Polyangiitis – MPA, GPA, EGPA
OVERVIEW
- similar but different diseases
- positive Antineutrophil cytopasmic antibiodies (ANCA)
- renal histology (focal necrotizing, pauci-immune glomerulonephritis)
MPA (Microscopic Polyangiitis)
- no granulomas
- MPO-ANCA (myeloperoxidase)
- lower rates of upper respiratory tract involvement
- lower rate of relapse after immunosuppression
GPA (Granulomatosis With Polyangiitis) [archaic: Wegener’s granulmatosis]
- granulomas
- PR3-ANCA
- involvement of respiratory tract
- more recurrence
EGPA (Eosinophilic granulomatosis with polyangiitis) [archaic: Churg–Strauss syndrome]
- eosinophil-rich, necrotizing granulomatous inflammation
- necrotizing vasculitis predominantly affecting small to medium vessels
- involvement of respiratory tract
HISTORY
- rhinorrhea, bloody nasal discharge, oral/nasal ulcers, sinus pain
- haemoptysis
- pleuritic chest pain
- haematuria
- stridor (subglottic stenosis)
- myalgias
- arthalgia
- conjunctivitis
- corneal ulceration
- skin lesions
- at high risk of DVT
EXAMINATION
- pleural effusions
- pulmonary infiltrates
- skin vasculitis lesions
INVESTIGATIONS
- leucocytosis
- thrombocytosis
- elevated ESR and CRP
- normochromic, normocytic anaemia
Antineutrophil cytopasmic antibiodies (ANCA)
- PR3-ANCA = GPA
- MPO-ANCA (myeloperoxidase) = MPA
Tissue biopsy
- chronic inflammation
- granulomas
- renal biopsy: segmental necrotizing glomerulonephritis, crescents
Urine
- casts
- proteinuria
CXR
- pulmonary infiltrates
- nodules
- alveolar or pleural opacities
- hilar adenopathy
MANAGEMENT
Induction
- proportional to severity (localised, early systemic, generalized, severe, refractory)
- cyclophosphamide 2mg/kg/day
- methylprednisolone 15mg/kg/day for 3 days -> prednisone 1mg/kg PO OD
- PCP prophylaxis (co-trimoxazole)
Alternatives
- methotrexate
- plasma exchange
Critical Care
Compendium
Chris is an Intensivist and ECMO specialist at The Alfred ICU, where he is Deputy Director (Education). He is a Clinical Adjunct Associate Professor at Monash University, the Lead for the Clinician Educator Incubator programme, and a CICM First Part Examiner.
He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives. He was one of the founders of the FOAM movement (Free Open-Access Medical education) has been recognised for his contributions to education with awards from ANZICS, ANZAHPE, and ACEM.
His one great achievement is being the father of three amazing children.
On Bluesky, he is @precordialthump.bsky.social and on the site that Elon has screwed up, he is @precordialthump.
| INTENSIVE | RAGE | Resuscitology | SMACC