CTD/Immunological/vasculitis

Question 1

Rheumatoid arthritis

Answer 1

Diagnostic clues: ILD + polyarthritis (looks at distal clavicular resorption)

Imaging:

• Distribution: lower lobes
• Pleural disease:
  
  • Effusion +/- loculation
  • Thickening
  • Rounded atelectasis
• Parenchymal disease:
  
  • Fibrosis: UIP or NSIP type pattern
  • COP less common
  • Rheumatoid nodules/masses (<5%):
    
    • solitary vs multiple
    • Peripheral
    • Waxing/waning
    • May cavitate (50%)
    • NEED TO RULE OUT INFECTION/MALIGNANCY
• Airway disease:
  
  • Bronchiectasis/Bronchitis
  • Constrictive bronchiolitis
  • Follicular bronchiolitis (rare)
• Drug reaction related changes: steroids (atypical infection), gold (peribronchovascular GGO/COP), methotrexate (hypersensitivity pneumonitis/NSIP), Anti-TNF-alpha (atypical infections)
• Other: PAH, lymphadenopahty, mediastinal fibrosis, pericardial effusion/thickening

Micro: UIP/NSIP pattern, COP, rheumatoid nodules (pathognomonic)

DDx:

• IPF
• Scleroderma
• COP
• Asbestosis

Question 2

Scleroderma (systemic sclerosis)

Answer 2

Pathology:

• Autoimmmune inflammatory condition that can result in fibrosis and vascular abnormalities that can effect many orans
• Skin > arteries > esophagus > lungs
• 2 types (according to distribution of skin invovlement):
  
  • Diffuse Systemic sclerosis (66%)
  • Limited systemic sclerosis (33%):
    
    • Calcinosis
    • Raynauds
    • Esophageal dysmotility
    • Sclerodactyly : skin thickening of digits
    • Telangectasia
  • Overlap syndrome (20%) with other CTD

Epi: F < M (5:1)

HRCT:

• Esophageal dilatation (80%)
• Lymphadenopathy (65%)
• Pulmonary artery hypertension
• Pleural thickening
• ILD:
  
  • NSIP > UIP
  • Thin walled subpleural cysts (mid-upper lungs)
• OTHER:
  
  • distal phalangeal tuft resorption on x-ray
  • Calcinosis

DDx:

• other causes of UIP/NSIP
• aspriation pneumonia

Question 3

Systemic Lupus erythematosus

Answer 3

HRCT:

• ILD less common than other CTD: UIP >> NSIP
• Centrilobular nodules
• Bronchiectasis/bronchitis
• Other:
  
  • Lymphadenopathy
  • PE/infarcts: thromboembolic disease from antiphospholipid syndrome
  • GGO: infection, hemorrhage, lupus pneumonitis

Diagnosis: requires at least 4 of the 11

• Skin (80%): malar rash, photosensitivity, discoid lesions
• Oral ulcerations (15%)
• Non-erosive Arthropathy (85%)
• Serositis (50%)
• Rnela protienuria/casts (50%)
• Neurological epilepsy/psychosis (40%)
• Hematological: anaemia/pancytopenia
• Immunologic abnormalities
• • ANA

DDx:

• pulmonary oedema
• pneumonia
• Good pasture sydnrome
• Other causes of UIP/NSIP

Question 4

Hematopoeic Stemcell Transplantation

Answer 4

2 types: Autologous vs Allogenic

3 phases:

• Neutropenic phase (2-3 weeks post)
• Early phase (2-3 weeks to 100 days post)
• Late phase ( 100 days +)

Imaging:

• Neutropenic phase:
  
  • Opportunistic infection: fungal/bacterial
  • Pulmonary oedema
  • Diffuse alveolar hemorrhage
  • Drug toxicity: DAD, HP
• Early phase:
  
  • Opportunistic infection: PCP, CMV, other viral
• Late phase:
  
  • Constrictive bronchiolitis
  • organising pneumonia
  • NSIP
  • GVHD (allogenic):

Question 5

HIV

Answer 5

• HIV: retrovirus that infects T-Cells/macrophages/dendritic cells
• AIDS: CD4 (glycoprotein found on surface of immune cells) < 200 cells/microL

Infections:

• Any CD4:
  
  • Bacterial infection most common
  • Lung cancer risk
  • Lymphocytic interstitial pneumonia
  • Bronchiectasis
  • Multicentric castlemans disease
• CD4 >200:
  
  • TB post primary
• CD4 <200:
  
  • PJP (bilateral perihilar/diffuse GGO, pneumatocoeles)
  • TB primary progressive
  • Kaposi sarcoma:​ associated with HHV8, flame shaped nodules, peribronchovascular, halo sign, perilymphatic thickening, lymnphadenopathy
• CD4<100:
  
  • Fungal (cryptococcus, histoplasmosis, coccididomycosis)
  • Lymphoma: associated with EBV
• CD4 <50: mycobacterium

Question 6

Good pastures syndrome

Answer 6

Pathology:

• Anti-GBM disease
• Type 2 antibody reaction to glomerular basement membrane and alveoalr basement membrane –> autoantibodies that attact type 4 collagen alpha chain –> glomerulonephritis/pulmonary hemorrahge
• Anti-GBM antibodies >90%
• Associated: HLA-DR2, p-ANCA, c-ANCA
• Micro:
  
  • Renal: linear igG along gbm (ELISA)
  • lung: linear igG in alveolar basement membrane, hemorrhage

Epi:

• Bimodal: young males, older women
• M>F (higher predilection for males in younger population)
• Rare in general: 0.5/100000

Clinical:

• Acute SOB, hemoptysis, hematuria, proteinuria, renal failure
• Renal + lung involvement (70%)> Renal alonge (30%) > lung alone <10%
• Early therapy –> better prognosisw
• Rx: immunosuppression, plasmaphoresis, renal transplant

Imaging:

• Acute, diffuse, ground-glass opacities and conoslidation with hemoptysis and renal disease
• Acute:
  
  • Distribution: bilateral and spares peripheries, apicies, lung bases I(near costophrenic angles)
  • Patchy GGO/consolidation
  • usuall no interlobular septal thickening
• Subacute:
  
  • GGO/consoliodations
  • Interlobular septal thickening (crazy paving)
  • Intralobular reticulations/lines
  • Clears within 2 weeks of single episode
• Recurrent/chronic:
  
  • Fibrosis: reticular opacities, architectural distortion
  • Lobular sparing
• No pleural effusions –> suggest other diagnosis or concurrent failure

DDx:

• Wegener’s granulomatosis
• SLE
• Microscopic polyangitis
• Non-cardiogenic pulmonary oedema

Question 7

Wegener’s granulomatosis

Answer 7

Pathology:

• Immune mediated vascular injury (unknown mechanism)
• Multisystem
• Non-caseating, granulomatous, ANCA positive vasculitis
• small to medium vessels
• Common sites: upper and lower respiratory tract, renal

Epi:

• 3/100,000
• peak 40-50
• M=F
• Ethnicity: caucasian (95%) >>>>> african/american

Clinical

• Triad: sinus, lung, renal disease
• Most common: sinusitis, rhinitis, otitis media
• Upper air way( 92%) > lower air way (85%) > kidney (80%) > joints (67%) > eye/skin (~50%) > nerve (20%)

Dx: biopsy of paranasal sinus, lung, renal

Prognosis:

• renal failure –> common cause of death
• Subglottic stenosis (later in course)
• No treatment: 90% mortality within 2 years

Rx:

• Systemic steroids
• Cyclophosphamide
• Rituximab
• Prophylactic co-trimoxazole

Imaging: CT

AIRWAY:

• Location: Subglottic
• Focal large airway narrowing: circumferential/smooth/irregular

LUNG:

• Distribution: bilateral, apices and subpleural regions tend to be spared
• Multiple pulmonary nodules/masses (most common) +/- cavitation (50%) in larger nodules
• GGO +/- interlobular septal thickening (crazy paving): represents hemorrhage +/- lymphatic congestion
• Mosaic attenuation: arteriolar invovlement
• Halo/Reverse Halo sign
• Feeding vessel sign: vessel courses directly into nodule
• Tree-in-bud (arteriolar invovlement)
• Fibrosis: UIP type pattern > NSIP
• Parenchymal bands, bronchial wall thickening
• Pleural effusion
• Mediastinal lymphadenopathy

Nuc med: Gallium avid - can use to monitor disease activity

DDx (for air way)

• TB
• Tracheobronchial amyloid
• Relapsing polychondritis
• IBD

DDx (for lung): cavitatory lung mass

• Mets
• Septic emboli
• Lung abscess