Criteria for the classification of Takayasu arteritis were developed by comparing 63 patients who had this disease with 744 control patients with other forms of vasculitis. Six criteria were selected for the traditional format elass$cation: onset at age 1 4 0 years, claudication of an extremity, decreased brachial artery pulse, >10 mm Hg difference in systolic blood pressure between arms, a bruit over the subclavian arteries or the aorta, and arteriographic evidence of narrowing or occlusion of the entire aorta, its primary branches, or large arteries in the proximal upper or lower extremities. The presence of 3 or more of these 6 criteria demonstrated a sensitivity of 90.5% and a specificity of 97.8%. A classification tree also was constructed with 5 of these 6 criteria, omitting claudication of an extremity. The classification tree demonstrated a sensitivity of 92.1% and a specificity of 97.0%.

Criteria for the classification of giant cell (temporal) arteritis were developed by comparing 214 patients who had this disease with 593 patients with other forms of vasculitis. For the traditional format classification, 5 criteria were selected: age 1 5 0 years at disease onset, new onset of localized headache, temporal artery tenderness or decreased temporal artery pulse, elevated erythrocyte sedimentation rate (Westergren) 2 5 0 mml hour, and biopsy sample including an artery, showing necrotizing arteritis, characterized by a predominance of mononuclear cell infiltrates or a granulomatous process with multinucleated giant cells. The presence of 3 or more of these 5 criteria was associated with a sensitivity of 93.5% and a specificity of 91.2%. A classijication tree was also constructed using 6 criteria. These criteria were the same as for the traditional format, except that elevated erythrocyte sedimentation rate was excluded, and 2 other variables were included: scalp tenderness and claudication of the jaw or tongue or on deglutition. The classification tree was associated with a sensitivity of 95.3% and specificity of 90.7%.

Criteria for the classification of Churg-Strauss syndrome (CSS) were developed by comparing 20 patients who had this diagnosis with 787 control patients with other forms of vasculitis. For the traditional format classification, 6 criteria were selected: asthma, eosinophilia >lo% on differential white blood cell count, mononeuropathy (including multiplex) or polyneuropathy, non-fixed pulmonary infiltrates on roentgenography, paranasal sinus abnormality, and biopsy containing a blood vessel with extravascular eosinophils. The presence of 4 or more of these 6 criteria yielded a sensitivity of 85% and a specificity of 99.7%. A classijication tree was also constructed with 3 selected criteria: asthma, eosinophilia > 10% on differential white blood cell count, and history of documented

Criteria for the classification of Wegener's gram ulomatosis (WG) were developed by comparing 85 patients who had this disease with 722 control patients with other forms of vasculitis. For the traditional format cZass@cation, 4 criteria were selected: abnormal urinary sediment (red cell casts or >5 red blood cells per high power field), abnormal findings on chest radiograph (nodules, cavities, or fixed infiltrates), oral ulcers or nasal discharge, and granulomatous inflammation on biopsy. The presence of 2 or more of these 4 criteria was associated with a sensitivity of 88.2% and a specificity of 92.0%. A classiJication tree was also constructed with 5 criteria being selected. These criteria were the same as for the traditional format, but included hemoptysis. The

The interleukin-1 receptor antagonist (IL-1Ra) is a member of the IL-1 family that binds to IL-1 receptors but does not induce any intracellular response. Two structural variants of IL-1Ra have previously been described: a 17-kDa form that is secreted from monocytes, macrophages, neutrophils, and other cells (sIL-1Ra) and an 18-kDa form that remains in the cytoplasm of keratinocytes and other epithelial cells, monocytes, and fibroblasts (icIL-1Ra). An additional 16-kDa intracellular isoform of IL-1Ra has recently been described in neutrophils, monocytes, and hepatic cells. Both of the major isoforms of IL-1Ra are transcribed from the same gene through the use of alternative first exons. The two promoters regulating transcription of the secreted and intracellular forms have been cloned, and some of the functional cis-acting DNA regions have been characterized. The production of IL-1Ra is stimulated by many substances including adherent IgG, other cytokines, and bacterial or viral components. The tissue distribution of IL-1Ra in mice indicates that sIL-1Ra is found predominantly in peripheral blood cells, lungs, spleen, and liver, while icIL-1Ra is found in large amounts in skin. Studies in transgenic and knockout mice indicate that IL-1Ra is important in host defense against endotoxin-induced injury. IL-1Ra is produced by hepatic cells with the characteristics of an acute phase protein. Endogenous IL-1Ra is produced in numerous experimental animal models of disease as well as in human autoimmune and chronic inflammatory diseases. The use of neutralizing anti-IL-1Ra antibodies has demonstrated that endogenous IL-1Ra is an important natural antiinflammatory protein in arthritis, colitis, and granulomatous pulmonary disease. Treatment of human diseases with recombinant human IL-1Ra showed an absence of benefit in sepsis syndrome. However, patients with rheumatoid arthritis treated with IL-1Ra for six months exhibited improvements in clinical parameters and in radiographic evidence of joint damage.

Summary: The interleukin-1 (IL-1), IL-18, and IL-33 families of cytokines are related by mechanism of origin, receptor structure, and signal transduction pathways utilized. All three cytokines are synthesized as precursor molecules and cleaved by the enzyme caspase-1 before or during release from the cell. The NALP-3 inflammasome is of crucial importance in generating active caspase-1. The IL-1 family contains two agonists, IL-1a and IL-1b, a specific inhibitor, IL-1 receptor antagonist (IL1Ra), and two receptors, the biologically active type IL-1R and inactive type II IL-1R. Both IL-1RI and IL-33R utilize the same interacting accessory protein (IL-1RAcP). The balance between IL-1 and IL-1Ra is important in preventing disease in various organs, and excess production of IL-1 has been implicated in many human diseases. The IL-18 family also contains a specific inhibitor, the IL-18-binding protein (IL-18BP), which binds IL-18 in the fluid phase. The IL-18 receptor is similar to the IL-1 receptor complex, including a single ligand-binding chain and a different interacting accessory protein. IL-18 provides an important link between the innate and adaptive immune responses. Newly described IL-33 binds to the orphan IL-1 family receptor T1/ST2 and stimulates T-helper 2 responses as well as mast cells.

No abstract

No abstract