The effect of granulocyte colony-stimulating factor (G-CSF) on the degranulation of secondary granule proteins from human neutrophils in vivo may be indirect

Granulocyte colony-stimulating factor (G-CSF) was administered at a dose of 7.5 or 10 μg/kg s.c. once daily for 6 d (days 1–6) to two groups consisting of eight and six healthy volunteers. The administration of G-CSF resulted in a rapid decrease in neutrophil counts and serum levels of the secondary granule protein, human neutrophil lipocalin (HNL) after 30 min, followed by a recovery and gradual increase within 180 min. The number of circulating neutrophils and plasma and serum levels of neutrophil secondary granule proteins were dramatically elevated on day 2 (1 d after the administration of G-CSF) and stayed so until day 7. The plasma levels of HNL and lactoferrin (LF) showed a biphasic pattern with peaks at day 2 and days 5–7, and remained highly elevated at day 12. The serum levels of HNL and LF increased rapidly (about 8-fold and 6-fold, respectively) on day 2 and stayed elevated until day 7, subsequently returning to baseline levels. At day 5, neutrophil release induced in vitro by f-MLP was significantly enhanced. The cellular contents of HNL and LF were reduced to about 50% of levels before G-CSF administration at day 5. The release of lactoferrin and HNL, but not of myeloperoxidase (MPO), was slightly enhanced after preincubation of isolated normal neutrophils with G-CSF in vitro, but no obvious release of these proteins was observed with G-CSF alone. The administration of G-CSF resulted in a dramatic increase in the alkaline phosphatase (AP) activity in the plasma membrane, with maximal activity occurring at day 5. Furthermore, during administration of G-CSF, TNF-α in plasma increased about 25-fold. TNF-α started to rise at day 2 and peaked at day 6. After discontinuation of G-CSF the levels of TNF-α gradually decreased. The elevated levels of TNF-α (tumour necrosis factor-α) were temporally correlated to the other signs of neutrophil activation. GM-CSF and IL-8, however, were not detected in plasma. Our data suggest that G-CSF affects the neutrophils not only directly but also indirectly by the induction of the production of other cytokines such as TNF-α.     

Serum concentrations of granulocyte colony-stimulating factor in healthy term and preterm neonates and in those with various diseases including bacterial infections

The neonate is uniquely susceptible to severe and overwhelming bacterial infections. One of the most important deficits in the neonatal host defense system seems to be a quantitative and qualitative deficiency of the myeloid and the phagocytic system. Future optimal therapy of neonatal sepsis may include the use of adjuvant immunologic therapy. Granulocyte colony-stimulating factor (G-CSF) has been shown to induce neutrophilia and to enhance mature effector neutrophil function. To evaluate the role of G-CSF with respect to infection, we examined serum levels of G-CSF in term and preterm neonates, using an enzyme-linked immunosorbent assay method. G-CSF levels in healthy neonates showed peak levels up to 7 hours after birth, followed by an increase in total neutrophil cell (TNC) counts. Both G-CSF levels determined between 4 and 7 hours after birth and peak TNC counts correlated with the gestational age of the neonates. The state of nutrition, maternal treatment with glucocorticoids, maternal infection and hypertension, and the mode of delivery influenced peak G-CSF levels. Neonates with signs of infection between 4 and 7 hours after birth had higher levels of G-CSF than did healthy neonates (1,312 +/- 396 pg/mL v 176 +/- 19 pg/mL). In conclusion, the presented results of serum concentrations of G-CSF in relation to TNC counts and various diseases suggests an important role of G-CSF in the regulation of granulopoiesis during the neonatal period.     

Respiratory burst activity in bronchopulmonary dysplasia and changes with dexamethasone

The first objective of this study was to evaluate longitudinal changes in respiratory burst activity in circulating neutrophils and monocytes in infants of less than 30 weeks of gestation with respiratory distress syndrome (RDS), and to examine differences in neonates who subsequently developed bronchopulmonary dysplasia (BPD) compared with those neonates who did not. The second objective was to investigate the effects of dexamethasone on respiratory burst activity in neutrophils and monocytes. We measured burst activity on neutrophils and monocytes in fresh heparinized blood in response to E. coli, N-formyl-met-leu-phe (fMLP), and phorbol 12-myristate 13-acetate stimulation on days 3, 7, 14, and 21 of life, before and 2-3 days after initiating a 6-day course of dexamethasone treatment. Infants with RDS participating in the study were followed until discharge, and were classified as non-BPD and either 1) BPD d28, reflecting their oxygen requirement at day of life 28, or 2) BPD 36 weeks, reflecting oxygen dependence at 36 weeks' corrected gestational age. The diagnosis of BPD was supported by radiological changes of BPD. The percentage of activated neutrophils producing a respiratory burst increased in all premature infants with increasing postnatal days during the first 28 days of life, when the physiological stimulus E. coli was used as an activator (P < 0.02). There was no significant difference in respiratory burst activity measured either as percent activation or as mean fluorescence intensity between non-BPD and BPD infants after adjusting for the difference in weight and gestational age between the two groups. The treatment of premature infants with dexamethasone was associated with decreased activation of neutrophils (P < 0.005) when E. coli was used as a stimulus. In conclusion, a significant increase in neutrophil respiratory burst activity occurs during the first month of life in very low birth weight infants. Greater pulmonary damage in BPD cannot be attributed to reduced burst activity in either neutrophils or monocytes. Dexamethasone treatment was associated with decreased neutrophil respiratory burst activity.     

Effect of cytokines and chemokines on sickle neutrophil adhesion to fibronectin

A role for leukocytes in sickle cell vaso-occlusive crisis is becoming increasingly recognized. Neutrophil counts are higher in sickle cell patients and neutrophils from these patients demonstrate increased adhesion to endothelial monolayers under certain circumstances. The effects of selected cytokines on the adhesion mechanisms of normal neutrophils and neutrophils from sickle cell anaemia patients (SCA neutrophils) were investigated. Neutrophils were separated from the blood of homozygous (HbSS) SCA patients and healthy controls. Following pre-incubation (25 min, 37 degrees C) of the cells with cytokines, the adhesion of the cells to fibronectin (FN)-coated plates (20 micro) was determined (60 min, 37 degrees C, 5% CO2). Basal adhesion of normal and SCA neutrophils to FN was not statistically different. Pretreatment of normal neutrophils with either IL-6 (10-100 pg/ml), GCSF (1- 10 ng/ml) or IL-8 (1-100 ng/ml) had no significant effect upon their adhesion to FN. In contrast, SCA neutrophil adhesion to FN was increased significantly following pre-incubation with IL-6, G-CSF and IL-8 (p < 0.01). RANTES (1-100 ng/ml) had no significant effect on either normal or SCA neutrophil adhesion to FN. Flow-cytometric analyses demonstrated that IL-8 (10 ng/ml) significantly augments CD11b (Mac-1 integrin subunit) expression on SCA neutrophils, but not normal neutrophils. IL-6 and G-CSF (10 pg/ml and 10 ng/ml, respectively), however, had no effect on SCA neutrophil adhesion molecule expression. In conclusion, SCA neutrophil adhesion mechanisms may increase in the presence of certain cytokines, in vivo, and this activation may contribute to the physiopathology of sickle cell disease.     

Randomized,double-blinded,placebo-controlled trial of early administration of recombinant human granulocyte colony-stimulating factor to non-neutropenic preterm newborns between 33 and 36 weeks with presumed sepsis

A randomized, double-blinded, placebo-controlled trial was conducted of early administration of recombinant granulocyte colony-stimulating factor (rGCSF) to 40 non-neutropenic, preterm infants between 33 and 36 weeks of gestational age with the diagnosis of presumed sepsis. The treatment group (n = 20) received 5 microg/kg per day of intravenous rGCSF once daily for 3 d and the control group (n = 20) received the same volume of physiological serum. Immediately before the first dose and on the 4th day, plasma levels of GCSF and tumour necrosis factor-alpha (TNF-alpha), absolute neutrophil counts (ANC), immature neutrophil count (INC), immature/total neutrophil (I/T) ratios and platelet counts were determined. At study entry, the plasma GCSF and TNF-alpha levels were similar. On day 4, there was no significant change in GCSF levels in either groups, whereas there was a significant decrease in TNF-alpha levels in the treatment group. ANC and INC of the treatment group also increased significantly. The I/T ratio continued at the same level in the treatment group, but decreased significantly on days 4 and 7 day in the control group. The length of time on the neonatal intensive care unit (NICU) was significantly shorter in the treatment group. In conclusion, early administration of 3 daily doses of rGCSF (5 microg/kg per day) to non-neutropenic, preterm infants who had presumed sepsis increased circulating ANC and INC, decreased plasma TNF-alpha levels and shortened the length of time on the NICU.     

Elevation of interleukin-8 and interleukin-6 precedes the influx of neutrophils in tracheal aspirates from preterm infants who develop bronchopulmonary dysplasia

The influx of inflammatory mediators and cells into the tracheobronchial effluent of preterm infants with respiratory distress syndrome (RDS) appears to be important in signaling the development of bronchopulmonary dysplasia (BPD). The mechanism that initiates this early inflammatory response is not well understood. The purpose of this study was to test the hypothesis whether increased interleukin-8 (IL-8), a potent chemoattractant for human neutrophils, appears in the airways of preterm infants with RDS in whom BPD develops before the influx of neutrophils. In addition, airway secretions were analyzed for the cytokine interleukin-6 (IL-6) to test the hypothesis whether this pro-inflammatory cytokine is an early marker of inflammation in preterm infants with RDS who progress to BPD. Sixty-five infants less than 32 weeks gestation with RDS were enrolled on the first day of life and 56 infants completed the study, with 31 recovering from RDS (Non-BPD) and 25 infants progressing to BPD. Infants were excluded from enrollment in the presence of maternal chorioamnionitis, infection at birth, or infection within the first week of life. There were no significant differences in birthweight, gestational age, or prolonged rupture of membranes between the two groups. Serial tracheal aspirates (TA) were collected on days 1, 3, 5, and 7 while the infants remained intubated. Significant elevations of TA neutrophil counts were detected in the BPD group on days 5 and 7. Cell-free TA revealed marked elevations of IL-8 in the BPD group compared to the Non-BPD group [median (25th percentile, 75th percentile), ng/ml epithelial lining fluid (ELF)] on day 1 [BPD 485 (195, 840); Non-BPD 63.1 (28.3, 197), P < 0.05] and day 3 [BPD 740 (319, 1310); Non-BPD 111 (54.3, 337); P < 0.05], while on days 5 and 7, the differences were not statistically significant. Interleukin-6 (IL-6) was measured as a marker of acute inflammation and was not different in the two groups on day 1, but was significantly elevated on day 3 [median (25th percentile, 75th percentile), ng/ml ELF; BPD 297 (62.1, 702); Non-BPD 72 (32.8, 266), P < 0.05] and on day 5 [BPD 270 (136, 672); Non-BPD 86.4 (57.8, 138), P < 0.05]. These studies demonstrate that elevation of IL-8 and IL-6 levels precedes the marked neutrophil influx seen in the TA of preterm infants in whom BPD develop. The presence of IL-8 and IL-6 in TA from these infants suggests that these cytokines either initiate the acute inflammatory cascade in the lungs, or they are early markers of the inflammatory process that places preterm infants at high risk for BPD. Pediatr. Pulmonol. 1997; 24:331–336. © 1997 Wiley-Liss, Inc.     

Blood neutrophil functions and cytokine release in severe alcoholic hepatitis: effect of corticosteroids

BACKGROUND/AIMS: Several observations point to an important role of interactions between polymorphonuclear neutrophils and cytokines in severe alcoholic hepatitis. The polymorphonuclear neutrophil activation status and the local and systemic pro- and anti-inflammatory cytokine responses were quantified. The effect of corticosteroids, widely used in this setting, was evaluated using these parameters. METHODS: We studied blood polymorphonuclear neutrophil functions in terms of L-selectin and beta2-integrin expression, H2O2 production and IL-8 and tumor necrosis factor alpha synthesis capacity. We also measured IL-8, tumor necrosis factor alpha and IL-10 plasma and liver tissue levels. Fifteen patients with alcoholic hepatitis were compared to 15 patients with alcoholic cirrhosis without alcoholic hepatitis, and to 10 healthy volunteers. The impact of a 28-day course of corticosteroids on blood neutrophils activation status and cytokine levels was evaluated in patients with alcoholic hepatitis. RESULTS: Blood polymorphonuclear neutrophils were activated, as shown by increased H2O2 production (48+/-6 vs 29+/-6 MFI in healthy controls), and decreased L-selectin expression (300+/-61 vs 449+/-59 in healthy controls). Upon stimulation, polymorphonuclear neutrophils synthesized large amounts of IL-8 (21.7+/-9.2 ng/ml vs 8.8+/-10 ng/ml in healthy controls) and tumor necrosis factor alpha (524+/-132 pg/ml vs 79+/-144 pg/ml in healthy controls). Tumor necrosis factor alpha and IL-8 plasma and tissue levels were markedly increased as IL-10 was barely detectable in alcoholic hepatitis patients, compared to cirrhotic patients and healthy controls. During steroid therapy, plasma levels of the pro-inflammatory cytokine IL-8 fell as early as day 14, while levels of the anti-inflammatory cytokine IL-10 increased on day 21. Finally, polymorphonuclear neutrophil functions returned to normal after treatment. CONCLUSION: Severe alcoholic hepatitis appears to be associated with polymorphonuclear neutrophil activation and an imbalance between pro- and anti-inflammatory cytokines; during steroid therapy a normalization of these parameters was observed.     

In vivo administration of granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage CSF, interleukin-1 (IL-1), and IL-4, alone and in combination, after allogeneic murine hematopoietic stem cell transplantation.

BALB/c mice (H-2d) given 10 Gy total body irradiation (TBI) followed by 10(7) bone marrow (BM) and 10(6) spleen cells from C57BL/6 (H-2b) donor mice received recombinant cytokines intraperitoneally (IP) twice daily. The effect on neutrophil recovery rate, graft-v-host disease (GVHD), and survival was assessed. Four reagents were used: granulocyte-colony-stimulating factor (G-CSF), granulocyte-macrophage CSF (GM-CSF), interleukin-1 (IL-1) and IL-4, both alone and in combination. The most effective combination for increasing the circulating absolute neutrophil account (ANC) above the control value at day 7 posttransplant was the combination of G-CSF and IL-1 (mean ANC 2.4 +/- 1.6 x 10(9)/L as compared with control value of 0.07 +/- 0.05, P less than .02), followed by G-CSF alone (mean ANC 1.1 +/- 0.2, P less than .0001), the combination of GM-CSF plus IL-1 (mean ANC 0.8 +/- 0.3, P less than .002), and the combination of G-CSF plus GM-CSF (mean ANC 0.8 +/- 0.3, p less than .005). At day 10 posttransplant, the most effective combination in raising the ANC was the combination of G-CSF plus GM-CSF (mean ANC 7.5 +/- 2.3 as compared with control value of 3.5 +/- 1.1, P less than .01), followed by G-CSF alone (mean ANC 6.9 +/- 2.1, P less than .02). At the doses used, neither G-CSF nor GM-CSF had a deleterious effect on the incidence or severity of GVHD; indeed, GM-CSF was associated with improved survival. In contrast, IL-1 at doses greater than or equal to 100 ng twice daily caused marked early mortality, and there was a suggestion that IL-4 at doses of 500 ng twice daily resulted in increased late mortality, possibly owing to exacerbation of GVHD. This model appears to be of value for exploring the use of hematopoietic growth factors before they are used clinically in marrow allograft recipients.     

Early indicators of chronic lung disease in preterm infants with respiratory distress syndrome and their inhibition by melatonin

Improved survival from advances in neonatal care has resulted in an increased number of infants at risk for chronic lung disease (CLD). Recently, it was reported that inflammatory mediators such as interleukin (IL)-1beta, IL-6, tumor necrosis factor (TNF)-alpha and IL-8 are present in higher concentrations in lung lavage from babies who develop CLD. Previously, we found that melatonin reduced the rises in proinflammatory cytokines (IL-6, IL-8 and TNF-alpha) and nitrite/nitrate levels in the serum of preterm newborns with respiratory distress syndrome (RDS). The values correlated with gestational age and iatrogenic trauma in the form of oxygen exposure and mechanical ventilation. Increased concentrations of proinflammatory cytokines may, therefore, be the most valuable early indicator of developing CLD and these measurements may assist in selecting infants for interventions such as melatonin treatment or more selective blockage of components of inflammation. In the current study, we extend the original observations and report results in which 120 newborns diagnosed with RDS were either treated with melatonin (60 children) or given placebo (60 children). The cytokine measures were consistent with the previously reported findings and showed that melatonin reduced these values and also lowered nitrite/nitrate levels in serum of newborns with respiratory distress. Furthermore, when nonmelatonin-treated newborns who developed CLD (eight infants) were examined separately, they had levels of IL-6, IL-8, TNF-alpha and nitrite/nitrate values much higher than those in children who did not develop CLD. Two of the nonmelatonin-treated newborns died while no children who received melatonin died. Melatonin was well tolerated by the newborns.     

Production of granulocyte colony-stimulating factor in vitro by monocytes from preterm and term neonates [see comments]

We postulated that defective generation of granulocyte colony- stimulating factor (G-CSF) by cells of newborn infants might underlie their deficiencies in upregulating neutrophil production and function during bacterial infection. To test this, we isolated monocytes from the blood of preterm neonates, term neonates, and adults and, after stimulation with various concentrations of interleukin-1 alpha (IL-1 alpha) or lipopolysaccharide (LPS), quantified G-CSF concentrations in cell supernatants and G-CSF mRNA in cell lysates. When stimulated with plateau concentrations of IL-1 alpha for 24 hours, G-CSF concentrations were higher in supernatants of adult cells (8,699 +/- 5,529 pg/10(6) monocytes) than in those from term infants (2,557 +/- 442 pg, P < .05) or from preterm infants (879 +/- 348 pg, P < .05 v adults). When stimulated with plateau concentrations of LPS, supernatants of monocytes from preterm neonates had less G-CSF than did those from term neonates or adults. G-CSF mRNA content was low in cells from preterm infants, higher in those from term infants, and highest in those from adults. On the basis of the in vitro studies, we speculated that serum G-CSF concentrations might be less elevated in neutropenic neonates than in neutropenic adults. Indeed, serum concentrations were relatively low in all nonneutropenic subjects; 92 +/- 34 pg/mL (mean +/- SEM) in 10 preterm neonates, 114 +/- 21 pg/mL in 16 term neonates, and 45 +/- 13 pg/mL in 11 healthy adults. Serum concentrations were not elevated in 7 neutropenic neonates (39 +/- 17 pg/mL) but were in 8 neutropenic adults (2101 +/- 942 pg/mL, P < .05 v healthy adults). Other studies suggested that the lower G-CSF production in neonates is not counterbalanced by a heightened sensitivity of G-CSF--responsive progenitors to G-CSF. Therefore, we speculate that newborn infants, particularly those delivered prematurely, generate comparatively low quantities of G-CSF after inflammatory stimulation, and that this might constitute part of the explanation for their defective upregulation of neutrophil production and function during infection.     

Lung inflammation in preterm infants with respiratory distress syndrome: effects of ventilation with different tidal volumes

Ventilation with an inappropriate tidal volume (Vt) triggers lung inflammation, an important predisposing factor of bronchopulmonary dysplasia. It still remains uncertain what the appropriate starting target Vt should be during the acute phase of respiratory distress syndrome (RDS). Our aim was to evaluate lung inflammation in preterm infants undergoing synchronized intermittent positive-pressure ventilation (SIPPV) with two different tidal volumes Vt during the acute phase of RDS. Thirty preterm infants (gestational age, 25-32 weeks) with acute RDS were randomly assigned to be ventilated with Vt = 5 ml/kg (n = 15) or Vt = 3 ml/kg (n = 15). Proinflammatory cytokines (interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor (TNF)-alpha) were determined in the tracheal aspirate on days 1, 3, and 7 of life. IL-8 and TNF-alpha levels collected on day 7 were significantly higher (P < 0.05), and mechanical ventilation lasted longer in the group with Vt = 3 ml/kg (16.8 +/- 4 vs. 9.2 +/- 4 days; P = 0.05). In conclusion, our data show significantly higher lung inflammation in preterm infants ventilated with Vt = 3 ml/kg, suggesting a role for Vt = 5 ml/kg in reducing both inflammatory response during the acute phase of RDS and the length of ventilation. Whether the use of this starting Vt prevents bronchopulmonary dysplasia requires further study.     

Subcellular distribution and mobilization of MAC-1 (CD11b/CD18) in neonatal neutrophils

The CD11b/CD18 (Mac-1) heterodimeric surface glycoprotein contributes to a broad range of adherence-dependent neutrophil inflammatory functions. Previous investigations have indicated that diminished expression or regulation of Mac-1 may underlie abnormalities of stimulated adhesion and chemotaxis of neonatal neutrophils in vitro and inflammatory deficits in human neonates. To define the pathogenic mechanisms contributing to these findings, we compared the distribution and translocation of Mac-1 in subcellular fractions of neonatal and adult neutrophils before and after chemotactic stimulation. The total cell content of Mac-1 and the proportions of Mac-1 in beta fractions (vitamin B12 binding protein-rich granules), pre-gamma fractions (gelatinase-rich granules), or gamma fractions (plasma membrane) of neonatal neutrophils were comparable with those of adult neutrophils. However, after stimulation with N-formyl-methionyl-leucyl-phenylalanine (FMLP; 10 nmol/L, 37 degrees C, 15 minutes), neonatal neutrophils demonstrated (1) diminished translocation of Mac-1 from pre-gamma fractions (P less than .05), and (2) diminished surface expression of Mac-1 (P less than .05), as compared with healthy adult neutrophils. As shown in enzymatic and immunochemical assays, neonatal cells contained significantly (P less than .01) diminished levels of neutrophil gelatinase. In response to FMLP (0.1 to 10 nmol/L, 37 degrees C, 15 minutes), neonatal suspensions also released significantly (P less than .001) less gelatinase, as compared with adult neutrophil suspensions. These observations demonstrate that diminished mobilization of Mac-1 from gelatinase-rich granular pools in neonatal neutrophils is associated with abnormal surface expression of this glycoprotein after chemotactic stimulation. This abnormality may contribute, in part, to abnormal migratory properties of neonatal neutrophils in response to inflammatory stimuli.     

Granulocyte colony-stimulating factor (G-CSF) increases neutrophil migration across vascular endothelium independent of an effect on adhesion: comparison with granulocyte-macrophage colony-stimulating factor (GM-CSF)

Granulocyte colony-stimulating factor (G-CSF) increases neutrophil counts, and enhances and primes many neutrophil functions, implicating a role for this growth factor in host defence. This study investigated whether G-CSF is able to directly influence the transendothelial migration of neutrophils, and how such effects might be related to other effects on neutrophil adhesive properties. G-CSF, like GM-CSF, increased surface levels of the adhesive receptor, CD11b/CD18, but down-regulated L-selectin expression on neutrophils. Unlike GM-CSF, however, G-CSF had no effect on neutrophil adhesion to endothelium. Despite the lack of effect on neutrophil adhesion, G-CSF was able to produce significant enhancement of neutrophil transmigration across unstimulated endothelium in vitro . When used at an optimal concentration of 100 ng/ml, G-CSF increased neutrophil migration to 217 ± 19% of baseline levels ( P <0.001, n  = 10). This effect was similar to that previously demonstrated for GM-CSF (which increased migration to 271 ± 40%, P <0.001, n  = 12). G-CSF-induced transmigration, like GM-CSF induced migration, was independent of concentration gradients, suggesting that these are not simply chemotactic effects. G-CSF differs from GM-CSF, however, in that although GM-CSF inhibited neutrophil migration across IL-1-activated endothelium (33 ± 8% inhibition, n  = 6, P <0.01), G-CSF had no effect on neutrophil migration across IL-1 activated endothelium. Hence G-CSF, despite having no effect on neutrophil adhesion to endothelium, is a powerful stimulator of transmigration, and, unlike GM-CSF, does not inhibit cell movement across inflamed endothelium. These results suggest that G-CSF is able to influence neutrophil recruitment into local infective sites, and, further, that G-CSF mobilized cells would be competent to migrate into tissues in response to inflammatory stimuli.     

Thrombin activatable fibrinolysis inhibitor activity, thrombin-antithrombin complex and D-dimer levels in preterm neonates with early respiratory distress syndrome

Intraalveolar fibrin deposition found in neonates with respiratory distress syndrome (RDS) is explained by the activation of the coagulation system and inefficient fibrinolysis. However, thrombin activatable fibrinolysis inhibitor activity (TAFIa), an inhibitor of fibrinolysis, and the ratio of D-dimer to thrombin-antithrombin complex (D-dimer/TAT), an index of fibrinolytic activity, have not been reported previously in neonatal RDS. Aim of this study is to evaluate the influence of plasma TAFIa levels on the fibrinolytic state in neonatal RDS. The RDS group (Group 1) consisted of 29 neonates, and 18 neonates served as the control group (Group 2). Plasma TAFIa levels and D-dimer/TAT ratios were evaluated in all neonates in the first 6 hr of life. Neonates in the RDS group were further divided into two subgroups; Group 1a consisted of 12 neonates with evidence of mild asphyxia (Apgar score at 5 min <7 and cord pH <7.26), and Group 1b consisted of 17 nonasphyxiated neonates. No significant difference was found in TAFIa levels and D-dimer/TAT ratios between Groups 1 and 2 [214% (56.2-361%) and 124.3 (4.4-3,921) in Group 1 and 201% (60.3-381%) and 147 (5.9-1,426) in Group 2]. There were negative correlations between cord pH and TAFIa levels in both groups. Increased TAFIa levels and decreased D-dimer/TAT ratios and platelet counts were detected in mildly asphyxiated neonates when compared with nonasphyxiated ones. TAFIa is not responsible for the hypofibrinolytic state reported in RDS. However, asphyxia influences TAFIa levels and increased TAFIa levels depress fibrinolysis.     

Neutrophil apoptosis, activation and anti-inflammatory cytokine response in granulocyte colony-stimulating factor-treated patients with community-acquired pneumonia

BACKGROUND:Despite antibiotic treatment, the mortality of severe community-acquired pneumonia (CAP), especially in patients with severe comorbidity, remains high. Innate defense mechanisms including polymorphonuclear neutrophil (PMN) activation and survival, orchestrated by cytokines, are primarily responsible for the elimination of bacterial organisms from the alveolus. OBJECTIVES: The aim of this study was to evaluate the effect of granulocyte colony-stimulating factor (G-CSF) on PMN activation, apoptosis and cytokine response in patients with CAP. METHODS: Patients received a single dose of G-CSF (1 x 300 or 480 microg s.c.) prior to standard antibiotic treatment (n=8) or standard treatment only (n=8). Apoptosis rate and expression of CD11b, CD66b, CD64 and CD114 surface molecules on systemic PMN were assessed using fluorescence-activated cell sorter analysis. Levels of the interleukin-1 receptor antagonist (IL-1 RA), the soluble tumor necrosis factor receptor inhibitor (sTNF-p55) and G-CSF were measured by ELISA. Results: In the treatment group, 12 h after G-CSF application, neutrophil count increased, neutrophil activation marker CD11b was stimulated (CD11b: 48.6+/-9.7 vs. 71.2+/-17.7, p<0.01), neutrophil apoptosis decreased (apoptosis: 1.36+/-0.27 vs. 0.2+/-0.12%, p <.01) and the concentration of IL-1RA and sTNF-p55 increased (IL-1RA 136.4+/-72.2 vs. 340.1+/-194.6 ng/ml, p<0.01; sTNF-p55,382+/-4,243 vs. 632+/-4,714 ng/ml, p<0.01; control group nonsignificant). These effects were not seen in the control group. Conclusions: The application of a single dose of G-CSF in patients with CAP caused a prolonged survival and increased activation of neutrophils combined with a sustained release of anti-inflammatory cytokines.     

Chemokines and leukocyte activation in the fetal circulation during preeclampsia

Preeclampsia is a potentially life-threatening disease for both mother and fetus. Endothelial dysfunction is pivotal in the pathogenesis of this disorder, possibly reflecting a state of persistent inflammation. In the present study, we examined whether signs of inflammation with production of chemokines and leukocyte activation were present in the fetal circulation during preeclampsia. Venous cord blood was sampled during cesarean sections from 36 neonates born after uncomplicated pregnancies and from 35 born after severe preeclamptic pregnancies with premature newborns. The expression of adhesion molecules on neutrophils and monocytes was analyzed by flow cytometry, and plasma levels of chemokines and soluble adhesion molecules were analyzed by enzyme immunoassay. Newborns of preeclamptic mothers had increased expression of CD15s (P=0.003), CD49d/CD29 (P=0.01/0.005), and CD31 (P=0.007) on neutrophils and CD15s (P<0.001), CD11c (P=0.009), and CD54 (P=0.001) on monocytes. This activation of neutrophils and monocytes was accompanied by raised plasma levels of the CXC chemokines interleukin-8 (P=0.007) and growth-related oncogene-alpha (P=0.01) and decreased plasma levels of soluble E-selectin (P=0.001) and L-selectin (P=0.002). Although raised levels of adhesion molecules on leukocytes or decreased levels of soluble adhesion molecules in plasma were not related to prematurity or the degree of preeclampsia, raised interleukin-8 levels were found only in neonates of preeclamptic mothers with the highest blood pressures. Our findings suggest the activation of neutrophils and monocytes in the fetus during preeclampsia involving enhanced chemokine activation, possibly contributing to the fetal morbidity of this disorder.     

A single dose of granulocyte-macrophage colony-stimulating factor induces systemic interleukin-8 release and neutrophil activation in healthy volunteers

Granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte colony-stimulating factor (G-CSF) are frequently used in the clinical management of neutropenia. These cytokines not only enhance the proliferation of myeloid precursor cells but also influence the function of mature leukocytes. In a previous study, we found that the in vivo effects of G-CSF on neutrophils differed from those in vitro. In the present study, we investigated the effects of a single dose of recombinant GM-CSF (7.5 microg/kg, subcutaneously) on neutrophils, eosinophils, and monocytes in healthy volunteers. We analyzed leukocyte kinetics, phenotypical changes, neutrophil degranulation, and systemic cytokine production. After GM-CSF injection, phenotypical changes included upregulation of CD11b on all three cell types and a decreased expression of L-selectin and Fc(gamma)RIII on neutrophils. Neutrophil degranulation was evident from the increased plasma concentrations of lactoferrin and elastase. GM-CSF induced the release of interleukin-8 (IL-8), but not of IL-6 or tumor necrosis factor alpha. In comparison to the results from our previous study with G-CSF in healthy volunteers, GM-CSF induced a stronger activation of mature neutrophils but had a much less pronounced effect on the production and maturation of neutrophil precursors. These data may help to guide the choice between the two cytokines in different clinical situations.     

Alveolar granulocyte colony-stimulating factor and alpha-chemokines in relation to serum levels, pulmonary neutrophilia, and severity of lung injury in ARDS

OBJECTIVES: To determine granulocyte colony-stimulating factor (G-CSF), epithelial neutrophil-activating peptide (ENA)-78, and interleukin (IL)-8 in BAL fluid (BALF), epithelial lining fluid (ELF), and serum for establishing the concentration gradient of G-CSF, ENA-78, and IL-8 between the blood and the alveolar space in ARDS and acute lung injury (ALI); and to evaluate the relationship of G-CSF, IL-8, and ENA-78 to pulmonary neutrophilia and severity of lung injury. DESIGN: Prospective study. SETTING: An adult trauma/surgical ICU. PATIENTS: Nineteen patients with ARDS and 10 patients with ALI. INTERVENTIONS: None. Measurements and main results: BAL and blood sampling simultaneously within 12 h and 24 h after onset of ARDS/ALI; G-CSF was detected in BALF in 18 of 19 patients with ARDS, in 7 of 10 patients with ALI, and in all serum samples. G-CSF in BALF and serum was significantly higher in ARDS than in ALI. ENA-78 was detected in BALF in 14 of 19 patients with ARDS, in 8 of 10 patients with ALI, and in serum of all patients. Levels in BALF and serum were not different between ARDS and ALI. IL-8 was detected in all patients; concentrations in BALF in ARDS were significantly higher than in ALI. Concentrations of G-CSF, ENA-78, and IL-8 in ELF were significantly higher than in serum. G-CSF in BALF and serum and IL-8 in BALF correlated positively with pulmonary neutrophilia. G-CSF in serum and IL-8 in BALF correlated negatively with PaO(2)/fraction of inspired oxygen (FIO(2)) ratio. However, ENA-78 did not show a correlation with neutrophil count or with PaO(2)/FIO(2) ratio. CONCLUSIONS: G-CSF may be pathophysiologically important for accumulation and activation of neutrophils in ARDS. Local G-CSF production is the likely driving force for neutrophils rather than elevation of circulating levels. In comparison to ENA-78, IL-8 seems to be the predominant neutrophil chemoattractant in the early phase of ARDS.     

Activation of Human Neutrophils by Granulocyte Colony-Stimulating Factor,Granulocyte-Macrophage Colony-Stimulating Factor,and Tumor Necrosis Factor α: Role of Phosphatidylinositol 3-Kinase

Stimulation of human neutrophils with granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage CSF (GM-CSF), or tumor necrosis factor alpha (TNF) resulted in phosphorylation of Akt, the potency being GM-CSF > G-CSF = TNF, which was inhibited by wortmannin. The findings indicated that phosphatidylinositol 3-kinase (PI3K) is activated by these cytokines. The possible participation of PI3K in activation of neutrophil functions induced by these cytokines was explored with PI3K inhibitors (wortmannin and LY294002). Superoxide release and adherence induced by GM-CSF or TNF were inhibited by PI3K inhibitors. Actin reorganization and morphological changes induced by G-CSF or GM-CSF were also inhibited by wortmannin, whereas these responses induced by TNF were unaffected by wortmannin. These findings suggested that PI3K is differentially involved in cytokine-mediated activation of neutrophil functions depending on the cytokines used. The results also showed that activation of extracellular signal-regulated kinase, but not p38 mitogen-activated protein kinase, induced by these cytokines is partly mediated by PI3K activation.