Pulmonary vascular limitation to exercise and survival in idiopathic pulmonary fibrosis.

BACKGROUND AND OBJECTIVE: Pulmonary hypertension is frequently observed in advanced idiopathic pulmonary fibrosis (IPF) and is associated with poor prognosis. Cardiopulmonary exercise testing (CPET) can be used to detect less advanced pulmonary vascular impairment, and therefore may be of prognostic use. We studied the predictive value of non-invasive exercise parameters that were associated with elevated systolic pulmonary artery pressure (sPAP) for survival in IPF patients. METHODS: From our interstitial lung disease database, we reviewed records of consecutive patients with IPF in whom CPET and echocardiography were performed within 2 weeks (n = 38). RESULTS: Eleven patients (29%) had increased sPAP (≥40 mm Hg). From all non-invasive CPET parameters, only the ventilatory equivalent for CO2 (V'E /V'CO2 ) at anaerobic threshold differed significantly between patients with and without sPAP ≥ 40 mm Hg. The receiver-operator characteristic curve for V'E /V'CO2 resulted in areas under the curve of 0.77 (95% CI: 0.569-0.970; P = 0.026), with a cut-off value for predicting sPAP ≥ 40 mm Hg of >45.0. Patients with V'E /V'CO2 > 45.0 had significantly worse survival compared with patients with V'E /V'CO2 ≤ 45.0 (P = 0.001). In contrast, sPAP did not predict survival. CONCLUSIONS: V'E /V'CO2 , the only CPET parameter associated with elevated sPAP, appears a potentially useful non-invasive marker for early detection of pulmonary vascular impairment, and therefore may be of use for a more accurate prognostic assessment in IPF patients.

Selective accumulation of differentiated CD8+ T cells specific for respiratory viruses in the human lung.

The lungs are frequently challenged by viruses, and resident CD8(+) T cells likely contribute to the surveillance of these pathogens. To obtain insight into local T cell immunity to respiratory viruses in humans, we determined the specificity, phenotype, and function of lung-residing CD8(+) T cells and peripheral blood CD8(+) T cells in a paired analysis. The lung contained markedly higher frequencies of influenza (FLU)-specific and respiratory syncytial virus (RSV)-specific CD8(+) T cells when compared with the circulation. This contrasted with an equal distribution of cytomegalovirus- and Epstein-Bar virus-specific CD8(+) T cells. Noticeably, a substantial fraction of the lung-residing FLU- and RSV-specific CD8(+) T cells had progressed to a relatively late differentiation phenotype, reflected by low expression of CD28 and CD27. Lung-derived FLU-specific CD8(+) T cells had low activation requirements, as expansion of these cells could be initiated by cognate peptide in the absence of helper cell-derived signals. Thus, the human lung contains high numbers of differentiated FLU- and RSV-specific memory CD8(+) T cells that can readily expand upon reexposure to virus. Resident lung T cells may provide immediate immunological protection against pulmonary virus infections.

Antibiotics in addition to systemic corticosteroids for acute exacerbations of chronic obstructive pulmonary disease.

RATIONALE: The role of antibiotics in acute exacerbations is controversial and their efficacy when added to systemic corticosteroids is unknown. OBJECTIVES: We conducted a randomized, placebo-controlled trial to determine the effects of doxycycline in addition to corticosteroids on clinical outcome, microbiological outcome, lung function, and systemic inflammation in patients hospitalized with an acute exacerbation of chronic obstructive pulmonary disease. METHODS: Of 223 patients, we enrolled 265 exacerbations defined on the basis of increased dyspnea and increased sputum volume with or without increased sputum purulence. Patients received 200 mg of oral doxycycline or matching placebo for 7 days in addition to systemic corticosteroids. Clinical and microbiological response, time to treatment failure, lung function, symptom scores, and serum C-reactive protein were assessed. MEASUREMENTS AND MAIN RESULTS: On Day 30, clinical success was similar in intention-to-treat patients (odds ratio, 1.3; 95% confidence interval, 0.8 to 2.0) and per-protocol patients. Doxycycline showed superiority over placebo in terms of clinical success on Day 10 in intention-to-treat patients (odds ratio, 1.9; 95% confidence interval, 1.1 to 3.2), but not in per-protocol patients. Doxycycline was also superior in terms of clinical cure on Day 10, microbiological outcome, use of open label antibiotics, and symptoms. There was no interaction between the treatment effect and any of the subgroup variables (lung function, type of exacerbation, serum C-reactive protein, and bacterial presence). CONCLUSIONS: Although equivalent to placebo in terms of clinical success on Day 30, doxycycline showed superiority in terms of clinical success and clinical cure on Day 10, microbiological success, the use of open label antibiotics, and symptoms. Clinical trial registered with www.clinicaltrials.gov (NCT00170222).

Associations between pre-employment immunologic and airway mucosal factors and the development of occupational allergy.

BACKGROUND: Sensitization to occupational allergens is frequently found in laboratory animal workers (LAWs) and can cause serious health problems. Atopy is a major risk factor for sensitization, but it is considered insufficient to advise against working with animals. OBJECTIVE: We investigated whether immunologic measures, including serology and cytokine production profiles of blood cells, and parameters for airway inflammation are associated with the development of occupational sensitization. METHODS: In a prospective cohort study 110 starting LAWs were followed for 2 years. At inclusion, results of health questionnaires, skin test results, lung function measures, methacholine threshold levels, and nasal lavage fluid were obtained. Blood was taken for measuring total IgE and allergen-specific IgE antibodies. Cytokine production profiles were measured in whole blood. RESULTS: Twenty-two new cases of sensitization were identified during follow-up. In multivariate logistic regression analysis a model including atopy and total IgE level predicted sensitization best. This was corroborated in a separate validation cohort. Parameters for airway inflammation or cytokine production profiles did not further contribute to the prediction of sensitization. Based on these results, pre-employment counseling aimed at applicant LAWs with atopy and a total IgE level of greater than 100 IU/mL might be able to reduce occupational sensitization by up to 45% to 50% with less than 10% false-positive predictions. CONCLUSION: The combination of atopy and total IgE level offered the best model to predict development of occupational sensitization. Other immunologic parameters and parameters of airway inflammation did not contribute significantly.

Arginine deficiency augments inflammatory mediator production by airway epithelial cells in vitro.

BACKGROUND: Previously we showed that reduced availability of the essential amino acid tryptophan per se attenuates post-transcriptional control of interleukin (IL)-6 and IL-8 leading to hyperresponsive production of these inflammatory mediators by airway epithelial cells. Availability of the non-essential amino acid arginine in the inflamed airway mucosa of patients with asthma is reduced markedly, but it is not known whether this can also lead to an exaggerated production of IL-6 and IL-8. METHODS: IL-6 and IL-8 were determined by ELISA in culture supernatants of NCI-H292 airway epithelial-like cells and normal bronchial epithelial (NHBE) cells that were exposed to TNF-alpha, LPS or no stimulus, in medium with or without arginine. Arginine deficiency may also result from exposure to poly-L-arginine or major basic protein (MBP), which can block arginine uptake. Epithelial cells were exposed to these polycationic proteins and L-(14)C-arginine uptake was assessed as well as IL-6 and IL-8 production. To determine the mode of action, IL-6 and IL-8 mRNA profiles over time were assessed as were gene transcription and post-transcriptional mRNA degradation. RESULTS: For both NCI-H292 and NHBE cells, low arginine concentrations enhanced basal epithelial IL-6 and IL-8 production and synergized with TNF-alpha-induced IL-6 and IL-8 production. Poly-L-arginine enhanced the stimulus-induced IL-6 and IL-8 production, however, blocking arginine uptake and the enhanced IL-6 and IL-8 production appeared unrelated. The exaggerated IL-6 and IL-8 production due to arginine deficiency and to poly-L-arginine depend on a post-transcriptional and a transcriptional process, respectively. CONCLUSION: We conclude that both reduced arginine availability per se and the presence of polycationic proteins may promote airway inflammation by enhanced pro-inflammatory mediator production in airway epithelial cells, but due to distinct mechanisms.

Lung function in idiopathic pulmonary fibrosis--extended analyses of the IFIGENIA trial.

BACKGROUND: The randomized placebo-controlled IFIGENIA-trial demonstrated that therapy with high-dose N-acetylcysteine (NAC) given for one year, added to prednisone and azathioprine, significantly ameliorates (i.e. slows down) disease progression in terms of vital capacity (VC) (+9%) and diffusing capacity (DLco) (+24%) in idiopathic pulmonary fibrosis (IPF). To better understand the clinical implications of these findings we performed additional, explorative analyses of the IFGENIA data set. METHODS: We analysed effects of NAC on VC, DLco, a composite physiologic index (CPI), and mortality in the 155 study-patients. RESULTS: In trial completers the functional indices did not change significantly with NAC, whereas most indices deteriorated with placebo; in non-completers the majority of indices worsened but decline was generally less pronounced in most indices with NAC than with placebo. Most categorical analyses of VC, DLco and CPI also showed favourable changes with NAC. The effects of NAC on VC, DLco and CPI were significantly better if the baseline CPI was 50 points or lower. CONCLUSION: This descriptive analysis confirms and extends the favourable effects of NAC on lung function in IPF and emphasizes the usefulness of VC, DLco, and the CPI for the evaluation of a therapeutic effect. Most importantly, less progressed disease as indicated by a CPI of 50 points or lower at baseline was more responsive to therapy in this study.

High-dose acetylcysteine in idiopathic pulmonary fibrosis.

BACKGROUND: Idiopathic pulmonary fibrosis is a chronic progressive disorder with a poor prognosis. METHODS: We conducted a double-blind, randomized, placebo-controlled multicenter study that assessed the effectiveness over one year of a high oral dose of acetylcysteine (600 mg three times daily) added to standard therapy with prednisone plus azathioprine. The primary end points were changes between baseline and month 12 in vital capacity and in single-breath carbon monoxide diffusing capacity (DL(CO)). RESULTS: A total of 182 patients were randomly assigned to treatment (92 to acetylcysteine and 90 to placebo). Of these patients, 155 (80 assigned to acetylcysteine and 75 to placebo) had usual interstitial pneumonia, as confirmed by high-resolution computed tomography and histologic findings reviewed by expert committees, and did not withdraw consent before the start of treatment. Fifty-seven of the 80 patients taking acetylcysteine (71 percent) and 51 of the 75 patients taking placebo (68 percent) completed one year of treatment. Acetylcysteine slowed the deterioration of vital capacity and DL(CO): at 12 months, the absolute differences in the change from baseline between patients taking acetylcysteine and those taking placebo were 0.18 liter (95 percent confidence interval, 0.03 to 0.32), or a relative difference of 9 percent, for vital capacity (P=0.02), and 0.75 mmol per minute per kilopascal (95 percent confidence interval, 0.27 to 1.23), or 24 percent, for DL(CO) (P=0.003). Mortality during the study was 9 percent among patients taking acetylcysteine and 11 percent among those taking placebo (P=0.69). There were no significant differences in the type or severity of adverse events between patients taking acetylcysteine and those taking placebo, except for a significantly lower rate of myelotoxic effects in the group taking acetylcysteine (P=0.03). CONCLUSIONS: Therapy with acetylcysteine at a dose of 600 mg three times daily, added to prednisone and azathioprine, preserves vital capacity and DL(CO) in patients with idiopathic pulmonary fibrosis better than does standard therapy alone.

The effects of additional care by a pulmonary nurse for asthma and COPD patients at a respiratory outpatient clinic: results from a double blind, randomized clinical trial.

OBJECTIVE: To assess the effects of additional information based nursing care program in the treatment of asthma and COPD patients at a pulmonary outpatient clinic. METHODS: In a double blind, randomized clinical trial, 191 patients were allocated to an additional care group or control group. Patients in the intervention group received a protocol-based education program on individual basis by a pulmonary nurse on individual basis (average duration 60 min per patient). All patients were masked for the trial objectives. Effectiveness was expressed in terms of knowledge, inhalation technique, self-management, exacerbation rate (primary outcomes), and health-related quality of life and satisfaction with care received (secondary outcomes). The time interval between the initial and final assessments was 6 months. RESULTS: Ninety-seven patients were randomized into the additional care group and 94 into the control group, of which 157 had a complete dataset. (Un)adjusted analyses did not show differences between treatment groups in terms of knowledge, inhalation technique, self-management, health-related quality of life, and satisfaction with care. Multivariate logistic regression adjusting for baseline covariates showed a significant treatment effect with regard to exacerbation rate (odds ratio=0.35; 95% confidence limits: 0.13/0.94, p=0.04). CONCLUSION: With the exception of exacerbation rate, we could not demonstrate efficacy of additional nursing care in a broad range of outcome parameters. PRACTICE IMPLICATIONS: At present we do not recommend to implement our patient-tailored education program in daily practice.

Reliability in the assessment of videotaped inhalation technique.

Inhalation medication is essential in the treatment of asthma and chronic obstructive pulmonary disease (COPD) patients. Incorrect inhalation technique reduces the effects of medication and has been reported to range from 22% to 95% from optimal. The objective of this study was to determine inter- and intraobserver reliability in inhalation technique assessment. For interobserver reliability three observers scored after three times viewing a total of 49 video recorded inhalation demonstrations using device-specific checklists and mutually agreed scoring rules. Intraobserver reliability was assessed for two observers after 8 months by scoring inhalation demonstrations a second time. Both inter- and intraobserver reliability were expressed by mean percent agreement and mean Kappa scores. All inhaler devices revealed a high mean percent agreement and a substantial or almost perfect Kappa scoring for both inter- and intraobserver reliability. Only one item, "exhale to residual volume," showed poor intraobserver reliability. Assessment of video recorded inhalation technique using device-specific checklists, triple viewing, and mutual agreed scoring rules is reliable. This method enables blind observation of inhalation technique.

IL-12 deficiency transiently improves viral clearance during the late phase of respiratory tract infection with influenza A virus in mice.

T helper 1-driven immune responses have been implicated in protective immunity against viral infections. Interleukin (IL)-12 is a heterodimeric proinflammatory cytokine formed by a p35 and a p40 subunit that can induce differentiation of naïve T cells towards a T helper 1-response. To determine the role of IL-12 in respiratory tract infection with influenza, p35 gene deficient (p35-/-) and normal wild type mice were intranasally infected with influenza A virus. IL-12 p35-/- mice displayed a transiently enhanced rather than an impaired viral clearance, as indicated by a 10-fold reduction in viral loads on day 8 after infection. Although interferon-gamma levels were significantly lower in the lungs of IL-12 p35-/- mice, their cellular immune responses were not altered, as reflected by similar T cell CD69 expression and influenza-specific T cell recruitment. Our data indicate that endogenous IL-12 impairs viral clearance during the late phase of influenza A virus infection in mice.

Inhalation of beta 2 agonists impairs the clearance of nontypable Haemophilus influenzae from the murine respiratory tract.

BACKGROUND: Nontypable Haemophilus influenzae (NTHi) is a common bacterial pathogen causing human respiratory tract infections under permissive conditions such as chronic obstructive pulmonary disease. Inhalation of beta2-receptor agonists is a widely used treatment in patients with chronic obstructive pulmonary disease. The aim of this study was to determine the effect of inhalation of beta2 agonists on the host immune response to respiratory tract infection with NTHi. METHODS: Mouse alveolar macrophages were stimulated in vitro with NTHi in the presence or absence of the beta2 receptor agonists salmeterol or salbutamol. In addition, mice received salmeterol or salbutamol by inhalation and were intranasally infected with NTHi. End points were pulmonary inflammation and bacterial loads. RESULTS: Both salmeterol and salbutamol inhibited NTHi induced tumor necrosis factor-alpha (TNFalpha) release by mouse alveolar macrophages in vitro by a beta receptor dependent mechanism. In line, inhalation of either salmeterol or salbutamol was associated with a reduced early TNFalpha production in lungs of mice infected intranasally with NTHi, an effect that was reversed by concurrent treatment with the beta blocker propranolol. The clearance of NTHi from the lungs was impaired in mice treated with salmeterol or salbutamol, an adverse effect that was prevented by propranolol and independent of the reduction in TNFalpha. CONCLUSION: These data suggest that inhalation of salmeterol or salbutamol may negatively influence an effective clearance of NTHi from the airways.

Limited beta2-adrenoceptor haplotypes display different agonist mediated airway responses in asthmatics.

BACKGROUND: In vitro and some in vivo studies suggested that genetic haplotypes may have an impact on beta2-agonist mediated airway responses in asthmatics. Due to strong linkage disequilibrium the single nucleotide polymorphisms (SNPs) in the beta2-adrenoceptor gene result in only a limited number of haplotypes. We intended to evaluate the impact of beta2-adrenoceptor haplotypes on beta2-agonist mediated airway responses and the development of tolerance in mild to moderate asthmatics. METHODS: Patients were genotyped for the part of the beta2-adrenoceptor gene with a known bearing on receptor function and regulation. Cumulative dose response curves of fenoterol versus PD20 methacholine and FEV1 were constructed after 2 week treatment periods with either terbutaline or placebo in a double blind, randomised and cross-over design. Analysis of the dose response curves was based on a repeated measurement analysis of covariance. RESULTS: In our study population comprising 45 asthmatic patients, we found three limited allelic haplotypes, resulting in six different genotypes. Our data support the existence of differences between these six genotypes both in the shape of the dose response relationship of the beta2-adrenoceptor agonist fenoterol as well as in the propensity to develop tolerance for these effects by pre-treatment with terbutaline. However, this could only be substantiated for the endpoint PD20 methacholine. CONCLUSION: Between beta2-adrenoceptor genotypes differences exist both in baseline beta2-agonist induced airway responses as well as in the propensity to develop tolerance during maintenance beta2-agonist therapy. The net differences after two weeks of therapy are, however, of magnitudes that are unlikely to be of clinical significance.

Semiquantitative 67Ga scintigraphy as an indicator of response to and prognosis after corticosteroid treatment in idiopathic interstitial pneumonia.

UNLABELLED: The prognosis in some forms of idiopathic interstitial pneumonia (IIP), especially idiopathic pulmonary fibrosis (IPF) and fibrotic nonspecific interstitial pneumonia (NSIP), is still poor. A minority of patients will respond to immunosuppressive treatment. In patients with IPF or fibrotic NSIP, pulmonary (67)Ga scintigraphy may be useful for predicting response to therapy and prognosis. The objective of the present study was to evaluate whether semiquantitative (67)Ga scintigraphy can be used to predict responsiveness to therapy with high-dose corticosteroids in a well-defined population of patients with IIP (IPF and fibrotic NSIP). METHODS: This study was performed in a tertiary referral center. We prospectively performed (67)Ga scintigraphy in 23 consecutive patients previously diagnosed with IIP (IPF and fibrotic NSIP) before and after treatment with 3 monthly courses of high-dose methylprednisolone. Lung function tests and bronchoalveolar lavage (BAL) were performed before and after these 3 courses, and patients were monitored for 1 y after the start of the treatment. RESULTS: During follow-up, 5 patients died, none during the first 3 mo. Although pulmonary (67)Ga uptake significantly decreased after treatment (P = 0.001), there was no correlation between either initial (67)Ga uptake or change in (67)Ga uptake on treatment and 1-y prognosis. This finding was independent of prior immunosuppressive treatment, diagnosis of IPF or NSIP, or whether initial (67)Ga uptake was elevated or not. BAL cellularity was correlated with neither pulmonary (67)Ga uptake nor response to treatment. CONCLUSION: Pulmonary (67)Ga uptake cannot be used to predict response to corticosteroid treatment or prognosis in patients with IIP. Apparently, the (inflammatory) process influenced by treatment with methylprednisolone does not determine the progression of disease. This finding supports the hypothesis that although inflammation is present in IPF and fibrotic NSIP, it is neither the hallmark of the disease nor the major factor determining prognosis.

Activation of coagulation and inhibition of fibrinolysis in the lung after inhalation of lipopolysaccharide by healthy volunteers.

Pneumonia is frequently associated with changes in coagulation and fibrinolysis in the bronchoalveolar space. To determine the effect of lipopolysaccharide (LPS) on the hemostatic balance in the human lung, six healthy subjects inhaled nebulized LPS or saline in a randomized cross-over study and bronchoalveolar lavage fluid was obtained six hours thereafter. LPS induced soluble tissue factor and thrombin-antithrombin complexes and inhibited plasminogen activator activity in BALF. Additionally plasminogen activator inhibitor type 1 production was upregulated after LPS inhalation. LPS also elicited local activation of neutrophils (release of elastase, myeloperoxidase and bactericidal/permeability increasing protein) and secretion of interleukin (IL)-6 and IL-8. Inhalation of LPS by healthy humans reproduces major features of the procoagulant response to inflammatory and infectious lung diseases and may be used as a novel model to evaluate pathogenetic mechanisms and new interventions.

E1A expression dysregulates IL-8 production and suppresses IL-6 production by lung epithelial cells.

BACKGROUND: The adenoviral protein E1A has been proposed to play a role in the pathophysiology of COPD, in particular by increasing IL-8 gene transcription of lung epithelial cells in response to cigarette smoke-constituents such as LPS. As IL-8 production is also under tight post-transcriptional control, we planned to study whether E1A affected IL-8 production post-transcriptionally. The production of IL-6 by E1A-positive cells had not been addressed and was studied in parallel. Based on our previous work into the regulation of IL-8 and IL-6 production in airway epithelial cells, we used the lung epithelial-like cell line NCI-H292 to generate stable transfectants expressing either E1A and/or E1B, which is known to frequently co-integrate with E1A. We analyzed IL-8 and IL-6 production and the underlying regulatory processes in response to LPS and TNF-alpha. METHODS: Stable transfectants were generated and characterized with immunohistochemistry, western blot and flow cytometry. IL-8 and IL-6 protein production was measured by ELISA. Levels of IL-8 and IL-6 mRNA were measured using specific radiolabeled probes. EMSA was used to assess transcriptional activation of relevant transcription factors. Post-transcriptional regulation of mRNA half-life was measured by Actinomycin D chase experiments. RESULTS: Most of the sixteen E1A-expressing transfectants showed suppression of IL-6 production, indicative of biologically active E1A. Significant but no uniform effects on IL-8 production, nor on transcriptional and post-transcriptional regulation of IL-8 production, were observed in the panel of E1A-expressing transfectants. E1B expression exerted similar effects as E1A on IL-8 production. CONCLUSION: Our results indicate that integration of adenoviral DNA and expression of E1A and E1B can either increase or decrease IL-8 production. Furthermore, we conclude that expression of E1A suppresses IL-6 production. These findings question the unique role of E1A protein in the pathophysiology of COPD, but do not exclude a role for adenoviral E1A/E1B DNA in modulating inflammatory responses nor in the pathogenesis of COPD.

Enzyme-linked immunosorbent assays using immune complexes for the diagnosis of tuberculosis.

The serodiagnosis of tuberculosis has long been the subject of investigation, but we still lack a test with widespread clinical utility. The poor sensitivity and specificity of commercial assays precludes their use as the sole means of diagnosis. All of these assays use mycobacterial antigens adsorbed onto a surface. Little attention has been paid to changes in antigen conformation that may occur as a result of passive coating of these antigens to solid supports like polystyrene. Such changes may cause technical artifacts resulting in false-positive (FP) and false-negative (FN) reactions. We have developed two different enzyme-linked immunosorbent assay (ELISA) systems, in which human serum antibodies and target antigens of Mycobacterium tuberculosis are able to associate and dissociate freely in solution to form immune complexes. In one ELISA, rabbit antibodies against M. tuberculosis, passively coated in the ELISA wells, capture the immune complexes (ICs). In the other ELISA, the ICs are detected by these same rabbit antibodies but are first captured by passively coated goat anti-rabbit IgG. We have compared these two ELISA systems with an ELISA using M. tuberculosis antigens passively adsorbed to the solid polystyrene surface of the plate. We studied sera from 81 patients with tuberculosis and 47 healthy subjects. The differences between tuberculosis (TB) patients and healthy subjects were statistically significant in all three of our ELISA systems. However, the ELISA systems using soluble M. tuberculosis antigens distinguished better between TB patients and healthy subjects than the ELISA using surface-adsorbed M. tuberculosis antigens. We suggest that in the latter ELISA, passive adsorption of the target antigens induces conformational change, generating altered epitopes that are recognized by antibodies present in the serum from even healthy people. These altered conformational epitopes are recognized by antibodies that were originally evoked by antigens other than M. tuberculosis, known as heterophile antigens.

Toll-like receptor 4 is not involved in host defense against respiratory tract infection with Sendai virus.

Toll-like receptors (TLR) induce innate immune responses upon stimulation by a wide variety of pathogens. TLR4 has been implicated in innate immunity against respiratory syncytial virus (RSV) by an interaction with the viral envelope fusion (F) protein. Sendai virus (mouse parainfluenza type 1) shares many features with RSV, including a structurally and functionally similar F protein. To determine the role of TLR4 in host defense against Sendai virus respiratory tract infection, TLR4 mutant and wildtype mice were intranasally infected with Sendai virus. Sendai infection resulted in an increase in viral RNA copies in lung homogenates peaking on day 4. Pulmonary viral loads, histopathology, cytokine levels and leukocyte influx were similar in TLR4 mutant and wildtype mice. In spite of the structural similarities shared by the F proteins of Sendai virus and RSV, TLR4 is not involved in host defense against respiratory tract infection with Sendai virus.

Evaluation of an algorithm for switching from IV to PO therapy in clinical practice in patients with community-acquired pneumonia.

BACKGROUND: In patients with community-acquired pneumonia (CAP), switching from IV to PO antibiotics offers advantages over IV therapy alone, including improved cost-effectiveness through reductions in the length of hospital stay and treatment costs. OBJECTIVE: The aim of this study was to determine whether a method for switching therapy in clinical practice could be used in patients with CAP and whether differences were found in the duration of IV treatment and length of hospital stay between the 5 risk classes of the Pneumonia Severity Index (PSI) after the therapy switch. METHODS: This was a prospective, observational study of patients aged >/=18 years presenting with CAP at our teaching hospital between December 1998 and November 2000. Microbiological and serological tests were performed, and signs and symptoms of CAP, C-reactive protein levels, and white blood cell counts were assessed throughout treatment and at the 1-month follow-up. Patients were stratified by PSI risk class. When the patient's temperature had been normalized for 72 hours and respiratory symptoms (dyspnea, coughing, and thoracal pain) had improved, patients were switched from IV to PO therapy (same drug). RESULTS: The study included 180 patients with CAP Clinical cure was seen in 174 (97%) patients. No significant difference between the 5 risk classes was found in duration of therapy. Patients in risk class V remained hospitalized for a significantly longer period than patients in risk classes I through IV (P < 0.001). Furthermore, after patients were switched to PO antibiotics, the level of C-reactive protein decreased in patients in all risk classes and was normalized by follow-up. CONCLUSIONS: In the population studied, use of specific criteria (ie, absence of fever for 72 hours and reduction in respiratory symptoms) allowed successful switch from IV to PO antibiotic therapy for the treatment of CAP Duration of therapy was not affected by PSI risk class, but those in risk class V were hospitalized longer than other risk classes.

Predictors of incorrect inhalation technique in patients with asthma or COPD: a study using a validated videotaped scoring method.

BACKGROUND: Inadequate technique reduces the effects of inhalation medication. Errors in inhalation technique have been reported to range up to 85%. Not only various patients' characteristics but also the device has an effect on correct inhalation technique. The purpose of this study was to determine the effect of patients' characteristics and type of inhaler device on inhalation technique in patient with asthma or chronic obstructive pulmonary disease (COPD). METHODS: A validated scoring method was used that consisted of triple viewing of video-recorded inhalations, using device-specific checklists. The following patient characteristics were investigated: gender, age, education level, diagnosis, treatment by a pulmonary physician, previously received inhalation instruction, exacerbation frequency, knowledge, self-management competence, pulmonary function, and use of multiple inhaler devices. Chi-square statistics were used for univariate associations between potential determinants and correctness of inhalation technique. Relevant determinants were entered into a multivariate logistic regression model. Moreover, inhalation technique errors were examined for six inhaler devices: three prefilled dry powder inhalers, one single-dose dry powder inhaler, a pressurized metered-dose inhaler (pMDI) and a pMDI with a spacer. RESULTS: Overall, 40% of the patients made at least one essential mistake in their inhalation technique. Patients who never received inhalation instruction and patients who used more than one inhaler device made significantly more errors (odds ratio both 2.2). Comparison between devices showed that a correct inhalation technique most likely occurred with the use of prefilled dry powder devices. CONCLUSION: Incorrect inhalation technique is common among asthma and COPD patients in a pulmonary outpatient clinic. Our study suggests that the use of prefilled dry powder inhalers as well as inhalation instruction increases correct inhalation technique. Simultaneous use of different types of inhalation devices has to be discouraged.

Procalcitonin vs C-reactive protein as predictive markers of response to antibiotic therapy in acute exacerbations of COPD.

BACKGROUND: Rational prescription of antibiotics in acute exacerbations of COPD (AECOPD) requires predictive markers. We aimed to analyze whether markers of systemic inflammation can predict response to antibiotics in AECOPD. METHODS: We used data from 243 exacerbations out of 205 patients from a placebo-controlled trial on doxycycline in addition to systemic corticosteroids for AECOPD. Clinical and microbiologic response, serum C-reactive protein (CRP) level (cutoffs 5 and 50 mg/L), and serum procalcitonin level (PCT) (cutoffs 0.1 and 0.25 µg) were assessed. RESULTS: Potential bacterial pathogens were identified in the majority of exacerbations (58%). We found a modest positive correlation between PCT and CRP (r = 0.46, P < .001). The majority of patients (75%) had low PCT levels, with mostly elevated CRP levels. Although CRP levels were higher in the presence of bacteria (median, 33.0 mg/L [interquartile range, 9.75-88.25] vs 17 mg/L [interquartile range, 5.0-61.0] [P = .004]), PCT levels were similar. PCT and CRP performed similarly as markers of clinical success, and we found a clinical success rate of 90% in patients with CRP ≤ 5 mg/L. A significant effect of doxycycline was observed in patients with a PCT level < .1 µg/L (treatment effect, 18.4%; P = .003). A gradually increasing treatment effect of antibiotics (6%, 10%, and 18%), although not significant, was found for patients with CRP values of ≤ 5, 6-50, and > 50 mg/L, respectively. CONCLUSIONS: Contrary to the current literature, this study suggests that patients with low PCT values do benefit from antibiotics. CRP might be a more valuable marker in these patients.