V genes in primates from whole genome sequencing data.

The adaptive immune system uses V genes for antigen recognition. However, the evolutionary diversification and selection processes within and across species and orders remain poorly understood. Here, we studied the amino acid (AA) sequences obtained from the translated in-frame V exons of immunoglobulins (IG) and T cell receptors (TR) from 16 primate species whose genomes have been sequenced. Multi-species comparative analysis supports the hypothesis that V genes in the IG loci undergo birth/death processes, thereby permitting rapid adaptability over evolutionary time. We also show that multiple cladistic groupings exist in the TRA (35 clades) and TRB (25 clades) V gene loci and that each primate species typically contributes at least one V gene to each of these clades. The results demonstrate that IG V genes and TR V genes have quite different evolutionary pathways; multiple duplications can explain the IG loci results, while coevolutionary pressures can explain the phylogenetic results of the TR V gene loci. Our results suggest that there exist evolutionary relationships between V gene clades in the TRA and TRB loci. Due to the long-standing preservation of these clades, such genes may have specific and necessary roles for the viability of a species.

Genomic V exons from whole genome shotgun data in reptiles.

Reptiles and mammals diverged over 300 million years ago, creating two parallel evolutionary lineages amongst terrestrial vertebrates. In reptiles, two main evolutionary lines emerged: one gave rise to Squamata, while the other gave rise to Testudines, Crocodylia, and Aves. In this study, we determined the genomic variable (V) exons from whole genome shotgun sequencing (WGS) data in reptiles corresponding to the three main immunoglobulin (IG) loci and the four main T cell receptor (TR) loci. We show that Squamata lack the TRG and TRD genes, and snakes lack the IGKV genes. In representative species of Testudines and Crocodylia, the seven major IG and TR loci are maintained. As in mammals, genes of the IG loci can be grouped into well-defined IMGT clans through a multi-species phylogenetic analysis. We show that the reptilian IGHV and IGLV genes are distributed amongst the established mammalian clans, while their IGKV genes are found within a single clan, nearly exclusive from the mammalian sequences. The reptilian and mammalian TRAV genes cluster into six common evolutionary clades (since IMGT clans have not been defined for TR). In contrast, the reptilian TRBV genes cluster into three clades, which have few mammalian members. In this locus, the V exon sequences from mammals appear to have undergone different evolutionary diversification processes that occurred outside these shared reptilian clans. These sequences can be obtained in a freely available public repository (http://vgenerepertoire.org).

Civilian perception of the role of the military in Nigeria's 2014 Ebola outbreak and health-related responses in the North East region.

INTRODUCTION: Civilian-military relations play an important yet under-researched role in low-income and middle-income country epidemic response. One crucial component of civilian-military relations is defining the role of the military. This paper evaluates the role of Nigerian military during the 2014-2016 West African Ebola epidemic. METHODS: Focus groups and key informant interviews were conducted throughout three states in North East region of Nigeria: Borno, Yobe and Adamawa. Participants were identified through mapping of stakeholder involvement in Nigerian epidemic response. English-translated transcripts of each key informant interview and focus group discussion were then coded and key themes were elucidated and analysed. RESULTS: Major themes elucidated include developing inclusive coordination plans between civilian and military entities, facilitating human rights reporting mechanisms and distributing military resources more equitably across geographical catchment areas. The Nigerian Military served numerous functions: 37% (22/59) of respondents indicated 'security/peace' as the military's primary function, while 42% (25/59) cited health services. Variations across geographic settings were also noted: 35% (7/20) of participants in Borno stated the military primarily provided transportation, while 73% (11/15) in Adamawa and 29% (7/24) in Yobe listed health services. CONCLUSIONS: Robust civilian-military relations require an appropriately defined role of the military and clear civilian-military communication. Important considerations to contextualise civilian-military relations include military cultural-linguistic understanding, human rights promotion, and community-based needs assessments; such foci can facilitate the military's understanding of community norms and civilian cooperation with military aims. In turn, more robust civilian-military relations can promote overall epidemic response and reduce the global burden of disease.

Efficacy of standard rehabilitation in COPD outpatients with comorbidities.

A prospective study was performed to confirm the prevalence pattern of the most frequent co-morbidities and to evaluate whether characteristics of patients, specific comorbidities and increasing number of comorbidities are independently associated with poorer outcomes in a population with complex chronic obstructive pulmonary disease (COPD) submitted for pulmonary rehabilitation (PR). 316 outpatients (mean ± SD age 68 ± 7 yrs) were studied. The outcomes recorded were comorbidities and proportion of patients with a pre-defined minimally significant change in exercise tolerance (6-min walk distance (6MWD) +54 m), breathlessness (Medical Research Council (MRC) score -1 point) and quality of life (St George's Respiratory Questionnaire -4 points). 62% of patients reported comorbidities; systemic hypertension (35%), dyslipidaemia (13%), diabetes (12%) and coronary disease (11%) were the most frequent. Of these patients, >45% improved over the minimum clinically important difference in all the outcomes. In a logistic regression model, baseline 6MWD (OR 0.99, 95% CI 0.98-0.99; p = 0.001), MRC score (OR 12.88, 95% CI 6.89-24.00; p = 0.001) and arterial carbon dioxide tension (OR 1.08, 95% CI 1.00-1.15; p = 0.034) correlated with the proportion of patients who improved 6MWD and MRC, respectively. Presence of osteoporosis reduced the success rate in 6MWD (OR 0.28, 95% CI 0.11-0.70; p = 0.006). A substantial prevalence of comorbidities in COPD outpatients referred for PR was confirmed. Only the individual's disability and the presence of osteoporosis were independently associated with poorer rehabilitation outcomes.

Bronchial vascular remodelling in patients with COPD and its relationship with inhaled steroid treatment.

BACKGROUND: Only a few studies have evaluated microvascular changes and proangiogenetic mediators in the bronchial mucosa of patients with chronic obstructive pulmonary disease (COPD), and the results have been discordant. Furthermore, the role of inhaled corticosteroids (ICS) in COPD has not been extensively studied. A study was undertaken to evaluate vascular remodelling, its relationship with inflammatory cells and treatment effects in the bronchial mucosa of patients with COPD. METHODS: The study comprised three groups: (1) 10 non-treated patients with COPD (COPD); (2) 10 patients with COPD treated with nebulised beclomethasone dipropionate 1600-2400 mug daily (equivalent to 800-1200 mug via metered dose inhaler) (COPD/ICS); and (3) 8 control subjects (CS). Bronchial biopsies were evaluated for number and size of vessels and vascular area. Specimens were also examined for vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and transforming growth factor beta (TGF-beta) expression and inflammatory cell counts were performed. RESULTS: Vascular area, vessel size, VEGF+ cells, bFGF+ cells and TGF-beta+ cells were significantly increased in the COPD group compared with the COPD/ICS and CS groups (all p<0.05). In addition, bFGF+ cells were significantly increased in the COPD/ICS group compared with the CS group, and CD8+ and CD68+ cells were significantly increased in the COPD group compared with the COPD/ICS and CS groups (p<0.05). In the COPD group the VEGF+ cells correlated with the number of vessels (p<0.05), vascular area (p<0.01) and vessel size (p<0.05), and TGF-beta+ cells correlated significantly with vascular area (p<0.05). CONCLUSION: Bronchial vascular remodelling in patients with COPD is mainly related to morphological changes of the mucosal microvessels rather than to new vessel formation, and may be reduced in patients treated with steroids.

The role of small airways in monitoring the response to asthma treatment: what is beyond FEV1?

The definition of asthma has evolved from that of an episodic disease characterized by reversible airways constriction to a chronic inflammatory disease of the airways, with at least partially reversible airway constriction. Increasing evidence supports the notion that small and large airways play a central role in asthma pathophysiology with regard to inflammation, remodeling and symptoms. The contribution of the distal airways to the asthma phenotype carries implications for the delivery of inhaled medications to the appropriate areas of the lung and for the monitoring of the response to asthma treatment. Asthma control is evaluated on the basis of symptoms, lung function and exacerbations. However, evidence suggests that dissociation between lung function and respiratory symptoms, quality of life and airway inflammation exists. In this study, common spirometric parameters offer limited information with regard to the peripheral airways, and it is therefore necessary to move beyond FEV(1). Several functional parameters and inflammatory markers, which are discussed in the present study, can be employed to evaluate distal lung function. In this study, extrafine formulations deliver inhaled drugs throughout the bronchial tree (both large and small airways) and are effective on parameters that directly or indirectly measure air trapping/airway closure.

The value of transbronchial lung biopsy using jumbo forceps via rigid bronchoscope in diffuse lung disease.

BACKGROUND: Transbronchial lung biopsy (TBLB) is a valuable procedure used to obtain a parenchymal specimen in the evaluation of diffuse lung infiltrates. Large forceps are expected to result in larger specimens and improve diagnostic yield. AIM: The objective of this study was to evaluate diagnostic yield of TBLB using large modified flexible gastroenterological forceps ("Jumbo forceps") compared with 'normal' flexible forceps via rigid bronchoscopy in patients with diffuse parenchymal lung disease (DPLD). METHODS: The study was a prospective analysis of 95 patients who underwent fluoroscopy guided TBLB over a two year period. Patients with a lung mass or solitary lung nodule undergoing TBLB were excluded. The larger and small forceps were used in a random sequence to avoid a reduction in diagnostic yield of the second series of biopsies related to possible bleeding by first series of biopsies. To minimize the consequence of haemorrhage, we performed every rigid bronchoscopy, placing a non inflated Fogarty balloon and a rigid aspirator (diameter 4 mm) in lobar bronchus near the biopsy segment. The Fogarty balloon has been inflated in case of bleeding. After the bleeding was controlled we continued to operate up to the biopsy segment. RESULTS: Diagnostic yield of TBLB using Jumbo forceps was significantly higher than using normal flexible forceps via rigid bronchoscopy in patients with DPLD (p = 0.001). In 74 out of 95 patients (78%) the diagnosis was placed with Jumbo forcep while the smaller forcep was diagnostic in 62 out of 95 patients (65%). Large forceps obtained significantly more tissue than the small forceps; the biopsy specimen taken with normal forcep measured in average 1.4 x 1.0 mm and the larger biopsy taken with jumbo forcep measured in average 2.5 x 1.9 mm (p < 0.005). CONCLUSION: The use of large biopsy forceps to perform TBLB via rigid bronchoscope can significantly increase diagnostic yield in the pathological diagnosis of diffuse infiltrative lung disease.

Assessment and monitoring of ventilatory function and cough efficacy in patients with amyotrophic lateral sclerosis.

Assessing and monitoring respiratory muscle function is crucial in patients with Amyotrophic Lateral Sclerosis, since impaired function can lead to either ventilatory failure or respiratory tract infection. Spirometry, diffusing capacity of the lung, breathing pattern, sleep study, blood gas analysis and respiratory muscle strength tests, as well as cough peak flow and cough expiratory volume measurements can provide relevant information on ventilatory function and cough efficacy. With regard to respiratory muscle strength testing, the rational approach consists in starting with volitional and non-invasive tests and later using invasive and non-volitional tests. This review focuses on both ventilatory and respiratory muscle strength testing, in order to undertake a timely treatment of respiratory failure and/or impaired cough efficacy. So far, the current literature has not highlighted any gold standard which stipulates when to commence ventilation and cough support in patients with Amyotrophic Lateral Sclerosis. A composite set of clinical and functional parameters is required for treatment scheduling to monitor lung involvement and follow-up in these patients.

Indications for flexible fiberoptic bronchoscopy and its safety in the very elderly.

AIM: To evaluate the indications and the safety of fiberoptic bronchoscopy (FOB) with bronchoalveolar lavage (BAL), protected specimen brushing (PSB), endobronchial biopsy (EBB), and transbronchial biopsy (TBB) in a population of very elderly patients. METHODS: We performed a retrospective study of all adult patients, aged 50 years or older, who underwent FOB in the Bronchology Unit of the University of Parma Hospital between 1 January, 2003 and 31 April, 2005. Bronchoscopy records of 436 consecutive patients, including 191 patients, 75 yrs of age and older ("very elderly"; = > 75 yrs), were reviewed. RESULTS: Patients aged < 75 years and aged =/> 75 years were no different with regard to gender, BMI, baseline FEV1/FVC ratio, baseline SaO2, and blood pressure. The primary indication in patients aged < 75 years, was to assist in the diagnosis of a pulmonary mass of unknown aetiology (33%) and to remove secretions in the very elderly patients (31%). Indications for FOB and sampling procedures in the two groups were similar. Approximately 30% of patients in each group required supplemental oxygen during the procedure and fever occurred in 9.2% and 10.3% of patients, respectively. Hypertension and bleeding were relatively rare and did not occur more often in the very elderly. CONCLUSIONS: Indication for FOB did not vary with age and adverse events in both groups were uncommon and generally not severe.

Mast cells in bronchoalveolar lavage fluid and in transbronchial biopsy specimens of patients with farmer's lung disease.

Recently, an increased number of mast cells have been reported in bronchoalveolar lavage fluid (BAL) of patients with farmer's lung disease. Some authors pointed out the pathogenetic importance of mast cells in farmer's lung on the basis of their correlation with the activity of the disease, with the BAL lymphocyte counts, and with the markers of lung fibrosis. To determine whether BAL reflects the histologic aspects of the lung histologic features in patients with farmer's lung disease, mast cells recovered from lavage fluid were compared with tissue sections from transbronchial lung biopsies in 15 patients. Mast cell counts in BAL and lung biopsy specimens were significantly correlated (r = 0.88; p less than 0.01), while no other correlations between BAL inflammatory cells and tissue mast cells were found. In lung tissue, there were four times the increased number of mast cells in respect to the control group (84.4 +/- 28.8 vs 20.4 +/- 13.4 mast cells per square millimeter); 83.2 percent of mast cells were found in the alveolar septa, 14.9 percent within alveoli, 0.7 percent among alveolar lining cells, and 1 percent along blood vessels. No mast cells were located within alveoli in controls. In BAL, only lymphocyte and mast cell counts (56.4 +/- 18.6 percent, p less than 0.001; 3.9 +/- 1.5 5 percent, p less than 0.001, respectively) were significantly increased. Our data suggest that in farmer's lung disease, BAL correctly samples the alveolitis. Mast cells, such as lymphocytes, seem to be primary inflammatory cells involved at the site of the disease activity.

Does the mast cell still have a key role in asthma?

In recent years, the emerging concept of bronchial inflammation as a prominent histopathologic characteristic of asthma has profoundly modified the view of the role of the mast cell, which was traditionally thought to be linked to the release of soluble chemical mediators substantially involved in the genesis of acute, immediate bronchospasm. The finding that the production of proinflammatory cytokines by mast cells in asthmatic airways is comparable, in some circumstances, to that of T-cell origin, has led to the hypothesis that mast cells, along with T lymphocytes and eosinophils, may also contribute to the genesis of chronic, persistent asthma. This hypothesis is further supported by the finding that mast cells are able to functionally interact with B cells (promoting IgE synthesis) and T lymphocytes (acting as antigen presenting cells), thus taking part in the immune network. Moreover, mast cells produce an exclusive family of proteases (tryptases and chymases) that exert many biological actions relevant to airways inflammation and remodeling. Future studies will better explain the role of mast cells in asthma and, more specifically, the links with bone marrow-where mast cell progenitors originate-and the airways, where mast cells develop, differentiate, and assume the functions of mature cells. This article reviews recent data available on these topics.

Mast cells in fibrotic lung disorders.

Fibrotic lung disorders are chronic inflammatory diseases in which inflammatory processes in the lower respiratory tract injure the lung and modulate the proliferation of mesenchymal cells that form the basis of the fibrotic scar. The pathogenesis of fibrosis in fibrotic lung disorders remains unclear; however, recent attention has focused on the potential role of the mast cell in the genesis of fibrosis. To determine whether mast cells are implicated in the pathogenesis of lung fibrosis, mast cells were compared with the degree of fibrosis in transbronchial lung biopsy specimens from 49 patients with fibrotic lung disorders (16 sarcoidosis, 15 farmer's lung disease, 9 cryptogenic fibrosing alveolitis, 6 bronchiolitis obliterans organizing pneumonia, 3 histiocytosis X). In lung tissue of patients with fibrotic lung disorders, there was an increased number of mast cells in respect to the control group (98.6 +/- 7.7 vs 27.8 +/- 5.1 mast cells per square millimeter, p < 0.01). Mast cell counts in lung biopsy specimens were significantly correlated with the degree of fibrosis (r = 0.87, p < 0.001); 80.8 percent of mast cells were found in the alveolar septa, 9.6 percent within alveoli, 1.9 percent among alveolar lining cells, and 5 percent along blood vessels. No mast cells were located within alveoli in controls. Our data suggest that mast cells participate in chronic inflammation and that their presence is related to interstitial fibrosis in a much broader spectrum of fibrotic lung disorders.

Inflammatory markers in bronchoalveolar lavage and in bronchial biopsy in asthma during remission.

Bronchoalveolar lavage and BB were performed in 13 asthmatic and six healthy subjects to characterize cellular markers of inflammation in BAL and BB; to compare cellular profile of BAL with cell infiltration in BB; to examine the relationship between bronchial responsiveness and markers of inflammation in BAL and BB. Eosinophils and mast cells were increased in BAL in asthmatic subjects; eosinophils were positively correlated with neutrophils and mast cells. Epithelial shedding was present in nine asthmatic and five control subjects. Intraepithelial cells and cells in submucosa were increased in asthmatic subjects. Eosinophils and intraepithelial mast cells were higher. Thickened basement membrane was associated with more marked cell infiltration in submucosa. Ciliated cells in BAL relate to intraepithelial cells; cells in BAL broadly reflect cell infiltration of submucosa. In the asthmatic group, the degree of bronchial responsiveness correlated with ciliated cells in BAL and with intra-epithelial cells in BB. Marked airway inflammation is associated with stable asthma; inflammatory changes within bronchial epithelium may be linked to the development of bronchial hyperresponsiveness.

Lung function and bronchial responsiveness after bronchoalveolar lavage and bronchial biopsy performed without premedication in stable asthmatic subjects.

We evaluated tolerance, safety, and effects on lung function and bronchial responsiveness of BAL (4 x 50 ml) combined with BB (three to five specimens) performed without premedication in 13 mild and stable asthmatics and eight healthy volunteers. All subjects tolerated bronchoscopy procedures well and without serious side effects. During procedures, no supplemental oxygen was administered and no ECG abnormalities were noted. The PEFR was measured before and immediately after bronchoscopy and at 5-min intervals up until recovery. The maximal percentage fall in PEFR after bronchoscopy was significantly greater in asthmatics (23.1 +/- 13.9 percent) compared to normal subjects (7.8 +/- 8.2 percent, p less than 0.01). Changes in PEFR returned to baseline values within 120 min in all asthmatics. The tcPO2 was recorded at baseline, during and after bronchoscopy. In both groups, a significant change in tcPO2 was measured during the infusion of BAL aliquots, and persisted throughout the procedure. A significant difference in asthmatics compared to healthy subjects was evident during BB and at the end of the procedure (p less than 0.05). In asthmatics, M challenge was performed on three different days over a three-week period prior to bronchoscopy, and was repeated at intervals of 2, 6, and 24 h following procedure. The PC20 M values measured before bronchoscopy were found to have a very high reproducibility (intraclass correlation coefficient = 0.93). The PC20 values measured during experiment times after bronchoscopy were not significantly different from baseline values. These data demonstrate that in mild and stable asthmatics, BAL combined with BB can be safely performed following administration of only local anesthesia. In carefully selected asthmatic subjects, transient bronchoconstriction and a lowering of oxygen tension can be induced by BAL and BB, whereas changes in bronchial responsiveness are more unlikely to occur.

Provocative dose and dose-response curve to inhaled propranolol in asthmatic patients with bronchial hyperresponsiveness to methacholine.

This study was carried out to compare bronchial responses to inhaled propranolol (P) and methacholine (M) in a group of asthmatic subjects with mild to moderate bronchial hyperresponsiveness to M; to determine the short term reproducibility of bronchial response to propranolol; and to examine the shape of dose-response curve to P relative to that of M. Doses of M and P were given in mumoles and bronchial responses to both agents were expressed as the provocative dose that induced a 20 percent fall in FEV1 (PD20 FEV1). In 16 asthmatic patients, there was no correlation between the PD20 of the two agents. Mean PD20 M (+/- SD in log scale) was approximately nine times lower than mean PD20 P (0.64 +/- 0.96 and 5.80 +/- 1.65, respectively). This difference was statistically significant (t = 4.58, p less than 0.001). In six asthmatic patients, the reproducibility of PD20 P was similar to that of M (intraclass correlation coefficient 0.969 and 0.957, respectively). The shape of the dose-response curves to P was different from that of M in five of nine asthmatic patients when all experimental points were analyzed by double-reciprocal plot. We noticed that even small doses of inhaled P may cause a severe bronchoconstriction. Therefore, special caution should be taken to increase P doses very gradually, when studying the dose-response curve. We demonstrated that P inhalation induced a measurable bronchoconstriction in subjects with mild to moderate hyperresponsiveness and it was reproducible. However, the bronchial sensitivity to P was lower than to M. Our findings suggest that P and M have different mechanisms of action.

Lower respiratory tract inflammation in chronic bronchitis. Evaluation by bronchoalveolar lavage and changes associated with treatment with Immucytal, a biological response modifier.

Chronic bronchitis (CB) is characterized by inflammatory changes in the bronchial tissue and by recurrent bronchitis exacerbations. In addition, defective systemic and local immune mechanisms have been demonstrated and biologic response modifiers (BRMs) have been recently introduced for clinical use in patients with CB. We studied 24 patients with CB by bronchoalveolar lavage (BAL), before and after a 4-week treatment protocol with inhaled Immucytal (Pierre-Fabre Pharma Srl, Milan, Italy), a BRM composed of bacterial ribosomal fractions and membrane proteoglycans. Compared with normal controls (NC), before treatment BAL in patients with CB contained increased proportions of neutrophils (NC, 0.8 +/- 0.2 percent; CB, 3 +/- 1 percent), of eosinophils (NC, 0.1 +/- 0.02 percent; CB, 0.6 +/- 0.2 percent); and of lymphocytes (NC, 6 +/- 1 percent; CB, 13 +/- 2 percent; p < 0.01 each comparison) with higher percentages of CD3+ and CD8+ lymphocytes (p < 0.01 each comparison). In BAL from patients with CB there were also higher levels of albumin and of the ratio IgG/albumin (p < 0.01 and p < 0.05, respectively, compared with NC). After Immucytal treatment, the proportions of lymphocytes in BAL in patients with CB were decreased (13 +/- 2 percent before, 6 +/- 1 percent after; p < 0.01). In addition, the posttreatment BAL samples contained significantly fewer neutrophils per milliliter of BAL (3.7 +/- 0.8 x 10(3) neutrophils per milliliter of BAL before, 1.5 +/- 0.5 x 10(3) neutrophils per milliliter after; p < 0.05). No differences were seen for the proportions of lymphocyte subpopulations and for the protein levels between the BAL obtained before and after Immucytal treatment. These data demonstrate the presence of a lower respiratory tract inflammation in patients with CB and suggest that treatment of patients with CB with a BRM may change the proportions of inflammatory cells present in BAL.

The effect of inflammation on mucociliary clearance in asthma: an overview.

Mucociliary clearance (MCC) is one of the most important nonspecific defense mechanisms of the respiratory tract, and its impairment is a well-documented feature of chronic respiratory diseases, including asthma. In vitro and in vivo data suggest that several inflammatory mediators influence the mucociliary apparatus. Epithelial damage and functional abnormalities have been described in bronchial asthma, along with changes in mucus-secreting cells and the chemical and rheological properties of airway fluid. Although the mechanisms of MCC impairment in asthma are not clearly understood, data in the recent literature suggest that airway inflammation plays a major role. In this article, we review studies on MCC alterations in light of up-to-date findings on pathogenetic mechanisms in asthma.

Airways remodeling is a distinctive feature of asthma and is related to severity of disease.

PURPOSE: Airways remodeling, evaluated as the subepithelial layer thickness, was compared in asthmatic patients with that of healthy subjects, and was related to clinical grading of disease, presence of atopy, and length of asthmatic history. SUBJECTS AND METHODS: Thirty-four patients with stable asthma (mean age+/-SD: 26.5+/-9.2 years; 10 female) treated with only inhaled beta2-agonists and eight healthy volunteers (mean age+/-SD: 24.6+/-2.5 years; four female) were recruited for the study. Twenty-seven of 34 asthmatics had atopy. Eleven patients had newly diagnosed conditions (duration of disease < or = 1 year), nine patients had long asthmatic history (> 1 year and < or = 10 years), and 14 had prolonged asthmatic history (> 10 years). Bronchial responsiveness to methacholine (M) was expressed as provocative concentration of M causing a 20% fall in FEV1 (PC20) (mg/mL). Degree of asthma severity was assessed using a 0- to 12-point score based on symptoms, bronchodilator use, and daily peak expiratory flow variability over a 3-week period. Bronchoscopy and bronchial biopsy were performed successfully for all subjects; the subepithelial layer thickness, in biopsy samples, was measured from the base of bronchial epithelium to the outer limit of reticular lamina. RESULTS: In asthmatics, baseline FEV1 values (percent of predicted) ranged from 75.7 to 137.0%, and PC20 M ranged from 0.15 to 14.4 mg/mL. According to the asthma severity score, 14 asthmatics were classified as having mild disease, 14 as having moderate disease, and six as having severe disease. The mean values of subepithelial layer thickness were 12.4+/-3.3 microm (range, 6.8 to 22.1 microm) in asthmatics, and 4.4+/-0.5 microm (range, 3.8 to 5.2 microm) in healthy subjects (p<0.001). Subepithelial layer thickness of those with severe asthma differed significantly from that of patients with moderate and mild asthma (16.7+/-3.1 microm vs 12.1+/-2.7 microm and 10.8+/-2.4 microm, p<0.01 and p<0.003, respectively). Moreover, in asthmatics, degree of thickening was positively correlated to asthma severity score (Spearman rank correlation coefficient [rs]=0.581; p<0.001), and negatively correlated with baseline FEV1 (rs=-0.553; p<0.001) and PC20 M (rs=-0.510; p<0.01). No difference was found between degree of thickening observed in atopic asthmatics, compared with that of nonatopic asthmatics, or between degree of thickening in patients with different lengths of asthmatic history. Lastly, multiple regression analysis revealed that asthma severity score was the significant predictive factor for thickness of subepithelial layer. CONCLUSIONS: We confirmed that airways remodeling is a very distinctive and characteristic pathologic finding of asthma. We also demonstrated that it is related to the clinical and functional severity of asthma, but not to atopy or length of asthmatic history.

Lung epithelial permeability and bronchial responsiveness in subjects with stable asthma.

Lung epithelial permeability of asthmatic patients has been reported to be similar or lower than that of healthy subjects and to be correlated or not to bronchial hyperresponsiveness. To clarify these discrepancies, we evaluated 99mTc-DTPA pulmonary clearance in a group of carefully selected asthmatic patients with mild, stable asthma (n = 13; seven women; mean age +/- SD = 27.69 +/- 6.63 years), and compared them with a group of healthy, nonsmoking subjects (n = 8; six women; mean age +/- SD = 24.38 +/- 5.15 years). Selection criteria for asthmatics were as follows: baseline FEV1 > or = 80% of predicted values, no bronchial infections, and/or no asthma attacks during 4 weeks prior to study and peak expiratory flow rate variability lower than 20%, over a period of 3 weeks. Patients controlled symptoms with beta 2-adrenergic drugs only, regularly or on demand. Mean baseline FEV1 (+/-SD) as percent of predicted was 102.38 +/- 13.97 and 112.88 +/- 18.36, respectively (p < 0.05). In the asthmatic group, bronchial responsiveness to methacholine (PC20 M FEV1) ranged between 0.55 and 28.5 mg/mL. Mean value (+/-SD) of DTPA clearance from lungs to blood (evaluated on the first 10 min out of 30 min of the curves) in the asthmatic group was not different from that of control group (68.31 +/- 21.46 and 69.5 +/- 15.73). In the asthmatic patients, there was no correlation between PC20 M values and DTPA T1/2 min of the whole lung, nor between PC20 M and inner and outer lung clearance zones. Moreover, both in asthmatics and healthy subjects, DTPA clearance of outer (alveolar) zones was significantly faster than that of inner (bronchial) zones (57.69 +/- 19.94 vs 102.08 +/- 38.19, p < 0.001, and 59.75 +/- 12.49 vs 103.5 +/- 31.86, p < 0.003, respectively). Our data show that DTPA clearance in patients with stable asthma is similar to that found in healthy subjects; it is not correlated to degree of bronchial responsiveness and occurs more rapidly in the outer zones than in the inner zones, both in asthmatic patients and in healthy subjects. Thus, to date, DTPA clearance index is not a valid tool for identifying and/or monitoring asthmatic patients.

Mast cell and histamine involvement in farmer's lung disease.

The aim of this study was to evaluate the cellular and biochemical characteristics of the bronchoalveolar lavage (BAL) fluid in patients with farmer's lung disease (FLD). Total cell numbers in BAL fluids from patients with FLD (n = 30) were significantly higher than in normal subjects (n = 7; p < 0.01), and differential cell counts were significantly different. Lymphocytes were the most numerous cell type in BAL fluids from patients with FLD (65.4 +/- 2.5 percent vs 6.8 +/- 0.5 percent), and analysis of lymphocyte subsets revealed increased percentages of CD3+ and CD8+ cells (91.8 +/- 0.9 percent vs 68.8 +/- 3 percent, p < 0.01, and 54.3 +/- 3.1 percent vs 30.1 +/- 3.2 percent, p < 0.01, respectively). A marked increase in mast cell numbers, as revealed by the specific alcian blue/safranin staining, was observed in patients with FLD (4.2 +/- 0.57 percent, n = 12, vs 0.18 +/- 0.04 percent, n = 7, p < 0.001). Histamine levels in BAL supernatants were increased in patients with FLD (mean = SEM, 4.4 +/- 0.8 ng/ml vs 0.9 +/- 0.1 ng/ml; median, 2.4 ng/ml vs 0.9 ng/ml, p < 0.01), and correlated positively with mast cell numbers and percentages (r = +0.63, p < 0.03, and r = +0.69, p < 0.02, respectively); conversely, a negative correlation was found between histamine levels and CD8+ lymphocyte percentages (r = -0.48, p < 0.01). Raised neutrophil percentages (5.1 +/- 0.8 vs 0.5 +/- 0.18, p < 0.05) and albumin concentrations (29.2 +/- 3.9 mg/dl vs 3.4 +/- 1.3 mg/dl, p < 0.01) were also found in patients with FLD. These findings show that increased numbers of mast cells, lymphocytes, and neutrophils can be found in BAL fluids of patients with FLD. The increased histamine levels in the supernatants of BAL fluids indicate that mast cells are activated. These data allow us to postulate a role for mast cell accumulation and histamine release in the inflammatory process of FLD.