interleukin-8 and Opportunistic-Infections

Urinary tract infections (UTIs) are frequently polymicrobial diseases mainly sustained by Escherichia coli in association with other opportunistic pathogens. Cystitis and pyelonephritis are usually accompanied by an inflammatory response, which includes neutrophil recruitment. Uropathogenic E. coli possess the ability to evade host defenses, modulating the innate immune response. The aim of this study was to determine whether particular E. coli strains correlate with polymicrobial bacteriuria and whether escape from the early host defenses and microbial synergy could lead to mixed UTIs. We evaluated 188 E. coli-positive urine samples and assessed the relationships among polymicrobism, neutrophil presence and several traits of E. coli isolates (virulence factors such as hlyA, fimA, papC and their relative products, i.e. hemolysin, type 1 and P fimbriae, and cnf1, their phylogenetic group) and their ability to suppress cytokine response in 5637 bladder epithelial cells. Escherichia coli susceptibility toward quinolones and fluoroquinolones, known to be linked to the pathogenicity of this species, was also considered. We found significant correlations among polymicrobial bacteriuria, absence of pyuria and quinolone/fluoroquinolone susceptibility of E. coli isolates and their enhanced capability to suppress interleukin-8 urothelial production when compared with the patterns induced by the resistant strains.

Topics: Aged; Anti-Bacterial Agents; Bacteriuria; Epithelial Cells; Escherichia coli; Escherichia coli Infections; Female; Humans; Interleukin-8; Male; Microbial Sensitivity Tests; Middle Aged; Opportunistic Infections; Quinolones; Tumor Cells, Cultured; Urinary Bladder; Urinary Tract Infections

The opportunistic fungal pathogen Candida albicans enters the bloodstream and causes hematogenously disseminated infection in hospitalized patients. During the initiation of a hematogenously disseminated infection, endothelial cells are one of the first host cells to come in contact with C. albicans. Endothelial cells can significantly influence the local host response to C. albicans by expressing leukocyte adhesion molecules and proinflammatory cytokines. Thus, it is of interest to investigate the response of endothelial cells to C. albicans in vitro. We describe the use of real-time PCR and enzyme immunoassays to measure the effects of C. albicans on the endothelial cell production of E-selectin and tumor necrosis factor alpha in vitro.

Topics: Candida albicans; Candidiasis; Cells, Cultured; Cytokines; E-Selectin; Endothelial Cells; Host-Pathogen Interactions; Humans; Immunoenzyme Techniques; In Vitro Techniques; Interleukin-8; Opportunistic Infections; Polymerase Chain Reaction; RNA, Messenger

To demonstrate whether serum Interleukin-8 (IL-8) is a relevant parameter to select hospitalised patients with chemotherapy-induced neutropenic fever with low or high probability of infection.. 90 assessable febrile episodes in 73 patients were evaluated; 46% of the febrile episodes were microbiologically documented infection (MDI), 8% clinical documented infection (CDI), and 47% fever of unknown origin (FUO). Median IL-8 level was lower in the FUO group compared to CDI and MDI (p<0.0005). In 45 of 48 episodes (94%) with CDI/MDI, IL-8 level at the start was > or =60 ng/l while in 18 of 21 episodes (86%) with IL-8 level <60 ng/l, no infectious cause was demonstrated. FUO and CDI/MDI patients with IL-8 > or =60 ng/l and responsive on antibiotic treatment showed a decline of IL-8 levels within days in contrast to non-responding patients.. Serum IL-8 level can be a useful marker to identify hospitalised FUO patients with low probability of infection.

Topics: Adult; Aged; Anti-Bacterial Agents; Antineoplastic Agents; Biomarkers; C-Reactive Protein; Female; Fever of Unknown Origin; Hospitalization; Humans; Interleukin-8; Male; Middle Aged; Neutropenia; Opportunistic Infections; Prospective Studies; Sensitivity and Specificity; Young Adult

Infectious complications in neutropenic patients are a major cause of morbidity and mortality. Clinical signs are unspecific and fever can be attributed to other causes. Inflammatory biomarkers have emerged as potentially useful in diagnosis of bacterial and fungal infection. Levels of several biomarkers were measured in patients with hematological malignancy at diagnosis and at the beginning of neutropenia due to cytostatic treatment or after hematopoietic stem cell transplantation, and daily until 6 days after presenting fever. Procalcitonin (PCT) and neopterin levels were not elevated at diagnosis or at the beginning of neutropenia. C-reactive protein (CRP) was moderately elevated. PCT levels were significantly higher in patients with Gram-negative bacteremia at 24-48 h after the onset of fever. Patients with probable fungal infection presented elevated PCT values when fever persisted for more than 4-5 days. CRP was more sensitive to predict bacteremia (both Gram-positive and Gram-negative) but the specificity was low. Neither neopterin, IL-6 nor IL-8 presented significant differences according to the origin or etiology of fever. Since it showed a high negative predictive value of Gram-negative bacteremia, clinical prediction rules that attempt to predict a high risk of severe infection might be improved by including measurement of PCT.

Topics: Adult; Aged; Bacterial Infections; Biomarkers; C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Female; Fever; Hematologic Neoplasms; Humans; Interleukin-6; Interleukin-8; Male; Middle Aged; Mycoses; Neopterin; Neutropenia; Opportunistic Infections; Predictive Value of Tests; Protein Precursors

Topics: Bacterial Infections; Biomarkers; Child; Cytokines; Humans; Interleukin-5; Interleukin-8; Neoplasms; Neutropenia; Opportunistic Infections

Anesthetics and sedatives contribute to postoperative immunosuppression. Interleukin-8 (IL-8) is a chemotactic and activating factor that mediates neutrophil adhesion and margination and is essential for host defense. We investigated the effect of anesthetics on isolated human polymorphonuclear leukocyte production of IL-8. Healthy human polymorphonuclear leukocytes were isolated using a single-step density gradient and stimulated with lipopolysaccharide in the presence of varying concentrations of propofol or midazolam for up to 20 h. IL-8 was measured in both culture supernatants and cell lysates using enzyme immunoassay, and IL-8 mRNA in cells was measured using Northern blotting and phosphorimaging. Data were analyzed using Kruskal-Wallis analysis of variance or the Mann-Whitney U-test as appropriate. Lipopolysaccharide increased extracellular accumulation of interleukin-8, which was suppressed by both propofol (P = 0.025) and midazolam (P = 0.028). However, intracellular IL-8 increased with exposure to lipopolysaccharide (P = 0.028) and remained increased with both anesthetics. Northern blot analysis also revealed increased IL-8 mRNA levels in the presence of both midazolam and propofol, which was confirmed by molecular imaging. These data strongly suggest that the anesthetics modulate transport or secretion of IL-8 protein from the cell. Suppression of IL-8 by anesthetics and sedatives may predispose postoperative and intensive care patients to infection.. Anesthesia causes immune suppression and alters neutrophil function. We investigated the effect of propofol and midazolam on interleukin-8, a neutrophil chemotactic agent in human neutrophils. Both anesthetics decreased extracellular interleukin-8 accumulation, but intracellular levels and mRNA remained high. This suggests that propofol and midazolam alter interleukin-8 secretion from cells.

Topics: Analysis of Variance; Anesthetics, Intravenous; Biological Transport; Blotting, Northern; Cell Adhesion; Cell Survival; Chemotactic Factors; Chemotaxis, Leukocyte; Critical Care; Humans; Hypnotics and Sedatives; Immune Tolerance; Interleukin-8; Lipopolysaccharides; Midazolam; Neutrophil Activation; Neutrophils; Opportunistic Infections; Postoperative Complications; Propofol; Risk Factors; RNA, Messenger

Topics: C-Reactive Protein; Humans; Interleukin-6; Interleukin-8; Leukemia; Neutropenia; Opportunistic Infections

Serum levels of interleukin 8 (IL-8) were examined in eight patients with acute myeloid leukaemia during 16 courses of chemotherapy. The patients experienced 14 episodes of fever which occurred in periods with granulocyte counts < 0.5 x 10(9)/l. Febrile episodes were classified as bacteriologically defined infection (n = 6), clinically defined infection (n = 2), and unexplained fever (n = 6). IL-8 was detected in 18/25 (72%), 2/3 (67%) and 3/7 (43%) of the serum samples in the respective groups. In contrast, IL-8 was detected in 22/90 (24%) of the samples taken when no fever was present (P < 0.00003 versus bacteriologically defined infection). The median concentration of IL-8 in samples taken during febrile episodes was 194 ng/ml (range 0-6358 ng/ml) and 0 (range 0-5392 ng/ml) on days without fever (not significant). In three patients with infections caused by, respectively, Streptococcus sanguis, Acinetobacter calcoanitratus and Candida albicans, IL-8 rose to a peak levels and declined during recovery. We conclude that IL-I is released systemically during infections with gram-positive and gram-negative bacteria and Candida albicans in patients with acute myeloid leukaemia and peripheral granulocytopenia due to chemotherapy. However, IL-8 can also be detected when no sign of infection is present.

Topics: Acute Disease; Adult; Agranulocytosis; Antineoplastic Combined Chemotherapy Protocols; Female; Fever; Humans; Interleukin-8; Leukemia, Myeloid; Leukocyte Count; Male; Middle Aged; Opportunistic Infections