months showed no increased risk of all-cause mortality, infection-related mortality, or hospitalised infections.
• No significant increase in all relapses or major relapses was observed with lower GC doses.
• Treatment initiation from 2020 onwards was associated with achieving a ≤10 mg/day GC dose at 6 months (OR 5.54).

Conclusions:

• A 6-month GC target of ≤10 mg/day appears safe in MPA patients, not increasing mortality or relapse risks.
• While a feasible intermediate target, more aggressive GC reduction may be necessary for optimal infection risk reduction.
• Individualized GC tapering and close patient monitoring remain essential for managing MPA effectively.