A forced expiratory flow at 25-75% value <65% of predicted should be considered abnormal: a real-world, cross-sectional study

Forced expiratory volume in 1 second (FEV1) is considered an important parameter for asthma diagnosis and follow-up. However, it has been proposed that forced expiratory flow at 25-75% (FEF(25-75)) could be more sensitive than FEV1 to detect slight airways obstruction. In this regard, a cutoff FEF(25-75) value has been recently established in a group of asthmatic children: FEF(25-75) < 65% of predicted has been considered impaired. However, the considered population was specifically selected. Therefore, the aim of the present study was to confirm an FEF(25-75) cutoff value in a large cohort of asthmatic children. Seven hundred allergic children (493 male subjects; median age, 11 years) with controlled and partly controlled asthma were evaluated by performing spirometry and skin-prick tests. Three hundred thirteen (44.7%) patients had FEF(25-75%) values of <65% of predicted. Two predictors were significantly associated with impaired FEF(25-75) values: (i) sensitization to perennial allergens (adjusted odds ratio [OR(Adj)], 3.4) and (ii) FEV(1) ≤ 86% of predicted (OR(Adj), 3.8). This study, conducted in real life, could suggest that FEF(25-75) value of <65% of predicted may be considered abnormal.     

Forced expiratory flow between 25 and 75% of vital capacity might be a predictive factor for bronchial hyperreactivity in children with allergic rhinitis, asthma, or both

Allergic rhinitis and asthma are closely associated. Bronchial hyperreactivity (BHR) is a pathophysiological characteristic of asthma. Forced expiratory flow between 25 and 75% of vital capacity (FEF(25-75)) has been previously shown to be able to predict BHR in adult patients with allergic rhinitis. Therefore, the aim of this study was (i) to evaluate the presence of BHR in a large group of children with allergic rhinitis, asthma or both and (ii) to confirm whether FEF(25-75) might be related to BHR and may predict BHR also in a pediatric population. Nine hundred fifty children with allergic rhinitis (350), asthma (300), or both (300) were enrolled. Clinical examination, skin-prick test, spirometry, and methacholine challenge were performed in all patients. Severe BHR was quite frequent in allergic children, mainly in asthmatic patients. FEF(25-75) values were significantly related to BHR grade, mainly in children with rhinitis (r = 0.69). Impaired FEF(25-75) values (such as ≤65% of predicted) constituted a relevant predictive factor for severe BHR, mainly in children with rhinitis (odds ratio, 8.9). In conclusion, this pediatric study confirmed that impaired FEF(25-75) values might predict severe BHR in children, mainly in those with allergic rhinitis. Therefore, low FEF(25-75) values could suggest BHR in children.     

Peak expiratory flow monitoring to screen for asthma in patients with allergic rhinitis.

AIM: To investigate the benefit of using peak expiratory flow (PEF) monitoring to screen for asthma in allergic rhinitis patients. METHODS: Eighty-nine consecutive patients with allergic rhinitis but never assessed for asthma were included in this prospective study.Their allergic status was determined by skin prick tests. All of the subjects filled in a questionnaire on asthma-like symptoms. If they reported such symptoms, pulmonary function tests were carried out. Then, PEF was checked twice daily for 3 weeks. RESULTS: Thirty-six percent of our study group were male and 64% were female patients with a mean (SD) age of 36.3 (14.0) years. Skin prick tests were positive to grass mixture in 71 (79.8%) patients, to tree mixture in 51 (57.3%), to mite in 46 (51.7%), and to epidermal mix in 26 (29.2%) patients. Thirty-six patients (41%) reported 3 or more asthma symptoms. Lung function test results for these 36 patients showed obstruction for 11.1% (4 patients); the remaining patients (88.9%) had normal function parameters. The subjects who reported 3 or more asthma symptoms but had normal lung function monitored their PEF for 3 weeks. Sixteen (50%) patients from this group and the 4 patients with demonstrated airway obstruction had more than 20% diurnal variation in PEF. These 20 patients' asthma symptoms disappeared after they received 3 months of low-dose inhaled corticosteroid therapy. CONCLUSION: It is necessary to look for asthma in patients suffering from allergic rhinitis. PEF monitoring is a low-cost, objective approach to asthma diagnosis that can be performed by a patient with allergic rhinitis even if spirometry is normal. Knowledge of this technique is of utmost importance because delay in diagnosis will result in the unsatisfactory treatment of the disease.     

Ratio between forced expiratory flow between 25% and 75% of vital capacity and FVC is a determinant of airway reactivity and sensitivity to methacholine

STUDY OBJECTIVE: The ratio between forced expiratory flow between 25% and 75% of vital capacity (FEF(25-75)) and FVC is thought to reflect dysanapsis between airway size and lung size. A low FEF(25-75)/FVC ratio is associated with airway responsiveness to methacholine in middle-aged and older men. The current study was designed to assess this relationship in both male and female subjects over a broader range of ages. STUDY DESIGN: Data analysis of consecutive subjects who had a >or= 20% reduction in FEV(1) after 相似文献   

Managing impairment in patients with allergic rhinitis.

Allergic rhinitis is a common medical problem in both the adult and the pediatric population. A main complication of this disease is a reduction in the patient's quality of life. Individuals with either seasonal or perennial allergic rhinitis often are impaired, adversely affecting work and/or school performance. This impairment can result from the disease itself and the treatment thereof. Oral antihistamines are the mainstay of treatment for allergic disease. First-generation antihistamines are considered sedating and frequently are impairing even when sedation is absent. Second-generation antihistamines show some class variability regarding impairment but as a group are clearly less impairing than their first-generation predecessors. Second-generation antihistamines are the preferred medication when antihistamines are necessary.     

Comparison of maximal midexpiratory flow rate and forced expiratory flow at 50% of vital capacity in children

BACKGROUND: The mid-portion of the maximal expiratory flow-volume (MEFV) curve is often described by values of the mean forced expired flow as lung volume decreases from 75% to 25% of vital capacity (ie, forced expiratory flow, midexpiratory phase [FEF(25-75)]). It is common practice to report also forced expired flow at 50% of vital capacity (FEF(50)). STUDY OBJECTIVE: To investigate whether FEF(50) and FEF(25-75) are highly correlated or whether the difference between them reflects a degree of airways obstruction. Also, we wanted to investigate the correlation between the two in cases of irregularly shaped MEFV curves (ie, "saw-toothing"). DESIGN: Analysis of the correlation between FEF(50) and FEF(25-75) in a single determination. We assessed the relationship between the FEF(50)/FEF(25-75) ratio and the degree of airways obstruction, as reflected by other traditional parameters such as FEV(1), FEV(1)/FVC ratio, and specific airway conductance (SGaw). PATIENTS: There were 1,350 forced expiratory maneuvers performed by children with a broad range of pulmonary abnormalities. RESULTS: FEF(50) correlated with FEF(25-75) as follows: FEF(50) (L/s) = 0.041 + 1.136*FEF(25-75)(L/s); r(2) = 0.956; standard error of the estimate = 0.013; p < 0.0001. The FEF(50)/FEF(25-75) ratio remained stable and did not correlate with FEV(1) (r = 0.12), FEV(1)/FVC ratio (r = 0.11), or SGaw (r = 0.02; difference not significant). The correlation between FEF(25-75) and FEF(50) was similar for both the smooth curve (r = 0.97) and the irregular curve (r = 0.96). CONCLUSIONS: Although not identical, FEF(25-75) and FEF(50) are highly correlated, and the ratio of the two is fairly constant. Therefore, the practice of reporting both of them is unnecessary. We suggest that it is reasonable to prefer FEF(50).     

Normal value and age and sex correlations of mean expiratory output (25-75%). Diagnostic value in early obstructive bronchopneumopathies]

The maximum output of half-expiration (MMFR) or DME 25-75% is studied in 136 subjects, evalued as non obstructive, after the determination of the MEVS/VC X 100. The values noted are reported to the body surface (S) in order to eliminate the biometric differences. A highly close correlation, of the exponential type, is thus put in evidence for each sex between the DME/S and the age of the subjects. The study of the DME in subjects with obstructive Tiffeneau makes possible: a) to determine an inferior limit of the normal condition; b) to bring confirmation of the fiability of the test. The study of the determination of the DME/S is then performed in subjects with normal MEVS/VC X 100 and clinically suspect of bronchial obstruction (tobacco addicts, patients at stage I of chronic bronchitis, asthmatic patients outside the attacks). The DME determination lets appear the presence of a bronchial obstruction in almost one half of the subjects submitted to study.     

The early allergic response in small airways of human precision-cut lung slices.

To study the role of small airways in the early allergic response (EAR), the method of human precision-cut lung slices (PCLS) was developed and used to examine the bronchoconstriction elicited by passive sensitisation and allergen provocation. Viable human PCLS of 250-microm thickness containing airways <1.5 mm in outer diameter were prepared from lung lobes obtained from lung resection and taken into culture. According to the low release of lactate dehydrogenase and the constant ciliary beat frequency, human PCLS were viable for at least 3 days. Following overnight passive sensitisation with serum from allergic individuals, administration of grass-pollen extract or activating immunoglobulin E antibody resulted in immediate airway contraction that was quantified by videomicroscopy. The extent of the EAR increased with decreasing airway size (outer airway diameter), with the strongest response occurring in the terminal bronchioles. Histamine receptor antagonism was ineffective, and leukotriene or thromboxane receptor antagonism attenuated the early allergic response only in some cases. However, simultaneous blockade of leukotriene and thromboxane receptors almost completely prevented the early allergic response in the precision-cut lung slices from all individuals, suggesting such a dual treatment as a potential future asthma therapy.     

Reproducibility of forced expiratory flow and volume measurements in infants with bronchiolitis

The end-tidal rapid thoracoabdominal compression (ETRTC) technique is an established method for lung function testing in infancy. Previous work in healthy infants, however, has shown that measurements with the newly developed raised volume rapid thoracoabdominal compression (RVRTC) technique are more reproducible than those with the ETRTC technique. So far, reproducibility of the two techniques has not been compared in infants with acute airway disease. Twenty-three infants with acute viral bronchiolitis underwent lung function assessment with both the ETRTC and the RVRTC technique. A series of 8-10 measurements with each technique was done in randomized order. Forced expired volumes at 0.5, 0.75, and 1 sec after chest compression (FEV(0.5), FEV(0.75), and FEV(1.0)) were measured with the RVRTC technique; maximum expiratory flow at functional residual capacity (V'(maxFRC)) was measured with the ETRTC technique. Group mean intrasubject coefficients of variation (CV) were 4.84% for FEV(0.5), 5.01% for FEV(0.75), 5.43% for FEV(1. 0), and 13.79% for V'(maxFRC), respectively. Differences between FEV parameters were statistically insignificant, whereas the difference between each FEV parameter and V'(maxFRC) was highly significant (P < 0.001). In infants with acute viral bronchiolitis, RVRTC measurements have significantly less intraindividual variability than flow rates assessed with the conventional ETRTC technique. This finding provides the basis for assessing disease course and effects of therapeutic interventions on an individual basis.     

Visual quantitation and observer variation of signs of small airways disease at inspiratory and expiratory CT.

Areas of decreased pulmonary attenuation representing small airways disease can be identified on computed tomography (CT). The objective was to quantify differences between inspiratory and expiratory CT for the detection of signs of small airways disease by four observers. Observer variation and the superiority of a fine versus a coarse grading system were also evaluated. Inspiratory and expiratory CT scans of 106 patients with conditions characterized by small airways disease and 19 healthy individuals were assessed by four observers. The extent of decreased attenuation was scored on a fine scale to the nearest 5% and also semiquantitatively on a coarser 5-point scale. Decreased attenuation was more extensive on expiratory CT (median. 6.7%; 0-76.7%) than on inspiratory CT (median, 3.8%; 0-81.7%). The fine scoring system had unacceptable interobserver variation (coefficient of variation, 80% for inspiratory CT, 70% for expiratory CT). The semiquantitative system had acceptable interobserver agreement (inspiratory CT k(w) = 0.64; expiratory CT, k(w) = 0.69) and good intra-observer agreement (inspiratory CT, k(w) = 0.80; expiratory CT, k(w) = 0.64). The major CT sign of small airways disease is more confidently quantified on expiratory CT. A fine scoring system is associated with unacceptable observer variation, and a coarse semiquantitative system is more suitable for quantitative studies of small airways disease.     

Symptoms of allergic rhinitis in women during early pregnancy are associated with higher prevalence of allergic rhinitis in their offspring.

BACKGROUND: Epigenetic control of gene expression profiles is a ubiquitous mechanism during cell differentiation, organogenesis and chronic inflammatory reactions. Recent studies have shown that allergen exposure during very early pregnancy increases bronchial hypersensitivity in offspring in a murine model of bronchial asthma. However, no such phenomena were reported in humans. In the present study, the role of epigenetic control in the onset of allergic diseases was investigated. METHODS: A total of 400 pairs of mothers with physician-diagnosed allergic rhinitis (AR) and their offspring (age 7-18 months) who participated in a large-scale medical check-up were enrolled in this retrospective cohort study. Family history of allergic diseases and the presence or absence of AR symptoms during pregnancy were inquired about using a self-answered questionnaire. A logistic regression model adjusted for age, gender, birth month and father's history of allergic diseases was statistically analyzed. RESULTS: Offspring whose mothers had any AR symptoms during early pregnancy showed a significantly higher adjusted odds ratio for the onset of AR in offspring than those whose mothers had no symptoms during pregnancy (adjusted Odds Ratio: 6.26, p = 0.036). However, the symptoms of AR during late pregnancy showed no effects on the odds ratio. In contrast, the presence or absence of AR symptoms during early or late pregnancy showed no association with the prevalence of food allergy, atopic dermatitis or asthma in offspring. CONCLUSIONS: Our results suggest the presence of possible epigenetic mechanisms regulating the onset of AR in humans presumably through increased organ-specific hypersensitivity.     

Bronchoconstriction induced by inhaled adenosine 5'-monophosphate in subjects with allergic rhinitis.

Adenosine and its related nucleotide, adenosine 5'-monophosphate (AMP) induce bronchoconstriction in asthmatics, probably caused by histamine release from airway mast cells. The objective of this study was to determine the effect of inhaled AMP on lung function in subjects with allergic rhinitis. A total of 52 adults (28 subjects with allergic rhinitis, 14 asthmatics and 10 healthy subjects) were challenged with increasing concentrations of AMP and methacholine. Airflow was assessed after each concentration and the response to each bronchoconstrictor agent was measured by the provocative concentration required to produce a 20% fall (PC20) in forced expired volume in one second (FEV1). All 14 asthmatics, 10 subjects with allergic rhinitis and none of the healthy controls were hyperresponsive to AMP. Subjects with allergic rhinitis had higher prevalence of hyperresponsiveness to AMP than healthy controls (p=0.038). Although the prevalence of hyperresponsiveness for methacholine and for AMP in subjects with allergic rhinitis was similar (39% and 36%, respectively), four subjects had hyperresponsiveness to methacholine but not to AMP, whereas three subjects had hyperresponsiveness to AMP but not to methacholine. To conclude, inhaled adenosine 5'-monophosphate causes airway narrowing in a significantly higher proportion of subjects with allergic rhinitis than healthy volunteers. Furthermore, methacholine and adenosine 5'-monophosphate hyperresponsiveness are not detected in the same individuals with allergic rhinitis, thus suggesting that responsiveness to the two bronchoconstrictor stimuli is not reflecting the same abnormalities of the airways.     

Detection of expiratory flow limitation in COPD using the forced oscillation technique.

Expiratory flow limitation (EFL) during tidal breathing is a major determinant of dynamic hyperinflation and exercise limitation in chronic obstructive pulmonary disease (COPD). Current methods of detecting this are either invasive or unsuited to following changes breath-by-breath. It was hypothesised that tidal flow limitation would substantially reduce the total respiratory system reactance (Xrs) during expiration, and that this reduction could be used to reliably detect if EFL was present. To test this, 5-Hz forced oscillations were applied at the mouth in seven healthy subjects and 15 COPD patients (mean +/- sD forced expiratory volume in one second was 36.8 +/- 11.5% predicted) during quiet breathing. COPD breaths were analysed (n=206) and classified as flow-limited if flow decreased as alveolar pressure increased, indeterminate if flow decreased at constant alveolar pressure, or nonflow-limited. Of these, 85 breaths were flow-limited, 80 were not and 41 were indeterminate. Among other indices, mean inspiratory minus mean expiratory Xrs (deltaXrs) and minimum expiratory Xrs (Xexp,min) identified flow-limited breaths with 100% specificity and sensitivity using a threshold between 2.53-3.12 cmH2O x s x L(-1) (deltaXrs) and -7.38- -6.76 cmH2O x s x L(-1) (Xexp,min) representing 6.0% and 3.9% of the total range of values respectively. No flow-limited breaths were seen in the normal subjects by either method. Within-breath respiratory system reactance provides an accurate, reliable and noninvasive technique to detect expiratory flow limitation in patients with chronic obstructive pulmonary disease.     

Direct cost assessments in subjects with seasonal allergic rhinitis living in Ankara, Turkey.

The characteristics of seasonal allergic rhinitis (SAR) including the severity at initial presentation and cost estimates are not established for Turkey. The aim of this study was to document the clinical features and direct cost of subjects with SAR when diagnosed and followed according to international treatment guidelines and to determine the effectiveness of treatment in relation to the regional pollen count in our country. The clinical features of SAR were determined cross-sectionally in 175 patients living in Ankara, Turkey. The direct medical cost analysis obtained by a symptom-medication score method was performed prospectively in a subgroup of patients evaluated at the beginning of the pollen season (n = 37). Airborne Gramineae pollen grains were counted also in the same period. SAR was mild in 12.6% of cases, moderate in 51.4% of cases, and severe in 36% of cases. Regional pollen counts were correlated with the number of patient visits and the initial severity of SAR. Mean cost of SAR per person without a comorbid disorder during a Gramineae pollen season for Ankara was 79.0 +/- 3.3 dollars, where it reached a mean of 138.60 +/- 0.5 dollars in the presence of asthma and/or conjunctivitis. No difference was observed among disease severity groups by means of total direct cost (p > 0.05). Regional pollen counts influence the initial severity of SAR in our country. Appropriate treatment seemed to induce effective symptom control. Hence, education of both public and primary care physicians about the international guidelines might provide better cost-effective management of SAR.     

黏液-纤毛标志物Mucin 5AC-acetylated alpha-tubulin在过敏性鼻炎患者鼻黏膜中的表达

［摘要］　目的　探究过敏性鼻炎（AR）患者鼻腔黏液-纤毛清除功能在鼻黏膜分子水平上的损伤表现和严重程度。方法　选取2021年3月至2022年3月期间在我院进行鼻中隔偏曲手术的40例患者的下鼻甲黏膜组织,其中AR患者21例（AR组）,非AR患者（对照组）19例。通过免疫荧光染色方法在蛋白水平上观察及评估黏液分泌标志物Mucin 5AC（MUC5AC）和纤毛标志物acetylated alpha-tubulin（acet. α-tubulin）表达情况。结果　与对照组相比,AR组黏液分泌的总免疫荧光强度增加32.365%,纤毛长度缩短将近1/2,纤毛脱落评分上升将近3倍,纤毛总免疫荧光强度下降24.555%。结论　AR患者黏液分泌量显著增加,纤毛排列不齐、变短、稀疏以及脱落增加可能是导致AR患者鼻腔黏膜黏液-纤毛清除功能减弱,继而加重AR症状严重程度的分子依据。