Vasculitis is a group of disorders that destroy blood vesselsbyinflammation.[2] Both arteries and veins are affected. Lymphangitis (inflammation of lymphatic vessels) is sometimes considered a type of vasculitis.[3] Vasculitis is primarily caused by leukocyte migration and resultant damage. Although both occur in vasculitis, inflammation of veins (phlebitis) or arteries (arteritis) on their own are separate entities.
There are several different etiologies for vasculitides. Although infections usually involve vessels as a component of more extensive tissue damage, they can also directly or indirectly cause vasculitic syndromes through immune-mediated secondary events. Simple vascular thrombosis usually only affects the luminal process, but through the process of thrombus organization, it can also occasionally cause a more chronic vasculitic syndrome. The autoimmune etiologies, a particular family of diseases characterized by dysregulated immune responses that produce particular pathophysiologic signs and symptoms, are more prevalent.[6]
Primary systemic, secondary, and single-organ vasculitis are distinguished using the highest classification level in the 2012 Chapel Hill Consensus Conference nomenclature.[7]
Primary systemic vasculitis is catogized by the size of the vessels mainly involved. Primary systemic vasculitis includes large-vessel vasculitis, medium-vessel vasculitis, small-vessel vasculitis, and variable-vessel vasculitis.[7]
The 2012 Chapel Hill Consensus Conference defines large vessel vasculitis (LVV) as a type of vasculitis that can affect any size artery, but it usually affects the aorta and its major branches more frequently than other vasculitides.[7]Takayasu arteritis (TA) and giant cell arteritis (GCA) are the two main forms of LVV.[8]
Medium vessel vasculitis (MVV) is a type of vasculitis that mostly affects the medium arteries, which are the major arteries that supply the viscera and their branches. Any size artery could be impacted, though.[7] The two primary types are polyarteritis nodosa (PAN) and Kawasaki disease (KD).[8]
Variable vessel vasculitis (VVV) is a kind of vasculitis that may impact vessels of all sizes (small, medium, and large) and any type (arteries, veins, and capillaries), with no particular type of vessel being predominantly affected.[7] This category includes Behcet's disease (BD) and Cogan's syndrome (CS).[8]
The subset of illnesses known as secondary vasculitis are those believed to be brought on by an underlying ailment or exposure. Systemic illnesses (such as rheumatoid arthritis), cancer, drug exposure, and infection are the primary causes of vasculitis; however, there are still few factors that have a conclusively shown pathogenic relationship to the condition.[9] Vasculitis frequently coexists with infections, and several infections, including hepatitis B and C, HIV, infective endocarditis, and tuberculosis, are significant secondary causes of vasculitis.[10] Except for rheumatoid vasculitis, the majority of secondary vasculitis forms are exceedingly rare.[11]
Single-organ vasculitis, formerly known as "localized," "limited," "isolated," or "nonsystemic" vasculitis, refers to vasculitis that is limited to one organ or organ system. Examples of this type of vasculitis include gastrointestinal, cutaneous, and peripheral nerve vasculitis.[9]
Other organ functional tests may be abnormal. Specific abnormalities depend on the degree of various organs involvement. A brain SPECT can show decreased blood flow to the brain and brain damage.
The definite diagnosis of vasculitis is established after a biopsy of involved organ or tissue, such as skin, sinuses, lung, nerve, brain, and kidney. The biopsy elucidates the pattern of blood vessel inflammation.
Some types of vasculitis display leukocytoclasis, which is vascular damage caused by nuclear debris from infiltrating neutrophils.[12] It typically presents as palpable purpura.[12] Conditions with leucocytoclasis mainly include hypersensitivity vasculitis (also called leukocytoclastic vasculitis) and cutaneous small-vessel vasculitis (also called cutaneous leukocytoclastic angiitis).
An alternative to biopsy can be an angiogram (x-ray test of the blood vessels). It can demonstrate characteristic patterns of inflammation in affected blood vessels.
18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT)has become a widely used imaging tool in patients with suspected Large Vessel Vasculitis, due to the enhanced glucose metabolism of inflamed vessel walls.[13] The combined evaluation of the intensity and the extension of FDG vessel uptake at diagnosis can predict the clinical course of the disease, separating patients with favourable or complicated progress.[14]
Acute onset of vasculitis-like symptoms in small children or babies may instead be the life-threatening purpura fulminans, usually associated with severe infection.
Laboratory Investigation of Vasculitic Syndromes[15]
Disease
Serologic test
Antigen
Associated laboratory features
Systemic lupus erythematosus
ANA including antibodies to dsDNA and ENA [including SM, Ro (SSA), La (SSB), and RNP]
Nuclear antigens
Leukopenia, thrombocytopenia, Coombs' test, complement activation: low serum concentrations of C3 and C4, positive immunofluorescence using Crithidia luciliae as substrate, antiphospholipid antibodies (i.e. anticardiolipin, lupus anticoagulant, false-positive VDRL)
Goodpasture's disease
Anti-glomerular basement membrane antibody
Epitope on noncollagen domain of type IV collagen
Small vessel vasculitis
Microscopic polyangiitis
Perinuclear antineutrophil cytoplasmic antibody
Myeloperoxidase
Elevated CRP
Granulomatosis with polyangiitis
Cytoplasmic antineutrophil cytoplasmic antibody
Proteinase 3 (PR3)
Elevated CRP
Eosinophilic granulomatosis with polyangiitis
perinuclear antineutrophil cytoplasmic antibody in some cases
Myeloperoxidase
Elevated CRP and eosinophilia
IgA vasculitis (Henoch-Schönlein purpura)
None
Cryoglobulinemia
Cryoglobulins, rheumatoid factor, complement components, hepatitis C
Medium vessel vasculitis
Classical polyarteritis nodosa
None
Elevated CRP and eosinophilia
Kawasaki's Disease
None
Elevated CRP and ESR
In this table: ANA = antinuclear antibodies, CRP = C-reactive protein, ESR = erythrocyte sedimentation rate, dsDNA = double-stranded DNA, ENA = extractable nuclear antigens, RNP = ribonucleoproteins; VDRL = Venereal Disease Research Laboratory
Treatments are generally directed toward stopping the inflammation and suppressing the immune system. Typically, corticosteroids such as prednisone are used. Additionally, other immune suppression medications, such as cyclophosphamide and others, are considered. In case of an infection, antimicrobial agents including cephalexin may be prescribed. Affected organs (such as the heart or lungs) may require specific medical treatment intended to improve their function during the active phase of the disease.[citation needed]
^ abcdefghJennette, J. C.; Falk, R. J.; Bacon, P. A.; Basu, N.; Cid, M. C.; Ferrario, F.; Flores-Suarez, L. F.; Gross, W. L.; Guillevin, L.; Hagen, E. C.; Hoffman, G. S.; Jayne, D. R.; Kallenberg, C. G. M.; Lamprecht, P.; Langford, C. A.; Luqmani, R. A.; Mahr, A. D.; Matteson, E. L.; Merkel, P. A.; Ozen, S.; Pusey, C. D.; Rasmussen, N.; Rees, A. J.; Scott, D. G. I.; Specks, U.; Stone, J. H.; Takahashi, K.; Watts, R. A. (27 December 2012). "2012 Revised International Chapel Hill Consensus Conference Nomenclature of Vasculitides". Arthritis & Rheumatism. 65 (1). Wiley: 1–11. doi:10.1002/art.37715. ISSN0004-3591. PMID23045170.
^Luqmani, Raashid Ahmed; Pathare, Sanjay; Kwok-fai, Tony Lee (2005). "How to diagnose and treat secondary forms of vasculitis". Best Practice & Research Clinical Rheumatology. 19 (2). Elsevier BV: 321–336. doi:10.1016/j.berh.2004.11.002. ISSN1521-6942. PMID15857799.
^Dellavedova L, Carletto M, Faggioli P, Sciascera A, Del Sole A, Mazzone A, Maffioli LS (2015). "The prognostic value of baseline 18F-FDG PET/CT in steroid-naïve large-vessel vasculitis: introduction of volume-based parameters". European Journal of Nuclear Medicine and Molecular Imaging. 55 (2): 340–8. doi:10.1007/s00259-015-3148-9. PMID26250689. S2CID21446786.
^Burtis CA, Ashwood ER, Bruns DE (2012). Tietz Textbook of Clinical Chemistry and Molecular Diagnostics, 5th edition. Elsevier Saunders. p. 1568. ISBN978-1-4160-6164-9.
