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Charles A. Dinarello

Bio: Charles A. Dinarello is an academic researcher from University of Colorado Denver. The author has contributed to research in topics: Interleukin & Cytokine. The author has an hindex of 190, co-authored 1058 publications receiving 139668 citations. Previous affiliations of Charles A. Dinarello include University of Guadalajara & Pennsylvania State University.


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Journal ArticleDOI
TL;DR: Results indicate that the LAL-reactive material is cellulose derived and is not pyrogenic.
Abstract: Hollow-fiber hemodialyzers containing cellulose-based membranes have been shown to produce positive results with the Limulus amebocyte lysate (LAL) test. This study was undertaken to determine whether endotoxin was causing the reaction. Rinses from 45 parallel-plate and hollow-fiber dialyzers from eight different manufacturers were tested using three lysates and four LAL methods. In addition, four in vitro cellular methods-human leukocytic pyrogen, lymphocytic activating factor, peritoneal macrophage, and arginase release-were used to evaluate endotoxin activity. The substance causing the reaction was identified using chromatographic methods. Results indicate that the LAL-reactive material is cellulose derived and is not pyro-genic.

63 citations

Journal ArticleDOI
TL;DR: Treatment with an IL-1 trap improved FMDBA without changing aPWV and reduced systemic inflammation in patients with CKD and rilonacept was well tolerated.
Abstract: Vascular endothelial dysfunction and increased arterial stiffness contribute to increased cardiovascular risk in patients with CKD who exhibit chronic systemic inflammation. Because chronic inflammation contributes to vascular dysfunction, blocking inflammation may reduce cardiovascular risk in patients with CKD. In a two-site, double-blind trial, we randomized 42 adult patients with stage 3-4 CKD who were already receiving optimal background therapy to receive either IL-1 trap rilonacept or placebo for 12 weeks. Coprimary end points included change in brachial artery flow-mediated dilation (FMDBA) and aortic pulse-wave velocity (aPWV) after 4, 8, and 12 weeks. Exploratory end points included change in high-sensitivity C-reactive protein (hsCRP), FMDBA after acute ascorbic acid infusion, and vascular endothelial cell protein expression of NADPH oxidase. Participants were 63±11 (mean±SD) years of age and 24% were women; mean eGFR was 38±13 ml/min per 1.73 m2 Compared with placebo, rilonacept improved FMDBA (baseline: 3.36%±2.06% [mean±SD], 12 weeks: 2.45%±2.29% with placebo and baseline: 3.75%±3.12%, 12 weeks: 4.86%±3.20% with rilonacept; P<0.01), without changing aPWV (P=0.56). Rilonacept also reduced hsCRP levels (median [interquartile range]) (baseline: 4.60 [1.90-8.22] mg/L, 12 weeks: 2.16 [0.92-7.38] mg/L; P<0.01) and endothelial cell NADPH oxidase expression (P<0.05). Acute infusion of ascorbic acid to inhibit superoxide production associated with a nonsignificant trend toward increased FMDBA in the placebo group (P=0.07) but not the rilonacept group (P=0.56). Rilonacept was well tolerated (five adverse events versus two with placebo). In conclusion, treatment with an IL-1 trap improved FMDBA without changing aPWV and reduced systemic inflammation in patients with CKD.

63 citations

Journal ArticleDOI
TL;DR: The importance of IL-1 or TNF, or both, in the pathogenesis of septic shock in patients must be proved by intervention studies showing improved survival when these cytokines are specifically blocked.
Abstract: The cytokines interleukin-1 (IL-1) and tumor necrosis factor (TNF) affect nearly every cell type by increasing the production of substances that promote local and systemic inflammatory processes. These include the up-regulation of the genes for cyclooxygenase and nitric oxide synthases, the release of platelet-activating factor, and the synthesis of endothelial adhesion molecules. Vasodilation, reduced tissue oxidation, and leukocyte-mediated necrosis are thought to contribute to organ failure and death in patients with septic shock. Although IL-1 and TNF are capable of inducing shock individually, of greater biological relevance is the synergistic action of these two cytokines. In animal models of disease, the roles of IL-1 and TNF have been defined by specifically inhibiting each cytokine. The anticytokine strategies for treatment of septic shock follow the same approach. Interleukin-1 can be blocked by reducing its synthesis [1]; infusing IL-1-receptor antagonist [2-4]; or administering soluble (extracellular) IL-1 receptors [5]. Blocking TNF can be accomplished by reducing its synthesis, infusing neutralizing antibodies, or administering TNF-binding proteins that are the soluble forms of p55 or p75 TNF receptors [6, 7]. These agents are now being assessed in clinical trials. What triggers the synthesis and release of IL-1 and TNF? The most potent agonist is bacterial lipopolysaccharide (or endotoxin), although it is important to remember that exotoxins from gram-positive bacteria and some fungal products can also stimulate IL-1 and TNF synthesis. Human blood monocytes are exquisitely sensitive to endotoxin, producing IL-1 and TNF in vitro in response to 25 to 50 pg/mL of endotoxin, a concentration achieved in the circulation during septic shock as reported by Casey and colleagues [8] in this issue of Annals. Human volunteers receiving an injection of 3 ng/kg of Escherichia coli-derived lipopolysaccharide show a dramatic increase in circulating TNF- (from <5 pg/mL to as much as 750 pg/mL, depending on the assay method). The theoretical maximum concentration of lipopolysaccharide in the blood of these volunteers would be approximately 25 pg/mL. Thus, it is of interest in understanding the pathogenesis of septic shock that Casey and colleagues report that circulating levels of IL-1 , TNF-, and IL-6 correlate with mortality in these patients. Moreover, when the data were analyzed by a lipopolysaccharide-cytokine score, which is based on lipopolysaccharide and cytokine concentrations, the correlation with mortality was highly significant. In the analysis of these patients, IL-6 was the cytokine that was most consistently elevated and that correlated best with mortality, as other studies have shown [9]. However, because IL-6 lacks the ability to induce a shock-like syndrome in animals or humans, the plasma IL-6 level is a marker rather than a cause of the syndrome. Interleukin-6 production appears to reflect biologically active IL-1 and TNF, in that blocking either of these latter cytokines significantly reduces the IL-6 level [10-12]. The importance of IL-1 or TNF, or both, in the pathogenesis of septic shock in patients must be proved by intervention studies showing improved survival when these cytokines are specifically blocked. Clearly, correlative clinical studies of plasma cytokine levels and mortality do not establish causality. Thus, the study by Casey and colleagues deserves a careful reading for other reasons. In a recent clinical trial of an anti-TNF monoclonal antibody for septic shock, increased survival was seen only in patients with the highest levels of circulating TNF- [9]. In a phase III trial of IL-1- receptor antagonist, a statistically significant improvement in survival was observed only in patients with sepsis who were at the highest risk for death [13]. Although the levels of circulating IL-1 are unknown in that study, we speculate that those patients with the highest risk for death would have shown the highest levels of IL-1 if it was collected and measured by validated methods [8, 14, 15]. Therefore, the value of measuring IL-1 and TNF- in the circulation may be to identify which patients are likely to benefit from anticytokine therapy. This information has the potential to improve the design of clinical trials and thus reduce the possibility that a useful therapy for septic shock will be disregarded because of apparent failure of the trial through misapplication of the therapy. Once a new therapy is approved, information on cytokine status can also reduce costs by identifying the appropriate patients for treatment. Although these are theoretical prospects, several pitfalls need to be overcome. First, plasma contains factors that interfere with cytokine assays (reviewed in [16]); these include nonspecific and specific binding proteins. Casey and colleagues carefully tested their assays to be sure that physiologically relevant amounts of the cytokines could be recovered. They checked samples with high immunoreactivity by diluting and retesting them, and they verified immunoassay results by bioassay. They also rapidly separated the plasma from the blood cells and thus avoided artifacts associated with clotted blood. The clinical study of cytokines is in disarray because of the proliferation of commercial assay kits that are poorly characterized by the manufacturers and are used indiscriminately by researchers. Casey and colleagues are to be commended for their careful attention to assay validation. A Danish group has recently validated an IL-1 enzyme-linked immunosorbent assay (ELISA) by column chromatography and bioassay procedures and showed a correlation between plasma IL-1 levels and mortality in patients with severe burn injury [15]. Second, validated assay systems can still yield different results. Although Casey and colleagues found that high circulating IL-1 levels were associated with high mortality, others have found contrasting results using different assay methods. Which method is correct? It is possible that each assay correctly answers different questions. Bioassays obviously measure biologically active forms of IL-1. These include mature 17-kd IL-1 and smaller fragments, regardless of whether IL-1 is free or bound to carrier proteins such as 2-macroglobulin. The radioimmunoassay used in some studies [17, 18] detects the relatively inactive 31-kd pro-IL-1 as well as bound and free forms of mature and fragmented IL-1 [14]. The IL-1 ELISA of Cistron that was used in Casey and colleagues' study detects about 10% to 15% pro-IL-1 [19] and does not detect IL-1 fragments nor IL-1 bound to carrier proteins. (Information provided on request from Richard Dondero of Cistron Biotechnologies. Clearly, such information is critical to the interpretation of assay results. Investigators pay a premium price for these assay kits and they have a right to demand that the kits are well characterized. All reputable kit manufacturers should furnish such information and data.) The bioassay and radioimmunoassay are better suited to determine if a host is producing IL-1 at all. It is important to remember that picomolar concentrations of IL-1 enhance host defense mechanisms [20] and that only excessive amounts promote disease. Free circulating IL-1 may exist only after natural binding proteins are diminished by disease or become saturated by excess IL-1 production resulting in a pathological state. Third, septic shock does not provide the clinician with the luxury of waiting several hours for the results of a cytokine assay before making a decision about treatment. We do not recommend routine cytokine assays for clinical decision making in septic shock. Interleukin-1 and TNF contribute to septic shock by increasing the expression of genes coding for the synthesis of small mediator molecules such as prostaglandins and nitric oxide. This increased expression can result in a 4- to 6-hour difference between peak cytokine levels in the circulation and the onset of clinical shock. We do recommend prospective studies designed to show a constellation of early clinical assessments that correlates with circulating cytokine levels and, at the same time, the risk for death in these patients. It is possible to determine in less than 4 hours the amount of IL-1 , TNF, and IL-6 messenger RNA in a small volume of blood using the polymerase chain reaction. If this method and cytokine assays can be applied to prospective trials, the design of anticytokine therapy trials and treatment of patients with septic shock could be improved. Studies in animals clearly show the disadvantage of late anticytokine treatment, and humans entered late into anticytokine intervention are probably also at a disadvantage.

63 citations

Journal ArticleDOI
TL;DR: C cultured human arterial smooth muscle cells differ from fibroblasts and lymphocytes in their response to human IL-1, which does not account for the growth-promoting activity for smooth muscle cell proliferation that is elaborated by activated macrophages (macrophage-derived growth factor).
Abstract: Monocyte products probably play a role in the initiation of smooth muscle cell proliferation in the arterial wall early in atherogenesis. Several groups have described mitogenic activity for arterial smooth muscle cells that is elaborated by mononuclear phagocytes (macrophage-derived growth factor). However, the biochemical nature of this mitogenic activity is unknown. Interleukin-1 (IL-1) is a well-characterized monocyte product that activates the growth of mitogen-stimulated lymphocytes and promotes the growth of fibroblasts. We tested whether IL-1 also affects the growth of arterial smooth muscle cells and might account for some of the mitogenic activity produced by activated monocytes. Highly purified human IL-1 did stimulate the growth of human fibroblasts of either adult or fetal origin. However, under identical conditions, IL-1 lacked significant mitogenic effects on human, bovine, rabbit, or canine arterial smooth muscle cells. This mediator also failed to stimulate the growth of cultured human or bovine vascular endothelial cells, another cell type that may respond to macrophage-derived growth factor. Interleukin-1 did not render smooth muscle cells competent to divide in the presence of plasma factors such as insulin (10(-6) M), or when growth of muscle cells was limited by incubation in a low (2%) concentration of serum. This monokine also failed to increase the mitogenic effect of purified platelet-derived growth factor on arterial smooth muscle cells incubated in serum-free medium. Thus, cultured human arterial smooth muscle cells differ from fibroblasts and lymphocytes in their response to human IL-1.(ABSTRACT TRUNCATED AT 250 WORDS)

62 citations

Journal ArticleDOI
TL;DR: It is demonstrated that blood collected in EDTA is optimal for measuring circulating TNFsRp55 and that this soluble receptor is present in health but elevated during endotoxemia.
Abstract: The tumor necrosis factor (TNF) soluble receptor derived from the cell surface p55 TNF receptor (TNFsRp55) is a naturally occurring substance generated during infection and inflammation. TNFsRp55 inhibits biologic effects of TNF. An RIA was developed to quantitate TNFsRp55 in human blood. Recovery of TNFsRp55 from blood anticoagulated with EDTA was optimal compared with recovery from serum or heparinized plasma. TNF did not interfere with the assay. With the RIA based on radiolabeled nonglycosylated Escherichia coli-derived recombinant TNFsRp55, a mean concentration of 198 +/- 15 pg/mL was found in 14 volunteers. When glycosylated CHO cell-derived TNFsRp55 was used, the mean level was 1656 +/- 95 pg/mL. Infusion of endotoxin into volunteers induced TNFsRp55, which peaked at 517 +/- 99 pg/mL for the E. coli-based RIA and 7300 +/- 1810 pg/mL for the CHO cell-based RIA. These findings demonstrate that blood collected in EDTA is optimal for measuring circulating TNFsRp55 and that this soluble receptor is present in health but elevated during endotoxemia.

62 citations


Cited by
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Journal ArticleDOI
01 Jun 1992-Chest
TL;DR: An American College of Chest Physicians/Society of Critical Care Medicine Consensus Conference was held in Northbrook in August 1991 with the goal of agreeing on a set of definitions that could be applied to patients with sepsis and its sequelae as mentioned in this paper.

12,583 citations

Journal ArticleDOI
29 Apr 1993-Nature
TL;DR: The ability to control the expression of genes encoding these molecules and to target specific cell types provides opportunities to develop new diagnostic and therapeutic agents to induce the regression of the lesions and, possibly, to prevent their formation.
Abstract: Atherosclerosis, the principal cause of heart attack, stroke and gangrene of the extremities, is responsible for 50% of all mortality in the USA, Europe and Japan. The lesions result from an excessive, inflammatory-fibroproliferative response to various forms of insult to the endothelium and smooth muscle of the artery wall. A large number of growth factors, cytokines and vasoregulatory molecules participate in this process. Our ability to control the expression of genes encoding these molecules and to target specific cell types provides opportunities to develop new diagnostic and therapeutic agents to induce the regression of the lesions and, possibly, to prevent their formation.

10,861 citations

Journal ArticleDOI
24 Jul 2008-Nature
TL;DR: The molecular pathways of this cancer-related inflammation are now being unravelled, resulting in the identification of new target molecules that could lead to improved diagnosis and treatment.
Abstract: The mediators and cellular effectors of inflammation are important constituents of the local environment of tumours. In some types of cancer, inflammatory conditions are present before a malignant change occurs. Conversely, in other types of cancer, an oncogenic change induces an inflammatory microenvironment that promotes the development of tumours. Regardless of its origin, 'smouldering' inflammation in the tumour microenvironment has many tumour-promoting effects. It aids in the proliferation and survival of malignant cells, promotes angiogenesis and metastasis, subverts adaptive immune responses, and alters responses to hormones and chemotherapeutic agents. The molecular pathways of this cancer-related inflammation are now being unravelled, resulting in the identification of new target molecules that could lead to improved diagnosis and treatment.

9,282 citations

Journal ArticleDOI
TL;DR: An update to the “Surviving Sepsis Campaign Guidelines for Management of Severe Sepsis and Septic Shock,” last published in 2008 is provided.
Abstract: Objective:To provide an update to the “Surviving Sepsis Campaign Guidelines for Management of Severe Sepsis and Septic Shock,” last published in 2008.Design:A consensus committee of 68 international experts representing 30 international organizations was convened. Nominal groups were assembled at ke

9,137 citations

Journal ArticleDOI
19 Dec 2002-Nature
TL;DR: The new appreciation of the role of inflammation in atherosclerosis provides a mechanistic framework for understanding the clinical benefits of lipid-lowering therapies and unravelling the details of inflammatory pathways may eventually furnish new therapeutic targets.
Abstract: Abundant data link hypercholesterolaemia to atherogenesis. However, only recently have we appreciated that inflammatory mechanisms couple dyslipidaemia to atheroma formation. Leukocyte recruitment and expression of pro-inflammatory cytokines characterize early atherogenesis, and malfunction of inflammatory mediators mutes atheroma formation in mice. Moreover, inflammatory pathways promote thrombosis, a late and dreaded complication of atherosclerosis responsible for myocardial infarctions and most strokes. The new appreciation of the role of inflammation in atherosclerosis provides a mechanistic framework for understanding the clinical benefits of lipid-lowering therapies. Identifying the triggers for inflammation and unravelling the details of inflammatory pathways may eventually furnish new therapeutic targets.

7,858 citations