Vasculitides
Recognizing and Treating Vasculitides Early
Vasculitides are serious diseases marked by inflammation of blood vessels, often affecting vital organs like the heart, lungs, or brain. With timely diagnosis and proper treatment, one-year survival exceeds 90%, underscoring the importance of early medical intervention.
Understanding Vasculitis: Causes and Cellular Clues
These conditions may occur on their own or as a secondary response to infections, systemic illnesses, cancers, medications, or toxic exposures (e.g., levamisole-contaminated cocaine). They may present with features like fibrinoid necrosis or granulomas, depending on the type and severity.
Classification of Vasculitides by Vessel Size
Large Vessel Vasculitides
Large vessel vasculitides affect the aorta and its major branches. The two main conditions are:
- Giant Cell Arteritis — seen almost exclusively in individuals older than 50 years. It can cause irreversible blindness in up to 15–20% of cases.
- Takayasu’s Arteritis — affects mostly women younger than 40 years old. It can lead to arterial limb claudication and/or strokes.
Medium Vessel Vasculitides
Medium vessel vasculitides include two main conditions:
- Polyarteritis Nodosa (PAN) — can affect individuals of all ages and cause infarctions of multiple organs, including the gut, kidneys, heart, muscle, and nerves. Before the development of the anti-hepatitis B virus vaccine and subsequent worldwide vaccination campaigns, more than half of PAN cases were due to HBV infection.
- Kawasaki Disease — seen mostly in children younger than 4 years old. It has a predilection for the coronary arteries.
Small Vessel Vasculitides
Small vessel vasculitides include several entities. The most well-known are associated with the presence of antineutrophil cytoplasm antibodies (ANCA) in the serum of affected patients.
ANCA-associated vasculitides include:
- Granulomatosis with Polyangiitis (Wegener’s)
- Microscopic Polyangiitis
- Eosinophilic Granulomatosis with Polyangiitis (Churg-Strauss syndrome)
These diseases can cause pulmonary-renal syndrome, characterized by lung hemorrhage and rapidly progressive renal failure.
Immune-complex mediated vasculitides (non-ANCA) include:
- Henoch-Schönlein purpura — usually self-limited, mostly seen in children
- Cryoglobulinemic vasculitis — most commonly associated with chronic hepatitis C virus infection
Anti-GBM (glomerular basement membrane) antibody disease — sometimes called Goodpasture disease when it affects lungs and kidneys — has been officially included in the list of small vessel vasculitides. It mainly causes renal disease (with linear deposition of anti-GBM antibodies in the glomeruli) and/or alveolar hemorrhage.
Other Vasculitides
- Behcet’s disease (or syndrome) is a particular vasculitis that can affect vessels of all sizes, including the veins.
- Isolated CNS vasculitis is an extremely challenging condition as it affects the vessels of the brain diffusely and can cause various clinical manifestations.
- Buerger’s disease (obliterans thromboangiitis) causes digital ischemia and gangrenous lesions, due to medium- and small-sized artery vasculitis and thrombosis, but also superficial vein thromboses and concerns almost exclusively smokers (classified as a medium-sized vessel vasculitis in Japan).
2012 Revised International Chapel Hill Consensus Conference
In 2012, the international Chapel Hill Consensus Conference updated the official nomenclature of vasculitides. The revised system provided clearer definitions and standardized classifications, helping clinicians and researchers better distinguish the different forms of vasculitis and improve communication in the field.
Classification of Vasculitides
- Large Vessel Vasculitis (LVV): Takayasu Arteritis (TAK) and Giant Cell Arteritis (GCA)
- Medium Vessel Vasculitis (MVV): Polyarteritis Nodosa (PAN) and Kawasaki Disease (KD)
- Small Vessel Vasculitis (SVV):
- ANCA-Associated Vasculitis (AAV): Microscopic Polyangiitis (MPA), Granulomatosis with Polyangiitis (Wegener’s) (GPA), and Eosinophilic Granulomatosis with Polyangiitis (Churg-Strauss) (EGPA)
- Immune Complex SVV: Anti-GBM Disease, Cryoglobulinemic Vasculitis, IgA Vasculitis (Henoch-Schönlein) (IgAV), and Hypocomplementemic Urticarial Vasculitis (Anti-C1q Vasculitis) (HUV)
- Variable Vessel Vasculitis (VVV): Behçet’s Disease (BD) and Cogan’s Syndrome (CS)
- Single Organ Vasculitis (SOV): Cutaneous Leukocytoclastic Angiitis, Cutaneous Arteritis, Primary CNS Vasculitis, and Isolated Aortitis
- Vasculitis Associated with Systemic Disease: Lupus Vasculitis, Rheumatoid Vasculitis, and Sarcoid Vasculitis
- Vasculitis Associated with Probable Etiology: Hepatitis C Virus-Associated Cryoglobulinemic Vasculitis, Hepatitis B Virus-Associated Vasculitis, Syphilis-Associated Aortitis, Serum Sickness-Associated Immune Complex Vasculitis, Drug-Associated Immune Complex Vasculitis, Drug-Associated ANCA-Associated Vasculitis, and Cancer-Associated Vasculitis.
Genetically determined vasculitides (such as DADA2 or VEXAS) are a newer, additional category in this group.