Relationship between Blood and Induced Sputum Eosinophils, Bronchial Hyperresponsiveness and Reversibility of Airway Obstruction in Mild-to-Moderate Chronic Obstructive Pulmonary Disease

Blood eosinophilia has been proposed as a surrogate marker for airway eosinophilia and as a predictor of treatment response in chronic obstructive pulmonary disease (COPD). The aim of the study was to assess the relationship between blood and sputum eosinophils and to investigate the association between blood and sputum eosinophil count and clinical features of mild-to-moderate COPD. We performed a retrospective analysis of blood and sputum eosinophil count, as well as demographic and lung function data in a cohort of 90 stable, steroid-naive (Global Initiative for Chronic Obstructive Lung Disease 1 or 2) COPD patients and 20 control subjects. Blood and sputum eosinophil count did not correlate both in patients with COPD (r = -0.04 p = 0.705) and in controls (r = 0.05, p = 0.838). Sputum eosinophilia (≥3%) was present in 40% of COPD patients. The median blood eosinophil count in patients with COPD was 180 (interquartile range 90-270)/μL; patients with low blood eosinophils (<180/μL) did not differ from those with high blood eosinophils (≥180/μL) in terms of forced expiratory volume in 1 second, bronchial reversibility or hyperresponsiveness. This was also the case when COPD patients with and without sputum eosinophilia were compared. At the same time, positive bronchial reversibility and positive bronchial hyperresponsiveness were observed in 2 (11%) COPD patients with high blood eosinophils and in 1 (5%) patient with sputum eosinophilia. There was a weak, albeit significant correlation (r = 0.22 p = 0.041) between blood eosinophil count and age in patients with COPD. Peripheral eosinophil count poorly reflects sputum eosinophils and lung function in stable steroid-naive mild-to-moderate COPD patients.

Serum estradiol concentration, estradiol-to-progesterone ratio and sputum IL-5 and IL-8 concentrations are increased in luteal phase of the menstrual cycle in perimenstrual asthma patients

Summary

Background. The results of the research on perimenstrual asthma (PMA) pathophysiology are inconsistent, and the role of sex hormones remains inconclusive. The aim of the study was to evaluate the influence of serum sex steroid (and other) hormones concentrations on lower airway inflammation of PMA patients. Methods. Thirty-three women of childbearing age diagnosed as: PMA (n = 13), non-PMA asthmatics (n = 10), and healthy controls (n = 10) were prospectively followed for 12 weeks over 2 consecutive menstrual cycles. On the 10^th and 26^th day of each cycle serum 17β-estradiol, progesterone, testosterone, androstendion, dehydroepiandrosteron, cortisol, thyroid-stimulating hormone and prolactin were measured, and sputum was induced. Sputum inflammatory cell count and IL-5, -6, -8, -10 concentrations were determined. Results. When compared to non-PMA asthmatics, the luteal phase of the cycle in PMA subjects was associated with increased serum estradiol concentration, estradiol-to-progesterone ratio (p < 0.001, p = 0.001, respectively) and sputum IL-5 and IL-8 concentrations (p = 0.045, p = 0.039, respectively). Decreased serum testosterone levels (p < 0.05) and a trend to increased serum prolactin levels in both phases of the menstrual cycle in PMA subjects were observed. Sputum analysis in PMA patients revealed increased total inflammatory cell count in both phases of the menstrual cycle (p < 0.05), when compared to non-PMA asthmatics. Conclusions. The luteal phase of the cycle in PMA patients is associated with increased serum estradiol levels with concurrent higher sputum concentration of IL-5 and IL-8. Serum testosterone levels are decreased, and total number of sputum inflammatory cells is increased in PMA patients in both phases of the menstrual cycle.

Application of Inflammatory Markers in Induced Sputum in Stable Chronic Obstructive Pulmonary Disease Patients with Positive Bronchodilation Tests

Positive bronchodilation (BD) tests can be noticed in some stable chronic obstructive pulmonary disease (COPD) patients. The characteristics of airway inflammation in this entity remain unclear. Our study aimed to identify the characteristics of airway inflammation in stable COPD patients with positive BD tests. The airway inflammation was assessed in 88 patients with stable COPD using the examination of induced sputum in the aftermath of lung function and BD tests. Cellular counts and the levels of molecular markers including eosinophil cationic protein (ECP), myeloperoxidase (MPO), interleukin-5 (IL-5), and IL-8 were assayed by Wright's stain, Immuno-CAP system, and ELISA, RT-PCR. Among the 88 patients with stable COPD, 20 (22.7%) showed positive BD tests. The values of eosinophils (4.7%±3.4%) and ECP (90.1±41.6 ng/mL) in induced sputum in stable COPD patients with positive BD tests were markedly elevated as compared with those in stable COPD patients with negative BD tests or in healthy controls (all P>0.05), but significantly lower than those in asthmatic patients (all P<0.01). The IL-5 in sputum supernatant was significantly decreased in stable COPD patients with positive BD tests as compared with the patients with asthma (12.5±7.8 vs. 48.2±26.0 ng/mL;.P<0.01). However, healthy controls exhibited similar concentrations of IL-5 in induced sputum with patients with stable COPD, whether with positive or negative BD tests (all P>0.05). Moreover, the values of neutrophils (61.8%±15.1%), MPO (574.0±111.8 ng/mL), and IL-8 (32.6±13.4 ng/mL) in induced sputum in stable COPD patients with positive BD tests were significantly higher than those in asthmatics or normal controls (all P<0.01). However, the values of the above inflammatory markers in induced sputum were similar among stable COPD patients with positive or negative BD tests (all P>0.05). The stable COPD patients with positive BD tests may present not only eosinophilic airway inflammation but also neutrophilic airway inflammation.

Features of cellular structure of the induced sputum and profile of cytokines at sintropiya of bronchial asthma and obesity at young patients

AIM

To estimate changes of cellular structure of the induced sputum at young patients with bronchial asthma at interrelations with BMI and level of cytokines in blood plasma.

MATERIALS AND METHODS

164 patients with bronchial asthma were divided into 2 groups taking into BMI: the 1st group included patients with bronchial asthma and BMI from 18 to 25 kg/m2, patients with bronchial asthma and BMI from 30 to 40 kg/m2 entered into the 2nd group. The group of control was made by 40 almost healthy volunteers. Estimated existence of excess weight and defined obesity degree according to recommendations of World Health Organization. Studied the level of control of bronchial asthma, cellular structure of the induced sputum, the IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, IL-15, IL-17, TNF-α, INF-γ levels in plasma of peripheral blood.

RESULTS

There are presented the results of the research of cellular profile of the induced sputum and profile of cytokines at patients with bronchial asthma depending on BMI and severity of the disease. The received results testify to prevalence of eosinophilic type of an inflammation in the group of patients with BMI less than 25 kg/m2 whereas at patients mainly paucigranulation inflammation decided on obesity. The highest content of the Il-17 was registered at patients with bronchial asthma and obesity as in comparison with indicators of patients with normal BMI, and with almost healthy that, perhaps, is the reason of low effect of steroid therapy at these patients.

CONCLUSION

Endotype assessment before basic antiinflammatory therapy at patients with the first time diagnosed bronchial asthma, will be able to help with selection of the most optimum treatment to each specific patient.

Prostaglandin E2 decrease in induced sputum of hypersensitive asthmatics during oral challenge with aspirin

BACKGROUND

A special regulatory role for prostaglandin E₂ (PGE₂ ) has been postulated in nonsteroidal anti-inflammatory drug (NSAID)-exacerbated respiratory disease (NERD).

OBJECTIVE

To investigate the effect of systemic aspirin (acetylsalicylic acid) administration on airway PGE₂ biosynthesis in induced sputum supernatant (ISS) among subjects with NERD or aspirin-tolerant asthma with chronic rhinosinusitis with nasal polyposis (ATA-CRSwNP), as well as healthy controls (HC).

METHODS

Induced sputum (IS) was collected from patients with NERD (n = 26), ATA-CRSwNP (n = 17), and HC (n = 21) at baseline and after aspirin challenge. Sputum differential cell count and IS supernatant (ISS) levels of prostanoids, PGE₂ , 8-iso-PGE₂ , tetranor-PGE-M, 8-iso-PGF₂ α, and leukotriene C₄ , D₄ , and E₄ , were determined using mass spectrometry. Urinary excretion of LTE₄ was measured by ELISA.

RESULTS

NERD subjects had elevated sputum eosinophilic count as compared to ATA-CRSwNP and HC (median NERD 9.1%, ATA-CRSwNP 2.1%, and HC 0.4%; P < 0.01). Baseline ISS levels of PGE₂ were higher in asthmatics as compared to HC at baseline (NERD vs HC P = 0.04, ATA-CRSwNP vs HC P < 0.05). Post-challenge ISS levels of PGE₂ compared to baseline significantly decreased in NERD and HC (P < 0.01 and P = 0.01), but not in ATA-CRSwNP. In NERD, a similar decrease in PGE₂ as in HC resulted from 2.8 times lower dose of aspirin.

CONCLUSION

Aspirin-precipitated bronchoconstriction is associated with a decrease in airway PGE₂ biosynthesis. These results support the mechanism of PGE₂ biosynthesis inhibition as a trigger for bronchoconstriction in NERD.

Inflammatory profile in optimally treated patients with adult versus early-onset asthma

Introduction: The age of asthma onset is often implicated in clinical manifestation, diagnosis, and management of the disease. Aim: To define demographic, clinical and functional features and inflammatory characteristics in induced sputum in patients with adult-onset asthma. Methods: Optimally treated patients from asthma clinics of two tertiary hospitals were included in the study. Patients underwent assessment of demographic characteristics, severity and treatment regimes, pulmonary function tests, and skin prick tests, as well as measurement of blood eosinophils and sputum induction for the assessment of sputum inflammatory cells, IL-8 and IL-13 levels in the supernatant. Results: Of the 333 patients recruited, 234 (70.2%) had adult-onset asthma. Adult-onset asthmatics were older, had a higher BMI, a shorter disease duration, and were less often atopic, compared to patients with early onset asthma. Higher proportions of patients with severe asthma presented increased levels of FeNO and blood eosinophils, both in the early and the adult-onset patient groups. Finally, obese patients with early onset asthma were characterized by less atopy compared to non-obese patients in the same group. Conclusion: Adult-onset asthma was characterized by less sputum eosinophilia, a nonatopic profile and a higher BMI compared to early-onset asthma. The presence of blood eosinophilia and increased FeNO in patients with severe asthma was comparable in the two groups.

Effect of CPAP on airway reactivity and airway inflammation in children with moderate-severe asthma

BACKGROUND AND OBJECTIVE

Asthma is characterized by airway hyperreactivity and airway inflammation. We previously demonstrated that adults with mild well-controlled asthma exhibited a marked decrease in airway reactivity (PC20 increased >2-fold) after using nocturnal continuous positive airway pressure (CPAP) for 1 week. If CPAP produces a similar suppression of airway reactivity in children with moderate-severe asthma, who require chronic use of corticosteroids, then this non-pharmacological therapy might provide a beneficial alternative or supplemental therapy in these subjects.

METHODS

Children aged 8-17 years with moderate-severe asthma were treated with 4 weeks of nocturnal CPAP (8-10 cm H2 O) or sham CPAP (<2 cm H2 O). Adherence was monitored with a modem installed in the equipment or by memory cards. Airway reactivity, assessed by methacholine bronchial challenge, was measured prior to and following treatment.

RESULTS

The percentage of subjects adherent to treatment was similar in both groups (19/27 CPAP vs 19/28 sham, ~70%). There was a tendency for PC20 to increase with treatment in both groups (3.0-5.3 mg/mL CPAP vs 3.2 to 4.3 mg/mL sham, P = 0.083); however, the change did not differ significantly between groups (P = 0.569).

CONCLUSION

We found that the 4-week treatment with nocturnal CPAP did not produce a twofold suppression of airway reactivity in children with moderate-severe asthma.

[Correlation between expressions of myeloperoxidase and eosinophil cationic protein in sputum and clinical features of asthma-chronic obstructive pulmonary disease overlap]

OBJECTIVE

To observe the role of myeloperoxidase(MPO)and eosinophilic cationic protein(ECP)in the airway inflammation and their correlation with clinical feature in asthma-COPD overlap (ACO) patients.

METHODS

Twenty patients with COPD, 20 with asthma, 20 with ACO and 20 control subjects underwent pulmonary function test for measurement of forced expiratory volume in 1 second (FEV₁), forced vital capacity (FVC), peak expiratory flow (PEF), and maximum midexpiratory flow (MMF_25/75). COPD assessment test (CAT) was used to evaluate the clinical symptoms of the patients with COPD and ACO. The asthma control test (ACT) was used to evaluate the asthma control in the patients with asthma and ACO. Induced sputum samples were collected from the subjects for analysis of neutrophil and eosinophil ratios, and enzyme-linked immunosorbent assay was used to determine the expression levels of MPO and ECP in the sputum.

RESULTS

No significant difference was observed in the CAT scores between ACO group and COPD group (P&gt; 0.05). Compared with the asthma group, the patients with ACO had significantly lower ACT scores and lower FEV₁, PEF and MMF_25/75 (P &lt; 0.05). The patients with ACO had significantly higher FVC and sputum eosinophil ratio than those with COPD (P &lt; 0.05), and a higher sputum neutrophil ratio than those with asthma (P &lt; 0.01). In ACO group, the MPO level in sputum was significantly higher than that in the asthma group (P &lt; 0.05), while sputum ECP level was significantly higher than that in both the asthma group and COPD group (P &lt; 0.05 or 0.01). In ACO group, sputum MPO level was positively correlated with sputum neutrophil ratio (r=0.8358, P &lt; 0.01) but was not correlated with CAT score or FEV₁ (P&gt; 0.05); sputum ECP level was positively correlated with sputum eosinophil ratio (r=0.4666, P &lt; 0.05) and was inversely correlated with ACT score (r=-0.4966, P &lt; 0.05) and FEV₁ (r=-0.4610, P &lt; 0.05).

CONCLUSIONS

Both neutrophilic and eosinophilic inflammations occur in the airway of patients with ACO, and their sputum ECP level is negatively correlated with asthma control and obstructive airflow limitation.

Mucus Hydration in Subjects with Stable Chronic Bronchitis: A Comparison of Spontaneous and Induced Sputum

Mucus hydration is important in mucus clearance and lung health. This study sought to test the relative utility of spontaneous sputum (SS) versus the reasonably noninvasive induced sputum (IS) samples for measurement of mucus hydration. SS and IS samples were collected over a 2-day study interval. Sputum was induced with escalating inhaled nebulized 3-5% hypertonic saline. Viscous portions of the samples ("plugs") were utilized for percent solids and total mucin analyses. Cytokines, nucleotides/nucleosides and cell differentials were measured in plugs diluted into 0.1% Sputolysin. Overall, 61.5% of chronic bronchitis (CB) subjects produced a SS sample and 95.2% an IS sample. Total expectorate sample weights were less for the SS (0.94 ± 0.98 g) than the IS (2.67 ± 2.33 g) samples. Percent solids for the SS samples (3.56% ± 1.95; n = 162) were significantly greater than the IS samples (3.08% ± 1.81; n = 121), p = 0.133. Total mucin concentrations also exhibited a dilution of the IS samples: SS = 4.15 ± 3.23 mg/ml (n = 62) versus IS= 3.34 ± 2.55 mg/ml (n = 71) (p = 0.371). Total mucins (combined SS and IS) but not percent solids, were inversely associated with FEV₁ percent predicted (p = 0.052) and FEV₁,/FVC % (p = 0.035). There were no significant differences between sample types in cytokine or differential cell counts. The probability of sample collections was less for SS than IS samples. Measurements of hydration revealed modest dilution of the IS samples compared to SS. Thus for measurements of mucus hydration, both SS and IS samples appear to be largely interchangeable.

Multiplex Droplet Digital PCR Assay for Quantification of Human T-Cell Leukemia Virus Type 1 Subtype c DNA Proviral Load and T Cells from Blood and Respiratory Exudates Sampled in a Remote Setting

During human T-cell leukemia virus type 1 (HTLV-1) infection, the frequency of cells harboring an integrated copy of viral cDNA, the proviral load (PVL), is the main risk factor for progression of HTLV-1-associated diseases. Accurate quantification of provirus by droplet digital PCR (ddPCR) is a powerful diagnostic tool with emerging uses for monitoring viral expression. Current ddPCR techniques quantify HTLV-1 PVL in terms of whole genomic cellular material, while the main targets of HTLV-1 infection are CD4⁺ and CD8⁺ T cells. Our understanding of HTLV-1 proliferation and the amount of viral burden present in different compartments is limited. Recently a sensitive ddPCR assay was applied to quantifying T cells by measuring loss of germ line T-cell receptor genes as method of distinguishing non-T-cell from recombined T-cell DNA. In this study, we demonstrated and validated novel applications of the duplex ddPCR assay to quantify T cells from various sources of human genomic DNA (gDNA) extracted from frozen material (peripheral blood mononuclear cells [PBMCs], bronchoalveolar lavage fluid, and induced sputum) from a cohort of remote Indigenous Australians and then compared the T-cell measurements by ddPCR to the prevailing standard method of flow cytometry. The HTLV-1 subtype c (HTLV-1c) PVL was then calculated in terms of extracted T-cell gDNA from various compartments. Because HTLV-1c preferentially infects CD4⁺ T cells, and the amount of viral burden correlates with HTLV-1c disease pathogenesis, application of this ddPCR assay to accurately measure HTLV-1c-infected T cells can be of greater importance for clinical diagnostics and prognostics as well as monitoring therapeutic applications.

Pathophysiological Mechanisms of Asthma

The recent Lancet commission has highlighted that "asthma" should be used to describe a clinical syndrome of wheeze, breathlessness, chest tightness, and sometimes cough. The next step is to deconstruct the airway into components of fixed and variable airflow obstruction, inflammation, infection and altered cough reflex, setting the airway disease in the context of extra-pulmonary co-morbidities and social and environmental factors. The emphasis is always on delineating treatable traits, including variable airflow obstruction caused by airway smooth muscle constriction (treated with short- and long-acting β-2 agonists), eosinophilic airway inflammation (treated with inhaled corticosteroids) and chronic bacterial infection (treated with antibiotics with benefit if it is driving the disease). It is also important not to over-treat the untreatable, such as fixed airflow obstruction. These can all be determined using simple, non-invasive tests such as spirometry before and after acute administration of a bronchodilator (reversible airflow obstruction); peripheral blood eosinophil count, induced sputum, exhaled nitric oxide (airway eosinophilia); and sputum or cough swab culture (bacterial infection). Additionally, the pathophysiology of risk domains must be considered: these are risk of an asthma attack, risk of poor airway growth, and in pre-school children, risk of progression to eosinophilic school age asthma. Phenotyping the airway will allow more precise diagnosis and targeted treatment, but it is important to move to endotypes, especially in the era of increasing numbers of biologicals. Advances in -omics technology allow delineation of pathways, which will be particularly important in TH2 low eosinophilic asthma, and also pauci-inflammatory disease. It is very important to appreciate the difficulties of cluster analysis; a patient may have eosinophilic airway disease because of a steroid resistant endotype, because of non-adherence to basic treatment, and a surge in environmental allergen burden. Sophisticated -omics approaches will be reviewed in this manuscript, but currently they are not being used in clinical practice. However, even while they are being evaluated, management of the asthmas can and should be improved by considering the pathophysiologies of the different airway diseases lumped under that umbrella term, using simple, non-invasive tests which are readily available, and treating accordingly.

Innate immune crosstalk in asthmatic airways: Innate lymphoid cells coordinate polarization of lung macrophages

BACKGROUND

Recent studies have emphasized the role of innate lymphoid cells (ILCs) in the development of asthma. The involvement of group 2 innate lymphoid cells (ILC2s) in asthma is well studied: however, the participation of other types of ILCs in the development of asthma remains unclear.

OBJECTIVE

This study aims to understand the role of various ILCs in patients with asthma, especially their effect on macrophage polarization.

METHODS

Each subset of ILCs and macrophages in induced sputum from 51 steroid-naive patients with asthma and 18 healthy donors was analyzed by using flow cytometry. Alveolar macrophages (AM) were sorted and cocultured with each subset of ILCs to determine whether the polarization of macrophages could be regulated by ILCs.

RESULTS

In addition to ILC2s, numbers of group 1 innate lymphoid cells (ILC1s) and group 3 innate lymphoid cells (ILC3s) were increased in induced sputum from asthmatic patients when compared with those in healthy control subjects. The dominance of macrophages in induced sputum was more prominent in asthmatic patients than in healthy control subjects. A positive correlation between numbers of ILC2s and numbers of M2 macrophages and those of ILC1s/ILC3s and M1 macrophages was observed. Coculture of ILC2s with AMs induced expression of M2 macrophage-related genes, whereas coculture of ILC1s and ILC3s with AMs induced expression of M1 macrophage-related genes through cytokine secretion, as well as cell-cell contact. According to the inflammatory signature, patients with eosinophilic asthma have more ILC2s and M2 macrophages, and those with noneosinophilic asthma have an M1 macrophage-dominant profile.

CONCLUSION

A different subset of ILCs regulates macrophage polarization, contributing to developing the distinct phenotype of asthma.

Looking for Airways Periostin in Severe Asthma: Could It Be Useful for Clustering Type 2 Endotype?

BACKGROUND

Severe asthma is heterogeneous clinically and biologically and is often difficult to control. In particular, the type 2 (T2) immunity endotype of severe asthma is gaining increasing interest because it is susceptible to newly developed biologic treatments that can transform the quality of life of these patients. The aim of this study was to analyze periostin concentrations in the airways of patients with severe asthma, evaluating its role in clustering the T2 endotype.

METHODS

We enrolled 40 consecutive patients with severe asthma (T2 endotype: n = 25; non-T2 endotype: n = 15), 21 patients with mild to moderate asthma, and 15 healthy control subjects. All subjects enrolled underwent exhaled breath condensate (EBC) and sputum collection, eosinophil count in blood, fractional exhaled nitric oxide, and IgE measurement. Periostin was assessed by an enzyme-linked immunosorbent assay kit on EBC and induced sputum (IS) supernatant.

RESULTS

We were able to detect higher periostin levels in the EBC (0.75 ± 0.46 vs 0.70 ± 0.19 vs 0.11 ± 0.05 ng/mL, P < .05 and P < .01) and in IS (0.55 ± 0.23 vs 0.31 ± 0.13 vs 0.16 ± 0.120 ng/mL, P < .05 and P < .01) of patients with severe asthma compared with patients with mild to moderate asthma and healthy control subjects, respectively. We further found an increase of periostin levels in both samples in T2 endotype compared with non-T2 endotype (EBC: 0.88 ± 0.46 vs 0.52 ± 0.46 ng/mL; IS: 0.69 ± 0.19 vs 0.39 ± 0.16 ng/mL; P < .05) and a correlation between periostin levels in EBC and sputum.

CONCLUSIONS

We found that periostin is measurable in the airways and increased in patients with severe asthma, especially in those from the T2 endotype. Unlike serum periostin, which may be derived from several sources outside the lung, airways periostin is a useful marker of severe eosinophilic asthma and may help to phenotype patients that will respond to the biologic agents.

Can inflammatory markers in induced sputum be used to detect phenotypes and endotypes of pediatric severe therapy-resistant asthma?

BACKGROUND

The phenotypes and endotypes of severe therapy-resistant asthma (STRA) have not been fully elucidated in children. The aim of the present study was to investigate inflammatory markers in the induced sputum of children with STRA and to compare them with those present in a group of children who achieved control.

METHODS

A prospective cohort of children (6-18 years of age) diagnosed with severe asthma (GINA criteria) who had undergone treatment for at least 6 months was comprehensively followed for 3 months. Inhalation technique, adherence to treatment, ACT score, and main comorbidities were assessed. Induced sputum samples were collected for cytology analysis and quantitative assessment of cytokines; the participants also underwent spirometry, plethysmography, and fractional exhaled nitric oxide (FeNO) measurement.

RESULTS

Forty patients were included (average age 12.8 years; 62.5% male); of these, 13 (32.5%) were classified as STRA at the end of follow-up. There were no significant differences between the STRA and control groups in demographic data, functional test results, or FeNO levels. The eosinophilic inflammatory pattern predominated in both groups; however, the STRA group showed a proportionally higher percentage of sputum neutrophils (P < 0.05). The median sputum levels of the cytokines IL-10, GM-CSF, IFN-γ, and TNF-α were significantly higher in the STRA group (P < 0.05). GM-CSF and TNF-α levels showed inverse correlations with ACT scores.

CONCLUSION

The presence of neutrophils, the cytokines IL-10, and IFN-γ and, more particularly, TNF-α, and GM-CSF in the sputum may play an important role in the pathophysiological mechanism of STRA in children and adolescents. Specific antagonists for these cytokines may represent a future therapeutic strategy.

IL-26 in the induced sputum is associated with the level of systemic inflammation, lung functions and body weight in COPD patients

Background

Chronic inflammatory process is the main link in COPD pathogenesis, which causes structural changes in the respiratory tract and lungs. In overweight patients, an adipose tissue could contribute to activation of the inflammatory process. Therefore, it is highly important to identify potential biomarkers of inflammation for patients with COPD and obesity. The aim of this study was to investigate the role of interleukin-26 (IL-26) and evaluate the relationship between the level of systemic inflammation, lung function, and body mass index (BMI) in patients with COPD.

Patients and methods

Eighty-three patients with COPD in the stable condition (stage 2 according to the 2016 Global Initiative for Chronic Obstructive Lung Disease recommendations), aged 40-70 years, were included in the study. All patients were divided into 2 groups: obese (n=53) (BMI - 30.0-39.9 kg/m2) and non-obese (n=30) (BMI - 18.5-24.9 kg/m2). We conducted patients' examination, spirometry, induced the sputum, determined the level of C-reactive protein (CRP), leptin in serum and IL-26 in sputum.

Results

Obese and non-obese COPD patients had a significant increase in IL-26 compared with healthy subjects by 2.3 and 2.6 (P=0.0003). We also observed a higher level of CRP by 1.38 times (P=0.0008), compared with the rate in non-obese COPD patients, and by 1.8 times (P=0.015) higher concentration level of leptin compared with healthy subjects. The sputum IL-26 level had positive correlation with BMI, CRP, and leptin, and a negative - with forced expiratory volume in 1 second (FEV1) and FEV1/forced vital capacity. Leptin level had positive correlation with BMI and CRP, and negative with FEV1, FEV1/forced vital capacity.

Conclusion

Obese COPD patients had a higher level of persistent systemic inflammation than non-obese ones, which is confirmed by a significant increase of CRP and leptin in serum. The data confirm that IL-26 can be considered as a perspective marker to detect the inflammation level in lung tissue of COPD patients.

Sputum interleukin-25 correlates with asthma severity: a preliminary study

Introduction

Interleukin 25 is an epithelial-derived cytokine associated with allergic Th2 inflammation. However, little is known about the role of IL-25 in different asthma phenotypes and its relationship with disease severity.

Aim

To evaluate and compare the mRNA and protein expression of IL-25 in patients with mild-to moderate/severe asthma and cough variant asthma (CVA).

Material and methods

Thirty-eight patients with stable asthma (11 patients with mild-to-moderate asthma, 14 patients with severe asthma and 13 patients with CVA) and 14 control subjects were enrolled. IL-25 protein concentration was measured in induced sputum (IS) supernatants by ELISA and IL-25 mRNA expression was evaluated in IS cells by real time PCR.

Results

No differences in IS IL-25 mRNA and IL-25 concentration between controls and the whole asthma group were found. In the detailed analysis, a lower IL-25 mRNA expression in sputum cells was observed in severe asthma compared to CVA and controls. IL-25 protein concentration in sputum supernatants was elevated in patients with severe asthma compared to controls, CVA and mild-to-moderate asthma. A sputum IL-25 level was increased in atopic vs. non-atopic asthma patients. The elevated IL-25 mRNA expression and protein concentration was associated with a lower eosinophil and higher neutrophil percentage in asthmatic airways.

Conclusions

Our results suggest that IL-25 is particularly associated with severe asthma. The relationship between IL-25 and neutrophilic airway inflammation suggests the pleiotropic role of IL-25 in the immune response in this disease.

Diagnostic value of fractional exhaled nitric oxide for asthma-chronic obstructive pulmonary disease overlap syndrome

To examine the difference in the fractional exhaled nitric oxide (FeNO) between chronic obstructive pulmonary disease (COPD) patients with asthma-COPD overlap syndrome (ACOS) and patients with Non-ACOS COPD (Non-ACOS) and to investigate the correlation between FeNO levels and the differential cell counts of eosinophils in induced sputum, in order to explore the diagnostic value of FeNO in ACOS.A prospective, case-control study was performed on 53 cases of ACOS group and 53 cases of Non-ACOS group in the Respiratory Medicine Outpatient of Zhangzhou Municipal TCM Hospital, Affiliated to Fujian University of Traditional Chinese Medicine. The FeNO levels and induced sputum cell counts were determined and the correlation between FeNO levels and eosinophile percentage was analyzed by Pearson linear correlation analysis.The FeNO levels in patients with ACOS (37[24.5-53.0]) ppb were significantly higher than those of patients with Non-ACOS (20 [15.5-24.5] ppb) (P < .01). Also, the percentage of eosinophils in induced sputum in the ACOS group (5.70 [1.50-17.62]%) were significantly higher than those of the Non-ACOS group (0.50 [0.00-1.00]%) (P < .01). FeNO in both groups correlated positively with the percentage of eosinophils in induced sputum (P < .01), with a correlation coefficient r of 0.521. The area under the receiver operating curve of FeNO for the diagnosis of ACOS phenotype was 0.815 (P < .01), the sensitivity and specificity reach highest when the cut off value was 25.50 ppb.The FeNO in patients from the ACOS group were significantly higher than those in Non-ACOS group and were moderately correlated with the percentage of eosinophils in induced sputum. The results indicated that FeNO may be used as a diagnostic index for ACOS, in addition to the induced sputum.

Microscopic Analysis and Quality Assessment of Induced Sputum From Children With Pneumonia in the PERCH Study

Background.

It is standard practice for laboratories to assess the cellular quality of expectorated sputum specimens to check that they originated from the lower respiratory tract. The presence of low numbers of squamous epithelial cells (SECs) and high numbers of polymorphonuclear (PMN) cells are regarded as indicative of a lower respiratory tract specimen. However, these quality ratings have never been evaluated for induced sputum specimens from children with suspected pneumonia.

Methods.

We evaluated induced sputum Gram stain smears and cultures from hospitalized children aged 1–59 months enrolled in a large study of community-acquired pneumonia. We hypothesized that a specimen representative of the lower respiratory tract will contain smaller quantities of oropharyngeal flora and be more likely to have a predominance of potential pathogens compared to a specimen containing mainly saliva. The prevalence of potential pathogens cultured from induced sputum specimens and quantity of oropharyngeal flora were compared for different quantities of SECs and PMNs.

Results.

Of 3772 induced sputum specimens, 2608 (69%) had <10 SECs per low-power field (LPF) and 2350 (62%) had >25 PMNs per LPF, measures traditionally associated with specimens from the lower respiratory tract in adults. Using isolation of low quantities of oropharyngeal flora and higher prevalence of potential pathogens as markers of higher quality, <10 SECs per LPF (but not >25 PMNs per LPF) was the microscopic variable most associated with high quality of induced sputum.

Conclusions.

Quantity of SECs may be a useful quality measure of induced sputum from young children with pneumonia.

Limited Utility of Polymerase Chain Reaction in Induced Sputum Specimens for Determining the Causes of Childhood Pneumonia in Resource-Poor Settings: Findings From the Pneumonia Etiology Research for Child Health (PERCH) Study

Background.

Sputum examination can be useful in diagnosing the cause of pneumonia in adults but is less well established in children. We sought to assess the diagnostic utility of polymerase chain reaction (PCR) for detection of respiratory viruses and bacteria in induced sputum (IS) specimens from children hospitalized with severe or very severe pneumonia.

Methods.

Among children aged 1–59 months, we compared organism detection by multiplex PCR in IS and nasopharyngeal/oropharyngeal (NP/OP) specimens. To assess whether organism presence or density in IS specimens was associated with chest radiographic evidence of pneumonia (radiographic pneumonia), we compared prevalence and density in IS specimens from children with radiographic pneumonia and children with suspected pneumonia but without chest radiographic changes or clinical or laboratory findings suggestive of pneumonia (nonpneumonia group).

Results.

Among 4232 cases with World Health Organization–defined severe or very severe pneumonia, we identified 1935 (45.7%) with radiographic pneumonia and 573 (13.5%) with nonpneumonia. The organism detection yield was marginally improved with IS specimens (96.2% vs 92.4% for NP/OP specimens for all viruses combined [P = .41]; 96.9% vs 93.3% for all bacteria combined [P = .01]). After accounting for presence in NP/OP specimens, no organism was detected more frequently in the IS specimens from the radiographic pneumonia compared with the nonpneumonia cases. Among high-quality IS specimens, there were no statistically significant differences in organism density, except with cytomegalovirus, for which there was a higher quantity in the IS specimens from cases with radiographic pneumonia compared with the nonpneumonia cases (median cycle threshold value, 27.9 vs 28.5, respectively; P = .01).

Conclusions.

Using advanced molecular methods with IS specimens provided little additional diagnostic information beyond that obtained with NP/OP swab specimens.

The Incremental Value of Repeated Induced Sputum and Gastric Aspirate Samples for the Diagnosis of Pulmonary Tuberculosis in Young Children With Acute Community-Acquired Pneumonia

Background.

Mycobacterium tuberculosis (Mtb) contributes to the pathogenesis of childhood acute community-acquired pneumonia in settings with a high tuberculosis burden. The incremental value of a repeated induced sputum (IS) sample, compared with a single IS or gastric aspirate (GA) sample, is not well known.

Methods.

Two IS samples were obtained for Mtb culture from children enrolled as cases in the Pneumonia Etiology Research for Child Health (PERCH) study in South Africa. Nonstudy attending physicians requested GA if pulmonary tuberculosis was clinically suspected. We compared the Mtb yield of 2 IS samples to that of 1 IS sample and GA samples.

Results

. Twenty-seven (3.0%) culture-confirmed pulmonary tuberculosis cases were identified among 906 children investigated with IS and GA samples for Mtb. Results from 2 IS samples were available for 719 children (79.4%). Of 12 culture-confirmed pulmonary tuberculosis cases identified among children with ≥2 IS samples, 4 (33.3%) were negative at the first IS sample. In head-to-head comparisons among children with both GA and IS samples collected, the yield of 1 GA sample (8 of 427; 1.9%) was similar to that of 1 IS sample (5 of 427, 1.2%), and the yield of 2 GA samples (10 of 300; 3.3%) was similar to that of 2 IS samples (5 of 300; 1.7%). IS samples identified 8 (42.1%) of the 19 culture-confirmed pulmonary tuberculosis cases that were identified through submission of IS and GA samples.

Conclusions.

A single IS sample underestimated the presence of Mtb in children hospitalized with severe or very severe pneumonia. Detection of Mtb is enhanced by combining 2 IS with GA sample collections in young children with acute severe pneumonia.

Safety of Induced Sputum Collection in Children Hospitalized With Severe or Very Severe Pneumonia

Background.

Induced sputum (IS) may provide diagnostic information about the etiology of pneumonia. The safety of this procedure across a heterogeneous population with severe pneumonia in low- and middle-income countries has not been described.

Methods.

IS specimens were obtained as part a 7-country study of the etiology of severe and very severe pneumonia in hospitalized children <5 years of age. Rigorous clinical monitoring was done before, during, and after the procedure to record oxygen requirement, oxygen saturation, respiratory rate, consciousness level, and other evidence of clinical deterioration. Criteria for IS contraindications were predefined and serious adverse events (SAEs) were reported to ethics committees and a central safety monitor.

Results.

A total of 4653 IS procedures were done among 3802 children. Thirteen SAEs were reported in relation to collection of IS, or 0.34% of children with at least 1 IS specimen collected (95% confidence interval, 0.15%–0.53%). A drop in oxygen saturation that required supplemental oxygen was the most common SAE. One child died after feeding was reinitiated 2 hours after undergoing sputum induction; this death was categorized as “possibly related” to the procedure.

Conclusions.

The overall frequency of SAEs was very low, and the nature of most SAEs was manageable, demonstrating a low-risk safety profile for IS collection even among severely ill children in low-income-country settings. Healthcare providers should monitor oxygen saturation and requirements during and after IS collection, and assess patients prior to reinitiating feeding after the IS procedure, to ensure patient safety.

Comparative Study of IL-33 and IL-6 Levels in Different Respiratory Samples in Mild-to-Moderate Asthma and COPD

IL-6 and IL-33 are involved in the inflammatory process in obstructive lung diseases. In contrast to IL-6, few data on the expression of IL-33 in different biological samples from asthma and COPD patients are available. The aim was to evaluate the expressions of IL-33 and IL-6 in bronchial mucosa and to compare these expressions with the concentrations of both cytokines in various respiratory samples from patients with mild-to-moderate asthma and COPD. Serum, induced sputum and exhaled breath condensate IL-6 and IL-33 levels, as well as their expression in bronchial mucosa were evaluated in 22 asthma and 33 COPD patients. There were significant differences between bronchial mucosa IL-6, but not IL-33 expression in asthma and COPD. Serum and IS IL-6 concentrations were higher in COPD than in asthma (3.4 vs. 2.02 pg/mL, p = 0.002 and 16.5 vs. 12.7 pg/mL, p = 0.007, respectively); IL-33 levels reached similar values in asthma and COPD in all investigated samples. In both diseases, the lowest levels of IL-6 and IL-33 were found in EBC. EBC levels of both cytokines did not correlate with their expression in other materials. The IL-33 and IL-6 are detectable in serum, IS and EBC not only in asthma but also in COPD patients. In the COPD group, serum and IS IL-6 concentrations were statistically higher than in the asthma group. The tissue expression of IL-33 and IL-33 concentrations in the investigated biological samples were on a comparable level in both diseases. Our findings may suggest that IL-33 activation is a common pathway in asthma and COPD.

Polymerase chain reaction test in induced sputum of patients with pulmonary tuberculosis

INTRODUCTION

Induced sputum (IS) is an alternative method of obtaining sputum, but IS smears are frequently negative. Culture is more time consuming in its results, and less useful to guide the diagnosis. Polymerase chain reaction (PCR) is the most common methodology for rapid diagnosis of tuberculosis (TB), and few studies evaluated its role in IS samples.

OBJECTIVES

The objective of this study is to determine the diagnostic yield of PCR for TB compared with culture in IS samples.

MATERIALS AND METHODS

Prospective study. Inpatients and outpatients of >18 years with respiratory symptoms suggestive of PTB were invited to participate. The subjects were interviewed using a standardized questionnaire, and collected IS. Three samples were obtained for AFB smear and culture. A fourth sample was obtained for PCR test.

RESULTS

A total of 116 IS samples were evaluated. The sensitivity, specificity, positive predictive value and negative predictive values of PCR were 95.2%, 48.4%, 29.0% and 97.9%, respectively. The area under the receiver operating characteristic curve was .72 for the PCR test (P < .0001).

CONCLUSIONS

Although the PCR specificity could be underestimated, if we consider PCR to be more sensitive than the culture method used, we believed that these PCR-positive tests mean false positives. The results of PCR should always be interpreted carefully in conjunction with clinical information.

Menopausal asthma-much ado about nothing? An observational study

OBJECTIVE

Menopausal asthma is considered a distinct asthma phenotype. Our aim was to identify potential specific features of asthma in postmenopausal women in a cohort of Polish females.

METHODS

Asthma severity and control, pulmonary function, exhaled nitric oxide (FE_NO), peripheral blood and induced sputum (IS) differential cell count were compared in three groups: women with premenopausal asthma (group 1), menopausal women with pre-existing asthma (group 2A) and menopausal women with asthma onset in the perimenopausal or menopausal period (group 2B).

RESULTS

We enrolled 27 women to group 1, 13 to group 2A and 16 to group 2B. Asthma severity and control, blood eosinophil count and FE_NO did not differ among the groups. Menopausal women had a higher incidence of irreversible airway obstruction (84.6% in group 2A and 56.2% in group 2B vs. 22.2% in group 1, p < 0.001 and p = 0.03, respectively). The proportion of patients with sputum eosinophilia was highest in menopausal women with pre-existing asthma, although the difference did not reach statistical significance (88.9% in group 2A vs. 66.7% in group 2B and 65.0% in group 1, respectively, p = 0.86).

CONCLUSIONS

Menopausal women with asthma are characterized by an increased incidence of irreversible airway obstruction regardless of disease duration. This may indicate that age may contribute to pulmonary function impairment in asthmatic women independently of their hormonal status at the time of asthma diagnosis. Our results failed to confirm the presence of specific asthma features which would allow to distinguish the phenotype of menopausal asthma.

Clinical, functional and inflammatory characteristics in patients with paucigranulocytic stable asthma: Comparison with different sputum phenotypes

BACKGROUND

According to induced sputum cell count, four different asthma phenotypes have been recognized (eosinophilic, neutrophilic, mixed and paucigranulocytic). The aim of this study was to detect functional and inflammatory characteristics of patients with paucigranulocytic asthma.

METHODS

A total of 240 asthmatic patients were categorized into the four phenotypes according to cell counts in induced sputum. All patients underwent pulmonary function tests, and measurement of fraction of exhaled nitric oxide (FeNO). The levels of IL-8, IL-13 and eosinophilic cationic protein (ECP) were also measured in sputum supernatant. Treatment, asthma control and the presence of severe refractory asthma (SRA) were also recorded.

RESULTS

Patients were categorized into the four phenotypes as follows: eosinophilic (40%), mixed (6.7%), neutrophilic (5.4%) and paucigranulocytic (47.9%). Although asthma control test did not differ between groups (P=.288), patients with paucigranulocytic asthma had better lung function (FEV₁ % pred) [median (IQR): 71.5 (59.0-88.75) vs 69.0 (59.0-77.6) vs 68.0 (60.0-85.5) vs 80.5 (69.7-95.0), P=.009] for eosinophilic, mixed, neutrophilic and paucigranulocytic asthma, respectively, P=.009). SRA occurred more frequently in the eosinophilic and mixed phenotype (41.6% and 43.7%, respectively) and less frequently in the neutrophilic and paucigranulocytic phenotype (25% and 21.7%, respectively, P=.01). FeNO, ECP and IL-8 were all low in the paucigranulocytic, whereas as expected FeNO and ECP were higher in eosinophilic and mixed asthma, while IL-8 was higher in patients with neutrophilic and mixed asthma (P<.001 for all comparisons). Interestingly, 14.8% of patients with paucigranulocytic asthma had poor asthma control.

CONCLUSION

Paucigranulocytic asthma most likely represents a "benign" asthma phenotype, related to a good response to treatment, rather than a "true" phenotype of asthma. However, paucigranulocytic patients that remain not well controlled despite optimal treatment represent an asthmatic population that requires further study for potential novel targeted interventions.