Prediction of respiratory symptoms by peripheral blood neutrophils and eosinophils in the First National Nutrition Examination Survey (NHANES I)

Combined association of urinary volatile organic compounds with chronic bronchitis and emphysema among adults in NHANES 2011-2014: The mediating role of inflammation

Evidence on the association of volatile organic compounds (VOCs) with chronic bronchitis (CB) and emphysema is spare and defective. To evaluate the relationship between urinary metabolites of VOCs (mVOCs) with CB and emphysema, and to identify the potential mVOC of paramount importance, data from NHANES 2011-2014 waves were utilized. Logistic regression was conducted to estimate the independent association of mVOCs with respiratory outcomes. Least absolute shrinkage and selection operator (LASSO) regression was performed to screen a parsimonious set of CB- and emphysema-relevant mVOCs that were used for further co-exposure analyses of weighted quantile sum (WQS) regression and Bayesian kernel machine regression (BKMR). Mediation analysis was employed to detect the mediating role of inflammatory makers in such associations. In single exposure analytic model, nine mVOCs were individually and positively associated with CB, while four mVOCs were with emphysema. In WQS regression, positive association between LASSO selected mVOCs and CB was identified (OR = 1.82, 95% CI: 1.25 to 2.69), and N-acetyl-S-(4-hydroxy-2-butenyl)-l-cysteine (MHBMA3) weighted the highest. Results from BKMR further validated such combined association and the significance of MHBMA3. As for emphysema, significantly positive overall trend of mVOCs was only observed in BKMR model and N-acetyl-S-(N-methylcarbamoyl)-l-cysteine (AMCC) contributed most to the mixed effect. White blood cell count (WBC) and lymphocyte number (LYM) were mediators in the positive pattern of mVOCs mixture with CB, while association between mVOCs mixture and emphysema was significantly mediated by LYM and segmented neutrophils num (NEO). This study demonstrated that exposure to VOCs was associated with CB and emphysema independently and combinedly, which might be partly speculated that VOCs were linked to activated inflammations. Our findings shed novel light on VOCs related respiratory illness, and provide a new basis for the contribution of certain VOCs to the risk of CB and emphysema, which has potential public health implications.

A profile of TNFR2+ regulatory T cells and CD103+ dendritic cells in the peripheral blood of patients with asthma

The interaction of tolerogenic CD103⁺ dendritic cells (DCs) with regulatory T (Tregs) cells modulates immune responses by inducing immune tolerance. Hence, we determined the proportion of these cells in the peripheral blood mononuclear cells (PBMC) of asthmatic patients. We observed lower trends of CD11b^-CD103⁺ DCs and CD86 within CD11b^-CD103⁺ DCs, while increased levels of Foxp3 expressing CD25^+/-TNFR2⁺ cells in asthmatics. There was a positive correlation in the expression of Foxp3 within CD3⁺CD4⁺CD25⁺TNFR2⁺ Tregs and CD11b^-CD103⁺ as well as the expression of CD86 within HLA-DR⁺CD11c⁺CD11b^-CD103⁺ DCs. In conclusion, we suggest that the increased levels of Tregs in blood could continuously suppress the T helper 2 (Th2) cells activation in the circulation which is also supported by the increase of anti-inflammatory cytokines IL-10 and TNF. Overall, functional immunoregulation of the regulatory cells, particularly Tregs, exhibit immune suppression and induce immune tolerance linked with the immune activation by the antigen presenting cells (APC).

Systemic inflammatory markers in relation to lung function in NHANES. 2007-2010

BACKGROUND

Low-grade systemic inflammation, mainly assessed by C-reactive protein (CRP), has been associated with impaired lung function. Few studies have studied if CRP, blood eosinophils, and blood neutrophils offer additive information in relation to lung function.

OBJECTIVES

To analyse associations between lung function and CRP, blood eosinophils, and blood neutrophils, with special regard to additive information of combining the inflammatory markers.

METHODS

Cross-sectional study on 7753 participants, 20-80 years of age, in the National Health and Nutrition Examination Survey. Gender-based tertiles for CRP, blood eosinophils, and blood neutrophils were analysed in relation to the following lung function parameters: forced expiratory volume in 1 s (FEV₁% predicted), forced vital capacity (FVC % predicted), and FEV₁/FVC ratio.

RESULTS

CRP, blood eosinophils, and blood neutrophils levels were inversely related to FEV₁ and FVC. Only blood eosinophils and blood neutrophils were inversely related to FEV₁/FVC ratio. Further, lower lung function was found with increased number of elevated inflammatory markers in the highest tertile (one, two or three vs. non elevated) for FEV₁ (β-coeff., -2.20, -4.43, and -6.43, p < 0.001) and FVC (β-coeff., -1.70, -3.15 and -5.33, p < 0.001), respectively.

CONCLUSIONS & CLINICAL RELEVANCE

CRP, blood eosinophils, and blood neutrophils offer independent and additive information in relation to lower FEV₁ and FVC in the general population. This indicates that a combination of biomarkers yields more information than the biomarkers assessed individually.

Association of Blood Eosinophil and Blood Neutrophil Counts with Asthma Exacerbations in the Copenhagen General Population Study

BACKGROUND

Blood eosinophil count is a marker of eosinophilic airway inflammation and disease severity in asthma. However, blood neutrophil count might also be associated with disease severity. We tested the hypothesis that high blood eosinophil and neutrophil counts are both associated with the risk of asthma exacerbations among individuals with asthma from the general population.

METHODS

From the Copenhagen General Population Study with 81351 participants, we included 4838 with self-reported asthma. We recorded baseline blood eosinophil and neutrophil counts, and asthma exacerbations during follow-up in 2003–2011, defined as moderate (short-course treatment of prednisolone) or severe (hospitalization).

RESULTS

The multivariable-adjusted incidence rate ratios (IRRs) were 1.28 (95% CI, 1.06–1.55) for moderate exacerbations and 1.55 (1.20–2.00) for severe exacerbations for individuals with blood eosinophil counts &gt;0.29 × 109/L (highest tertile) vs individuals with blood eosinophil counts &lt;0.18 × 109/L (lowest tertile). For blood neutrophils, the multivariable-adjusted IRRs were 2.14 (1.74–2.63) for moderate exacerbations and 1.18 (0.89–1.55) for severe exacerbations for individuals with blood neutrophil counts &gt;4.85 × 109/L (highest tertile) vs individuals with blood neutrophil counts &lt;3.77 × 109/L (lowest tertile). Blood eosinophil and neutrophil counts interacted on moderate exacerbations (P = 3 × 10−4), but not on severe exacerbations.

CONCLUSIONS

High blood eosinophil counts are associated with an increased risk of both moderate and severe asthma exacerbations, while high blood neutrophil counts are associated with an increased risk of moderate, but not severe exacerbations.

Impact of yoga on biochemical profile of asthmatics: A randomized controlled study

BACKGROUND

Asthma is a chronic inflammatory disorder of the airways. The chronic inflammation causes an associated increase in airway hyperresponsiveness that leads to recurrent episodes of wheezing, breathlessness, chest tightness, and coughing at night or in the early morning. Most of the studies have reported, as the effects of yoga on bronchial asthma, significant improvements in pulmonary functions, quality of life, and decrease in medication use, but none of the studies has attempted to show the effect of yoga on biochemical changes.

OBJECTIVE

To evaluate the effect of yoga on biochemical profile of asthmatics.

MATERIALS AND METHODS

In the present study, 276 patients of mild to moderate asthma (FEV 1> 60%) aged between 12 to 60 years were recruited from the Department of Pulmonary Medicine, King George's Medical University, U.P., Lucknow, India. They were randomly divided into two groups: Yoga group (with standard medical treatment and yogic intervention) and control group as standard medical treatment (without yogic intervention). At completion of 6 months of the study period, 35 subjects were dropped out, so out of 276 subjects, only 241 subjects completed the whole study (121 subjects from yoga group and 120 subjects from control group). Biochemical assessment was carried out at baseline and after 6 months of the study period.

RESULTS

In yoga group, there was significant improvement found in the proportion of hemoglobin and antioxidant superoxide dismutase in comparison to control group and significant decrease was found in total leukocyte count (TLC) and differential leukocytes count in comparison to control group. There was no significant change found in TLC, polymorphs, and monocytes in between group comparison.

CONCLUSIONS

Yoga group got significantly better improvement in biochemical variables than control group. Result shows that yoga can be practiced as adjuvant therapy with standard inhalation therapy for better outcome of asthma.

High blood eosinophil count is associated with more frequent asthma attacks in asthma patients

BACKGROUND

The clinical importance of eosinophils in asthma has been shown by the observation of frequent exacerbation in patients with high sputum eosinophil counts and a corresponding decrease in exacerbations when anti-inflammatory therapy was adjusted to maintain low sputum eosinophil percentages. However, less is known of the relation between blood eosinophilia and asthma exacerbation.

OBJECTIVE

To examine whether patients with asthma and a higher blood eosinophil count have more asthma attacks than those with a lower count.

METHODS

The authors analyzed data from the National Health and Nutrition Examination Survey, an annual cross-sectional survey of the US general population. Patients with asthma and asthma attacks were identified based on participants' self-report or parental report. A high blood eosinophil count was defined using 200, 300, or 400 cells/μL as cutoffs. The primary analysis used data from 2001 through 2010 after adjusting for demographic variables, obesity, smoking, neutrophil level, and past treatment for wheezing. A secondary analysis used data from 2007 through 2010 and included recent treatment for asthma and fraction of exhaled nitric oxide level as additional adjustment variables.

RESULTS

In survey years 2001 through 2010, 3,162 patients with asthma had blood eosinophil data and approximately half (54% of children and 52% of adults) reported an asthma attack in the previous year. In the primary analysis, higher blood eosinophil counts were associated with more asthma attacks in children but not in adults. The secondary analysis suggested an association in both children and adults.

CONCLUSION

Patients with asthma with higher blood eosinophil counts experienced more asthma attacks than those with lower eosinophil counts.

Effects of asthma on cell components in peripheral blood among smokers and non-smokers

BACKGROUND

Eosinophils play a central role in asthma, but the interplay of the effects of smoking, eosinophils and asthma remains unclear.

OBJECTIVE

The primary objective of our study was to investigate the extent to which smoking modifies the effect of asthma on circulating eosinophils, CD4+ and CD8+ T cell counts.

METHODS

Data were collected semiannually between 1987 and 1994 from HIV-negative participants in the Multicenter AIDS Cohort Study. Asthma was defined by a questionnaire at baseline as a self-report of diagnosed asthma. A total of 1420 blood samples from 197 asthmatics and 15 822 from 1997 non-asthmatics were collected.

RESULTS

Eosinophil levels were higher in asthmatics (28% of asthmatics had eosinophils >/=4% and 16% of non-asthmatics) regardless of smoking history, but smoking modified the association between eosinophils and asthma. Namely, the odds ratios for eosinophils being >/=4% in asthmatics to non-asthmatics decreased from 2.7 (95% CI: 2.0, 3.6) in never, to 2.1 (1.4, 3.1) in former, and to 1.5 (0.9, 2.3) in current smokers. Cross-sectional and longitudinal analyses coherently showed that smoking increased eosinophils in non-asthmatics, but the converse was true for asthmatics. In contrast, no differences in peripheral blood T cell counts between asthmatics and non-asthmatics were observed.

CONCLUSION

Under the established link between increased eosinophils and asthma, these data indicate that smoking modified this relationship. This finding suggests that smoking plays a different immunological role in asthmatics and non-asthmatics.

Prevalence of serious eosinophilia and incidence of Churg-Strauss syndrome in a cohort of asthma patients

BACKGROUND

Some leukotriene receptor antagonists, such as zafirlukast and montelukast, have been associated with systemic eosinophilia, with interest focused on Churg-Strauss syndrome (CSS).

OBJECTIVE

To calculate the background incidence rate of CSS and prevalence of eosinophilia among people with asthma who have not used leukotriene receptor antagonists.

METHODS

We conducted a cohort study in the setting of three geographically diverse UnitedHealthcare health plans. We identified 36,230 people who received a diagnosis of asthma during the period October 1994 through September 1997. We identified 241 potential cases from the claims data. Using a standardized hospital record abstract form, nurses abstracted relevant clinical data from the hospital charts of potential cases. We applied several a priori case definitions to the abstracted clinical data and computed incidence rates of CSS among patients with asthma. We additionally used these data to compute the prevalence of serious eosinophilia.

RESULTS

Incidence rates of definite CSS among asthma patients ranged from zero (90% confidence interval 0.0 to 23.0) to 67 (90% confidence interval 22.5 to 160.6) cases per 1,000,000 person-years, depending on the definition used. All patients who met the criteria for CSS expressed symptoms consistent with mild asthma.

CONCLUSIONS

This report is the first direct measurement of the incidence rate of CSS among asthma patients. We believe that the prevalence and incidence information that we report is a useful description of population rates in the United States for these conditions.

The relation between peripheral blood leukocyte counts and respiratory symptoms, atopy, lung function, and airway responsiveness in adults

STUDY OBJECTIVES

Eosinophils and neutrophils play major roles, respectively, in the pathogenesis of asthma and COPD, and it is well recognized that levels of these cells in peripheral blood are increased in relation to their pulmonary involvement. However, the relation between peripheral blood cell counts of the other major leukocyte groups and these lung diseases or markers of allergy or airflow obstruction is less clear. We have therefore investigated the association between peripheral blood levels of eosinophils, neutrophils, basophils, monocytes, and lymphocytes and the occurrence of chronic respiratory symptoms, atopy, lung function, and bronchial hyperresponsiveness, and the modifying effect of age, in adults.

DESIGN

A cross-sectional general population study.

SETTING

Data on > 2,000 British adults, who originally participated in a study of diet and lung health, were analyzed using multiple linear and logistic regression to adjust for potential confounders, including age, sex, and smoking history.

RESULTS

We found that, like eosinophils, the peripheral basophil count was increased in relation to asthma and associated symptoms, and to airway hyperreactivity and increased total IgE, but differed from eosinophils in that basophils were unrelated to atopy. Monocytes were predominantly associated with symptoms indicative of obstructive airway disease, in similar relation to neutrophils, but both of these leukocyte counts were also increased in asthma patients in older age groups. Lymphocyte counts were unrelated to any objective or subjective marker of disease.

CONCLUSIONS

If peripheral blood cell counts reflect pulmonary involvement of these leukocyte groups, basophils and monocytes may play a distinct role in the pathogenesis of allergic and nonallergic respiratory disease.

Smoking and airway hyperresponsiveness especially in the presence of blood eosinophilia increase the risk to develop respiratory symptoms: a 25-year follow-up study in the general adult population

Airway hyperresponsiveness (AHR) constitutes a risk for development of respiratory symptoms. We assessed whether blood eosinophilia (>/= 275 eosinophils/microliters), skin test positivity (sum score >/= 3) and cigarette smoking (never, ex-smoker, 1-14 cig/d, 15-24 cig/d, >/= 25 cig/d) at the first of two successive surveys are related to the development of respiratory symptoms (chronic cough or phlegm, bronchitis, persistent wheeze, dyspnea, and asthma) at the second survey, and whether these relations are the same in subjects with (PC10 </= 8 mg/ml histamine) and without AHR. We analyzed data of the longitudinal Vlagtwedde-Vlaardingen Study (1965 to 1990) using logistic regression analyses with paired observations, taking multiple measurements within a person into account. In total, 995 men and 792 women contributed 4,403 paired observations. Eosinophilia in hyperresponsive subjects significantly increased the risk to develop one or more respiratory symptoms (odds ratio [OR] = 3.67, 95% confidence interval [CI] = 1.79 to 7.52), wheeze (OR = 5. 06, 95% CI = 2.11 to 12.13), and dyspnea (OR = 2.73, 95% CI = 1.13 to 6.60), independent of smoking, age, sex, area of residence, and time between two successive surveys. Smoking at the first of two successive surveys increased the risk to develop symptoms in a dose-dependent relation. Subjects with positive skin tests in the past were less likely to develop one or more respiratory symptoms (OR = 0.64, 95% CI = 0.46 to 0.88) and chronic phlegm (OR = 0.65, 95% CI = 0.42 to 1.00), independent of AHR. This longitudinal study in the general adult population shows that cigarette smoking and hyperresponsive subjects are at increased risk to develop respiratory symptoms, and especially so when eosinophilia is present in hyperresponsive persons.