By Eric L. Matteson, MD, MPH
Mayo Clinic – Minnesota
The new nomenclature for the various forms of systemic vasculitis has just been released. This system of naming vasculitis is an update of the vasculitis nomenclature, first published in 1994 as a result of work of the first International Chapel Hill Consensus Conference on the Nomenclature of Systemic Vasculitides.
What is meant by vasculitis nomenclature?
The system of nomenclature gives names and specific definitions to the most common forms of vasculitis. The naming helps physicians, patients and scientists to have a common understanding of what is meant when discussing a particular form of vasculitis. It specifies the name to be used when the disease a patient has fulfills the definition of the specific form of vasculitis, and provides these definitions.
How was the new nomenclature system developed?
Following months of preparation, experts in vasculitis from 12 countries, including experts involved in the original 1994 nomenclature effort, met in Chapel Hill, North Carolina in May, 2012 to discuss updates to the nomenclature system. Several months of work to refine the nomenclature followed, which resulted in the new system.
Why was an update of the naming system necessary?
Because of advances in our understanding of vasculitis, new names and categories of disease were necessary. At the same time, in updating the names, every effort was made to adopt names and definitions that were already widely accepted. As in the previous version, the new naming system uses the size of the involved blood vessel (small, medium, large) as an important organizing principle.
What is new in the 2012 version?
Major changes include the addition of a new category of vasculitis, referred to as ANCA associated Vasculitis, or AAV. This addition is in recognition of the important role that antineutrophil cytoplasmic antibodies (ANCA) play in these diseases. These diseases include microscopic polyangiitis (MPA), granulomatosis with polyangiitis (GPA, formerly Wegener’s), and eosinophilic granulomatosis with polyangiitis (EGPA, formerly Churg-Strauss). Polyarteritis nodosa (PAN) was recognized as not ANCA related.
Some other innovations include a category of variable vessel vasculitis (Cogan’s, Behçet’s) which are forms of vasculitis which do not involve a single predominant size of blood vessel. Also new is the category of Single Organ Vasculitis, which includes diseases like central nervous system vasculitis and leukocytoclastic vasculitis limited to the skin. This category recognizes that vasculitis can occur in a single organ, and may not (although occasionally could) become systemic, a fact that can have important management consequences.
As elsewhere in medicine, the use of eponyms (that is, naming a disease for a person) is being phased out in the naming of vasculitis. The use of each vasculitis eponym was thoughtfully deliberated by the experts to determine if a non-eponymous replacement term was suitable which better characterized the disease. In some cases, this was possible, for example the replacement of Churg-Strauss with EGPA, Wegener’s with GPA, and Henoch-Schönlein purpura with IgA vasculitis. In other cases, such as Takayasu’s, Behçet’s, and Cogan’s, suitable alternative names could not be agreed upon.
The new naming system recognizes advances in our understanding of vasculitis. It separates forms of vasculitis due to known causes such as infections from those without known causes, and is more specific for the disease process resulting in blood vessel inflammation. It will help workers in the field of vasculitis, and patients who suffer from them, to better communicate in a common language in pursuit of better understanding and treatment of these diseases.
Names for Vasculitides Adopted by the 2011-2012 International Chapel Hill Consensus Conference Nomenclature of the Vasculitides
Large Vessel Vasculitis (LVV)
Takayasu Arteritis (TAK)
Giant Cell Arteritis (GCA)
Medium Vessel Vasculitis (MVV)
Polyarteritis Nodosa (PAN)
Kawasaki Disease (KD)
Small Vessel Vasculitis (SVV)
ANCA-Associated Vasculitis (AAV)
Microscopic Polyangiitis (MPA)
Granulomatosis with Polyangiitis (Wegener’s) (GPA)
Eosinophilic Granulomatosis with Polyangiitis (Churg Strauss) (EGPA)
Immune Complex SVV
Cryoglobulinemic Vasculitis (CV)
IgA Vasculitis (Henoch-Schönlein)(IgAV)
Hypocomplementemic Urticarial Vasculitis (Anti-C1q Vasculitis)
Variable Vessel Vasculitis (VVV)
Behçet’s Disease (BD)
Cogan’s Syndrome (CS)
Single Organ Vasculitis (SOV)
Cutaneous Leukocytoclastic Angiitis
Primary CNS Vasculitis
Vasculitis Associated with Systemic Disease
Vasculitis Associated with Probable Etiology
Hepatitis C Virus-Associated Cryoglobulinemic Vasculitis
Hepatitis B Virus-Associated Vasculitis
Drug-Associated Immune Complex Vasculitis
Drug-Associated ANCA-Associated Vasculitis