interleukin-8 and Pneumonia--Pneumocystis

This thesis is based on studies carried out during my appointment as a research fellow at the Department of Infectious Diseases, Hvidovre Hospital, University of Copenhagen, Denmark from 1993 to 1997. Part of this period was spent as a guest researcher at the Critical Care Medicine Department, National Institutes of Health, Bethesda, Maryland, USA. Pneumocystis carinii pneumonia (PCP) is the most frequent AIDS defining illness over the past 20 years. PCP is associated with considerable morbidity and mortality. An inflammatory reaction to P. carinii is believed to cause respiratory failure. This thesis has attempted to delineate important mechanisms of the inflammatory cascade, and to determine how inflammation is initiated during PCP. In histopathological studies of lung specimens it was shown that PCP caused significant inflammation and destruction of tissue. Specific pathological changes of the alveolar epithelium was observed in PCP but not for other HIV related lung diseases. By determining concentrations of soluble markers of immune activation we found that anti-microbial therapy exacerbated an ongoing inflammatory reaction. Adjuvant glucocorticosteroids suppressed levels of soluble immune markers. Bronchoalveolar lavage (BAL) neutrophilia has been associated with disease severity, and an increased risk of death from PCP. Through competitive inhibitory studies, we showed that BAL fluid neutrophil chemotactic activity largely was explained by the presence of interleukin-8 (IL-8). Further, we showed a correlation between high levels of BAL fluid IL-8 and mortality. Adjuvant treatment with glucocorticosteroids lowered BAL fluid IL-8 levels. In experimental studies we found that P. carinii Major Surface Antigen (MSG) induced IL-8 and tumor necrosis factor-alpha secretion from human monocytes and an alveolar epithelial cell line (A549). Binding of MSG to monocytes appeared to be mediated by mannose receptors, while A549 cells recognized MSG through mannose and glucan receptors. Glucocorticosteroids attenuated IL-8 secretion from A549 cells. These studies have confirmed that P. carinii infection induces tissue damage through a significant inflammatory response initiated by secretion of inflammatory mediators. Glucocorticosteroids attenuates the inflammatory response.

Topics: AIDS-Related Opportunistic Infections; Biomarkers; Humans; Hydro-Lyases; Interleukin-8; Pneumonia, Pneumocystis; Tumor Necrosis Factor-alpha

Pneumocystis carinii pneumonia (PCP) may cause severe respiratory distress. This is believed to be partly caused by the accumulation of neutrophils in the lung. Interleukin-8 (IL-8) and leukotriene B4 (LTB4) are potent neutrophil chemo-attractants and activators. Eicosanoids [i.e. prostaglandins (PG) and leukotrienes (LT)] are pro-inflammatory mediators released from arachidonic acid by action of phospholipase A2 (PLA2) and have been implicated in the host response to micro-organisms. Bronchoalveolar lavage (BAL) was performed on patients with PCP as part of a randomized study of adjuvant corticosteroids vs. placebo, in addition to standard antimicrobial therapy. Re-bronchoscopy was offered at day 10. BAL fluid was available for 26 patients who had follow-up bronchoscopy performed. At diagnosis, IL-8 levels were elevated in patients with PCP, compared to healthy controls, and correlated with relative BAL neutrophilia and P(A-a)O2. LTB4 was also elevated in PCP, but failed to correlate with either BAL neutrophilia or P(A-a)O2. PLA2 activity in patients correlated with IL-8 levels and BAL neutrophilia, but not with P(A-a)O2. A trend towards a decrease in IL-8 levels in BAL fluid was detected in the corticosteroid-treated patients from days 0-10, whereas no change was detected in the placebo group. No change in levels of LTB4, LTC4, PGE2, PGF2a and PLA2 were detected cover time in either treatment group. This study establishes a correlation between IL-8, BAL neutrophilia and P(A-a)O2, and suggests a role of IL-8 as a mediator in the pathogenesis of PCP, whereas the role of eicosanoids seems less clear.

Topics: Adult; AIDS-Related Opportunistic Infections; Bronchoalveolar Lavage Fluid; Eicosanoids; Female; Humans; Interleukin-8; Lung; Male; Middle Aged; Neutrophils; Phospholipases A; Phospholipases A2; Pneumonia, Pneumocystis; Prednisolone

Objective. To identify blood biomarkers to predict severity and mortality in AIDS PCP patients. Methods. Biomarkers including clinical parameters and plasma inflammatory cytokines were assessed in 32 HIV-infected patients with Pneumocystis pneumonia (PCP) at time of admission. Predictive value of the biomarkers for clinical severity and in-hospital mortality was evaluated by corresponding ROC curve. Results. Levels of CRP, WBC, LDH, HBDH, and Ferritin were significantly higher in the severe and nonsurvivor AIDS PCP patients. These important biochemical indicators have inverse correlation with oxygenation index, especially levels of LDH (P = 0.008, R (2) = 0.258), HBDH (P = 0.001, R (2) = 0.335), and Ferritin (P = 0.005, R (2) = 0.237). Plasma IL-8 and IL-6 levels were significantly higher in patients with PaO2/FiO2 ≤ 200 mmHg and nonsurvivors than in those with PaO2/FiO2 > 200 mmHg and survivors. Severe and nonsurvival groups showed higher ratio of mean IL-6/IL-10 level (1.78 ± 1.56, P < 0.001; 1.11 ± 0.72, P = 0.043), larger AUC (95% CI 0.781-1.000, P < 0.001; 95% CI 0.592-0.917, P = 0.043), and more significantly inverse correlation with the oxygenation index. Conclusion. Plasma IL-8, LDH, and HBDH levels and IL-6/IL-10 ratio could be helpful for early evaluation of the severity and predicting fatal outcomes in AIDS PCP patients.

Topics: Acquired Immunodeficiency Syndrome; Adult; Biomarkers; Female; Humans; Inflammation Mediators; Interleukin-10; Interleukin-6; Interleukin-8; Lactate Dehydrogenases; Male; Middle Aged; Pneumonia, Pneumocystis; Prognosis; ROC Curve; Severity of Illness Index; Tomography, X-Ray Computed

Topics: Animals; Bronchoalveolar Lavage Fluid; CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; Disease Models, Animal; Disease Progression; Flow Cytometry; Interferon-gamma; Interleukin-8; Macaca mulatta; Pneumocystis; Pneumonia, Pneumocystis; Simian Acquired Immunodeficiency Syndrome; Time Factors

Human immunodeficiency virus (HIV)-infected patients are at increased risk of contracting bacterial infections, mainly pneumonia. Despite this, little is known about immunopathogenic mechanisms in HIV-related bacterial pneumonia. This paper investigates the presence of the neutrophil chemotactic mediators, interleukin-8 (IL_8) and leukotriene B4 (LTB4), in bronchoalveolar lavage (BAL) fluid from 27 HIV-infected patients with bacterial pneumonia. Significantly elevated levels of IL-8 were found in BAL fluid of patients with bacterial pneumonia [529 pg ml-1 (296-1161 pg ml-1)] compared to matched patients with Pneumocystis carinii pneumonia (PCP) [59 pg ml-1 (42-254 pg ml-1)] and healthy controls [58 pg ml-1 (37-82 pg ml-1)]. Levels of LTB4 were not elevated during bacterial pneumonia when compared to PCP patients and healthy controls. Furthermore, a positive correlation was found between IL-8 levels in BAL fluid and relative BAL neutrophilia (r = 0.60, P = 0.001) in bacterial pneumonia. In conclusion, elevated IL-8 levels in BAL fluid were found in patients suffering from bacterial pneumonia, which may account for the influx of neutrophils to the lung, whereas LTB4 appears not to be an important chemotactic factor in this setting.

Topics: Bronchoalveolar Lavage Fluid; CD4 Lymphocyte Count; Chemotaxis, Leukocyte; Haemophilus Infections; HIV Infections; Humans; Interleukin-8; Leukotriene B4; Neutrophils; Pneumococcal Infections; Pneumonia, Bacterial; Pneumonia, Pneumocystis; Staphylococcal Infections

Pneumocystis carinii pneumonia (PCP) is accompanied by an acute inflammatory infiltration of the lung parenchyma. The cellular infiltrate is characterized by inflammatory cells including neutrophils, lymphocytes and macrophages. Furthermore, neutrophilia in bronchoalveolar lavage (BAL) fluid has been shown to confer a poor prognosis in PCP. We therefore investigated the potential of BAL fluid from 17 patients with PCP to induce neutrophil chemotaxis. BAL fluid from patients induced considerable neutrophil chemotactic activity compared to normal controls. Elevated levels of IL-8 were detected in patient samples as compared to controls. A specific anti-IL-8 antibody significantly reduced chemotactic activity of patient samples by more than 50%. In conclusion, IL-8 appears to be a significant participant of neutrophil chemotaxis in AIDS-associated PCP, and may participate in the recruitment of neutrophils to the lung during PCP.

Topics: Adult; AIDS-Related Opportunistic Infections; Antibodies, Blocking; Bronchoalveolar Lavage Fluid; CD4 Lymphocyte Count; Chemotaxis; Humans; Interleukin-8; Leukotriene B4; Middle Aged; Neutrophils; Pneumonia, Pneumocystis; Recombinant Proteins

We evaluated the significance of interleukin-8 (IL-8) in Pneumocystis carinii pneumonia (PCP). Bronchoalveolar lavage (BAL) fluid and serum was prospectively collected in 76 consecutive HIV-infected patients with a primary episode of PCP, as well as in ten healthy control subjects. Patients were found to have elevated levels of IL-8 in BAL fluid compared to control subjects (p < 0.01). Nine patients died during the course of PCP. Non-survivors had significantly higher IL-8 levels in BAL fluid than survivors (p < 0.05). Furthermore patients with levels of IL-8 in BAL greater then 90 pg/ml (i.e. greater than control subjects) had significantly worse vital prognosis (log rank test, p < 0.05). Thirteen patients required mechanical ventilation (MV), and these patients had significantly elevated levels of IL-8 compared with patients not requiring MV (p < 0.05).. i) IL-8 in BAL fluid correlates to the clinical severity of the pneumonia, and ii) is a predictor of mortality and severe respiratory compromise.

Topics: Adult; AIDS-Related Opportunistic Infections; Bronchoalveolar Lavage Fluid; Denmark; Humans; Interleukin-8; Middle Aged; Pneumonia, Pneumocystis; Prognosis; Prospective Studies

Polymorphonuclear leukocytes (PMN) are the predominant inflammatory cells recruited in acute lung injury. This study compares the concentration of interleukin-8 (IL-8) to those of GRO alpha, both of which are CXC chemokines, in bronchoalveolar lavage fluid (BALF) in three acute pathologic states: bacterial pneumonia (BPN); adult respiratory distress syndrome (ARDS); and Pneumocystis carinii pneumonia (PCP). Levels of both IL-8 and GRO alpha were below 5 pg/ml in 16 nonsmoking volunteers who served as controls. Despite more than twice as many neutrophils in the BALF of the BPN group (n = 12) than in the group with ARDS (n = 13), both groups had similar levels of IL-8, of 569 +/- 120 pg/ml and 507 +/- 96 pg/ml, respectively. The GRO alpha concentrations in the BPN and ARDS patients were respectively 3.3 and 3.4 times those of IL-8, reaching 1,870 +/- 314 pg/ml for the BPN and 1,699 +/- 377 for the ARDS patients. In the PCP group (n = 48, 45 human immunodeficiency virus [HIV]-positive, 3 HIV-negative), GRO alpha levels (897 +/- 172 pg/ml) were sevenfold higher than IL-8 levels (123 +/- 40 pg/ml). In all pathologic states there was a good correlation between GRO alpha and IL-8 (r = 0.53, p = 0.0001). GRO alpha or IL-8 both correlate with the absolute neutrophil number/ml when all groups were studied together (r = 0.52, p = 0.0001). Only in the PCP and ARDS groups did IL-8 correlate with the PMN number.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adolescent; Adult; AIDS-Related Opportunistic Infections; Bronchoalveolar Lavage Fluid; Bronchopneumonia; Chemokine CXCL1; Chemokines; Chemokines, CXC; Chemotactic Factors; Chemotaxis, Leukocyte; Growth Substances; HIV-1; Humans; Intercellular Signaling Peptides and Proteins; Interleukin-8; Male; Neutrophils; Pneumonia, Bacterial; Pneumonia, Pneumocystis; Respiratory Distress Syndrome; Statistics, Nonparametric

Interleukin-8 (IL-8) is a potent neutrophil chemoattractant and activator. Pneumocystis carinii pneumonia is associated with an accumulation of neutrophils in bronchoalveolar lavage (BAL) fluid. Thus, we hypothesized that IL-8 is involved in the pathogenesis of P. carinii pneumonia. BAL fluid and serum were prospectively collected in 76 consecutive HIV-infected patients with a primary episode of P. carinii pneumonia, as well as in 10 healthy control subjects. Patients were found to have elevated levels of IL-8 in BAL fluid compared with control subjects (p < 0.01). Nine patients died during the course of P. carinii pneumonia. Comparing survivors with nonsurvivors, the median IL-8 level in BAL fluid was 127 (0 to 3,900) versus 584 (127 to 6,100) pg/ml (p < 0.05). Furthermore, patients with levels of IL-8 in BAL fluid greater than 90 pg/ml (i.e., greater than control subjects) had significantly worse vital prognosis (log rank test, p < 0.05). Thirteen percent required mechanical ventilation (MV). Patients requiring MV had a median IL-8 level of 396 (25 to 6,100) versus 129 (0 to 3,900) pg/ml for patients not requiring MV (p < 0.05).. i) IL-8 in BAL fluid correlates to the clinical severity of the pneumonia, and ii) is a predictor of mortality and severe respiratory compromise.

Topics: Adult; AIDS-Related Opportunistic Infections; Biomarkers; Bronchoalveolar Lavage Fluid; Humans; Interleukin-8; Middle Aged; Pneumonia, Pneumocystis; Prognosis; Prospective Studies

Topics: AIDS-Related Opportunistic Infections; Bacterial Infections; Biomarkers; Bronchoalveolar Lavage Fluid; Enzyme-Linked Immunosorbent Assay; Granulocyte Colony-Stimulating Factor; Humans; Interleukin-8; Pneumonia; Pneumonia, Pneumocystis; Tuberculosis

To investigate the pathogenesis of lung injury in Pneumocystic carinii pneumonia and nonspecific interstitial pneumonitis (NIP), common pulmonary complications of human immunodeficiency virus (HIV) infection. The efficacy of corticosteroid therapy in P carinii pneumonia and the observation that bronchoalveolar lavage (BAL) neutrophilia predicts a poor prognosis support the premise that the lung injury of P carinii pneumonia is due to the host's inflammatory response to the infection.. In vitro measurements on previously collected BAL fluid samples.. The Clinical Center of the National Institutes of Health, a research hospital and tertiary care referral center.. Five normal volunteers, 5 asymptomatic HIV-positive patients, 10 HIV-positive patients with NIP (5 asymptomatic and 5 with respiratory symptoms), and 19 HIV-positive patients with P carinii pneumonia.. BAL leukotriene B4 (LTB4), interleukin 8 (IL-8), and phospholipase A2 (PLA2) were measured. IL-8 and PLA2 were elevated in patients with P carinii pneumonia, and IL-8 correlated with BAL fluid absolute neutrophil count. LTB4, IL-8, and PLA2 levels were elevated in patients with NIP; LTB4 and PLA2 levels correlated with absolute neutrophil count, and IL-8 correlated with alveolar-arterial oxygen pressure difference. IL-8 was elevated in the asymptomatic HIV-positive patients, and there was a trend toward elevation of PLA2 in this group.. IL-8 appears to play a role in the pathogenesis of lung injury in P carinii pneumonia and may be the principal neutrophil chemotaxin in this disease; PLA2 may also be involved in the pathogenesis of P carinii pneumonia. Both LTB4 and IL-8 may be involved in the recruitment of neutrophils and subsequent lung injury of NIP. These data suggest that there are varying mechanisms by which inflammatory cells are recruited to the lung in different HIV-related lung diseases.

Topics: Adult; AIDS-Related Opportunistic Infections; Bronchoalveolar Lavage Fluid; Chromatography, High Pressure Liquid; Female; HIV Infections; HIV Seropositivity; Humans; Interleukin-8; Leukotriene B4; Lung Diseases; Male; Middle Aged; Phospholipases A; Phospholipases A2; Pneumonia, Pneumocystis; Pulmonary Fibrosis