Pulmonary Renal Syndromes - OnePager Summary
Autoimmune ANCA vasculitis (AAV): GPA (granulomatous with polyangiitis), EGPA (eosinophilic granulomatosis w polyangiitis), MPA (microscopic polyangiitis)
Anti-basement membrane: Goodpasture
Pulmonary Renal Syndromes (PRS) are life-threatening diseases with pulmonary hemorrhage (DAH) & renal failure (glomerulonephritis). Although pulmonary and renal involvement is the defining feature, PRS can affect many organs:
• Pulmonary: pulmonary hemorrhage (DAH), asthma in EGPA, tracheal (subglottic stenosis) in GPA, pulmonary nodules, asthma (EGPA)
• Renal: (AKI, proteinuria, hematuria)
• Inflammatory eye disease: scleritis, uveitis, episcleritis
• ENT: sinus, nasal, hearing loss, saddle nose deformity
• Cardiac (in EGPA)
• Digital ischemia
• Cutaneous: palpable purpura 2/2 vasculitis, ulcers, nodules
• Neuro: neuropathy, mononeuritis multiplex
WORKUP & DIAGNOSIS
Labs:
• BMP (quantify renal injury), Coags (r/o coagulopathy)
• CBC w differential (check eosinophil count for EGPA)
• Auto-antibodies: ANCA antibody, Anti-GBM antibody
• Urine: UA, Urine protein to creatinine (UPC) ratio
• Cardiac: consider BNP, troponin if concern for EGPA
• ESR and CRP (non-specific, ESR usually low in anti-GBM)
Other tests:
• CT chest to evaluate pulmonary involvement
• Bronchoscopy: confirm DAH, r/o infection
• Echocardiogram for EGPA (↓ LVEF, pericardial effusion)
• PFTs (outpatient; increased DLCO after recent DAN)
• EMG/NCS for mononeuritis multiplex/neuropathy
Diagnosis of PRS: Biopsy (gold standard) or serologies + symptoms (not-optimal but may be necessary)
PULMONARY FINDINGS:
• AAV or Goodpasture's cause pulmonary capillaritis leading to diffuse alveolar hemorrhage (DAH)
• Diffuse ground glass or consolidative opacities with sparing of the lung periphery is typically seen on chest CT.
• BAL reveals increasing blood retum in serial lavages and hemosiderin laden macrophages (diagnostic of DAH)
RENAL FINDINGS:
• U/A: microscopic or gross hematuria, RBC casts, low grade proteinuria
• Path: rapidly progressive (crescentic) glomerulonephritis (fibrinoid necrosis, hypercellular glomeruli, & cellular crescents)
• IF staining patterns in crescentic GN
by Nick Mark MD @nickmmark and Mithu Maheswaranathan MD @MithuRheum
#PRS #Pulmonary #Renal #Syndromes #differential #diagnosis #management #treatment
