Interaction of BMI and respiratory status in obstructive sleep apnea, a cross-sectional COPD study.

This cross-sectional study of 136 patients with chronic obstructive pulmonary disease (COPD) investigated the mechanism underlying overlap syndrome, defined as coexisting COPD and obstructive sleep apnea (OSA). OSA was defined as a respiratory event index (REI) ≥ 5 events/h, determined using type-3 portable monitors. The mean REI was 12.8 events/h. Most participants (60.1%) had mild OSA (REI: 5-15 events/h). The REI was positively correlated with forced expiratory volume in one second (%FEV1) (r = 0.33, p < 0.001), body mass index (BMI) (r = 0.24, p = 0.005), and fat-free mass index (r = 0.31, p = 0.005), and negatively correlated with residual volume divided by total lung capacity (r = -0.27, p = 0.003). Receiver-operating characteristic curve analysis revealed an optimal BMI cutoff of 21.96 kg/m2 for predicting moderate/severe OSA. A BMI ≥ 21.96 kg/m2 was associated with OSA among participants with %FEV1 ≥ 50%, but not those with %FEV1 < 50%. This study revealed an interaction between airflow limitation and hyperinflation, nutritional status, and OSA.

Assessing anti-SARS-CoV-2 cellular immunity in 571 vaccines by using an IFN-γ release assay.

Memory T cell responses have been analyzed only in small cohorts of COVID-19 vaccines. Herein, we aimed to assess anti-SARS-CoV-2 cellular immunity in a large cohort using QuantiFERON assays, which are IFN-γ release assays (IGRAs) based on short-term whole blood culture. The study included 571 individuals receiving the viral spike (S) protein-expressing BNT162b2 mRNA vaccine. QuantiFERON assays revealed antigen-specific IFN-γ production in most individuals 8 weeks after the second dose. Simultaneous flow cytometric assays to detect T cells expressing activation-induced markers (AIMs) performed for 28 randomly selected individuals provided data correlating with the QuantiFERON data. Simultaneous IFN-γ enzyme-linked immunospot and AIM assays for another subset of 31 individuals, based on short-term peripheral blood mononuclear cell culture, also indicated a correlation between IFN-γ production and AIM positivity. These observations indicated the acquisition of T cell memory responses and supported the usability of IGRAs to assess cellular immunity. The QuantiFERON results were weakly correlated with serum IgG titers against the receptor-binding domain of the S protein and were associated with pre-vaccination infection and adverse reactions after the second dose. The present study revealed cellular immunity after COVID-19 vaccination, providing insights into the effects and adverse reactions of vaccination.

Dynamics of antibody titers and cellular immunity among Japanese healthcare workers during the 6 months after receiving two doses of BNT162b2 mRNA vaccine.

BACKGROUND: The antibody titer is known to wane within months after receiving two doses of the Pfizer-BioNTech BNT162b2 mRNA SARS-CoV-2 vaccine. However, knowledge of the cellular immune response dynamics following vaccination is limited. This study to aimed to determine antibody and cellular immune responses following vaccination, and the incidence and determinants of breakthrough infection. METHODS: This prospective cohort study a 6-month follow-up period was conducted among Japanese healthcare workers. All participants received two doses of BNT162b2 vaccine. Anti-SARS-CoV-2 antibody titers and T-cell immune responses were measured in serum samples collected at several timepoints before and after vaccination. RESULTS: A total of 608 participants were included in the analysis. Antibody titers were elevated 3 weeks after vaccination and waned over the remainder of the study period. T-cell immune responses showed similar dynamics. Six participants without predisposing medical conditions seroconverted from negative to positive on the IgG assay for nucleocapsid proteins, indicating breakthrough SARS-CoV-2 infection. Five of the six breakthrough infections were asymptomatic. CONCLUSIONS: Both humoral and cellular immunity waned within 6 months after BNT162b2 vaccination. The incidence of asymptomatic breakthrough infection within 6 months after vaccination was approximately one percent. UMIN CLINICAL TRIALS REGISTRY ID: UMIN000043340.

Young age, female sex, and presence of systemic adverse reactions are associated with high post-vaccination antibody titer after two doses of BNT162b2 mRNA SARS-CoV-2 vaccination: An observational study of 646 Japanese healthcare workers and university staff.

BACKGROUND: SARS-CoV-2 vaccination has started worldwide, including Japan. Although high rates of vaccine response and adverse reactions of BNT162b2 vaccine have been reported, knowledge about the relationship between sex differences and antibody response is limited. Furthermore, it is uncertain whether adverse reactions are associated with the vaccine response. METHODS: This prospective observational study included 673 Japanese participants working in a medical school and its affiliated hospital in Tokyo, Japan (UMIN000043340). Serum samples were collected before the first dose and three weeks after the second dose of BNT162b2 vaccine, and antibody titers against the receptor-binding domain of the spike protein of SARS-CoV-2 were measured. Answers to questionnaires about background characteristics and adverse reactions were obtained at the time of sample collection, and the relationship between antibody titers was analyzed. RESULTS: After excluding participants who did not complete receiving two doses of vaccination or two series of serum sample collection, 646 participants were analyzed. Although all participants became sero-positive after vaccination, antibody titers were highly variable among individuals (260.9-57,399.7A U/mL), with a median titer of 13478.0AU/mL. Mean titer was higher in females than in males and higher in young (≤45 years old) participants than in aged (>45 years old) participants. Participants who experienced adverse reactions demonstrated a higher antibody titer after vaccination than those without adverse reactions. Multivariable analysis demonstrated that young age, female sex, and adverse reactions after the second dose were independently related to higher antibody titers after the second dose. DISCUSSION: A favorable antibody response was observed after two doses of BNT162b2 vaccination among mostly healthy Japanese participants, especially among female and young participants. Although further investigation is essential, our results imply that the systemic adverse reactions (i.e., fever and general fatigue) are associated with a higher antibody response that indicates the acquisition of humoral immunity.

Differences in airway lumen area between supine and upright computed tomography in patients with chronic obstructive pulmonary disease.

BACKGROUND: No clinical studies to date have compared the inspiratory and expiratory airway lumen area between supine and standing positions. Thus, the aims of this study were twofold: (1) to compare inspiratory and expiratory airway lumen area (IAA and EAA, respectively) on computed tomography (CT) among supine and standing positions; and (2) to investigate if IAA and EAA are associated with lung function abnormality in patients with chronic obstructive pulmonary disease (COPD). METHODS: Forty-eight patients with COPD underwent both low-dose conventional (supine position) and upright CT (standing position) during inspiration and expiration breath-holds and a pulmonary function test (PFT) on the same day. We measured the IAA and EAA in each position. RESULTS: For the trachea to the third-generation bronchi, the IAA was significantly larger in the standing position than in the supine position (4.1-4.9% increase, all p < 0.05). The EAA of all bronchi was significantly larger in the standing position than in the supine position (9.7-62.5% increases, all p < 0.001). The correlation coefficients of IAA in the standing position and forced expiratory volume in 1 s were slightly higher than those in the supine position. The correlation coefficients of EAA or EAA/IAA in the standing position and residual volume, and the inspiratory capacity/total lung capacity ratio were higher than those in the supine position. CONCLUSIONS: Airway lumen areas were larger in the standing position than in the supine position. IAAs reflect airway obstruction, and EAAs reflect lung hyperinflation. Upright CT might reveal these abnormalities more precisely. Trial registration University Hospital Medical Information Network (UMIN 000026587), Registered 17 March 2017. URL: https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000030456 .

The Effectiveness of Nasal Airway Stent Therapy for the Treatment of Mild-to-Moderate Obstructive Sleep Apnea Syndrome.

BACKGROUND: Patients with obstructive sleep apnea syndrome (OSAS) experience excessive daytime sleepiness and insomnia and they are at risk of developing cardiovascular disease and stroke. Continuous positive airway pressure therapy could improve symptoms and decrease these risks; however, adherence is problematic. Although the oral appliance is another therapeutic option, patient satisfaction is limited and the effect of the nasal airway stent - a new device - remains unclear. OBJECTIVES: The aim of this study was to evaluate the effect of NAS therapy in patients with mild-to-moderate OSAS in a prospective, single-arm, interventional pilot study. METHOD: Patients with mild/moderate sleep apnea (n = 71; Apnea-Hypopnea Index [AHI], 5-20 events/h on polysomnography) were recruited. Sleep-associated events were measured using a portable device (WatchPAT200) pre- and immediately post-treatment and at 1 month follow-up. AHI (including supine and non-supine AHI), Oxygen Desaturation Index (ODI), Respiratory Disturbance Index (RDI), percutaneous oxygen saturation, heart rate, and snore volume were evaluated. Symptoms were assessed using the Epworth Sleepiness Scale, Pittsburgh Sleep Quality Index, and Hospital Anxiety and Depression Scale. RESULTS: NAS use significantly improved AHI, supine AHI, RD, ODI, and snore volume compared to pre-intervention (r = 0.44, 0.48, 0.3, 0.42, and 0.34; p < 0.001, p < 0.001, p = 0.011, p < 0.001, and p = 0.048, respectively). Additionally, 25 and 10% of patients showed complete and partial response for AHI, respectively; these improvements remained significant 1 month later. Pittsburgh Sleep Quality Index scores improved from 6.0 to 5.3 (r = 0.46, p = 0.022). CONCLUSIONS: NAS therapy reduced severity and snoring in patients with mild-to-moderate OSAS. Approximately 30% of patients did not tolerate NAS due to side effects.

Prevalence and clinical characteristics of obstructive- and central-dominant sleep apnea in candidates of catheter ablation for atrial fibrillation in Japan.

INTRODUCTION: We aimed to study the prevalence and types of sleep apnea (SA) as well as their clinical characteristics in atrial fibrillation (AF) ablation candidates in Japan. METHODS: Before catheter ablation, 197 consecutive AF patients (age: 60 ±â€¯9 years, body mass index; 25.0 ±â€¯3.0) were evaluated with portable polygraphy. We compared the clinical characteristics, according to the severity of SA as well as its types, as defined by the presence of obstruction and the mixed vs. central apnea indices. RESULTS: The mean apnea-hypopnea index (AHI) was 17.7 ±â€¯11.9, with 135 AF patients having an AHI ≥10 (68.5%). Patients with an AHI ≥10 had a significantly higher body mass index, plasma brain natriuretic peptide (BNP) level, prevalence of hypertension, and larger left atrial size. Among patients with an AHI ≥10, the incidence of obstructive-dominant SA was 60.9% and that of central-dominant SA was 7.6%. The prevalence of hypertension was significantly higher in obstructive-dominant SA patients (obstructive vs. central: 48.3% vs. 20.0%, P = 0.038). The obstructive apnea index correlated with plasma BNP level and age, but the central and mixed apnea indices did not. CONCLUSIONS: The prevalence of SA was common in AF ablation candidates, even without an obesity epidemic, and the SA type was predominantly obstructive. Portable polygraphy was useful for detecting undiagnosed SA patients in AF ablation candidates.

Association between severity of obstructive sleep apnea and glycated hemoglobin level in Japanese individuals with and without diabetes.

Aim of this study was to examine the association between the severity of obstructive sleep apnea (OSA) and dysglycemia in Japanese individuals with and without type 2 diabetes (T2DM). We enrolled 115 individuals diagnosed with OSA with an apnea hypopnea-index (AHI) ≥ 20 in whom continuous positive airway pressure (CPAP) therapy was introduced (N = 115, 44 with T2DM, age 62 ± 11 years, BMI 27.0 ± 4.4 kg/m2 and AHI median 36.1; interquartile range 27.2-48.1). During admission, the severity of OSA was evaluated by polysomnography, and its association with glycated hemoglobin (HbA1c) level was examined. Continuous glucose monitoring (CGM) was also conducted during the admission in 94 individuals. Apnea-hypopnea index (AHI), non-rapid eye movement (REM) AHI, minimum peripheral capillary oxygen saturation (SpO2) and percentage of sleep time (%TST) with SpO2 < 90% were significantly associated with HbA1c level in total and non-diabetic individuals (all p < 0.05) but not in those with T2DM, the majority of whom were treated with anti-diabetic medications. The associations of the non-REM AHI and %TST with SpO2 < 90% with HbA1c level remained significant after adjustment for age, sex and BMI in non-diabetic and T2DM subjects treated with dietary therapy only. Mean glucose level, but not SD or coefficient of variation of glucose, assessed by CGM was significantly associated with AHI and non-REM AHI in non-diabetic subjects after adjustment for age, sex and BMI. In conclusion, the severity of OSA was associated with increased HbA1c level independently of BMI in Japanese individuals, especially in those without diabetes.

Obstructive sleep apnea syndrome should be considered as a cause of nocturia in younger patients without other voiding symptoms.

INTRODUCTION: This study aimed to evaluate urination frequency among patients with obstructive sleep apnea syndrome (OSAS) and the effect of continuous positive airway pressure (CPAP) treatment. METHODS: We evaluated 138 men with moderate-to-severe OSAS by using polysomnography. Urination status was assessed at baseline and three months using the International Prostate Symptom Score and Overactive Bladder Symptom Score. Nocturia was defined as ≥2 nighttime urinations and patients were classified into Group A (<50 years old with nocturia), Group B (≥50 years old with nocturia), and Group C (patients without nocturia). OSAS severity and other urinary symptoms were also evaluated. RESULTS: Patients with nocturia exhibited more severe OSAS, compared to patients without nocturia (apnea-hypopnea index [AHI]: 52.0 vs. 44.7; p=0.021). Group A had the worst AHI, but did not have additional voiding symptoms, compared to Group B (p<0.001). The number of urinations was significantly correlated with OSAS severity in <50-year-old patients (p=0.013). CPAP reduced the number of urinations in Group A (75% of patients) and Group B (90% of patients). Patients with and without improved nocturia exhibited significant differences in their baseline OSAS severity (AHI: 53.7 vs. 37.3; p=0.042). CONCLUSIONS: OSAS severity was associated with the number of urinations in <50-year-old patients. CPAP decreased the nocturia frequency in 85% of patients with nocturia and was most effective in patients with severe AHI. However, additional studies should evaluate voiding volume in order to elucidate the mechanism of nocturia in patients with OSAS.

Correlation of a decline in aerobic capacity with development of emphysema in patients with chronic obstructive pulmonary disease: a prospective observational study.

In patients with COPD, CT assessment of emphysema and airway disease is known to be associated with lung function and 6-minute walk distance. However, it remains to be determined whether low attenuation area (LAA) on CT is associated with aerobic capacity assessed using cardiopulmonary exercise testing (CPET). In this prospective observational study, we repeatedly conducted high-resolution CT and CPET using a treadmill in 81 COPD patients over a median interval of 3.5 years. Two investigators independently scored LAA on images obtained at the aortic arch level, tracheal bifurcation level, and supradiaphragmatic level. Grades for the images of each lung were added to yield the total LAA score. Total LAA score was negatively correlated with peak aerobic capacity ([Formula: see text]) (p<0.001, r = -0.485). LAA scores of the upper (aortic arch level) and the lower (supradiaphragmatic level) lungs were both significantly associated with peak [Formula: see text]. There was a significant correlation between total LAA score and peak CO2 output ([Formula: see text]) (p<0.001, r = -0.433). Total LAA score was correlated with oxygen saturation at peak exercise (p<0.001, r = -0.634) and the estimated dead space fraction (p<0.001, r = 0.416). The mean annual change in total LAA score was significantly correlated with those in peak [Formula: see text] (p<0.001, r = -0.546) and peak [Formula: see text] (p<0.001, r = -0.488). The extent of emphysema measured by CT was associated with the results of CPET. The time-dependent changes in CPET data were also correlated with that in total LAA score. CT assessment could be a non-invasive tool to predict aerobic capacity in patients with COPD.

Serum (1 → 3) ß-D-glucan assay for discrimination between Pneumocystis jirovecii pneumonia and colonization.

Polymerase chain reaction (PCR) technique is being increasingly used for the microbiological diagnosis of Pneumocystis pneumonia (PCP). As PCR is highly sensitive, it can be positive even in a patient with Pneumocystis colonization. In this study, we evaluated whether the ß-d-glucan assay could be used to differentiate between PCP and Pneumocystis jirovecii colonization in immunocompromised patients with pulmonary infiltrates. We retrospectively evaluated data from 166 consecutive patients who underwent bronchoalveolar lavage for the diagnosis of PCP. Serum levels of ß-d-glucan in the negative, colonization, probable PCP, and definite PCP groups were 20.2 ± 6.3, 48.8 ± 15.9, 89.9 ± 20.2, 224.9 ± 25.9 pg/mL, respectively. The ß-D-glucan levels in the definite PCP group were significantly higher than those in the other 3 groups (p < 0.001). Serum ß-d-glucan levels in patients with either definite or probable PCP (173.1 ± 18.8 pg/mL) were significantly greater than those in patients with colonization who had positive PCR results but improved without anti-PCP treatment (p < 0.002). The cut-off level for discrimination was estimated to be 33.5 pg/mL, with which the positive predictive value was 0.925. These results indicate that ß-D-glucan is a useful marker to differentiate between PCP and Pneumocystis colonization. A positive ß-D-glucan assay result might be a good indication to begin anti-PCP treatment.

Cytokine profile of bronchoalveolar lavage fluid in patients with combined pulmonary fibrosis and emphysema.

BACKGROUND AND OBJECTIVE: Combined pulmonary fibrosis and emphysema (CPFE) is characterized by upper lobe emphysema together with lower lobe fibrosis. The aim of this study was to examine whether cytokine levels in the alveolar space are associated with emphysematous changes superimposed on pulmonary fibrosis. METHODS: Consecutive patients (n = 102), diagnosed with pulmonary fibrosis were retrospectively evaluated. Cytokine levels and differential cell counts in bronchoalveolar lavage (BAL) fluid, pulmonary function, computed tomography (CT) scores and levels of serum markers were compared between patients with or without emphysema. RESULTS: Among the 102 patients (14 females, mean age 68 years), 38 (37%) had evidence of upper lobe emphysema on computed tomography (CT). Levels of epithelial neutrophil activating peptide 78 (ENA-78/CXCL5) and interleukin (IL)-8/CXCL8 in BAL fluid were significantly higher in patients with emphysema. Vital capacity (VC, % predicted) was greater, and ratio of forced expiratory volume in 1 s/forced vital capacity and diffusing capacity of carbon monoxide (DL(CO))/alveolar volume (V(A)) were lower in patients with emphysema. CXCL8 and CXCL5 levels were associated with percentage or absolute numbers of neutrophils in BAL fluid. In addition, CXCL8 levels were inversely correlated with VC and DL(CO)/V(A), and positively correlated with composite physiological index (CPI) and the extent of areas of low attenuation on CT. CONCLUSIONS: Increased CXC chemokine levels in the airspaces may be associated with emphysematous lung changes in patients with pulmonary fibrosis.

Association between beta-adrenoceptor gene polymorphisms and relative response to beta 2-agonists and anticholinergic drugs in Japanese asthmatic patients.

BACKGROUND AND OBJECTIVE: Whether beta(2)-adrenoceptor gene (ADRB2) polymorphisms are associated with airway responsiveness to beta(2)-agonist medications remains controversial, partly due to factors that may confound pharmacogenetic associations, including age, cigarette smoking and airway remodelling. To overcome these problems, we performed an analysis using parameters that reflected the specific bronchodilator response to beta(2)-agonists. METHODS: The increases in FEV(1) after inhalation of procaterol hydrochloride (Delta FEV(1) procaterol) or oxitropium bromide (Delta FEV(1) oxitropium), and after sequential inhalation of procaterol and oxitropium (total airway reversibility), were measured in 81 Japanese patients with moderate to severe asthma. Approximately 3 kb of the DNA sequence of the coding and 5'-flanking regions of ADRB2 were genotyped by direct sequencing and PCR-restriction fragment length polymorphism assay. RESULTS: The mean age of the participants was 54 years, and 38 (47%) were smokers. Although Delta FEV(1) procaterol and Delta FEV(1) oxitropium adjusted for predicted FEV(1) were not associated with ADRB2 polymorphisms, the ratio of Delta FEV(1) procaterol to total airway reversibility was significantly associated with the ADRB2 A46G genotype (P < 0.05). Patients who were homozygous for the A46 allele (arginine at amino acid 16) were more responsive than carriers of the G46 (glycine 16) allele (P = 0.008). Multivariate linear regression analysis showed that Delta FEV(1) procaterol was correlated with the number of A46 alleles (P = 0.014), and also with total airway reversibility (P < 0.001) and smoking index in current smokers (P = 0.009). CONCLUSIONS: The ADRB2 A46G polymorphism was associated with a relatively greater bronchodilator responsiveness to beta(2)-agonists even in elderly asthmatic patients and smokers.

Elevated serum adiponectin level in patients with Mycobacterium avium-intracellulare complex pulmonary disease.

BACKGROUND: Patients with Mycobacterium avium-intracellulare complex (MAC) pulmonary disease often suffer from weight loss. Adipokines are factors secreted by adipocytes, including leptin and adiponectin, as well as some inflammatory cytokines, tumor necrosis factor-alpha (TNF-alpha) and interleukin 6 (IL-6). Body mass index (BMI) is known to be inversely correlated with adiponectin and positively with leptin, TNF-alpha, and IL-6. OBJECTIVE: We aimed to evaluate the levels of serum adipokines, including adiponectin, leptin, TNF-alpha, and IL-6 in patients with MAC pulmonary disease. METHODS: Forty consecutive patients with MAC pulmonary disease (8 males; median age 62 years; median BMI 18.1) were examined. Serum levels of adiponectin, leptin, TNF-alpha, and IL-6 were measured with ELISA. Age-, sex- and BMI-matched healthy subjects served as controls. RESULTS: Serum adiponectin was significantly elevated in patients with MAC pulmonary disease compared with the controls (p < 0.01). In both the patients and controls, serum adiponectin levels were inversely correlated with BMI (p < 0.05). No significant correlation was observed between serum adiponectin levels and C-reactive protein or lung function. Serum leptin levels, which were positively correlated with BMI, did not differ between patients and controls. Serum levels of TNF-alpha and IL-6 were significantly greater in patients with MAC pulmonary disease than in controls. The levels of TNF-alpha and IL-6 were not correlated with BMI and other adipokines examined. CONCLUSION: The results of the present study indicate that, in patients with MAC pulmonary disease, adiponectin is inappropriately secreted and may play a role in the pathophysiology of the disease.

Elevated CC chemokine level in bronchoalveolar lavage fluid is predictive of a poor outcome of idiopathic pulmonary fibrosis.

BACKGROUND: CC chemokines play important roles in the pathogenesis of interstitial lung diseases. Elevated CC chemokine levels have been observed in bronchoalveolar lavage (BAL) fluid of patients with idiopathic pulmonary fibrosis (IPF). OBJECTIVES: We aimed to examine whether the levels of four CC chemokines, i.e. monocyte chemoattractant protein-1 (MCP-1/CCL2), macrophage inflammatory protein-1 alpha (MIP-1 alpha/CCL3), thymus- and activation-regulated chemokine (TARC/CCL17), and macrophage-derived chemokine (MDC/CCL22), in BAL fluid are predictive of the prognosis of IPF patients. METHODS: We compared the chemokine levels of patients alive 5 years after diagnosis and those who had died. Lung function data, CT scores, and serum markers were also compared. RESULTS: Among 39 patients (29 males, median age, 60 years), 19 patients (48%) died within 5 years after the diagnosis. Whereas percent vital capacity was not different, percent lung diffusion capacity for carbon monoxide was significantly higher in the surviving patients than in the nonsurviving patients (p < 0.01). Median CCL2 levels of surviving and nonsurviving patients were 154.3 (interquartile range, IQR: 67.3-381.8) and 427.2 (IQR: 329.2-1184.1) pg/ml, respectively (p < 0.02). CCL3 levels in BAL fluid did not differ between the surviving and nonsurviving patients. CCL17 was detected in BAL fluid of 7 patients, 6 of whom died within 5 years. CCL22 was detectable in BAL fluid of 10 patients, only 1 of whom survived. Serum levels of KL-6 and lactate dehydrogenase did not differ between the surviving and nonsurviving patients. CONCLUSION: Elevated levels of CCL2, CCL17 and CCL22 in BAL fluid might be predictive of a poor outcome in patients with IPF.

Effects of TNF-alpha-converting enzyme inhibition on acute lung injury induced by endotoxin in the rat.

We studied the effects of TNF-converting enzyme inhibition with Y-41654, which down-regulates the production of soluble TNF-alpha (sTNF-alpha), on acute lung injury induced by intratracheal administration of LPS. We first verified in vitro that pretreatment of isolated alveolar macrophages from Sprague-Dawley male rats with 20 microL of 0.1-mM Y-41654, decreased significantly (P < 0.05) the concentration of sTNF-alpha in cell supernatants induced by 10 microg/mL of LPS. We then studied four groups of rats (each n = 10) including 1) a control group, 2) an LPS group (300 microg /kg, instilled intratracheally), 3) a Y-41654 group, and 4) a treatment group treated with Y-41654 after LPS instillation. Y-41654, 10 mg/kg in 0.7 mL of phosphate-buffered saline, was administered (i.v.), 15 min before and 0.5, 1.5, 2.5, and 3.5 h after saline or LPS instillation. The animals were observed for 4 h. In the animals treated with Y-41654, the concentrations of sTNF-alpha and protein in bronchoalveolar lavage fluid, and the number of neutrophils in lung tissue and bronchoalveolar lavage fluid were significantly lower at 4 h than in the LPS group (P < 0.05). In conclusion, sTNF-alpha plays an important role in the development of acute lung injury induced by intratracheal administration of LPS, in part modulating neutrophil kinetics.