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python3 << 'EOF' from pptx import Presentation from pptx.util import Pt import os path = "/tmp/workspace/attachments/87288f40-bc32-4894-a97d-24329f0fd88f/Lecture #6 Vasculitis.pptx" prs = Presentation(path) print(f"Total slides: {len(prs.slides)}\n") print("="*80) for i, slide in enumerate(prs.slides, 1): print(f"\n{'='*60}") print(f"SLIDE {i}") print(f"{'='*60}") for shape in slide.shapes: if shape.has_text_frame: text = shape.text_frame.text.strip() if text: print(f"[{shape.shape_type}] {text}") # Check for tables if shape.has_table: print(f"[TABLE]") for row in shape.table.rows: row_data = [] for cell in row.cells: row_data.append(cell.text.strip()) print(" | ".join(row_data)) EOF

Here is a detailed explanation of all 25 slides in Lecture #6: Immunology of Systemic Vasculitis:

Lecture #6 - Immunology of Systemic Vasculitis

Slide 1 - Title Slide

Topic: Immunology of Systemic Vasculitis
This lecture covers the immune mechanisms, classification, clinical features, and management of the major forms of systemic vasculitis.

Slide 2 - Introduction to Vasculitis

Core definition: Vasculitides are a group of multi-system diseases characterized by:
  • Inflammation of blood vessels
  • Endothelial injury
  • Tissue damage
Skin manifestations shown (clinical signs to recognize):
  • Livedo reticularis - net-like purplish skin discoloration
  • Petechiae - pinpoint red/purple spots
  • Urticarial lesions - hive-like raised wheals
  • Ulcers - open skin wounds from ischemia
  • Palpable purpura - raised, non-blanching spots (hallmark of small-vessel vasculitis)
  • Nodules - firm, raised lumps under skin
  • Necrosis - tissue death from vessel occlusion
The slide also shows the classic image of Giant Cell Arteritis/Temporal Arteritis to anchor the topic visually.

Slide 3 - Classification of Vasculitis

Introduces the framework for classifying vasculitis. The classification is primarily based on vessel size - a key organizing principle throughout the lecture.

Slide 4 - Chapel Hill Consensus Conference (CHCC)

The gold standard classification system:
  • First published in 1994
  • Revised and updated at the 2012 International CHCC to reflect new understanding
  • The 2012 CHCC system divides vasculitis according to vessel size into three categories:
    1. Small-vessel vasculitis
    2. Medium-vessel vasculitis
    3. Large-vessel vasculitis

Slide 5 - Leukocytoclastic Vasculitis (LCV)

LCV is a pattern, not a diagnosis:
  • It is a cutaneous manifestation and histopathologic pattern of small-vessel vasculitis
  • When LCV is found, you must search for the underlying cause
Underlying etiologies to consider:
  • Isolated cutaneous disease
  • Part of systemic vasculitis
  • Drug-induced
  • Infection-related
  • Autoimmune disease
  • Malignancy-associated
Immunologically, LCV may be:
  • Immune complex-mediated (complement activation, deposition of Ag-Ab complexes)
  • ANCA-associated (pauci-immune) - little or no immune complex deposition

Slide 6 - Cryoglobulinemic Vasculitis (Immune Complex Small-Vessel Vasculitis)

What are cryoglobulins? Serum proteins that precipitate at low temperatures and redissolve upon warming.
Three types:
TypeCompositionAssociation
Type 1Monoclonal Ig (usually IgM)B-cell malignancies (myeloma)
Type 2Monoclonal IgM (RF activity) + polyclonal IgGHepatitis C (strongly), B-cell malignancy, SLE
Type 3Polyclonal IgM (RF activity) + polyclonal IgGAutoimmune diseases
Organs most affected: Skin, joints, peripheral nerves, kidneys
Classic signs: Constitutional symptoms (fever, fatigue, myalgias) + palpable purpura on lower limbs (occurs in nearly all patients)
Treatment:
  • Treat the underlying disorder (e.g., antivirals for Hep C)
  • Avoid cold environments, wear warm clothing
  • Plasmapheresis and immunosuppression in severe cases

Slide 7 - ANCA-Associated Vasculitides (AAV) - Overview

The three cardinal AAV forms:
  1. GPA - Granulomatosis with Polyangiitis (formerly Wegener's)
  2. MPA - Microscopic Polyangiitis
  3. EGPA - Eosinophilic Granulomatosis with Polyangiitis (formerly Churg-Strauss)
All three are associated with Anti-Neutrophil Cytoplasmic Antibodies (ANCA).

Slide 8 - Pathogenesis of AAV: ANCA, Neutrophils & NETosis

Key concept - Controversy in classification:
  • Traditionally: classified by clinical phenotype (GPA vs. MPA)
  • New proposal: classify by ANCA specificity:
    • PR3-ANCA disease (C-ANCA pattern)
    • MPO-ANCA disease (P-ANCA pattern)
Mechanism: ANCA autoantibodies activate neutrophils, which then:
  • Degranulate
  • Form Neutrophil Extracellular Traps (NETs) - a process called NETosis
  • This directly damages vessel walls (pauci-immune mechanism - minimal immune complexes)

Slide 9 - Development of ANCAs

Normal state: MPO and PR3 are sequestered inside primary granules - hidden from the immune system.
How tolerance breaks down:
  1. Defective neutrophil apoptosis or impaired clearance of apoptotic cell fragments
  2. Prolonged antigen exposure leads to immune sensitization
  3. Infection/Molecular mimicry - antibodies against microbial antigens cross-react with neutrophil MPO or PR3 antigens
Clinical significance of ANCA type:
  • PR3-ANCA: Higher relapse rates
  • MPO-ANCA: Higher mortality

Slide 10 - Disease Mechanisms in AAV (Pauci-Immune Vasculitis)

Step-by-step pathogenic sequence:
  1. Resting neutrophils become primed (often by TNF or IL-18)
  2. ANCA binds to PR3 or MPO on the neutrophil surface in the intravascular space
  3. Full neutrophil activation occurs
  4. Neutrophils invade the vessel wall
  5. Formation of Neutrophil Extracellular Traps (NETs)
  6. Chronic extravascular inflammation continues
  7. Result: necrotizing vasculitis with minimal/no immune complex deposition ("pauci-immune")

Slide 11 - Granulomatosis with Polyangiitis (GPA) - formerly Wegener's

Classic triad of involvement: Upper airways + Lower airways + Kidneys
ENT/Upper airway features:
  • Chronic sinusitis, nasal crusting, bleeding, obstruction
  • Nasal septal perforation
  • "Saddle-nose" deformity - collapse of nasal bridge from cartilage destruction
Pulmonary features:
  • Lung nodules
  • Leukocytoclastic vasculitis in the lung
  • "Geographic" necrosis - neutrophilic microabscesses in vessel walls coalesce into large necrotic areas
Renal: Necrotizing crescentic pauci-immune glomerulonephritis → acute kidney injury
Labs: PR3-ANCA positive (c-ANCA pattern)
Other signs: Arthralgia, leukocytoclastic skin rash
Important mimicker: Cocaine use can cause local nasal/palatal necrosis and mimic AAV

Slide 12 - Microscopic Polyangiitis (MPA)

Key distinguishing features from GPA:
  • No upper airway disease (no sinusitis, no saddle-nose)
  • No granulomas (critical distinction from GPA)
  • Typically MPO-ANCA positive (P-ANCA pattern)
Clinical course: Typically acute
Major organ involvement:
  • Kidneys: Necrotizing glomerulonephritis with crescent formation; can present as isolated microscopic hematuria + hypertension
  • Lungs: Pulmonary capillaritis → life-threatening pulmonary hemorrhage - requires aggressive treatment
  • Skin: Palpable purpura, leukocytoclastic vasculitis, sometimes ulcers/necrosis
Biopsy finding: Pauci-immune on immunofluorescence (minimal complement/Ig deposition)

Slide 13 - Eosinophilic Granulomatosis with Polyangiitis (EGPA) - Churg-Strauss

Distinctive clinical pattern dominated by:
  • Upper airway disease (allergic rhinitis, nasal polyps)
  • Lower airway disease (asthma - often severe and refractory)
  • Neurological features: Mononeuritis multiplex or sensory peripheral neuropathy
Hallmark lab: Hypereosinophilia (blood and tissue eosinophilia)
ANCA: MPO-ANCA positive in ~40% of cases
Key clinical rule: The combination of adult-onset asthma + eosinophilia + vasculitis = think EGPA

Slide 14 - Henoch-Schönlein Purpura (HSP / IgA Vasculitis) - Non-ANCA Vasculitis

Classic tetrad:
  1. Nonthrombocytopenic purpura (lower extremities and buttocks)
  2. Arthritis
  3. Abdominal pain
  4. Renal disease (IgA nephropathy pattern)
Epidemiology: Most common vasculitis in children; can occur at any age
Trigger: ~2/3 of patients have an upper respiratory infection ~10 days before onset
Immunopathology:
  • Elevated serum IgA
  • IgA-containing circulating immune complexes
  • IgA deposition in inflamed vessel walls (diagnostic hallmark on biopsy)

Slide 15 - Differential Diagnosis of Small-Vessel Vasculitis

This slide presents a summary table/framework for distinguishing between small-vessel vasculitides, helping clinicians differentiate based on:
  • ANCA status (positive vs. negative)
  • Immunofluorescence pattern (pauci-immune vs. immune complex-mediated)
  • Organ involvement
  • Key labs and biopsy findings

Slide 16 - Medium-Vessel Vasculitis: Kawasaki Disease

Kawasaki Disease:
  • Acute, self-limited medium-vessel vasculitis
  • Affects children under 5 years primarily
Most important complication: Coronary artery aneurysm (CALs - coronary artery lesions)
Pathogenesis:
  • Likely triggered by an unknown infectious agent
  • Immune activation: monocytes/macrophages + lymphocytes release IL-6, TNF-α, IFN-γ
  • Cytokines cause endothelial injury and vessel wall inflammation
  • MMP-9 (matrix metalloproteinase-9) from activated endothelial cells contributes to aneurysm formation
Acute phase labs:
  • ↑ ESR, ↑ CRP
  • Neutrophilic leukocytosis
  • Thrombocytosis (especially after 1st week)

Slide 17 - Polyarteritis Nodosa (PAN)

Key features:
  • Systemic necrotizing vasculitis of medium-sized muscular arteries
  • Classically associated with Hepatitis B virus (HBV) infection (incidence decreased after HBV vaccination)
  • Typically ANCA-negative
  • Spares the pulmonary circulation (important distinguishing feature)
Clinical manifestations (from ischemia of medium arteries):
  • GI tract: Postprandial abdominal pain ("intestinal angina"), bowel ischemia/infarction
  • Peripheral nerves: Mononeuritis multiplex
  • Skin: Livedo reticularis, nodules, ulcers
  • Kidneys: Renovascular hypertension WITHOUT glomerulonephritis (no renal microvasculature involvement)
Labs: Anemia of inflammation, leukocytosis, thrombocytosis, elevated ESR and CRP

Slide 18 - Large-Vessel Vasculitis - Classification

Two major forms:
  1. Giant Cell Arteritis (GCA) - affects older adults (>50 years)
  2. Takayasu Arteritis (TA) - affects young women
Important distinction:
  • Polymyalgia Rheumatica (PMR) is closely related clinically to GCA
  • However, PMR does NOT have typical vascular lesions
  • PMR is NOT classified as a vasculitis

Slide 19 - Takayasu Arteritis (TA)

Profile: Young women, usually of Asian descent
Early symptoms (nonspecific):
  • Fever, cough, malaise, weight loss
  • Night sweats, myalgias, arthralgias
Late/vascular signs (ischemic - from stenosis/occlusion of aorta and branches):
  • Aortic insufficiency
  • Cerebral ischemia
  • Face and neck pain
  • Ocular ischemia (visual changes)
  • "Pulseless disease" - absent radial/brachial pulse (subclavian stenosis)

Slide 20 & 21 - Giant Cell Arteritis (GCA)

Pathology: Granulomatous inflammation of large and medium arteries, especially:
  • Branches of the carotid artery
  • Temporal artery (hence "temporal arteritis")
Biopsy finding:
  • Transmural thickening of the arterial wall
  • Lymphohistiocytic infiltrate
  • Multinucleate giant cells (pathognomonic)
Two major disease components:
  1. Granulomatous intramural inflammation - causes vascular wall remodeling and stenosis
  2. Extravascular inflammation - drives the systemic acute phase response, myalgias, and constitutional symptoms
Clinical features:
  • Headache (temporal)
  • Jaw claudication
  • Visual loss (ischemic optic neuropathy) - ophthalmic emergency
  • Elevated ESR and CRP
  • Often coexists with PMR

Slide 22 - Urticarial Vasculitis

Two forms:
  1. Normocomplementemic Urticarial Vasculitis (NUV) - normal complement levels; generally milder
  2. Hypocomplementemic Urticarial Vasculitis (HUV) - low complement; more systemic, associated with SLE
Key clinical feature:
  • Recurring urticarial rash lasting >24 hours
  • "Burns" rather than "itches" (unlike ordinary urticaria)
  • Leaves marks (hyperpigmentation) when it clears

Slide 23 - Behçet's Disease (Variable-Vessel Vasculitis)

Unique classification: Can affect vessels of all sizes (small, medium, and large) - a true variable-vessel vasculitis
Key features:
  • Idiopathic, multisystem, relapsing vasculitis
  • HLA-B51 association (strongest genetic link)
  • Geographic distribution: Found along the ancient Silk Road (Turkey, Middle East, Central Asia, East Asia) - prevalence 80-370/100,000 in endemic areas
Classic triad:
  • Recurrent oral aphthous ulcers
  • Genital ulcers
  • Uveitis (ocular inflammation)

Slide 24 - Management of Vasculitides

This slide covers the general treatment principles for vasculitis:
General approach:
  • Induction of remission - aggressive immunosuppression to stop active disease
  • Maintenance of remission - long-term lower-dose therapy to prevent relapse
  • Treatment of complications (renal, pulmonary, etc.)
Common agents used:
  • Corticosteroids - first-line for most vasculitides
  • Cyclophosphamide - for severe/organ-threatening AAV (GPA, MPA)
  • Rituximab (anti-CD20) - now preferred over cyclophosphamide for GPA/MPA remission induction
  • Methotrexate/Azathioprine - for maintenance
  • IVIG + Aspirin - for Kawasaki disease (to prevent coronary aneurysms)
  • Antiviral therapy - for HBV-associated PAN or HCV-associated cryoglobulinemia

Slide 25 - Thank You / Conclusion

Closing slide.

Summary Overview

Vessel SizeDiseaseKey ANCAKey Feature
SmallGPAPR3-ANCASaddle-nose, lung nodules, GN
SmallMPAMPO-ANCAPulmonary hemorrhage, no granulomas
SmallEGPAMPO-ANCA (~40%)Asthma + eosinophilia
SmallHSP/IgA VasculitisNegativeIgA deposits, children
SmallCryoglobulinemiaNegativeTypes I/II/III, Hep C, purpura
MediumPANNegativeHBV, ANCA-neg, no lung involvement
MediumKawasakiN/AChildren, coronary aneurysm
LargeGCANegativeTemporal HA, visual loss, elderly
LargeTakayasuNegativePulseless disease, young women
VariableBehçet'sNegativeHLA-B51, Silk Road, ulcers + uveitis
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