Circulating KL-6, a biomarker of lung injury, in obstructive sleep apnoea

In obstructive sleep apnoea (OSA), oxidative stress contributes to endothelial dysfunction in the peripheral circulation. In the lung, oxidative stress can lead to alveolar injury. The present authors hypothesised that patients with OSA would have biomarker evidence of increased alveolar wall permeability. Sleep characteristics, brachial artery flow-mediated dilation and plasma KL-6 levels were observed in 11 otherwise healthy patients with OSA and 10 controls. Median (interquartile range) plasma KL-6 levels were higher in patients with OSA compared with controls: 317 (232-506) U.mL(-1) versus 226 (179-257) U.mL(-1), respectively. Higher plasma KL-6 levels were associated with greater time spent asleep with an oxyhaemoglobin saturation <90%, lower nadir saturation, more frequent desaturation of >4% during sleep and lower brachial artery flow-mediated dilation. Adjustment for nadir saturation or flow-mediated dilation attenuated the association between plasma KL-6 levels and OSA. Circulating KL-6 levels are elevated in some patients with obstructive sleep apnoea, possibly reflecting increased alveolar wall permeability.

Accuracy of an interferon-gamma release assay to detect active pulmonary and extra-pulmonary tuberculosis

OBJECTIVE

To examine the performance of an interferon-gamma (IFN-gamma) release assay (QuantiFERON-TB 2G assay [QFT-G]) to detect Mycobacterium tuberculosis infection in a Japanese general hospital, for the diagnosis of active pulmonary tuberculosis (PTB) and extra-pulmonary tuberculosis (EPTB).

DESIGN

We prospectively examined the performance of QFT-G in 194 patients suspected of active TB. Diagnosis was confirmed by 1) positive M. tuberculosis cultures, or 2) clinical manifestations or laboratory or pathological findings consistent with active TB and response to specific therapy.

RESULTS

Three patients with indeterminate QFT-G results were excluded. Among the remaining 191 patients, 77 had active TB. When the cut-off concentration of IFN-gamma was set at 0.35 IU/ml, as recommended by the manufacturer, the assay was positive in 69 patients and negative in 122. The sensitivity of the assay was 76.6% in all patients, 74.5% in the 47 patients with PTB and 80.0% in the 30 patients with EPTB. The overall specificity of the assay was 91.2%.

CONCLUSION

Although the specificity of the QFT-G to detect active TB was high and its sensitivity low, it was as accurate for the detection of active EPTB as for PTB when the 0.35 IU/ml INF-gamma cut-off concentration was used.

Neutrophil elastase inhibitor improves postoperative clinical courses after thoracic esophagectomy

Sivelestat sodium hydrate is a selective inhibitor of neutrophil elastase (NE), and is effective in acute lung injury associated with systemic inflammatory response syndrome (SIRS). The effect of Sivelestat for postoperative clinical courses after transthoracic esophagectomy was investigated. Consecutive patients with carcinoma of the thoracic esophagus who underwent transthoracic esophagectomy between 2003 and 2004 were assigned to the Sivelestat-treated group (n = 18), and those between 1998 and 2003 were assigned to the control group (n = 25). The morbidity rate, duration of postoperative SIRS, mechanical ventilation, and intensive care unit (ICU) stay, and the sum of the sequential organ failure assessment scores at all time points after the operation were compared. Serum NE activities and serum concentrations of TNF-alpha, IL-1beta, IL-6, and high mobility group box chromosomal protein 1 (HMGB1) were measured. Postoperative complications developed in three patients in the control group, and one in the Sivelestat-treated group. The durations of SIRS, mechanical ventilation, and ICU stay were significantly shorter in the Sivelestat-treated group. Even in patients without complications, the durations of mechanical ventilation, and ICU stay were also significantly shorter, and the arterial oxygen pressure/fraction of inspired oxygen ratio at postoperative day 1 was significantly higher in the Sivelestat-treated group. Serum NE activities and serum concentrations of IL-1beta, IL-6, and HMGB1 were significantly suppressed in the Sivelestat-treated group. Postoperative Sivelestat treatment after transthoracic esophagectomy improves the condition of SIRS and postoperative clinical courses, even in patients without complications.

Role of Toll-like receptor 4 in hyperoxia-induced lung inflammation in mice

OBJECTIVE

Prolonged exposure to hyperoxia causes lung inflammation, but the role of Toll-like receptor 4 (TLR4) in hyperoxia-induced signal transduction remains unclear.

MATERIAL OR SUBJECTS

We evaluated neutrophil accumulation, signal transduction and cytokine production during hyperoxia, comparing TLR4 mutant (C3H/HeJ) and wild type (C3H/HeN) mice.

METHODS

The mice were exposed to 80% oxygen in a hyperoxic chamber for 0 (control), 48, or 96 h. After the exposure, bronchoalveolar lavage (BAL) was performed for differential cell counting and cytokine measurement. In lung homogenate, activation of NF-kappaB and STAT1 was also examined.

RESULTS

In C3H/HeJ mice, hyperoxia-induced neutrophil accumulation in BAL fluid was significantly decreased compared with C3H/HeN. Hyperoxia for 96 h caused NF-kappaB translocation in C3H/HeN mice, which was significantly attenuated in C3H/HeJ mice (p < 0.05). In contrast, STAT1 activation occurred as early as after 48 h of oxygen exposure, which did not differ between the two strains. The levels of TNF-alpha, IL-6, and KC in BAL fluid were increased after oxygen exposure, which was suppressed by the lack of TLR4 signaling.

CONCLUSION

These results suggest that TLR4-dependent NF-kB activation may be an important process of the upregulation of proinflammatory mediators and subsequent neutrophil accumulation into the lung during hyperoxia.

Serum concentrations of high-mobility group box chromosomal protein 1 before and after exposure to the surgical stress of thoracic esophagectomy: a predictor of clinical course after surgery?

High-mobility group box chromosomal protein 1 (HMGB-1) has recently been shown as an important late mediator of endotoxin shock, intra-abdominal sepsis, and acute lung injury. However, its role in the systemic inflammatory response syndrome after major surgical stress, which may lead to multiple organ dysfunction syndrome, has not been thoroughly investigated. We hypothesized that serum HMGB-1 participates in the pathogenesis of postoperative organ system dysfunction after exposure to major surgical stress. A prospective clinical study was performed to consecutive patients (n = 24) with carcinoma of the thoracic esophagus who underwent transthoracic esophagectomy with three field lymph node resection between 1998 and 2003 at Keio University Hospital, Japan. Serum HMGB-1 concentrations were measured by enzyme-linked immunosorbent assay. Preoperative serum HMGB-1 levels correlated with postoperative duration of SIRS, mechanical ventilation, and intensive care unit stay. Three of the 24 patients had serious postoperative complications: sepsis in two, and acute lung injury in one. Serum HMGB-1 levels in patients without complications increased within the first 24 h postoperatively, remained high during postoperative days 2-3, and then decreased gradually by postoperative day 7. In patients with serious complications, serum HMGB-1 was significantly higher than that found in patients without postoperative complications at every time point except postoperative day 2. Preoperative serum HMGB-1 concentration seems to be an important predictor of the postoperative clinical course. Transthoracic esophagectomy induces an increase in HMGB-1 in serum even in patients without complications. Postoperative serum HMGB-1 concentrations were higher in patients who developed complications, and may be a predictive marker for complications in this setting.

Limitation of cigarette consumption by CYP2A6*4, *7 and *9 polymorphisms

The whole gene deletion CYP2A6*4, the defect of the main nicotine oxidase, contributes to limiting lifelong and daily cigarette consumption. However, the effects on smoking habits of CYP2A6*7 and *9, two major functional polymorphisms common in Asian populations, have not been reported. The present study examined the relationship between polymorphisms *4, *7 and *9 with the smoking habits of 200 Japanese smokers who visited the Keio University Hospital (Tokyo, Japan). The allele frequencies of *1 (wild type), *4, *7 and *9 were 52, 17, 11 and 20%, respectively. When the three polymorphisms were considered simultaneously, the percentages of homozygous wild type, heterozygote, and homozygous mutants and compound heterozygotes were 26.0, 52.5 and 21.5%, respectively. Homozygous mutants and compound heterozygotes (n = 43) smoked fewer cigarettes daily than heterozygotes (n = 105) and homozygous wild-type individuals (n = 52). Smokers with *7/*7, *9/*9 or *7/*9 had lower daily cigarette consumption than smokers with *1/*1. In conclusion, polymorphisms *4, *7 and *9 of CYP2A6 were detected in approximately three out of four Japanese smokers, and their daily cigarette consumption was genetically modulated by these functional polymorphisms.

Detection of mycobacteria in patients with pulmonary tuberculosis undergoing chemotherapy using MGIT and egg-based solid medium culture systems

SETTING

National Minami-Yokohama Hospital, Kanagawa, Japan.

OBJECTIVE

To compare the performance of a liquid medium system using the Mycobacteria Growth Indicator Tube (MGIT) with that of the conventional Japanese culture system using egg-based Ogawa medium, equivalent to Lowenstein-Jensen medium, in cases with pulmonary tuberculosis on chemotherapy.

DESIGN

A single-centre prospective case study of 61 hospitalised patients from 1 May to 31 July 1998 on a standard 6-month regimen of anti-tuberculosis chemotherapy including isoniazid, rifampin, streptomycin or ethambutol, and pyrazinamide. Sputum cultures using both culture systems were performed bi-weekly up to week 16 of treatment, and were further monitored by MGIT alone at the end of chemotherapy and every 6 months after the end of chemotherapy up to 2 years.

RESULTS

The detection time by MGIT gradually became longer with the progression of chemotherapy. The recovery rate at weeks 2, 4, 6, 8, and 10 by MGIT were significantly higher (P < 0.05) than on the Ogawa slants. Although one case was microbiologically diagnosed as a relapse, using the more sensitive MGIT system did not increase the relapse rate.

CONCLUSION

The gradual prolongation of detection time with the progression of treatment and an attainment of negativity of sputum culture at 4 months after chemotherapy could be a useful intermediate marker to monitor the efficacy of treatment for patients with pulmonary tuberculosis by the MGIT system. Further evaluation is necessary to establish the utility of MGIT in monitoring the treatment process.

Differential expression of CCR3 ligand mRNA in guinea pig lungs during allergen-induced inflammation

OBJECTIVE AND DESIGN

The gene expression profile of CCR3 ligands, eotaxin, RANTES, and monocyte chemoattractant protein-3 (MCP-3), was examined in normal and inflamed guinea pig lungs.

MATERIAL

Male Hartley guinea pigs (n = 49).

METHODS

Pulmonary mRNA was obtained from naive animals, animals treated with intravenous lipopolysaccharide administration, and animals repeatedly exposed to aerosolized allergen (ovalbumin). Northern analysis was performed to quantify pulmonary expression of eotaxin, RANTES, and MCP-3 mRNA. Pulmonary eosinophil peroxidase (EPO) activity was measured to quantify eosinophil accumulation.

RESULTS

Eotaxin and RANTES mRNAs, but not MCP-3 mRNA, were constitutively expressed in guinea pig lungs. Lipopolysaccharide treatment increased MCP-3 mRNA expression, but not eotaxin or RANTES mRNA. In contrast, allergen exposure in sensitized animals caused an increase in eotaxin mRNA, which demonstrated good temporal and quantitative correlation with pulmonary EPO activity, but not in MCP-3 or RANTES mRNA.

CONCLUSIONS

Guinea pig CCR3 ligands demonstrated different gene expression profiles in normal and inflamed airways, suggesting that they play different physiological and pathophysiological roles in the airway.

Attenuation of live E. coli-induced acute lung injury by X-ray irradiation in guinea pigs

Irradiation is suspected to injure inflammatory cells, such as neutrophils and mononuclear phagocytes, cells known to contribute to the development of acute lung injury (ALI). This study examined whether preexposure to x-ray irradiation modifies ALI induced by E. coli injected intravenously in guinea pig. Thirty animals were divided into two control and two irradiated subgroups: the first control group received saline only (n = 8), and the second control group received E. coli, 2 x 10(9)/kg body weight, suspended in saline (n = 6), IV. The first irradiated group received a single 12-Gy dose + saline (n = 6), and the second irradiated group received a single 12-Gy dose + E. coli (n = 10). The lung wet-to-dry-weight ratio (W/D) and 125I-albumin lung tissue/plasma ratio (T/P) were measured as markers of lung injury. W/D was significantly higher in the control E. coli group than in the other groups. T/P in the control E. coli group was also increased compared with T/P measured in the other groups. In the control E. coli group, a marked increase in bronchoalveolar lavage (BAL) neutrophils was observed compared with the control saline group. However, no significant difference in BAL neutrophil counts was observed between the control and irradiated E. coli groups. In contrast, BAL macrophages were significantly reduced in the irradiated E. coli groups compared with the control E. coli group. These findings suggest that x-ray irradiation attenuates E. coli-induced ALI in guinea pigs, an effect explained, at least in part, by a reduction in the number of alveolar macrophages.

Usefulness of pulmonary vascular leakiness assessment in interstitial pneumonitis

STUDY OBJECTIVE

Pulmonary vascular leakiness of (67)Ga-circulating transferrin in interstitial pneumonitis (IP) was estimated by our previously described method, and its ability to evaluate disease activity was compared with conventional (67)Ga scintigraphy.

DESIGN

Using 30-min dynamic scanning data after IV injection of (67)Ga citrate, the exponential equilibration coefficient of (67)Ga between the intravascular and pulmonary interstitial compartments was calculated and defined as the leak index (LI). Pulmonary (67)Ga uptake was assessed by gallium index, determined by conventional static images taken 48 h after (67)Ga citrate injection.

SETTING

Hospitalized patients.

PARTICIPANTS

The study population consisted of 17 control patients and 20 patients with IP.

RESULTS

The mean LI in patients with IP was significantly higher than in the control group (p < 0.0001), whereas no significant increase in gallium index was noted between the IP group and the control group. No significant correlation was found between gallium index and LI among all study participants. Mean LI in patients with active IP was significantly higher than in patients with stable IP (p = 0.0024).

CONCLUSIONS

An increase in pulmonary vascular leakiness was found in patients with IP. LI may be useful to assess the disease activity.

New bronchoscopic microsample probe to measure the biochemical constituents in epithelial lining fluid of patients with acute respiratory distress syndrome

OBJECTIVE

A noninvasive bronchoscopic microsampling (BMS) probe was developed to sample biochemical constituents of the epithelial lining fluid in small airways.

DESIGN

Observational, controlled study.

SETTING

Intensive care unit of academic medical center. PATIENTS AND PROCEDURE: BMS was applied in a control group of seven patients who had hemoptysis or small solitary peripheral nodules but no hypoxemia or other signs of acute inflammation and in four patients with acute respiratory distress syndrome (ARDS), to test whether BMS can ascertain the presence of acute pulmonary inflammation without complications.

MEASUREMENTS AND RESULTS

Complications, including a significant decrease in arterial oxygen saturation, were observed neither during nor after BMS. In the ARDS group, albumin, lactate dehydrogenase, interleukin-6, basic fibroblast growth factor, and neutrophil elastase concentrations in epithelial lining fluid were significantly higher (p <.0001, p =.012, p <.0001, p <.0001, and p <.0001, respectively) than in the control group. Serial BMS was safely performed in one patient with ARDS, allowing us to observe a correlation between changes in the concentration of inflammation-related biochemical markers and clinical course of the disease.

CONCLUSIONS

These results suggest that BMS is safe and useful to monitor pulmonary biochemical events in ARDS.

Pretreatment with FK506 improves survival rate and gas exchange in canine model of acute lung injury

The novel effects of FK506 on shock induced by lipopolysaccharide and phorbol myristate acetate (LPS/PMA) were studied using beagles. Five groups were studied: endotoxin shock control group (both 0.5 mg/kg of LPS and 30 microg/kg of PMA, n = 6); methylprednisolone-treated endotoxin shock group (n = 5); FK506-treated endotoxin shock groups in which intravenous infusions of FK506 at 2.5 microg/kg/h (low dose, n = 5), 8 microg/kg/h (medium dose, n = 5), and 25 microg/kg/h (high dose, n = 5) were administered. In the control group, the survival rate was 33%. Also, arterial hypoxemia, systemic hypotension, and marked increases in pulmonary vascular resistance (PVR) and wet-to-dry weight ratio (W/D) were observed. FK506 treatment at both medium and high doses significantly attenuated these LPS/PMA-induced physiological changes, and the survival rates were 80 and 100%, respectively. On the other hand, in the methylprednisolone group, no obvious effects were observed. The present study suggests that FK506 could have prophylactic potential against acute lung injury in endotoxin shock.

Specific HLA in pulmonary MAC infection in a Japanese population

Patients with pulmonary Mycobacterium avium complex (MAC) infection occasionally have neither past histories of pulmonary diseases nor underlying immunodeficiency conditions. Therefore, we hypothesized that MAC may be linked with a disease-susceptibility gene and determined human leukocyte-associated antigens (HLA) in patients with pulmonary MAC infection. HLA phenotypes were tested in 59 patients with pulmonary MAC infection, and diagnosed according to the criteria of the American Thoracic Society. Data of a Japanese population reported at the Tenth Japan HLA Workshop were used as a control. HLA-A33 (28.8% versus 12.5%, p = 5 x 10(-)(4)) and HLA-DR6 (50.8% versus 20.2%, p = 5 x 10(-)(8)) antigen frequencies in patients with MAC were significantly increased compared with those of the control population. Frequency of a haplotype A33-B44-DR6 in the MAC patients was also significantly increased compared with those of the control population (23.7% versus 4.2%; p = 3 x 10(-)(9)). These data suggest that development of pulmonary MAC infection is associated with specific HLA in a Japanese population.

Importance of interleukin-8 in the development of reexpansion lung injury in rabbits

Reexpansion of a collapsed lung induces increased microvascular permeability leading to reexpansion pulmonary edema (REPE). This study was designed to prove the hypothesis that local overproduction of interleukin-8 (IL-8) induces inflammatory cell accumulation which leads to the induction of REPE. Initially, we examined the detailed characteristics of a rabbit model of REPE in association with IL-8 production and its mRNA expression. The lung tissue to plasma ratio of radiolabeled albumin (T/P ratio), the lung wet to dry ratio, and bronchoalveolar lavage (BAL) neutrophil counts were significantly increased in the reexpanded lung. IL-8 concentrations and mRNA expression were significantly increased in the reexpanded lung homogenate. Immunohistochemically, alveolar macrophages (AMs) and epithelial cells in the reexpanded lung and AMs in the collapsed lung were positive for IL-8. Second, we examined the effect of pretreatment with a specific monoclonal anti-IL-8 antibody (Ab) or control IgG on the development of REPE. The T/P ratio and BAL neutrophil counts were conspicuously decreased by pretreatment with anti-IL-8 Ab, but not with control IgG. On a histopathological study, lung injury and leukocyte infiltration were attenuated by the pretreatment with anti-IL-8 Ab. In conclusion, IL-8 production is enhanced in the reexpanded lung, and contributes to the development of REPE. The pretreatment with anti-IL-8 antibody may be useful as a novel protective therapy for this disease.

[Assessment of pulmonary epithelial permeability in interstitial lung diseases]

The pulmonary epithelial permeability of 99mTc-DTPA (diethylene triamine penta acetate) was assessed in patients with interstitial lung diseases including radiation pneumonitis, idiopathic interstitial pneumonia/pulmonary fibrosis, sarcoidosis, unclassified interstitial pneumonia, and in healthy subjects. Pulmonary epithelial permeability was estimated by the rate constant (kep) of inhaled 99mTc-DTPA clearance from the lungs. Healthy nonsmokers had a mean kep value of 0.82 +/- 0.26% min, and their kep values were constant irrespective of age or sex. Of healthy smokers, 53% showed an increase in kep. This increase correlated with their cigarette consumption per day, but was reversible after cessation of smoking. The provocative concentration of histamine to decrease FEV 1.0 by more than 20% caused an increase in epithelial permeability. However, its effect on permeability was transient, limited, and not dose-dependent. During lung inflation by continuous external negative pressure or by positive end-expiratory pressure, pulmonary 99mTc-DTPA clearance was increased, suggesting changes in epithelial permeability. The patients with diffuse interstitial lung diseases also showed increased permeability compared with healthy nonsmokers. In the patients with pre-existing radiation pneumonitis, the mean kep value obtained from the area with infiltration on chest X-ray films was significantly higher than that from the opposite lung. In the prospective study, 3 of 11 patients developed radiation pneumonitis during the course of radiation therapy. The mean kep value obtained in the 3 patients who developed radiation pneumonitis increased just before onset, and further increased when the disease manifested clinically. We believe that 99mTc-DTPA aerosol inhalation is a sensitive test for the detection of inflammatory changes in the bronchioalveolar epithelium.

Clinical and immunoregulatory effects of roxithromycin therapy for chronic respiratory tract infection

The clinical and immunoregulatory effects of long-term macrolide antibiotic therapy for patients with chronic lower respiratory tract infections (CLRTI) were investigated. Clinical parameters and neutrophil chemotactic mediators in the epithelial lining fluid (ELF) of CLRTI patients (n = 10) were examined before and after 3 months oral administration of roxithromycin (RXM). The in vitro effects of RXM were also examined on the release of these mediators from alveolar macrophages (AM) and neutrophils. Arterial oxygen tension (p<0.05), vital capacity (VC) (p<0.001), %VC (p<0.05) and forced expiratory volume in one second (p<0.01) were improved after RXM treatment, but airway bacteria were not eradicated. Among the mediators, the levels of interleukin (IL)-8, neutrophil elastase (NE) and leukotriene B4 (LTB4) were higher in ELF than in plasma of CLRTI patients and they decreased after RXM treatment (n = 7, p<0.05 for each). RXM concentrations were significantly increased in the bronchoalveolar lavage cells of the treated patients. In in vitro experiments, RXM showed inhibitory effects on IL-8 release from AM and neutrophils. In conclusion, interleukin-8, neutrophil elastase and leukotriene B4 contribute to the neutrophilic inflammation in the airways of chronic lower respiratory tract infection patients and the clinical effects of roxithromycin may, in part, be attributable to the suppression of excess release of the chemotactic mediators from inflammatory cells.

Clinical and immunoregulatory effects of roxithromycin therapy for chronic respiratory tract infection

The clinical and immunoregulatory effects of long-term macrolide antibiotic therapy for patients with chronic lower respiratory tract infections (CLRTI) were investigated. Clinical parameters and neutrophil chemotactic mediators in the epithelial lining fluid (ELF) of CLRTI patients (n = 10) were examined before and after 3 months oral administration of roxithromycin (RXM). The in vitro effects of RXM were also examined on the release of these mediators from alveolar macrophages (AM) and neutrophils. Arterial oxygen tension (p<0.05), vital capacity (VC) (p<0.001), %VC (p<0.05) and forced expiratory volume in one second (p<0.01) were improved after RXM treatment, but airway bacteria were not eradicated. Among the mediators, the levels of interleukin (IL)-8, neutrophil elastase (NE) and leukotriene B4 (LTB4) were higher in ELF than in plasma of CLRTI patients and they decreased after RXM treatment (n = 7, p<0.05 for each). RXM concentrations were significantly increased in the bronchoalveolar lavage cells of the treated patients. In in vitro experiments, RXM showed inhibitory effects on IL-8 release from AM and neutrophils. In conclusion, interleukin-8, neutrophil elastase and leukotriene B4 contribute to the neutrophilic inflammation in the airways of chronic lower respiratory tract infection patients and the clinical effects of roxithromycin may, in part, be attributable to the suppression of excess release of the chemotactic mediators from inflammatory cells.

Oral-facial-digital syndrome type IX in a patient with Dandy-Walker malformation

We report a girl with oral, facial, and digital anomalies including multiple alveolar frenula, lobulated tongue with nodules, a posterior cleft palate, hypertelorism, a prominent forehead with a large anterior fontanelle, and postaxial polydactyly in both hands and the right foot, features compatible with the oral-facial-digital syndrome (OFDS). In addition, she had bilateral microphthalmia, optic disc coloboma, and retinal degeneration with partial detachment, thus establishing a diagnosis of OFDS type IX. Dandy-Walker malformation and retrobulbar cysts were observed on MRI. These additional malformations have not been reported in OFDS type IX. The frequent apnoeic spells which occurred immediately after birth were relieved after cystoperitoneal shunt implantation for hydrocephalus. Considering our case and previous reports of OFDS type IX, including two male sibs, a boy born to consanguineous parents, and three females, inheritance is probably autosomal recessive.

Downmodulation of IL-8 receptors, type A and type B, on human lung neutrophils in vivo

We examined the expression of interleukin (IL)-8 receptors (Rs), type A (IL-8-RA) and type B (IL-8-RB), on peripheral blood and bronchoalveolar lavage (BAL) fluid neutrophils; we also examined IL-8 and other chemoattractants in the epithelial lining fluid (ELF) of patients with chronic lower respiratory tract infection (CLI) to elucidate the in vivo regulation of IL-8Rs. Neutrophils were stained with monoclonal antibodies specific for IL-8-RA and IL-8-RB. We detected higher levels of IL-8 (81.6 +/- 25.4 ng/ml, mean +/- SE), leukotriene (LT) B4, and IL-1 beta in the ELF of the CLI patients than in their serum (P < 0.05). The expression of IL-8Rs on BAL neutrophils was significantly lower than that on peripheral blood neutrophils (P < 0.01 for both). In vitro analysis showed that low-level IL-8 (50 ng/ml) alone did not affect IL-8R expression but that it was downregulated by high-level IL-8 (500 ng/ml) alone and by low-level IL-8 in combination with LTB4 or IL-1 beta. Staurosporine reduced the downmodulation by low-level IL-8 plus LTB4 or IL-1 beta but not by high-level IL-8 alone. We speculate that pulmonary IL-8-RA and IL-8-RB may have been downmodulated by the combined effect of local chemoattractants through, in part, a protein kinase C-dependent mechanism.

[Spinal cord ischemia caused by dissecting aortic aneurysm in a patient with acute exacerbation of pulmonary emphysema]

A 61-year-old man with pulmonary emphysema was admitted due to acute exacerbation of chronic respiratory failure and a complaint of chest pain. A chest CT scan on admission showed aneurysmal dissection from the ascending aorta to the descending aorta. Analgesia was noted below the fourth thoracic vertebra, which supplies the accessory respiratory muscles including the intercostal muscles. Even after recovery from circulatory failure, his chest muscles were weak and he could not be removed from mechanical ventilation. An autopsy revealed ischemia of the spinal cord at the T4 level. In contrast, The C3 level of the spinal cord, which supplies the diaphragm, was intact. Paralysis of accessory respiratory muscles including intercostal muscles may have caused the continuation of the respiratory failure. This case shows the importance of accessory respiratory muscles in maintaining chest wall movement in patients with chronic pulmonary emphysema.

A derivative of cationic antimicrobial protein attenuates lung injury by suppressing cell adhesion

Cationic antimicrobial protein of 18 kD (CAP18) was identified and purified from rabbit granulocytes and shown to inhibit various activities of lipopolysaccharide (LPS). We investigated the effect of a 32-amino-acid C-terminal fragment of CAP18 (CAP18-derived peptide, CDP) on the pathogenesis of acute lung injury caused by intravenous endotoxin. Guinea pigs were divided into six groups: (I) saline control (n = 8), (2) CDP-alone (n = 8), (3) LPS-alone (n = 8), (4) LPS+CDP0m (n = 8), (5) LPS+CDP10m (n = 8), and (6) LPS+CDP60m (n = 8). A CDP dose of 0.2 mg/kg was injected at various time points after LPS injection. Lung wet-to-dry weight ratio, [125I]albumin leakage in lung tissue and bronchoalveolar lavage (BAL) fluid, differential cell count in BAL fluid, and histopathologic features were examined 4 h after intravenous administration of 0.02 mg/kg of LPS. The LPS+CDP0m and the LPS+CDP10m groups showed significantly attenuated lung injury compared to that seen in the LPS-alone group, however the LPS+CDP60m group revealed no attenuation of lung injury. The accumulation of peripheral white blood cells into pulmonary vasculature was attenuated only in the LPS+CDP0m but not in the LPS+CDP10m groups. We examined the effect of CDP on the expression of adhesion molecules using human umbilical vein endothelial cells, the result of which showed that CDP suppressed the LPS-induced expression of adhesion molecules in a dose-dependent manner. We conclude that CDP attenuates inflammatory cell migration into alveoli resulting in the attenuation of lung injury.

[Role of adhesion molecules in an animal model of endotoxin-induced acute lung injury]

We studied the role of adhesion molecules in acute lung injury caused by lipopolysaccharide (LPS). Forty-eight female guinea pigs were divided into three groups: saline (n = 12); B464, an LPS antagonist, (0.2 mg/kg i.v.) (n = 12); LPS (0.02 mg/kg i.v.) (n = 12); and LPS + B464 (n = 12). The numbers of polymorphonuclear cells (PMN) in blood sampled over 4 hours were counted. Accumulation of PMNs in the lungs was determined by counting the number of PMNs in lung-tissue samples fixed for light-microscopic examination. The lung wet-to-dry weight ratio and the 125I-albumin tissue-to-plasma ratio were used to assess lung injury. Human umbilical-vein endothelial cells were treated with B464 and then stimulated with either LPS or tumor necrosis factor. Expression of ICAM-1 and ELAM-1 was estimated by enzyme-linked immunosorbent assay. After LPS injection, light microscopy revealed decreases in peripheral PMN counts, and accumulation of PMNs in the lungs. Increases in the two indices of lung injury were also observed. These changes were attenuated by prior treatment with B464. The LPS-induced increases in ICAM-1 and ELAM-1 expression were dose-dependently suppressed by B464. These results suggest that pulmonary accumulation of activated PMNs plays an important role in LPS-induced lung injury.

Protective effect of B464, a lipid A analog, on endotoxin-induced cellular responses and acute lung injury

B464 is a novel synthetic analog of lipid A, a toxic component of endotoxin (LPS; lipopolysaccharide). We investigated the effects of B464 on both LPS-induced cellular responses in vitro and acute lung injury in vivo. In the in vitro study, B464 inhibited tumor necrosis factor-alpha (TNF-alpha) production from human monocytes, priming and stiffening of neutrophils, and expression of adhesion molecules on endothelial cells induced by LPS. We then studied the effects of B464 pretreatment on acute lung injury elicited by intravenous LPS administration in vivo. Guinea pigs were divided into saline control, B464 alone, LPS alone, and LPS + B464 groups. Animals were observed for 4 h after LPS administration, and lung injury was evaluated by extravascular lung water, 125I-albumin leakage in lung tissue, and lung neutrophil accumulation. In the LPS alone group, rapid and sustained peripheral neutropenia (p < 0.001 versus saline at 15 min and at 1, 2, and 4 h), an increased plasma TNF-alpha concentration (p < 0.005 at 1 h), and increases in lung injury parameters (p < 0.05) were observed. In the LPS + B464 group, no changes were observed in either plasma TNF-alpha or lung injury parameters. Transient peripheral neutropenia and subsequent rapid recovery (p > 0.05, p < 0.001, p < 0.01, and p > 0.05 at 15 min and 1, 2, and 4 h, respectively) were observed in the LPS + B464 group. These in vivo data, together with in vitro evidence of suppressed cellular responses, suggest that B464 (1) inhibits neutrophil accumulation in lung tissue, and (2) attenuates the development of acute lung injury by blocking the activation of neutrophils and mononuclear cells as well as the interaction between neutrophils and endothelial cells.

[Roles of inflammatory cells in the pathogenesis of acute lung injury in guinea pigs exposed to heat-killed bacteria]

To study the contribution of polymorphonuclear (PMN) and mononuclear (MN) phagocytes to the development of acute lung injury, we studied lung injury after intratracheal instillation of lipopolysaccharide (0.02 mg/kg) in guinea pigs previously exposed to heat-killed Corynebacterium parvum. In on group, cyclophosphamide was given to deplete peripheral PMNs. In another group, gadolinium chloride (GdCl3) was injected to suppress the function of MNs. Four hours after instillation of lippoly soccharide, the animals were killed, bronchoalveolar lavage was done, and the lungs were examined histopathologically. 125I-labeled albumin was injected to estimate the endothelial damage, and 131I-labeled albumin was injected to correct for blood contamination in the samples. In the group given cyclophosphamide, lung injury was no less than in the control group. In contrast, lung injury was less sever in the group given GdCl3 than in the control group. These findings suggest that MN are important in the pathogenesis of lung injury, especially in individuals who are immunologically primed by infection.

[Effects of intravenous 2-chloroadenosine on endotoxin-induced acute lung injury]

To assess the effects of 2-chloroadenosine (2CA) on acute lung injury caused by endotoxin (lipopolysaccharide), guinea pigs were given 2CA intravenously. Three groups were used: saline control, endotoxin control and 2CA+ endotoxin. In the endotoxin and 2CA+ endotoxin groups, neutrophils accumulated in bronchoalveolar lavage fluid and in lung tissue. However, neutrophil accumulation did not differ significantly between the endotoxin and the 2CA+ endotoxin groups. The number of macrophages in bronchoalveolar lavage fluid was significantly higher in the endotoxin group than in the saline control group, but the difference between the saline control and the 2CA+ endotoxin groups was not significant. The lung wet-dry weight ratio and 125I-albumin lung tissue-plasma ratio, which were used to measure acute lung injury, were significantly higher in the endotoxin group than in the 2CA+ endotoxin and the saline control groups. However, these ratios did not differ between the 2CA+ endotoxin and the saline control groups. These results suggest that 2CA attenuated endotoxin induced acute lung injury in guinea pigs.

Augmentation of endotoxin-induced pulmonary responses by mononuclear cell phagocytosis in the reticuloendothelial system

OBJECTIVE

To test the hypothesis that the effects of intravenous injection of latex particles would demonstrate the contribution of phagocytosis by mononuclear phagocytes to the development of Escherichia coli-induced acute lung injury in neutropenic guinea pigs.

DESIGN

Prospective, controlled, experimental study. Intravenously injected the latex particles into 41 guinea pigs to investigate the contribution of the phagocytosis in acute lung injury.

SUBJECTS

Forty-one guinea pigs.

INTERVENTIONS

Forty-one guinea pigs were divided into five experimental groups: a saline group (n=9); an endotoxin group (n=10) receiving 2 mg/kg of intravenous E. coli endotoxin; a latex group (n=7) receiving 2 x 10(9)/kg of intravenous polystyrene latex (mean diameter 3.19 micrometers); an endotoxin + latex group (n=8); and an E. coli group (n=7) receiving 2 x 10(9) live E. coli/kg.

MEASUREMENTS AND MAIN RESULTS

The lung wet/dry ratio was increased in the live E. coli-treated guinea pigs (6.71 +/- 0.16 [SEM], p < .01) as compared with the saline control (5.40 +/- 0.16, whereas the ratio was not increased in the endotoxin (5.52 +/- 0.14) or latex (5.58 +/- 0.20) groups. However, the lung wet/dry ratio was greater in the endotoxin + latex group (6.11 +/- 0.16, p < .05) than in the saline control. The 125I albumin lung tissue/plasma ratio was greater in the E. coli (2.00 +/- 0.29, p < .01) and endotoxin + latex (0.84 +/- 0.12, p < .05) groups than in the saline group (0.18 +/- 0.07), whereas no increases were observed in the endotoxin group (0.22 +/- 0.10) and the latex (0.34 +/- 0.13) group. More than 40% of the injected radiolabeled latex was observed to have accumulated in the reticuloendothelial system (liver and spleen), in both the saline control (40.1 +/- 2.3%, n=4) and endotoxin (57.3 +/- 6.8%, n=5) groups, with 2.6 +/- 1.5% and 3.1 +/- 1.7% in the lungs for the saline control and the endotoxin groups, respectively. The percent deposition of radiolabeled latex in the liver was greater in the endotoxin group (51.7 +/- 3.8%, p < .05) than in the saline group (37.6 +/- 5.9%).

CONCLUSIONS

These findings suggest that, in neutropenic guinea pigs: a) the combination of endotoxin and latex particles induces acute lung injury; and b) the phagocytic properties of mononuclear phagocytes in the reticuloendothelial system augment endotoxin-induced pulmonary responses and may play a role in the development of live E. coli-induced acute lung injury.

Flow cytometric detection of cell-associated cytokines in alveolar macrophages

To elucidate the cytokine-producing capacity of alveolar macrophages (AMs), we have introduced a method of flow cytometry combined with saponin treatment to detect the cell-associated cytokines. We studied bronchoalveolar lavage fluid cells from six patients with sarcoidosis (SAR) and six control (CTL) subjects. Cells were either left uncultured, or cultured with and without lipopolysaccharide (LPS), then treated with paraformaldehyde and saponin and analysed for cell-associated interleukin-1 beta (IL-1 beta) and tumour necrosis factor-alpha (TNF-alpha) by flow cytometry. Cell-associated IL-1 beta and TNF-alpha were also analysed by immunoassays. The flow cytometric cytokine values were correlated with the immunoreactive cell-associated cytokines (IL-1 beta: r = 0.45, p < 0.05; TNF-alpha: r = 0.82, p < 0.001). The histograms of cell-associated IL-1 beta yielded a single peak both in the patients and controls, whereas the histograms of cell-associated TNF-alpha exhibited two peaks in SAR patients, but just a single peak in the CTL subjects. The mean value of the cell-associated TNF-alpha in LPS+ AMs was higher in the SAR patients than in the CTL subjects (p < 0.001). In conclusion, the flow cytometric method can be applied to the semiquantitative detection of cell-associated cytokines in alveolar macrophages at the single cell level.

Local Pseudomonas instillation induces contralateral lung injury and plasma cytokines

We investigated whether local bacterial instillation leads to lung injury in noninstilled lung regions and examined local and systemic cytokine accumulation. Rats were challenged by intrabroncheal instillation of Pseudomonas aeruginosa, 10(7) colony-forming units (CFU) (HD group, n = 11), 4 x 10(6) CFU (LD group, n = 10), or saline (control group, n = 12). 99mTc-labeled macroaggregated albumin was added to the P. aeruginosa or saline solution for later documentation of the instilled area. At 4 h the right lung, including instilled segment, and the left lung were sampled. Lung injury was assessed by lung tissue to plasma 125I-labeled albumin (T/P) and lung wet-dry (W/D) ratios. We measured plasma and bronchoalveolar lavage fluid (BALF) levels of tumor necrosis factor (TNF) and cytokine-induced neutrophil chemoattractant (CINC). HD bacterial instillation induced neutrophil recruitment and TNF and CINC elevation in BALF (p < 0.05) associated with increased T/P (p < 0.005) and W/D (p < 0.05) ratios in both instilled and the noninstilled lungs as compared with the saline-instilled and noninstilled controls. LD bacterial instillation induced neutrophil recruitment and TNF and CINC elevation only in the instilled lung (p < 0.05), and not in the noninstilled lung, and did not increase the T/P or W/D ratio. Plasma levels of TNF and CINC were increased in the HD, but not the LD, group when compared with the saline controls (p < 0.05). These data indicate that, when the dose is high enough to cause an excess inflammatory response, local bacterial instillation leads to neutrophil sequestration, lung injury, and cytokine elevation in the noninstilled lung associated with systemic cytokine release.

[High concentrations of interleukin-8 in bronchoalveolar lavage fluid from a patient with adult respiratory distress syndrome]

A 75-year-old man was admitted to the hospital due to acute onset of a dry cough and dyspnea on exertion. Arterial blood gas analysis showed hypoxemia (PaO2 = 63 Torr) on room air. Chest radiography and computed tomography showed diffuse bilateral infiltrates. Adult respiratory distress syndrome was diagnosed from the findings described above and from the lack of evidence of left heart failure. Diffuse alveolar damage was confirmed at autopsy. During the course of his illness, the patient underwent bronchoalveolar lavage five times. The recovered fluid had high concentrations of interleukin-8 (IL-8), with a maximum of 6260 pg/ml and a minimum of 190 pg/ml, and these values correlated with the number of polymorphonuclear cells in the fluid. Levels of leukotriene B4, another chemotactic factor for PMN, in the lavage fluid were not high. We conclude that IL-8 was a major chemoattractant for PMN in the alveoli of this patient.

Heat-killed Corynebacterium parvum enhances endotoxin lung injury with increased TNF production in guinea pigs

Corynebacterium parvum (CP) is known to increase susceptibility to endotoxin, which is associated with increased production of tumor necrosis factor (TNF). We investigated the effect of CP-priming on the pathogenesis of acute lung injury caused by intratracheal Escherichia coli endotoxin (lipopolysaccharide [LPS]). Guinea pigs were divided into four groups: (1) control (n=6), (2) CP-alone (n=6), (3) LPS-alone (n=6) and (4) CP + LPS (n=6). A CP dose of 4 mg/kg was injected intraperitoneally 7 d before the study. Animals were observed for 4 h after intratracheal administration of 0.02 mg/kg of LPS. The lung wet-to-dry weight ratio (W/D), [125I] albumin concentration ratio of lung tissue to plasma (T/P) and of bronchoalveolar lavage (BAL) fluid to plasma (B/P) and differential cell count in BAL fluid were examined. In the LPS-alone group, neither excess lung water nor increased albumin leakage was observed. The CP + LPS group showed increased lung water and albumin leakage as compared with the other three groups (p<0.05). We also observed increased cell counts in BAL fluid (p<0.05), in the CP + LPS group. The spleen weight was increased in guinea pigs pretreated with CP, indicating reticuloendothelial system (RES) activation. In the CP + LPS group, the TNF level was increased in both plasma and BAL fluid. We conclude that pretreatment with CP enhances LPS-induced acute lung injury in parallel with increasing TNF production, which suggests that the activation of mononuclear phagocytes contributes to increased susceptibility to intratracheal endotoxin in guinea pigs.

Effect of a specific neutrophil elastase inhibitor, ONO-5046, on endotoxin-induced acute lung injury

Because excessive neutrophil elastase (NE) activity is involved in the pathogenesis of acute lung injury, we speculated that administering anti-NE might prevent lung injury. In a guinea pig model of acute lung injury induced by Escherichia coli endotoxin (lipopolysaccharide [LPS]), we investigated the effect of ONO-5046, a low-molecular-weight and specific inhibitor of NE. ONO-5046 produced concentration-dependent inhibition of guinea pig NE, whereas there were no inhibitory effects on neutrophil chemotaxis or the expression of adhesion molecules in endothelial cells. Detectable NE activity in bronchoalveolar lavage (BAL) fluid was present in the LPS-alone group. No NE activity in BAL fluid was detected in the LPS+ONO-5046 groups. Neutrophil counts in BAL fluid, the lung tissue wet to dry weight ratio, and the lung tissue or BAL fluid to plasma ratio of 125I-albumin were increased in the LPS-alone group as compared with the saline group (p < 0.05). In the LPS+ONO-5046 group, neutrophil counts in BAL fluid, the lung tissue wet to dry weight ratio and BAL fluid to plasma ratio of 125I-albumin were decreased as compared with the LPS-alone group (p < 0.05). These data suggest that ONO-5046 can attenuate LPS-induced acute lung injury.

[Pathophysiology and Diagnosis of the acute respiratory distress syndrome]

We studied methods for diagnosing the acute respiratory distress syndrome (ARDS) based on its characteristic abnormalities. A gamma-ray external counting method with Tc-99m human serum albumin revealed that pulmonary microvascular permeability was abnormally high in patients with ARDS. With this method, ARDS could be distinguished from cardiogenic pulmonary edema. Levels of interleukin-8 in bronchoalveolar fluid from patients with septic ARDS, reexpansion pulmonary edema, and inhalation burn injury were abnormally high. In 21 patients with acute lung injury, 15 of whom had ARDS, plasma concentrations of three inflammatory markers were measured: thiobarbituric acid reactive material which reflects cell membrane lipid peroxidation; 7S collagen, a component of basement membrane; and the soluble form of P-selectin, an adhesion molecule. Levels of all three were abnormally high in patients with ARDS, and correlated with the degree of lung injury and with the outcome in these patients. We conclude that these measurements in plasma or bronchoalveolar lavage fluid may enable us to assess the severity of ARDS.

Neutrophil-induced lung protection and injury are dependent on the amount of Pseudomonas aeruginosa administered via airways in guinea pigs

We investigated the roles of neutrophils in mediating both the protective effect against bacterial infection and the harmful effect of lung injury induced after the intratracheal instillation of live bacteria. We examined the mortality rate, lung injury, and bacterial clearance following the intratracheal instillation of Pseudomonas aeruginosa in low (10(4) colony-forming units [CFU]) and high doses (10(8) CFU) in normal (control) guinea pigs, others made neutropenic with cyclophosphamide (CPA), and guinea pigs made neutrophilic with recombinant granulocyte colony-stimulating factor (rG-CSF). Lung injury was assessed by the ratio of the concentration of 125I-labeled albumin in lung tissue to that in plasma (T/P) and the animals' lung weight-to-body weight (LW/BW) ratio. With 10(4) CFU, the CPA group showed an increased T/P ratio of 0.22 +/- 0.03 versus 0.14 +/- 0.01 in the control and 0.11 +/- 0.01 (mean +/- SEM) in the rG-CSF groups (p < 0.01). Viable bacteria were recovered from bronchoalveolar lavage fluid (BALF) in the CPA group. Neutrophil recruitment was observed in the lungs of animals in the control and rG-CSF groups. With 10(8) CFU, the mortality rate was increased in the rG-CSF group (7 of 10) as compared with the control (0 of 9) and CPA groups (1 of 9) (p < 0.05), which reflected an increased LW/BW (g/kg) ratio (16 +/- 2 versus 12 +/- 1) in the CPA group (p < 0.05). We conclude that neutrophils protect against lung injury during low-level bacterial challenge, but enhance lung injury and contribute to mortality during high-level bacterial challenge.