Dick Menzies and colleagues report findings from a collaborative, individual patient-level meta-analysis of treatment outcomes among patients with multidrug-resistant tuberculosis.
Rationale: The small conducting airways are the major site of airflow obstruction in chronic obstructive pulmonary disease and may precede emphysema development.Objectives: We hypothesized a novel computed tomography (CT) biomarker of small airway disease predicts FEV 1 decline.Methods: We analyzed 1,508 current and former smokers from COPDGene with linear regression to assess predictors of change in FEV 1 (ml/yr) over 5 years. Separate models for subjects without and with airflow obstruction were generated using baseline clinical and physiologic predictors in addition to two novel CT metrics created by parametric response mapping (PRM), a technique pairing inspiratory and expiratory CT images to define emphysema (PRM emph ) and functional small airways disease (PRM fSAD ), a measure of nonemphysematous air trapping.Measurements and Main Results: Mean (SD) rate of FEV 1 decline in ml/yr for GOLD (Global Initiative for Chronic Obstructive Lung Disease) 0-4 was as follows: 41.8 (47.7), 53.8 (57.1), 45.6 (61.1), 31.6 (43.6), and 5.1 (35.8), respectively (trend test for grades 1-4; P , 0.001). In multivariable linear regression, for participants without airflow obstruction, PRM fSAD but not PRM emph was associated with FEV 1 decline (P , 0.001). In GOLD 1-4 participants, both PRM fSAD and PRM emph were associated with FEV 1 decline (P , 0.001 and P = 0.001, respectively). Based on the model, the proportional contribution of the two CT metrics to FEV 1 decline, relative to each other, was 87% versus 13% and 68% versus 32% for PRM fSAD and PRM emph in GOLD 1/2 and 3/4, respectively.Conclusions: CT-assessed functional small airway disease and emphysema are associated with FEV 1 decline, but the association with functional small airway disease has greatest importance in mildto-moderate stage chronic obstructive pulmonary disease where the rate of FEV 1 decline is the greatest.Clinical trial registered with www.clinicaltrials.gov (NCT 00608764).
Rationale: Obesity may alter glucocorticoid response in asthma. Objectives: To evaluate the relationship between body mass index (BMI, kg/m 2 ) and glucocorticoid response in subjects with and without asthma. Methods: Nonsmoking adult subjects underwent characterization of lung function, BMI, and spirometric response to prednisone. Dexamethasone (DEX, 10 26 M)-induced mitogen-activated protein kinase phosphatase-1 (MKP-1) and baseline tumor necrosis factor (TNF)-a expression were evaluated by polymerase chain reaction in peripheral blood mononuclear cells (PBMCs) and bronchoalveolar lavage cells. The relationship between BMI and expression of MKP-1 and TNF-a was analyzed. Measurements and Main Results: A total of 45 nonsmoking adults, 33 with asthma (mean [SD] FEV 1 % of 70.7 [9.8]%) and 12 without asthma were enrolled. DEX-induced PBMC MKP-1 expression was reduced in overweight/obese versus lean patients with asthma, with mean (6 SEM) fold-induction of 3.11 (60.46) versus 5.27 (60.66), respectively (P 5 0.01). In patients with asthma, regression analysis revealed a 20.16 (60.08)-fold decrease in DEX-induced MKP-1 per unit BMI increase (P 5 0.04). PBMC TNF-a expression increased as BMI increased in subjects with asthma, with a 0.27 unit increase in log (TNF-a [ng/ml]) per unit BMI increase (P 5 0.01). The ratio of PBMC log (TNF-a):DEX-induced MKP-1 also increased as BMI increased in patients with asthma (10.09 6 0.02; P 5 0.004). In bronchoalveolar lavage cells, DEX-induced MKP-1 expression was also reduced in overweight/obese versus lean patients with asthma (1.36 6 0.09-fold vs. 1.76 6 0.15-fold induction; P 5 0.05). Similar findings were not observed in control subjects without asthma. Conclusions: Elevated BMI is associated with blunted in vitro response to dexamethasone in overweight and obese patients with asthma.
Multidrug-resistant tuberculosis, a disease caused by Mycobacterium tuberculosis strains that are resistant at least to rifampin and isoniazid, entails extended treatment, expensive and toxic regimens, and higher rates of treatment failure and death. We retrospectively analyzed the outcomes in 205 patients treated at our center for multidrug-resistant tuberculosis, with strains resistant to a median of six drugs, and compared the results with those of our previous series. Logistic regression and survival analysis were used to evaluate short- and long-term outcomes, respectively. Initial favorable response, defined as at least three consecutive negative sputum cultures over a period of at least 3 months, was 85% compared with 65% in the prior cohort. The current cohort had greater long-term success rates, 75% versus 56%, and lower tuberculosis death rates, 12% versus 22%, than the earlier one. Surgical resection and fluoroquinolone therapy were associated with improved microbiological and clinical outcomes in the 205 patients studied after adjusting for other variables. The improvement was statistically significant for surgery and among older patients for fluoroquinolone therapy.
Rationale: Acute exacerbations of chronic obstructive pulmonary disease (COPD) increase the risk of death and drive healthcare costs, but whether they accelerate loss of lung function remains controversial. Whether exacerbations in subjects with mild COPD or similar acute respiratory events in smokers without airflow obstruction affect lung function decline is unknown.Objectives: To determine the association between acute exacerbations of COPD (and acute respiratory events in smokers without COPD) and the change in lung function over 5 years of follow-up.Methods: We examined data on the first 2,000 subjects who returned for a second COPDGene visit 5 years after enrollment. Baseline data included demographics, smoking history, and computed tomography emphysema. We defined exacerbations (and acute respiratory events in those without established COPD) as acute respiratory symptoms requiring either antibiotics or systemic steroids, and severe events by the need for hospitalization. Throughout the 5-year follow-up period, we collected self-reported acute respiratory event data at 6-month intervals. We used linear mixed models to fit FEV 1 decline based on reported exacerbations or acute respiratory events. Measurements and Main Results:In subjects with COPD, exacerbations were associated with excess FEV 1 decline, with the greatest effect in Global Initiative for Chronic Obstructive Lung Disease stage 1, where each exacerbation was associated with an additional 23 ml/yr decline (95% confidence interval, 2-44; P = 0.03), and each severe exacerbation with an additional 87 ml/yr decline (95% confidence interval, 23-151; P = 0.008); statistically significant but smaller effects were observed in Global Initiative for Chronic Obstructive Lung Disease stage 2 and 3 subjects. In subjects without airflow obstruction, acute respiratory events were not associated with additional FEV 1 decline.Conclusions: Exacerbations are associated with accelerated lung function loss in subjects with established COPD, particularly those with mild disease. Trials are needed to test existing and novel therapies in subjects with early/mild COPD to potentially reduce the risk of progressing to more advanced lung disease.Clinical trial registered with www.clinicaltrials.gov (NCT 00608764).
Rationale: Glucocorticoids (GCs) are highly effective in the treatment of asthma. However, some individuals have GC-insensitive asthma. Objectives: To evaluate the functional response to steroids of bronchoalveolar lavage (BAL) cells from sites of airway inflammation from patients with GC-insensitive versus GC-sensitive asthma. As well, to attempt to define the functional role of glucocorticoid receptor (GCR) (a splicing variant, and dominant negative inhibitor of, the classic GCR␣) in controlling GCR␣ nuclear translocation and transactivation at a molecular level. Methods and Measurements: Fiberoptic bronchoscopy with collection of BAL fluid was performed on seven patients with GC-sensitive asthma and eight patients with GC-insensitive asthma. GCR␣ cellular shuttling in response to 10 ؊6 M dexamethasone treatment and GCR expression were analyzed in BAL cells by immunofluorescence staining. The effects of overexpression and silencing of GCR mRNA on GCR␣ function were assessed. Main Results: Significantly reduced nuclear translocation of GCR␣ in response to steroids was found in BAL cells from patients with GC-insensitive asthma. BAL macrophages from patients with GCinsensitive asthma had significantly increased levels of cytoplasmic and nuclear GCR. It was demonstrated that GCR␣ nuclear translocation and its transactivation properties were proportionately reduced by level of viral transduction of the GCR gene into the DO-11.10 cell line. RNA silencing of GCR mRNA in human BAL macrophages from patients with GC-insensitive asthma resulted in enhanced dexamethasone-induced GCR␣ transactivation. Conclusions: GC insensitivity is associated with loss of GCR␣ nuclear translocation in BAL cells and elevated GCR, which may inhibit GCR␣ transactivation in response to steroids.
Rationale: Among patients with nontuberculous mycobacterial lung disease is a subset of previously healthy women with a slender body morphotype, often with scoliosis and/or pectus excavatum. We hypothesize that unidentified factors predispose these individuals to pulmonary nontuberculous mycobacterial disease. Objectives: To compare body morphotype, serum adipokine levels, and whole-blood cytokine responses of patients with pulmonary nontuberculous mycobacteria (pNTM) with contemporary control subjects who are well matched demographically. Methods: We enrolled 103 patients with pNTM and 101 uninfected control subjects of similar demographics. Body mass index and body fat were quantified. All patients with pNTM and a subset of control subjects were evaluated for scoliosis and pectus excavatum. Serum leptin and adiponectin were measured. Specific cytokines important to host-defense against mycobacteria were measured in whole blood before and after stimulation. Measurements and Main Results: Patients with pNTM and control subjects were well matched for age, gender, and race. Patients with pNTM had significantly lower body mass index and body fat and were significantly taller than control subjects. Scoliosis and pectus excavatum were significantly more prevalent in patients with pNTM. The normal relationships between the adipokines and body fat were lost in the patients with pNTM, a novel finding. IFN-g and IL-10 levels were significantly suppressed in stimulated whole blood of patients with pNTM. Conclusions: This is the first study to comprehensively compare body morphotype, adipokines, and cytokine responses between patients with NTM lung disease and demographically matched controls. Our findings suggest a novel, predisposing immunophenotype that should be mechanistically defined.Keywords: leptin; adiponectin; pectus excavatum; scoliosis; Marfan syndrome Chronic lung disease due to nontuberculous mycobacteria (NTM) is a growing public health concern (1-3). Recent studies estimate the incidence in the United States to be five to six cases per 100,000 and as high as 15.5 cases per 100,000 in persons over 50 years of age (3-5). Because the duration of symptomatic NTM lung disease is often years, the prevalence of disease is estimated to be 10 to 40 cases per 100,000 (1).In the United States, the most common NTM species associated with lung disease are Mycobacterium avium complex (MAC), Mycobacterium kansasii, and Mycobacterium abscessus. Although NTM are widespread in water and soil (6, 7), relatively few persons develop disease. Thus, intact immunity is likely pivotal for protection against NTM.Chronic lung disease is the most common form of NTM infection, manifested by two main radiographic patterns: (i) an upper lobe fibrocavitary pattern that occurs mostly in men with underlying lung disease such as chronic obstructive pulmonary disease (COPD) and (ii) a nodular-bronchiectasis pattern that often involves the right middle lobe and lingula and which appears to be more common in women with no clear risk factors (8)...
Distal lung inflammation may be important in asthma pathophysiology. The goal of this study was to measure cellular inflammation in the large airway and four distal lung regions (small airway inner and outer wall, alveolar attachments, and peripheral alveolar tissue) and to correlate the specific inflammatory cells with several lung function parameters. Sections of concurrently obtained endobronchial and transbronchial/surgical biopsy tissue from 20 individuals with severe asthma were immunostained for T-lymphocyte, eosinophil, monocyte/macrophage, neutrophil, and two mast cell markers (tryptase and chymase). Specific cell distributions were determined and correlated with lung function measures. The number of inflammatory cells generally increased toward the periphery, but the percentage of T-lymphocytes, eosinophils, monocytes/macrophages, and neutrophils remained similar or decreased from large to small airways. In contrast, mast cell number, percentage, and the chymase-positive phenotype increased in small airway regions. After the analysis was adjusted for multiple comparisons, only chymase-positive mast cells significantly and positively correlated with lung function. Such a relationship was seen only in the small airway/alveolar attachments lung region (r(s) = 0.61-0.89; p = 0.001 for all correlations). These data suggest that induction of chymase-positive mast cells, particularly in the small airway outer wall/alveolar attachments region, may be protective for lung function in severe asthma.
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