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Showing papers by "William P. Arend published in 1995"


Journal ArticleDOI
TL;DR: The evidence to date shows that 5 of 6 criteria for identifying mediators of tissue damage in human autoimmune diseases are satisfied and the last criterion, prevention of clinical progression in patients with RA, is currently being evaluated.
Abstract: This review has summarized information published over the last 5 years on the presence and pathophysiologic role of IL-1 and TNF alpha in RA. The evidence to date shows that 5 of 6 criteria for identifying mediators of tissue damage in human autoimmune diseases are satisfied (Table 1). The last criterion, prevention of clinical progression in patients with RA, is currently being evaluated. Many new therapeutic approaches are currently being developed, including the use of soluble receptors to IL-1 or TNF, monoclonal antibodies to TNF alpha, a specific IL-1 receptor antagonist, and gene therapy with the latter molecule. It should be emphasized that both IL-1 and TNF alpha play important roles in normal host defense; the possible complications of blocking their production or effects need to be carefully evaluated in long-term studies. A recent review has emphasized that although IL-1 and TNF alpha have many overlapping biologic properties, each may exhibit distinct effects in joint disease (99). Anti-TNF treatment may be primarily antiinflammatory but blocking IL-1 may be more effective in preventing cartilage destruction (100). The possibility exists that simultaneous inhibition of TNF alpha and IL-1 may be more therapeutically efficacious than blockade of either agent alone, as was recently demonstrated with IL-1ra and soluble TNF receptors in bacterial cell wall-induced arthritis in rats (101). The next level of clinical studies in rheumatoid arthritis should include the use of two biologic response modifiers together, or one agent combined with a more traditional form of therapy.

946 citations


Journal ArticleDOI
TL;DR: It is concluded that there are important differences between the natural and recombinant forms of soluble IL‐1RI and thatIL‐1ra binds differently to these molecules and to cellular IL‐ 1RI.
Abstract: A recently described factor, interleukin-1 receptor antagonist binding factor (IL-1raBF), in serum of normal individuals is immunologically related to the interleukin-1 receptor type I (IL-1RI). It is presumably a soluble form of the receptor that binds exclusively to interleukin-1 receptor antagonist (IL-1ra). Recombinant soluble human IL-1RI expressed in COS cells (sIL-1RI) consists of the extracellular part of the receptor and binds all three known IL-1 species but preferentially to Il-1ra. We further characterized the sizes and binding of IL-1raBF and sIL-1RI to IL-1ra by polyacrylamide gel electrophoresis in the presence of sodium dodecylsulfate, ligand binding interference analyses, N-glycosidase treatment, concanavalin A affinity chromatography, and with the use of monoclonal antibodies (mAb) to human recombinant IL-1ra. We also evaluated the binding of IL-1ra to cellular IL-1RI on MRC5 fibroblasts and the interference afforded by the soluble receptors. The results show that the protein backbones of IL-1raBF and sIL-1RI are of similar size (approximately 35-40 kDa) and that there are differences in the glycosylation of the two molecules. These carbohydrates were necessary for optimal binding of both molecules to IL-1ra. Both factors blocked binding of IL-1ra to cellular IL-1RI, as did mAb to IL-1ra, but the sites on IL-1ra which bound to the mAb, and to IL-1raBF and sIL-1RI, differed. We conclude that there are important differences between the natural and recombinant forms of soluble IL-1RI and that IL-1ra binds differently to these molecules and to cellular IL-1RI.

36 citations