interleukin-8 and Hemolytic-Uremic-Syndrome

The life-threatening sequela of hemorrhagic colitis induced by Shiga toxins (Stx)-producing Escherichia coli (STEC) infections in humans is hemolytic uremic syndrome (HUS), the main cause of acute renal failure in early childhood. The key step in the pathogenesis of HUS is the appearance of Stx in the blood of infected patients because these powerful virulence factors are capable of inducing severe microangiopathic lesions in the kidney. During precocious toxemia, which occurs in patients before the onset of HUS during the intestinal phase, Stx bind to several different circulating cells. An early response of these cells might include the release of proinflammatory mediators associated with the development of HUS. Here, we show that primary human monocytes stimulated with Shiga toxin 1a (Stx1a) through the glycolipid receptor globotriaosylceramide released larger amounts of proinflammatory molecules (IL-1β, TNFα, IL-6, G-CSF, CXCL8, CCL2, CCL4) than Stx1a-treated neutrophils. The mediators (except IL-1β) are among the top six proinflammatory mediators found in the sera from patients with HUS in different studies. The molecules appear to be involved in different pathogenetic steps of HUS, i.e. sensitization of renal endothelial cells to the toxin actions (IL-1β, TNFα), activation of circulating monocytes and neutrophils (CXCL8, CCL2, CCL4) and increase in neutrophil counts in patients with poor prognosis (G-CSF). Hence, a role of circulating monocytes in the very early phases of the pathogenetic process culminating with HUS can be envisaged. Impairment of the events of precocious toxemia would prevent or reduce the risk of HUS in STEC-infected children.

Topics: Cells, Cultured; Cytokines; Hemolytic-Uremic Syndrome; Humans; Interleukin-8; Monocytes; Neutrophils; Shiga Toxin 1; Shiga-Toxigenic Escherichia coli; Trihexosylceramides

Infection with enterohemorrhagic Escherichia coli (EHEC) can result in severe disease, including hemorrhagic colitis and the hemolytic uremic syndrome. Shiga toxins (Stx) are the key EHEC virulence determinant contributing to severe disease. Despite inhibiting protein synthesis, Shiga toxins paradoxically induce the expression of proinflammatory cytokines from various cell types in vitro, including intestinal epithelial cells (IECs). This effect is mediated in large part by the ribotoxic stress response (RSR). The Shiga toxin-induced RSR is known to involve the activation of the stress-activated protein kinases (SAPKs) p38 and JNK. In some cell types, Stx also can induce the classical mitogen-activated protein kinases (MAPKs) or ERK1/2, but the mechanism(s) by which this activation occurs is unknown. In this study, we investigated the mechanism by which Stx activates ERK1/2s in IECs and the contribution of ERK1/2 activation to interleukin-8 (IL-8) expression. We demonstrate that Stx1 activates ERK1/2 in a biphasic manner: the first phase occurs in response to StxB1 subunit, while the second phase requires StxA1 subunit activity. We show that the A subunit-dependent ERK1/2 activation is mediated through ZAK-dependent signaling, and inhibition of ERK1/2 activation via the MEK1/2 inhibitors U0126 and PD98059 results in decreased Stx1-mediated IL-8 mRNA. Finally, we demonstrate that ERK1/2 are activated in vivo in the colon of Stx2-intoxicated infant rabbits, a model in which Stx2 induces a primarily neutrophilic inflammatory response. Together, our data support a role for ERK1/2 activation in the development of Stx-mediated intestinal inflammation.

Topics: Animals; Butadienes; Cell Line; Enterohemorrhagic Escherichia coli; Enzyme Activation; Epithelial Cells; Escherichia coli Infections; Extracellular Signal-Regulated MAP Kinases; Flavonoids; Glyceraldehyde-3-Phosphate Dehydrogenase (Phosphorylating); HEK293 Cells; Hemolytic-Uremic Syndrome; Humans; Inflammation; Interleukin-8; Intestinal Mucosa; JNK Mitogen-Activated Protein Kinases; MAP Kinase Kinase Kinases; Nitriles; p38 Mitogen-Activated Protein Kinases; Protein Kinases; Rabbits; RNA Interference; RNA, Small Interfering; Shiga Toxin 1; Shiga Toxin 2

Hemolytic uremic syndrome (HUS), a vascular disease characterized by hemolytic anemia, thrombocytopenia, and acute renal failure, is caused by enterohemorrhagic Shiga toxin (Stx)-producing bacteria, which mainly affect children. Besides Stx, the inflammatory response mediated by neutrophils (PMN) is essential to HUS evolution. PMN can release neutrophil extracellular traps (NET) composed of DNA, histones, and other proteins. Since NET are involved in infectious and inflammatory diseases, the aim of this work was to investigate the contribution of NET to HUS. Plasma from HUS patients contained increased levels of circulating free-DNA and nucleosomes in comparison to plasma from healthy children. Neutrophils from HUS patients exhibited a greater capacity to undergo spontaneous NETosis. NET activated human glomerular endothelial cells, stimulating secretion of the proinflammatory cytokines IL-6 and IL-8. Stx induced PMN activation as judged by its ability to trigger reactive oxygen species production, increase CD11b and CD66b expression, and induce NETosis in PMN from healthy donors. During HUS, NET can contribute to the inflammatory response and thrombosis in the microvasculature and thus to renal failure. Intervention strategies to inhibit inflammatory mechanisms mediated by PMN, such as NETosis, could have a potential therapeutic impact towards amelioration of the severity of HUS.

Topics: Acute Kidney Injury; Anemia, Hemolytic; Apoptosis; Bacterial Infections; Cells, Cultured; Child; Endothelial Cells; Extracellular Traps; Hemolytic-Uremic Syndrome; Humans; Interleukin-6; Interleukin-8; Kidney; Neutrophil Activation; Neutrophils; Reactive Oxygen Species; Shiga Toxin; Thrombocytopenia

Proinflammatory cytokines are related to the pathogenesis of enterohemorrhagic Escherichia coli (EHEC) infection and hemolytic-uremic syndrome (HUS). We assessed the kinetics of the release of cytokines such as neopterin, interleukin (IL)-6, IL-8 and tumour necrosis factor (TNF)-α and the soluble forms of type I and II TNF receptors during EHEC O111-induced HUS (EHEC O111/HUS). Fourteen patients with EHEC O111/HUS were enrolled in this study. Serum concentrations of all cytokines other than TNF-α were significantly elevated in patients with severe HUS compared with those in patients with mild HUS. Although serum concentrations of TNF-α were not significantly higher in patients with severe HUS, most patients with acute encephalopathy showed elevated TNF-α levels. Serum concentrations of these cytokines rapidly and markedly increased, and massive hypercytokinaemia developed 1 day before the diagnosis of HUS in patients with severe HUS. Changes in the number of white blood cells and concentration of serum lactate dehydrogenase were significantly larger between the onset of hemorrhagic colitis and the time of the diagnosis of HUS in patients with severe HUS compared with those in patients with mild HUS. Proinflammatory cytokines play an important role in the pathogenesis of EHEC infection and development of severe complications, including HUS and encephalopathy. Monitoring the cytokine profile may be useful for assessing disease activity of EHEC O111 infections.

Topics: Adolescent; Adult; Child; Cytokines; Enterohemorrhagic Escherichia coli; Escherichia coli Infections; Female; Hemolytic-Uremic Syndrome; Humans; Infant; Interleukin-6; Interleukin-8; L-Lactate Dehydrogenase; Leukocyte Count; Male; Neopterin; Receptors, Tumor Necrosis Factor; Tumor Necrosis Factor-alpha; Young Adult

Infection with Shiga toxin (Stx)-producing Escherichia coli can lead to development of hemolytic uremic syndrome (HUS). Patients with severe HUS often exhibit central nervous system (CNS) pathology, which is thought to involve damage to brain endothelium, a component of the blood-brain barrier. We hypothesized that this neuropathology occurs when cerebral endothelial cells of the blood-brain barrier, sensitized by exogenous TNF-alpha and stimulated by Stx1, produce and release proinflammatory cytokines. This was tested by measuring changes in cytokine mRNA and protein expression in human brain endothelial cells (hBEC) in vitro when challenged by TNF-alpha and/or Stx. High doses of Stx1 alone were somewhat cytotoxic to hBEC; Stx1-treated cells produced increased amounts of IL-6 mRNA and secreted this cytokine. IL-1beta and TNF-alpha mRNA, but not protein, were increased, and IL-8 secretion increased without an observed increase in mRNA. Cells pretreated with TNF-alpha were more sensitive to Stx1, displaying greater Stx1-induction of mRNA for TNF-alpha, IL-1beta, and IL-6, and secretion of IL-6 and IL-8. These observations suggest that in the pathogenesis of HUS, Stx can induce cytokine release from hBEC, which may contribute toward the characteristic CNS neuropathology.

Topics: Brain; Cells, Cultured; Cytokines; Endothelial Cells; Escherichia coli; Gene Expression Regulation; Hemolytic-Uremic Syndrome; Humans; Interleukin-1; Interleukin-6; Interleukin-8; RNA, Messenger; Shiga Toxin 1; Tumor Necrosis Factor-alpha

Thrombotic microangiopathy (TMA) has attracted attention as a complication of bone marrow transplantation (BMT). The association of Helicobacter pylori (H. pylori) with thrombotic thrombocytopenic purpura and hemolytic uremic syndrome (TTP/HUS) after BMT was studied. Among 74 consecutive patients undergoing transplantation, six developed TTP/HUS (the TTP/HUS group) and 68 did not (controls). These six patients were compared with the other 68 patients to investigate differences of the IL-12 and 8 levels, H. pylori and various clinical characteristics. The patients who developed TTP/HUS seemed not apparently different from those who did not in background characteristics, except that they had a significantly higher H. pylori-positive rate (p < 0.05). In the TTP/HUS group, however, the levels of interleukin-12 and interleukin-8 increased significantly during the leukocyte recovery after BMT and at the onset of TTP/HUS, respectively, to 45.8 +/- 57.6 pg/mL and 274.8 +/- 65.9 pg/mL (p < 0.05 for both), when compared with their levels of 5.0 pg/mL in the control group. Thus, H. pylori may play a role in the pathogenesis of TTP/HUS after BMT, with cytokines (interleukin-8 and interleukin-12) also being involved.

Topics: Adolescent; Adult; Bone Marrow Transplantation; Colony Count, Microbial; Female; Helicobacter Infections; Helicobacter pylori; Hemolytic-Uremic Syndrome; Humans; Interleukin-12; Interleukin-8; Leukocytes; Male; Middle Aged; Purpura, Thrombotic Thrombocytopenic; Retrospective Studies; Risk Factors; Transplantation Conditioning

Shiga toxin (Stx)-producing E. coli is a causative agent of the epidemic form of hemolytic uremic syndrome (HUS), the most common cause of acute renal failure in children. Endothelial injury and leukocyte activation are instrumental to the development of microangiopathic lesions. To obtain more insight into the mechanisms favoring endothelium-leukocyte interaction, we studied (1) the effect of Stx-2 on leukocyte adhesion and transmigration in human endothelial cells under flow; (2) the effect of Stx-2 on endothelial expression of monocyte chemoattractant protein-1 (MCP-1) and interleukin-8 (IL-8) and their functional role in the adhesive phenomena; and (3) the role of nuclear factor-kappaB (NF-kappaB) in endothelial chemokine expression.. For adhesion experiments, human umbilical vein endothelial cells (HUVEC) and human glomerular endothelial cells (GEC) were incubated for 24 hours with Stx-2 (25 pmol/L), with or without anti-IL-8 or MCP-1 antibodies, and then exposed to leukocyte suspension under flow (1.5 dynes/cm2). IL-8 and MCP-1 expression was evaluated in Stx-2 treated endothelial cells (6 hours) by Northern blot. NF-kappaB activity was assessed by electrophoretic mobility shift assay. The role of NF-kappaB in Stx-induced chemokines was evaluated by transfecting HUVEC with an adenovirus coding for IkappaBalpha.. Stx-2 significantly enhanced the number of leukocytes that adhered and then migrated across the endothelium. Stx-2 increased the expression of IL-8 and MCP-1, which was preceded by NF-kappaB activation. Blocking of endothelial IL-8 and MCP-1 with corresponding antibodies significantly inhibited Stx-induced leukocyte adhesion and migration either in HUVEC or GEC. Adenovirus-mediated gene transfer of IkappaBalpha down-regulated IL-8 and MCP-1 mRNA and also inhibited the adhesion and transmigration of leukocytes in Stx-treated HUVEC.. Stx-2 via a transcriptional activation mechanism specifically mediated by NF-kappaB up-regulates endothelial MCP-1 and IL-8. Both chemokines are important modulators of leukocyte adhesion and transmigration under flow. These findings might be relevant to understand the nature of microvascular lesions in HUS and open future perspectives for better treatment of microvascular thrombosis.

Topics: Adenoviridae; Cell Adhesion; Cell Movement; Cells, Cultured; Chemokine CCL2; Endothelium, Vascular; Gene Expression; Hemolytic-Uremic Syndrome; Humans; I-kappa B Proteins; Interleukin-8; Kidney Glomerulus; Leukocytes; NF-kappa B; NF-KappaB Inhibitor alpha; RNA, Messenger; Shiga Toxin 2; Transfection; Umbilical Veins; Up-Regulation

Leukocytes are implicated in the pathogenesis of diarrhea-associated hemolytic uremic syndrome (D(+) HUS). We hypothesized that increased circulating levels of granulocyte colony-stimulating factor (G-CSF), and the chemokines epithelial cell-derived neutrophil-activating protein-78 (ENA-78), growth related oncogen-alpha (GRO-alpha), macrophage inflammatory protein-1beta (MIP-1beta), and monocyte chemotactic protein-1 (MCP-1) are related to the severity of illness in Escherichia coli O157:H7 infections. We compared the circulating concentrations of these mediators in the course of E. coli O157:H7 enteritis, hemorrhagic colitis, and HUS. Our data show that, on admission, children with HUS presented 10-fold abnormally increased levels of G-CSF (p < 0.007), 3-fold increased MIP-1beta concentrations (p < 0.001), and 2-fold lower values of ENA-78 (p < 0.0001). One week later, a further 4-fold decrease in ENA-78 concentration was noted (p < 0.0001) whereas MIP-1beta levels returned to normal. HUS patients requiring peritoneal dialysis showed 6-fold increased G-CSF (p < 0.001) and 5-fold decreased ENA-78 (p < 0.001) levels. On admission, children with uncomplicated O157:H7 hemorrhagic colitis (HC) presented 3-fold abnormally increased concentrations of G-CSF (p < 0.001) and MIP-1beta (p < 0.0001). Those with O157:H7 enteritis but no bloody stools showed higher rates of abnormal GRO-alpha, MIP-1beta, and MCP-1 measurements than children with O157:H7 HC or HUS: GRO-alpha (50% enteritis, 36% HC, 17% HUS; p < 0.06), MIP-1beta (40% enteritis, 22% HC, 11% HUS; p < 0.02), MCP-1 (77% enteritis, 20% HC, 18% HUS; p < 0.0001). The data indicates that GRO-alpha, MIP-1beta, and MCP-1 are produced during E. coli O157:H7 enteritis, whether or not HC or HUS develops. Our data suggest that children with O157:H7 associated HUS may present abnormally increased circulating levels of G-CSF and decreased ENA-78 concentrations. The mechanisms responsible for leukocytes recruitment in O157:H7 infections are unclear and await further studies.

Topics: Adolescent; Case-Control Studies; Chemokine CCL2; Chemokine CCL4; Chemokine CXCL1; Chemokine CXCL5; Chemokines; Chemokines, CC; Chemokines, CXC; Chemotactic Factors; Child; Child, Preschool; Colitis; Enteritis; Escherichia coli Infections; Escherichia coli O157; Female; Granulocyte Colony-Stimulating Factor; Hemolytic-Uremic Syndrome; Humans; Intercellular Signaling Peptides and Proteins; Interleukin-8; Macrophage Inflammatory Proteins; Male; Peritoneal Dialysis

Diarrhea-associated hemolytic uremic syndrome (D+HUS) is characterized by endothelial injury and activation of inflammatory cytokines. Basic fibroblast growth factor (bFGF) is an angiogenic peptide released in response to vascular damage. The plasma concentrations and urinary excretion of bFGF during the course of D+HUS were determined, in comparison with the levels of various inflammatory cytokines, and changes were correlated with clinical and laboratory features of the disease. Serial plasma and urine samples were collected from 31 children with D+HUS, during the acute (days 1 to 7 of hospitalization) and recovery (through day 60 after discharge from the hospital) phases of the disease. The patients were enrolled in the multicenter trial of SYNSORB Pk (SYNSORB Biotech, Calgary, Alberta, Canada) treatment for D+HUS. bFGF, interleukin-1alpha (IL-1alpha), IL-8, and tumor necrosis factor-alpha levels were determined with enzyme-linked immunosorbent assays. bFGF was detected in urine and plasma samples more frequently than were IL-1alpha, IL-8, and tumor necrosis factor-alpha. There was an acute increase in urinary bFGF excretion, which returned to normal during convalescence. Urinary excretion of bFGF during the acute phase was higher among patients who required dialysis, compared with those who did not (48.9 +/- 15.0 and 28.9 +/- 9.0 pg/ml, respectively; P < 0.05). Plasma bFGF concentrations were persistently elevated throughout the period of hospitalization and the follow-up period among patients with D+HUS. Urinary excretion and plasma levels of bFGF were comparable for the SYNSORB Pk-treated (n = 19) and placebo-treated (n = 12) groups. Measurements of urinary and plasma concentrations of bFGF among patients with D+HUS may be useful indices for assessment of the severity of acute renal disease and the timing and adequacy of the systemic angiogenic process during early convalescence.

Topics: Adolescent; Child; Child, Preschool; Cytokines; Diarrhea; Fibroblast Growth Factor 2; Hemolytic-Uremic Syndrome; Humans; Infant; Interleukin-1; Interleukin-8; Osmolar Concentration

We monitored the levels of various cytokines and chemokines, as well as an adhesion molecule and factors related to vascular endothelial damage, in three patients with thrombotic thrombocytopenic purpura and hemolytic uremic syndrome after bone marrow transplantation. Measurements were done at the onset of this condition and during plasma exchange for treatment. At the onset of thrombotic thrombocytopenic purpura and hemolytic uremic syndrome, the levels of interleukin-8, thrombomodulin, and plasminogen activator inhibitor-1 were all markedly increased. A close relationship was observed between improvement in symptoms by plasma exchange and a decrease in interleukin-8 level, suggesting that this chemokine may be related to the development of thrombotic thrombocytopenic purpura and hemolytic uremic syndrome after bone marrow transplantation.

Topics: Adult; Biomarkers; Blood Coagulation Factors; Bone Marrow Transplantation; Cell Adhesion Molecules; Cytokines; Endothelium, Vascular; Female; Hematologic Neoplasms; Hemolytic-Uremic Syndrome; Humans; Interleukin-8; Male; Purpura, Thrombotic Thrombocytopenic; Transplantation, Homologous

Shiga toxin, produced by Escherichia coli O157:H7, is important for the pathogenicity of the epidemic form of hemolytic uremic syndrome (HUS). This toxin has recently been found to stimulate endothelin-1 synthesis in cultured endothelial cells in vitro.. We investigated endothelin and cytokine levels in sera during a large outbreak of E. coli O157:H7 infection in Osaka, Japan, in 1996. Eleven patients with HUS and 9 patients with hemorrhagic colitis at the onset of E. coli O157:H7 infection were studied.. Serum IL-6 (p < 0.01), IL-8 (p < 0.05), IL-10 (p < 0.001) and endothelin (p < 0.001) levels were significantly increased in patients with HUS compared to those with colitis only. The serum thrombomodulin level, a molecular marker of endothelial damage, also showed a significant positive correlation with serum IL-6 (p < 0.01), IL-8 (p < 0.01), IL-10 (p < 0.01) and endothelin (p < 0.001) levels. In a HUS patient, the increase in serum IL-10 and endothelin levels reached a plateau prior to the peak of serum creatinine levels.. Increased serum endothelin synthesis by Shiga toxin in vivo was proven in HUS secondary to E. coli O157:H7 infection. Increased serum endothelin and IL-10 levels were speculated to be associated with the development of HUS through vascular endothelial damage caused by E. coli O157:H7 infection.

Topics: Case-Control Studies; Colitis; Creatinine; Disease Outbreaks; Endothelin-1; Escherichia coli Infections; Escherichia coli O157; Female; Gastrointestinal Hemorrhage; Hemolytic-Uremic Syndrome; Humans; Interleukin-10; Interleukin-6; Interleukin-8; Japan; Male; Thrombomodulin; Time Factors

The objective of this study was to identify parameters indicating a risk for developing typical haemolytic uremic syndrome (D+HUS) during the prodromal phase of diarrhea caused by enterohaemorrhagic Escherichia coli (EHEC). Forty-eight children were studied prospectively with regard to inflammatory serum factors on admission to hospital. Ten patients developed D+HUS (group I), 15 suffered from viral-gastroenteritis (group IIa) and 23 from other types of bacterial gastroenteritis (group IIb). Mean levels of IL-8 tended to be elevated in group I compared to groups IIa and IIb. Neopterin and IL-10 levels particularly were significantly decreased in HUS in comparison to both gastroenteritis groups. Low IL-10 levels indicate a substantial disregulation of the immune response in HUS, as IL-10 downregulates the pro-inflammatory response and suppresses pro-coagulant activity in experimental endotoxemia. Our results suggest low neopterin, high IL-8 and especially low IL-10 levels are indicators of a high risk for developing HUS.

Topics: Bacterial Infections; Biomarkers; C-Reactive Protein; Child; Child, Preschool; Cytokines; Gastroenteritis; Hemolytic-Uremic Syndrome; Humans; Inflammation; Interleukin-10; Interleukin-6; Interleukin-8; Reference Values; Risk Factors; Tumor Necrosis Factor-alpha; Virus Diseases

Experimental data suggest that the host's inflammatory response is involved in the pathophysiology of verotoxin-producing Escherichia coli (VTEC)-associated hemolytic uremic syndrome (HUS). We compared the circulating levels of pro- [interleukin (IL)-6, IL-8] and anti-inflammatory [IL-10 and IL-1 receptor antagonist (Ra)] mediators on enrollment among children with HUS due to E. coli O157:H7, according to the severity of renal dysfunction. The latter was evaluated by the occurrence of oligoanuria, the requirement for dialysis, and a glomerular filtration rate (GFR)

Topics: Child; Child, Preschool; Cytokines; Escherichia coli; Female; Glomerular Filtration Rate; Hemolytic-Uremic Syndrome; Humans; Infant; Inflammation; Interleukin-10; Interleukin-6; Interleukin-8; Male; Receptors, Interleukin-1

The epidemic form of the hemolytic uremic syndrome (HUS) in children is hallmarked by endothelial cell damage, most predominantly displayed by the glomerular capillaries. The influx of mononuclear (MO) and polymorphonuclear cells (PMNs) into the glomeruli may be an important event in the initiation, prolongation, and progression of glomerular endothelial cell damage in HUS patients. The molecular mechanisms for the recruitment of these leukocytes into the kidney are unclear, but monocyte chemoattractant protein-1 (MCP-1) and IL-8 are suggested to be prime candidates. In this study, we analyzed the presence of both chemokines in 24-h urinary (n = 15) and serum (n = 14) samples of HUS children by specific ELISAs. Furthermore, kidney biopsies of three different HUS children were examined for MO and PMN cell infiltration by histochemical techniques and electron microscopy. Whereas the chemokines MCP-1 and IL-8 were present in only very limited amounts in urine of 17 normal control subjects, serial samples of HUS patients demonstrated significantly elevated levels of both chemokines. HUS children with anuria showed higher initial and maximum chemokine levels than their counterparts without anuria. A strong positive correlation was observed between urinary MCP-1 and IL-8 levels. Whereas initial serum IL-8 levels were significantly increased in HUS children, serum MCP-1 levels were only slightly elevated compared with serum MCP-1 in control children. No correlation was found between urinary and serum chemokine concentrations. Histologic and EM studies of HUS biopsy specimens clearly showed the presence of MOs and to a lesser extent of PMNs in the glomeruli. The present data suggest an important local role for MOs and PMNs in the process of glomerular endothelial-cell damage. The chemokines MCP-1 and IL-8 may possibly be implicated in the pathogenesis of HUS through the recruitment and activation of MOs and PMNs, respectively.

Topics: Biomarkers; Biopsy; Blood Cell Count; Chemokine CCL2; Child; Child, Preschool; Female; Hemolytic-Uremic Syndrome; Humans; Infant; Interleukin-8; Kidney; Male; Monocytes; Neutrophils; Reference Values

The systemic inflammatory response to Escherichia coli O157 infection was studied from the profiles of circulating inflammatory and anti-inflammatory cytokines. Twelve patients transferred sequentially to our hospital for the intensive care with acute illness due to Escherichia coli O157 infection and the possible form of haemolytic uraemic syndrome were included in this study. Increased circulating concentrations of tumour necrosis factor, interleukin 6, interleukin 8, granulocyte colony-stimulating factor, and interleukin 10 were found in patients with various stages of this infection and haemolytic uraemic syndrome. Especially, the degree of the increase of circulating interleukin 10 in those who had a typical signs of haemolytic uraemic syndrome was higher than those of other inflammatory cytokines. Two groups of E. coli infection could be classified into one with a typical haemolytic uraemic syndrome and the other with atypically bacteremic state over haemolytic uraemic syndrome according to these cytokine levels.

Topics: Adult; Aged; Aged, 80 and over; Anti-Inflammatory Agents; Child; Cytokines; Escherichia coli Infections; Escherichia coli O157; Female; Granulocyte Colony-Stimulating Factor; Hemolytic-Uremic Syndrome; Humans; Interleukin-10; Interleukin-6; Interleukin-8; Male; Middle Aged; Tumor Necrosis Factor-alpha

The epidemic form of the hemolytic uremic syndrome (HUS) has been associated with a verocytotoxin producing Escherichia coli infection. Endothelial cell damage of glomeruli and arterioles of the kidney plays a central role in the pathogenesis of HUS. A number of observations in vivo and in vitro indicate that inflammatory mediators contribute to this process. In this study we investigated the binding of 125I-verocytotoxin-1 (VT-1) to freshly isolated human nonadherent monocytes as well as the nature of the ligand to which VT-1 binds on monocytes. On the average, freshly isolated monocytes have 0.07 x 10(5) specific binding sites for 125I-VT-1 per cell. Preincubation of nonadherent monocytes with bacterial lipopolysaccharide (LPS) caused a 23- to 30-fold increase of specific binding sites for VT-1 as shown by Scatchard plot analysis. Thin-layer chromatography of extracted neutral glycolipids of the cells and subsequent binding of 125I-VT-1 showed that human monocytes bind VT-1 to a globotriaosylceramide (Gb3) species that is different from that found on endothelial cells, probably a short-chain fatty acyl Gb3 or an alpha-OH-Gb3. In addition, we evaluated the functional consequences of VT-1 binding to human monocytes by investigating the effects of VT-1 on the total protein synthesis and, specifically, the production of the cytokines interleukin-1 beta (IL-1 beta), tumor necrosis factor-alpha (TNF-alpha), IL-6, and IL-8. We observed that VT-1 did not inhibit overall protein synthesis, nor under basal conditions, neither after stimulation with LPS, in contrast to previous observations with endothelial cells. Furthermore, we found that VT-1 induces the synthesis of the cytokines IL-1 beta, TNF-alpha, IL-6, and IL-8 in nonstimulated monocytes by a LPS-independent cell activation. The increase in the production of cytokines was parallelled by an increase in mRNA, as was demonstrated for IL-6 by reverse transcription-polymerase chain reaction. These data suggest that inflammatory mediators locally produced by VT-1-stimulated monocytes may contribute to the pathogenic mechanism of the HUS.

Topics: Bacterial Toxins; Binding Sites; Cell Culture Techniques; Cell Survival; Cells, Cultured; Escherichia coli; Gene Expression Regulation; Hemolytic-Uremic Syndrome; Humans; Interleukin-1; Interleukin-6; Interleukin-8; Interleukins; Ligands; Lipopolysaccharides; Male; Monocytes; Polytetrafluoroethylene; Protein Biosynthesis; Shiga Toxin 1; Trihexosylceramides; Tumor Necrosis Factor-alpha

Polymorphoneutrophil leucocytes (PMNLs) are implicated in the pathogenesis of diarrhea-associated hemolytic uremic syndrome (D+ HUS). We investigated mechanisms of PMNL involvement by measuring tumor necrosis factor alpha (TNF alpha) and the novel cytokine, interleukin-8 (IL-8), a potent activator of neutrophils, together with alpha 1- antitrypsin-complexed elastase (alpha 1-AT-E) as a marker of neutrophil degranulation, and anti-neutrophil cytoplasmic antibodies (ANCA). IL-8 was not detected in the 17 normal children, but was significantly elevated in 20 of 25 D+ HUS children (P less than 0.005), and in three of nine children with non-diarrhea-associated (D-) HUS. Sequential data showed that IL-8 peaked transiently in the circulation, reaching a maximum just before a more protracted burst of alpha 1-AT-E. The IL-8 levels correlated significantly with circulating alpha 1-AT-E concentrations (r = 0.50, P less than 0.05). In D+ HUS IL-8 levels also correlated with the PMNL count (r = 0.63, P less than 0.005), and the highest values were seen in those children who died in the acute phase of the disease. TNF alpha was raised in only 1 of 16 D+ HUS children and in no patients were ANCA detected. The data suggest that PMNLs in HUS are recruited by IL-8, that this cytokine plays a key role in the PMNL activation which occurs, and that agents which suppress this recruitment and activation might play a therapeutic role in this disorder.

Topics: alpha 1-Antitrypsin; Antibodies, Antineutrophil Cytoplasmic; Autoantibodies; Child; Diarrhea; Hemolytic-Uremic Syndrome; Humans; Interleukin-8; Leukocyte Count; Neutrophils; Tumor Necrosis Factor-alpha