Systemic vasculitis

Large-vessel vasculitis The 2012 Chapel Hill Consensus Conference defines large vessel vasculitis (LVV) as a type of vasculitis that can affect any size artery, but usually affects the aorta and its major branches more frequently than other vasculitides. Takayasu's arteritis (TA) and giant cell arteritis (GCA) are the two main forms of LVV. Takayasu's arteritis (TA) is a large-vessel, granulomatous arteritis of unknown cause that primarily affects the aorta, significant branches of it, and (less frequently) the pulmonary arteries. The disease's symptoms can range from catastrophic neurological impairment to an asymptomatic condition brought on by impalpable pulses or bruits. Non-specific features include mild anemia, muscle pain, joint pain, unintentional weight loss, generally feeling unwell, night sweats, and fever. Giant cell arteritis (GCA) is the most common type of systemic vasculitis in adults. Polymyalgia rheumatica (PMR), headache, jaw claudication, and visual symptoms are the classic manifestations; however, 40% of patients present with a variety of occult manifestations. Medium vessel vasculitis Medium vessel vasculitis is a type of vasculitis that mostly affects the medium-sized arteries, which are the major arteries that supply the organs and their branches. Any size artery could be impacted, though. Kawasaki disease is a type of systemic vasculitis of medium-sized vessels with an acute onset that primarily affects young children. Fever, conjunctivitis, infection of the skin and mucous membranes, and swollen lymph node glands in the neck are the main signs and symptoms. Small vessel vasculitis Small vessel vasculitis (SVV) is separated into immune complex SVV and antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). Granulomatosis with polyangiitis is a rare immune-mediated systemic disease. Its cause is unknown. It manifests pathologically as an inflammatory response pattern in the kidneys, upper and lower respiratory tracts, and granulomatous inflammation, which includes cell death (necrosis). Microscopic polyangiitis belongs to the group of vasculitides associated with ANCA. Its distinct histology reveals a pauci-immune vasculitis, or necrotizing small vessel vasculitis, with minimal or no immune deposits. The most typical features of microscopic polyangiitis are kidney manifestations and general symptoms; lung involvement is also frequently observed. Immune complex small vessel vasculitis (SVV) is a vasculitis that primarily affects small vessels and has moderate to significant immunoglobulin and complement component deposits on the vessel wall. Cryoglobulinemic vasculitis is a type of small-vessel vasculitis that primarily affects the kidneys, skin, joints, and peripheral nervous system. Monoclonal immunoglobulins associated with an underlying B-cell lymphoproliferative disorder are known as type I cryovalent vasculitis. Cryoglobulins type II and III, also known as mixed cryoglobulinemia, are composed of polyclonal immunoglobulin (Ig)G and either monoclonal IgM or both with rheumatoid factor activity. The disease can present with a wide range of symptoms, including fatigue, purpura, or joint pain, to more serious complications, such as glomerulonephritis and widespread vasculitis, which can be fatal. Immunoglobulin A (IgA) vasculitis, formerly referred to as Henoch–Schönlein purpura, is a type of immune complex vasculitis that primarily affects IgA deposits in small vessels. Acute enteritis, glomerulonephritis, arthralgias and/or arthritis, and cutaneous purpura are the most common clinical manifestations. Children are more likely than adults to develop IgA vasculitis. Adults tend to have a more severe case. Anti-glomerular basement membrane disease is an uncommon kind of small vessel vasculitis that affects the kidney and lung capillary beds. This illness is also known by its eponym, "Goodpasture syndrome". Variable vessel vasculitis Variable vessel vasculitis 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. Cogan syndrome is an uncommon type of autoimmune systemic vasculitis that causes inflammation in the eyes and malfunctions the vestibulo-auditory system, usually resulting in neurosensory deafness but also tinnitus and vertigo. An upper respiratory tract infection, or less frequently, diarrhea, a dental infection, or an immunization, precedes the onset of the disease. == History ==

Kussmaul and Maier provided the first detailed description of systemic necrotizing arteritis in 1866. In 1919 Karl Theodor Fahr described acute arterial lesions which were always present in malignant nephrosclerosis. These injuries were the most severe and widespread in the kidneys and occurred less frequently and severely in other organs, particularly in the pancreas, adrenal glands, and intestines. Fahr believed that necrotizing arteriolitis was the primary cause of the lesions, malignant necrosis, and high blood pressure in these cases by narrowing the kidney vascular bed. == Signs and symptoms ==

Prodromal symptoms, constitutional abnormalities, and organ-specific manifestations are common in vasculitis patients. Patients may show up at the emergency room with life-threatening symptoms (such as coughing up massive amounts of blood or kidney failure) or with nonspecific signs and symptoms (such as a rash, fever, muscle pain, joint pain, a general sense of feeling unwell, or unintentional weight loss) at their family physician's office. The size, location, and extent of the vessels involved all affect the manifestations. Takayasu's arteritis (TA) is typically documented in three distinct phases. Constitutional inflammatory symptoms are often present during the first stage. Patients may report fever of unknown cause during this phase. Patients may refer to dorsal and thoracic pain in the following phase, and infrequently, neck pain as well. Arterial bruits, intermittent extremity claudication, decreased or absent pulses, and/or variations in arterial blood pressure among upper extremities are the hallmarks of the final phase. Giant cell arteritis (GCA) often exhibits a wide range of symptoms in its early stages, all of which are related to the localized consequences of systemic and vascular inflammation. The symptoms of GCA include jaw claudication, headaches, and tenderness in the scalp. The most common symptom is headache, which is restricted to the temporal region. Polyarteritis nodosa (PAN) can affect one organ or cause systemic failure as its clinical manifestation. Although any tissue may be impacted, PAN rarely affects the lungs for unclear reasons. A variety of clinical indicators, including common symptoms like fever, chills, weight loss, myalgia, and arthralgia, are typically present when PAN first manifests. Peripheral nerves and skin are typically involved in PAN. Skin manifestations include purpura, necrotic ulcers, subcutaneous nodules, and livedoid. Mononeuritis multiplex is the main neurological symptom, typically presenting as a drop in the foot or wrist. Hyperviscosity and/or thrombosis are the principal signs and symptoms of type I cryoglobulinemia. As a result, the conditions most frequently manifested as Raynaud's phenomenon, distal gangrene, ischemic ulcers, purpura, livedo reticularis, headache, retinal hemorrhages, and encephalopathy. Nonspecific systemic and musculoskeletal symptoms, such as cutaneous vasculitis and neuropathy, can also be seen in patients with mixed cryoglobulinemia. Ninety-five percent of cases of immunoglobulin A vasculitis start with a skin rash. Additionally, the illness manifests as the standard tripartite of symptoms of the gastrointestinal, kidney, and musculoskeletal systems. Recurrent urticaria, with skin eruptions primarily affecting the trunk, face, and upper extremities, is the primary clinical manifestation of hypocomplementemic urticarial vasculitis. Canker sores of the mouth are the defining feature of Behçet's disease and manifest in 98% of patients. Compared to oral lesions, genital aphthae are less common. == Diagnosis ==

To confirm the diagnosis, the initial evaluation consists of a thorough clinical assessment, serological tests, histology when possible, and radiography when necessary. Individuals experiencing active vasculitis frequently exhibit low levels of red blood cells and platelets in the bloodstream, and high levels of white blood cells in the blood. One of the main characteristics of eosinophilic granulomatosis with polyangiitis is eosinophilia. In patients with Takayasu arteritis, echocardiography is used to measure the degree of coronary stenosis and coronary artery blood flow. For the diagnosis and ongoing monitoring of large-vessel vasculitis, ultrasound may be helpful. Individuals diagnosed with giant cell arteritis may present with superficial temporal artery narrowing, blockage (occlusion), or halo sign (a dark patch surrounding the artery due to vessel wall swelling). Systemic vasculitides, such as polyarteritis nodosa, granulomatosis with polyangiitis, and eosinophilic granulomatosis with polyangiitis, can result in motor and sensory neuropathy. Neurological manifestations should be evaluated by nerve conduction testing. A sample (biopsy) of the affected tissue (such as the skin, the sinuses, lung, artery, nerve, or kidney) is used to make a definitive diagnosis of vasculitis by identifying the pattern of vessel inflammation. Determining the precise type of vasculitis may be made easier by searching for immunoglobulins and complement on sectioned tissue with immunofluorescence. Although a negative biopsy cannot rule out vasculitis, biopsies are especially useful in ruling out other causes. == Treatment ==

Treatment is targeted at the underlying cause. However, most vasculitides are treated with corticosteroid medications (e.g., methylprednisolone), since the underlying cause of the vasculitis is due to hyperactive immune system-mediated damage. Immunosuppressants, such as cyclophosphamide and azathioprine, may also be given. A systematic review of antineutrophil cytoplasmic antibody-positive vasculitides identified the best treatments depending on whether the goal is to induce or maintain remission and the severity of the vasculitides. == References ==