Avacopan's potential to decrease MPO-ANCA titres concurrent with ameliorated activity in ANCA-associated vasculitis.

Area of Science:

• Immunology
• Rheumatology
• Pharmacology

Background:

• Microscopic polyangiitis (MPA) is an ANCA-associated vasculitis.
• Avacopan inhibits C5a, reducing neutrophil priming.
• The effect of avacopan on MPO-ANCA production is not fully understood.

Purpose of the Study:

• To investigate the effect of avacopan on MPO-ANCA levels in a patient with MPA.
• To explore the potential role of C5a inhibition in MPO-ANCA production.

Main Methods:

• Case report of a single MPA patient.
• Treatment with high-dose steroids and azathioprine.
• Addition of avacopan to the treatment regimen.
• Monitoring of MPO-ANCA titres.

Main Results:

• High MPO-ANCA levels persisted despite standard therapy.
• Addition of avacopan led to a reduction in MPO-ANCA titres.
• The patient had MPA without major organ damage.

Conclusions:

• Avacopan may reduce MPO-ANCA levels in MPA.
• C5a inhibition by avacopan might influence MPO-ANCA production.
• Further research with larger studies is needed to confirm these findings.