Corticosteroid plus β<Subscript>2</Subscript>-agonist in a single inhaler as reliever therapy in intermittent and mild asthma: a proof-of-concept systematic review and meta-analysis

Background

Current guidelines recommend a single inhaler maintenance and reliever therapy (SMART) regimen for moderate to severe asthma. However, evidence for the inhaled corticosteroid plus fast-onset-acting β₂-agonist (ICS/FABA) as reliever therapy in management of intermittent and mild asthma patients is lacking.

Objective

To systematically explore efficacy and safety of the proof-of-concept of the ICS plus FABA regimen in a single inhaler as reliever therapy across children and adults with intermittent and mild persistent asthma.

Methods

We searched online bibliographic databases for randomized controlled trials (RCTs) involving the as-needed use of ICS/FABA as monotherapy in intermittent or mild asthma patients. The primary outcomes were exacerbations and the hazard ratio (HR) of the time to first exacerbation.

Results

Six RCTs (n?=?1300) met the inclusion criteria. Compared with the as-needed FABA regimen, the as-needed use of ICS/FABA as monotherapy statistically reduced exacerbations (RR?=?0.56, P?=?0.001). Compared with regular ICS regimen, the as-needed ICS/FABA therapy had slightly higher risk of exacerbations (RR?=?1.39, P?=?0.011). The HR for time to first exacerbations in the ICS/FABA regimen was significant lower when compared with FABA regimen (HR?=?0.52, P?=?0.002) but had no difference when compared with ICS regimen (HR?=?1.30, P?=?0.286). The corticosteroid exposure in the daily ICS regimen was 2- to 5-fold compared with as-needed use of ICS/FABA regimen.

Conclusions

Our analysis shows that the ICS/FABA as a symptom-driven therapy may be a promising alternative regimen for the patients with intermittent or mild asthma, but it needs further real-world RCTs to confirm these findings.

     

Epidemiology of asthma and associated factors in an urban Pakistani population: adult asthma study-Karachi

Background

This study was conducted in order to determine the prevalence of asthma and associated risk factors in the adult population of Karachi, Pakistan.

Methods

This multi-stage, cross-sectional survey was conducted from May 2014–August 2015; comprising 1629 adults in 75 randomly selected clusters in Karachi, Pakistan. Definitions included: ‘self-reported asthma’, ‘reversibility in FEV₁^’ and ‘respiratory symptoms and reversibility in FEV₁’.

Results

Prevalence of asthma was 1.8% (self-reported) (95% CI: 1.0–2.6), 11.3% (reversibility in FEV₁) (95% CI: 9.4–13.3) and 6.6% (symptoms and reversibility in FEV₁) (95% CI: 5.1–8.1). Asthmatics were more likely to belong to the age group ≥38?years according to ‘reversibility in FEV₁’ and ‘respiratory symptoms and reversibility in FEV₁’ (AOR: 1.9, 95% CI: 1.2–3.3) and (AOR: 2.1, 95% CI: 1.1–4.2), respectively. Asthmatics were more likely to report history of allergies (AOR: 1.9, 95% CI: 1.2–2.9) and (AOR: 2.8, 95% CI: 1.7–4.8); and were exposed to environmental tobacco smoke (AOR: 1.6, 95% CI: 1.1–2.5) and (AOR: 1.9, 95% CI: 1.1–3.3) according to ‘reversibility in FEV₁’ and ‘respiratory symptoms and reversibility in FEV₁’, respectively. Asthmatics were more likely to report pack years of smoking ≥5 (AOR: 2.3, 95% CI: 1.1–4.7) according to ‘respiratory symptoms and reversibility in FEV₁’.

Conclusion

This study reports a high prevalence of asthma among Pakistani adults and calls for developing appropriate public health policies for prevention and control of asthma in the country. Further studies should be conducted to determine the national prevalence as well as follow-up studies to identify preventable causes for adult asthma.

     

Pulmonary function,exhaled nitric oxide and symptoms in asthma patients with obesity: a cross-sectional study

Background

Obesity is a risk factor for the development of asthma. In patients with obesity the diagnosis of asthma is often based on symptoms, but without objective measurements. Nevertheless, obesity-associated asthma is recognized as a distinct asthma phenotype. Therefore, this study explores lung function and symptoms in asthma patients with and without obesity.

Methods

The Netherlands Epidemiology of Obesity (NEO) study is a population-based cohort study with 6671 participants (aged 45–65 years) of whom 472 had asthma. Of this latter group, linear regression analysis was used to examine differences in lung function and symptoms between asthma patients with (n?=?248) and without obesity (n?=?224), and between asthma patients with and without increased Fe_NO. Analyses were adjusted for confounders.

Results

Asthma patients with obesity had lower predicted FEV₁ and FVC values than patients without obesity [adjusted mean difference (MD) -3.3% predicted, 95% CI -6.5, ?0.2; adjusted MD ?5.0% predicted, 95% CI -7.8, ?2.1]. The prevalence of symptoms was higher in patients with obesity. Asthma patients with obesity and with increased Fe_NO had lower FEV₁ and FEV₁/FVC values compared with those with low Fe_NO (adjusted MD ?6.9% predicted, 95% CI -11.7, ?2.0; ?2.4%, 95% CI -4.6, ?0.2).

Conclusion

Asthma patients with obesity had lower FEV₁ and FVC values than patients without obesity. This suggests that patients with obesity have restrictive lung function changes, rather than obstructive changes. Asthma patients with obesity and increased Fe_NO showed more obstructive changes. Fe_NO might help to identify patients with eosinophilic inflammation-driven asthma, whereas patients with low Fe_NO might have an obesity-associated asthma phenotype in which symptoms are partly caused by the obesity.

     

Prediction of BOS by the single-breath nitrogen test in double lung transplant recipients

Background

The present study analyses the ability of the alveolar slope of the single-breath nitrogen washout test (N₂-slope) to diagnose and predict the development of the bronchiolitis obliterans syndrome (BOS).

Methods

We present a retrospective analysis of 61 consecutive bilateral lung or heart-lung transplant recipients who were followed at regular control visits during a three year follow-up. The operating characteristics of the N₂-slope to diagnose BOS and potential BOS (BOS 0-p) and to predict BOS were determined based on cut off values of 95% specificity.

Results

The sensitivity of the N₂-slope to identify BOS was 96%, and BOS 0-p 100%. The predictive ability to predict BOS with a N₂-slope > 478% of the predicted normal was 56%, and if combined with a coincident FEV₁ < 90% of the basal value, the predictive ability was 75%.

Conclusions

The predictive ability of either the N₂-slope or of FEV₁ to diagnose BOS is limited but the combination of the two appears useful. Follow-up protocols of bilateral lung and heart-lung transplant recipients should consider including tests sensitive to obstruction of the peripheral airways.

     

Cytotoxic lymphocytes in COPD airways: increased NK cells associated with disease,iNKT and NKT-like cells with current smoking

Background

Cytotoxic lymphocytes are increased in the airways of COPD patients. Whether this increase is driven primarily by the disease or by smoking is not clear, nor whether it correlates with the rate of decline in lung function.

Methods

Bronchoscopy with BAL was performed in 52 subjects recruited from the longitudinal OLIN COPD study according to pre-determined criteria; 12 with COPD and a rapid decline in lung function (loss of FEV₁?≥?60?ml/year), 10 with COPD and a non-rapid decline in lung function (loss of FEV₁?≤?30?ml/year), 15 current and ex-smokers and 15 non-smokers with normal lung function. BAL lymphocyte subsets were determined using flow cytometry.

Results

In BAL fluid, the proportions of NK, iNKT and NKT-like cells all increased with pack-years. Within the COPD group, NK cells – but not iNKT or NKT-like cells – were significantly elevated also in subjects that had quit smoking. In contrast, current smoking was associated with a marked increase in iNKT and NKT-like cells but not in NK cells. Rate of lung function decline did not significantly affect any of the results.

Conclusions

In summary, increased proportions of NK cells in BAL fluid were associated with COPD; iNKT and NKT-like cells with current smoking but not with COPD. Interestingly, NK cell percentages did not normalize in COPD subjects that had quit smoking, indicating that these cells might play a role in the continued disease progression seen in COPD even after smoking cessation.

Trial registration

Clinicaltrials.gov identifier NCT02729220.

     

Automated computed tomographic scoring of lung disease in adults with primary ciliary dyskinesia

Background

The present study aimed to develop an automated computed tomography (CT) score based on the CT quantification of high-attenuating lung structures, in order to provide a quantitative assessment of lung structural abnormalities in patients with Primary Ciliary Dyskinesia (PCD).

Methods

Adult (≥18?years) PCD patients who underwent both chest CT and spirometry within a 6-month period were retrospectively included. Commercially available lung segmentation software was used to isolate the lungs from the mediastinum and chest wall and obtain histograms of lung density. CT-density scores were calculated using fixed and adapted thresholds based on various combinations of histogram characteristics, such as mean lung density (MLD), skewness, and standard deviation (SD). Additionally, visual scoring using the Bhalla score was performed by 2 independent radiologists. Correlations between CT scores, forced expiratory volume in 1?s (FEV₁) and forced vital capacity (FVC) were evaluated.

Results

Sixty-two adult patients with PCD were included. Of all histogram characteristics, those showing good positive or negative correlations to both FEV₁ and FVC were SD (R?=???0.63 and???0.67; p?<?0.001) and Skewness (R?=?0.67 and 0.67; p?<?0.001). Among all evaluated thresholds, the CT-density score based on MLD?+?1SD provided the best negative correlation with both FEV₁ (R?=???0.68; p?<?0.001) and FVC (R?=???0.71; p?<?0.001), close to the correlations of the visual score (R?=???0.60; p?<?0.001 for FEV₁ and R?=???0.62; p?<?0.001, for FVC).

Conclusions

Automated CT scoring of lung structural abnormalities lung in primary ciliary dyskinesia is feasible and may prove useful for evaluation of disease severity in the clinic and in clinical trials.

     

Monitoring of pre-frontal oxygen status in helicopter pilots using near-infrared spectrophotometers

Background

There are few in-flight studies of cognition-related cerebral oxygen status in helicopter pilots.

Methods

Four male helicopter pilots volunteered for nine sorties during visual flight in a BK117 and UH-60J. The pilots' pre-frontal oxy-hemoglobin (O₂Hb) and deoxy-hemoglobin (HHb) concentration were continuously monitored from the right/left sections of the forehead using near-infrared spectrophotometers with a consideration of motion artifacts.

Results

The concentration of O₂Hb progressively increased (13.98 μmol?L^-1 as a maximum increased concentration) in both the right/left sections of the forehead from the basal level during the heightened cognitive demand of helicopter flight. There was comparatively little change (4.32 μmol?L^-1 as a maximum increased concentration) in HHb concentration during measurement of helicopter flight. HHb changes were apparently not affected by a heightened cognitive demand of helicopter pilots.

Conclusion

These results demonstrate that near-infrared spectroscopy, especially O₂Hb measurements, provides a sensitive method for the monitoring of cognitive demand (maneuvers) in helicopter pilots.

     

Low incidence of pneumonia in COPD patients treated with inhaled corticosteroids undergoing pulmonary rehabilitation

Background

Based on meta-analyses results, it is currently acknowledged that there is an increased risk of pneumonia in patients with chronic obstructive pulmonary disease (COPD) undergoing inhaled corticosteroids (ICS) treatment. However, this is not found to be true in those with asthma. No data on this risk are available for COPD patients involved in pulmonary rehabilitation program (PR).

Methods

For 1 year, we prospectively studied 2 cohorts of COPD patients—undergoing PR and not undergoing PR. The first group included 438 patients undergoing PR of which 353 were treated with ICS, and 85 were treated with bronchodilators only. The second group was comprised of 76 COPD patients who were treated with ICS, but not PR. The control group consisted of 49 ICS-treated patients with asthma. The diagnosis of pneumonia, when suspected, had to be confirmed with a chest x-ray.

Results

Overall, 6 cases of pneumonia were diagnosed in the first study group: 5 ICS-treated patients and 1 patient treated only with bronchodilators. This corresponded to a rate of 1.41 and 1.17%, respectively, compared to a rate of 6.6% in COPD patients not treated with PR, which was significantly higher (p?=?0.029) than that in the first study group. No case of pneumonia was registered among patients with asthma.

Conclusions

These findings suggest that a significantly lower incidence of pneumonia is found in COPD patients treated with ICS and PR than in patients treated with ICS but not with PR. This observation deserves to be investigated in large populations of PR-treated COPD patients, possibly in multi-centric cohort studies.

     

Optimization of fecal sample preparation for untargeted LC-HRMS based metabolomics

Introduction

Collecting feces is easy. It offers direct outcome to endogenous and microbial metabolites.

Objectives

In a context of lack of consensus about fecal sample preparation, especially in animal species, we developed a robust protocol allowing untargeted LC-HRMS fingerprinting.

Methods

The conditions of extraction (quantity, preparation, solvents, dilutions) were investigated in bovine feces.

Results

A rapid and simple protocol involving feces extraction with methanol (1/3, M/V) followed by centrifugation and a step filtration (10 kDa) was developed.

Conclusion

The workflow generated repeatable and informative fingerprints for robust metabolome characterization.

     

Roflumilast attenuates allergen-induced inflammation in mild asthmatic subjects

Background

Phosphodiesterase 4 (PDE4) inhibitors increase intracellular cyclic adenosine monophosphate (cAMP), leading to regulation of inflammatory cell functions. Roflumilast is a potent and targeted PDE4 inhibitor. The objective of this study was to evaluate the effects of roflumilast on bronchoconstriction, airway hyperresponsiveness (AHR), and airway inflammation in mild asthmatic patients undergoing allergen inhalation challenge.

Methods

25 subjects with mild allergic asthma were randomized to oral roflumilast 500 mcg or placebo, once daily for 14 days in a double-blind, placebo-controlled, crossover study. Allergen challenge was performed on Day 14, and FEV₁ was measured until 7 h post challenge. Methacholine challenge was performed on Days 1 (pre-dose), 13 (24 h pre-allergen), and 15 (24 h post-allergen), and sputum induction was performed on Days 1, 13, 14 (7 h post-allergen), and 15.

Results

Roflumilast inhibited the allergen-induced late phase response compared to placebo; maximum % fall in FEV₁ (p = 0.02) and the area under the curve (p = 0.01). Roflumilast had a more impressive effect inhibiting allergen-induced sputum eosinophils, neutrophils, and eosinophil cationic protein (ECP) at 7 h post-allergen (all p = 0.02), and sputum neutrophils (p = 0.04), ECP (p = 0.02), neutrophil elastase (p = 0.0001) and AHR (p = 0.004) at 24 h post-allergen.

Conclusions

This study demonstrates a protective effect of roflumilast on allergen-induced airway inflammation. The observed attenuation of sputum eosinophils and neutrophils demonstrates the anti-inflammatory properties of PDE4 inhibition and supports the roles of both cell types in the development of late phase bronchoconstriction and AHR.

Trial Registration

ClinicalTrials.gov: NCT01365533

     

Centrilobular emphysema and coronary artery calcification: mediation analysis in the SPIROMICS cohort

Background

Chronic obstructive pulmonary disease (COPD) is associated with a two-to-five fold increase in the risk of coronary artery disease independent of shared risk factors. This association is hypothesized to be mediated by systemic inflammation but this link has not been established.

Methods

We included 300 participants enrolled in the SPIROMICS cohort, 75 each of lifetime non-smokers, smokers without airflow obstruction, mild-moderate COPD, and severe-very severe COPD. We quantified emphysema and airway disease on computed tomography, characterized visual emphysema subtypes (centrilobular and paraseptal) and airway disease, and used the Weston visual score to quantify coronary artery calcification (CAC). We used the Sobel test to determine whether markers of systemic inflammation mediated a link between spirometric and radiographic features of COPD and CAC.

Results

FEV₁/FVC but not quantitative emphysema or airway wall thickening was associated with CAC (p?=?0.036), after adjustment for demographics, diabetes mellitus, hypertension, statin use, and CT scanner type. To explain this discordance, we examined visual subtypes of emphysema and airway disease, and found that centrilobular emphysema but not paraseptal emphysema or bronchial thickening was independently associated with CAC (p?=?0.019). MMP3, VCAM1, CXCL5 and CXCL9 mediated 8, 8, 7 and 16% of the association between FEV₁/FVC and CAC, respectively. Similar biomarkers partially mediated the association between centrilobular emphysema and CAC.

Conclusions

The association between airflow obstruction and coronary calcification is driven primarily by the centrilobular subtype of emphysema, and is linked through bioactive molecules implicated in the pathogenesis of atherosclerosis.

Trial Registration

ClinicalTrials.gov: Identifier: NCT01969344.

     

A lost opportunity for science: journals promote data sharing in metabolomics but do not enforce it

Introduction

Data sharing is being increasingly required by journals and has been heralded as a solution to the ‘replication crisis’.

Objectives

(i) Review data sharing policies of journals publishing the most metabolomics papers associated with open data and (ii) compare these journals’ policies to those that publish the most metabolomics papers.

Methods

A PubMed search was used to identify metabolomics papers. Metabolomics data repositories were manually searched for linked publications.

Results

Journals that support data sharing are not necessarily those with the most papers associated to open metabolomics data.

Conclusion

Further efforts are required to improve data sharing in metabolomics.

     

Lung hyperinflation and functional exercise capacity in patients with COPD – a three-year longitudinal study

Background

Lung hyperinflation contributes to dyspnea, morbidity and mortality in chronic obstructive pulmonary disease (COPD). The inspiratory-to-total lung capacity (IC/TLC) ratio is a measure of lung hyperinflation and is associated with exercise intolerance. However, knowledge of its effect on longitudinal change in the 6-min walk distance (6MWD) in patients with COPD is scarce. We aimed to study whether the IC/TLC ratio predicts longitudinal change in 6MWD in patients with COPD.

Methods

This prospective cohort study included 389 patients aged 40–75?years with clinically stable COPD in Global Initiative for Chronic Obstructive Lung Disease stages II-IV. The 6MWD was measured at baseline, and after one and 3 years. We performed generalized estimating equation regression analyses to examine predictors for longitudinal change in 6MWD. Predictors at baseline were: IC/TLC ratio, age, gender, pack years, fat mass index (FMI), fat-free mass index (FFMI), number of exacerbations within 12?months prior to inclusion, Charlson index for comorbidities, forced vital capacity (FVC), forced expiratory volume in 1?s (FEV₁), and light and hard self-reported physical activity.

Results

Reduced IC/TLC ratio (p?<?0.001) was a statistically significant predictor for decline in 6MWD. With a 0.1-unit decrease in baseline IC/TLC ratio, the annual decline in 6MWD was 12.7?m (p?<?0.001). Study participants with an IC/TLC ratio in the upper quartiles maintained their 6MWD from baseline to year 3, while it was significantly reduced for the patients with an IC/TLC ratio in the lower quartiles. Absence of light and hard physical activity, increased age and FMI, decreased FEV₁ and FVC, more frequent exacerbations and higher Charlson comorbidity index were also predictors for lower 6MWD at any given time, but did not predict higher rate of decline over the timespan of the study.

Conclusion

Our findings demonstrated that patients with less lung hyperinflation at baseline maintained their functional exercise capacity during the follow-up period, and that it was significantly reduced for patients with increased lung hyperinflation.

     

The effect of changes to GOLD severity stage on long term morbidity and mortality in COPD

Background

The Global Initiative for Chronic Obstructive Lung Disease (GOLD) severity stage classifies Chronic Obstructive Pulmonary Disease (COPD) into groups based on symptoms, exacerbations and forced expiratory volume in one second (FEV₁). This allows patients to change to less severe COPD stages, a novel aspect of assessment not previously evaluated. We aimed to investigate the association between temporal changes in GOLD severity stage and outcomes in COPD patients.

Methods

This was a record-linkage study using patients registered with a Scottish regional COPD network 2000–2015. Annual spirometry & symptoms were recorded and linked to healthcare records to identify exacerbations, hospitalisations and mortality. Spirometry, modified Medical Research Council (mMRC) dyspnoea scale and acute exacerbations over the previous year were used to assign GOLD severity at each visit. A time-dependent Cox model was used to model time to death. Secondary outcomes were respiratory specific mortality and hospitalisations. Effect sizes are expressed as Hazard Ratios HR (95%CI).

Results

Four thousand, eight hundred and eighty-five patients (mean age 67.3?years; 51.3% female) with 21,348 visits were included. During a median 6.6?years follow-up there were 1530 deaths. For the secondary outcomes there were 712 respiratory deaths and 1629 first hospitalisations. Across 16,463 visit-pairs, improvement in COPD severity was seen in 2308 (14%), no change in 11,010 (66.9%) and worsening in 3145 (19.1). Compared to patients staying in GOLD stage A, those worsening had a stepwise increased mortality and hospitalisations.

Conclusions

Improving COPD severity classification was associated with reduced mortality and worsening COPD severity was associated with increased mortality and hospitalisations. Change in GOLD group has potential as monitoring tool and outcome measure in clinical trials.

     

Azithromycin versus placebo for the treatment of HIV-associated chronic lung disease in children and adolescents (BREATHE trial): study protocol for a randomised controlled trial

Background

Human immunodeficiency virus (HIV)-related chronic lung disease (CLD) among children is associated with substantial morbidity, despite antiretroviral therapy. This may be a consequence of repeated respiratory tract infections and/or dysregulated immune activation that accompanies HIV infection. Macrolides have anti-inflammatory and antimicrobial properties, and we hypothesised that azithromycin would reduce decline in lung function and morbidity through preventing respiratory tract infections and controlling systemic inflammation.

Methods/design

We are conducting a multicentre (Malawi and Zimbabwe), double-blind, randomised controlled trial of a 12-month course of weekly azithromycin versus placebo. The primary outcome is the mean change in forced expiratory volume in 1 second (FEV₁) z-score at 12 months. Participants are followed up to 18 months to explore the durability of effect. Secondary outcomes are FEV₁ z-score at 18 months, time to death, time to first acute respiratory exacerbation, number of exacerbations, number of hospitalisations, weight for age z-score at 12 and 18 months, number of adverse events, number of malaria episodes, number of bloodstream Salmonella typhi infections and number of gastroenteritis episodes. Participants will be followed up 3-monthly, and lung function will be assessed every 6 months. Laboratory substudies will be done to investigate the impact of azithromycin on systemic inflammation and on development of antimicrobial resistance as well as impact on the nasopharyngeal, lung and gut microbiome.

Discussion

The results of this trial will be of clinical relevance because there are no established guidelines on the treatment and management of HIV-associated CLD in children in sub-Saharan Africa, where 80% of the world’s HIV-infected children live and where HIV-associated CLD is highly prevalent.

Trial registration

ClinicalTrials.gov, NCT02426112. Registered on 21 April 2015.

     

Clinical expression of cystic fibrosis in a large cohort of Italian siblings

Background

A clinical heterogeneity was reported in patients with Cystic Fibrosis (CF) with the same CFTR genotype and between siblings with CF.

Methods

We investigated all clinical aspects in a cohort of 101 pairs of siblings with CF (including 6 triplets) followed since diagnosis.

Results

Severe lung disease had a 22.2% concordance in sib-pairs, occurred early and the FEV₁% at 12?years was predictive of the severity of lung disease in the adulthood. Similarly, CF liver disease occurred early (median: 15?years) and showed a concordance of 27.8% in sib-pairs suggesting a scarce contribution of genetic factors; in fact, only 2/15 patients with liver disease in discordant sib-pairs had a deficiency of alpha-1-antitrypsin (a known modifier gene of CF liver phenotype). CF related diabetes was found in 22 pairs (in 6 in both the siblings). It occurred later (median: 32.5?years) and is strongly associated with liver disease. Colonization by P. aeruginosa and nasal polyposis that required surgery had a concordance >?50% in sib-pairs and were poorly correlated to other clinical parameters. The pancreatic status was highly concordant in pairs of siblings (i.e., 95.1%) but a different pancreatic status was observed in patients with the same CFTR mutations. This suggests a close relationship of the pancreatic status with the “whole” CFTR genotype, including mutations in regulatory regions that may modulate the levels of CFTR expression. Finally, a severe course of CF was evident in a number of patients with pancreatic sufficiency.

Conclusions

Physicians involved in care of patients with CF and in genetic counseling must be aware of the clinical heterogeneity of CF even in sib-pairs that, at the state of the art, is difficult to explain.

     

Pseudo current density maps of electrophysiological heart,nerve or brain function and their physical basis

Background

In recent years the visualization of biomagnetic measurement data by so-called pseudo current density maps or Hosaka-Cohen (HC) transformations became popular.

Methods

The physical basis of these intuitive maps is clarified by means of analytically solvable problems.

Results

Examples in magnetocardiography, magnetoencephalography and magnetoneurography demonstrate the usefulness of this method.

Conclusion

Hardware realizations of the HC-transformation and some similar transformations are discussed which could advantageously support cross-platform comparability of biomagnetic measurements.

     

Untargeted metabolomics suffers from incomplete raw data processing

Introduction

Untargeted metabolomics is a powerful tool for biological discoveries. To analyze the complex raw data, significant advances in computational approaches have been made, yet it is not clear how exhaustive and reliable the data analysis results are.

Objectives

Assessment of the quality of raw data processing in untargeted metabolomics.

Methods

Five published untargeted metabolomics studies, were reanalyzed.

Results

Omissions of at least 50 relevant compounds from the original results as well as examples of representative mistakes were reported for each study.

Conclusion

Incomplete raw data processing shows unexplored potential of current and legacy data.

     

Extraction of natural products from bark of <Emphasis Type="Italic">Betula pendula</Emphasis> using ionic liquids

Introduction

Aqueous–methanol mixtures have successfully been applied to extract a broad range of metabolites from plant tissue. However, a certain amount of material remains insoluble.

Objectives

To enlarge the metabolic compendium, two ionic liquids were selected to extract the methanol insoluble part of trunk from Betula pendula.

Methods

The extracted compounds were analyzed by LC/MS and GC/MS.

Results

The results show that 1-butyl-3-methylimidazolium acetate (IL-Ac) predominantly resulted in fatty acids, whereas 1-ethyl-3-methylimidazolium tosylate (IL-Tos) mostly yielded phenolic structures. Interestingly, bark yielded more ionic liquid soluble metabolites compared to interior wood.

Conclusion

From this one can conclude that the application of ionic liquids may expand the metabolic snapshot.

     

Metabolomic profiling of maternal hair suggests rapid development of intrahepatic cholestasis of pregnancy

Introduction

Intrahepatic cholestasis of pregnancy (ICP) is a common maternal liver disease; development can result in devastating consequences, including sudden fetal death and stillbirth. Currently, recognition of ICP only occurs following onset of clinical symptoms.

Objective

Investigate the maternal hair metabolome for predictive biomarkers of ICP.

Methods

The maternal hair metabolome (gestational age of sampling between 17 and 41 weeks) of 38 Chinese women with ICP and 46 pregnant controls was analysed using gas chromatography–mass spectrometry.

Results

Of 105 metabolites detected in hair, none were significantly associated with ICP.

Conclusion

Hair samples represent accumulative environmental exposure over time. Samples collected at the onset of ICP did not reveal any metabolic shifts, suggesting rapid development of the disease.