High-Altitude Climate Therapy Reduces Local Airway Inflammation and Modulates Lymphocyte Activation

An unusually high prevalence of allergic rhinitis at high altitudes in 6-7 year old children - An epidemiological study

Objectives

To compare the epidemiology and disease patterns of allergic rhinitis (AR) at 2 different altitudes in children aged 6-7 years, and subsequently to compare with and augment data from international studies.

Materials and methods

This is a multistage, clustered and stratified random sample study. The study area comprises 2 distinct areas within Yunnan Province, China. Low altitude was represented by Xishuangbanna Prefecture (XB), while high altitude was represented by Diqing Prefecture (DiQ). Each study area was subdivided into 3 sub-areas, and children aged 6-7 years were randomly sampled based on proportion-weighted sampling. The area studied includes the well-known area of Shangri-La city. Questionnaires were distributed and jointly completed by study participants and their parents or guardians, under the guidance of professional medical staff.

Results

2796 valid questionnaires out of 2933 distributed were obtained (survey response rate 95.3%). The prevalence of AR is statistically significantly higher at high altitude (DiQ, 36.0%, 95%CI 33.2-38.8) as compared to low altitude (XB, 19.7%, 95%CI 17.8-21.6) (p < 0.001). Both areas studied had a greater prevalence of AR compared to international data. In both XB and DiQ, male gender, history of early antibiotic use, urban place of birth and place of residence, presence of smokers within the same household, family history of allergic diseases (such as atopic dermatitis), as well as higher parental educational level were all associated with a higher prevalence of AR (p < 0.05). In DiQ, the prevalence of AR in Han ethnicity was greater than that of ethnic minorities (p < 0.05). In XB, being a single child was associated with an increased prevalence of AR compared to those who had siblings (p < 0.05).

Conclusion

Our study found that the prevalence of AR is relatively greater at higher altitudes. Genetic and environmental factors both play an important role in the pathogenesis of AR. While altitude may be an important environmental factor, confounding factors may include humidity, temperature and distribution pattern of common aeroallergens.

Association between individual sensor behavior of an electronic nose and airways inflammation in children with asthma: a pilot study at alpine altitude climate

BACKGROUND

Markers of airway inflammation can be helpful in the management of childhood asthma. Residential activities, such as intensive asthma camps at alpine altitude climate (AAC), can help reduce bronchial inflammation in patients who fail to achieve optimal control of the disease. Analysis of volatile organic compounds (VOCs) can be obtained using electronic devices such as e-Noses. We aimed to identify alterations in urinary e-Nose sensors among children with asthma participating in an intensive camp at AAC and to investigate associations between urinary e-Nose analysis and airway inflammation.

METHODS

We analyzed data collected in children with asthma recruited between July and September 2020. All children were born and resided at altitudes below 600 m asl. Urinary VOCs (measured using the Cyranose 320® VOC analyzer), Fractional exhaled Nitric Oxide (FeNO) and spirometry were evaluated upon children's arrival at the Istituto Pio XII, Misurina (BL), Italy, at 1756 m asl (T0), and after 7 (T1) and 15 days (T2) of stay.

RESULTS

Twenty-two patients (68.2% males; median age: 14.5 years) were enrolled. From T0 to T1 and T2, the negative trend for FeNO was significant (p < .001). Significant associations were observed between e-Nose sensors S7 (p = .002), S12 (p = .013), S16 (p = .027), S17 (p = .017), S22 (p = .029), S29 (p = .021), S31 (p = .009) and ΔFeNO at T0-T1. ΔFeNO at T0-T2 was significantly associated with S17 (p = .015), S19 (p = .004), S21 (p = .020), S24 (p = .012), S25 (p = .018), S26 (p = .008), S27 (p = .002), S29 (p = .007), S30 (p = .013).

CONCLUSIONS

We showed that a decrease in FeNO levels after a short sojourn at AAC is associated with behaviors of individual urinary e-Nose sensors in children with asthma.

Chronic developmental hypoxia alters rat lung immune cell transcriptomes during allergic airway inflammation

Populations that are born and raised at high altitude develop under conditions of chronic developmental hypoxia (CDH), which results in pulmonary adaptations of increased lung volume and diffusion capacity to increase gas exchange. It is not clear how CDH may alter allergic inflammation in the lung. In this study, we sought to characterize the impact of CDH on immune cell populations in the rat lung during a murine model of asthma. Rats were bred and raised in either hypoxic (15% oxygen, CDH) or normobaric room air (20% oxygen). At 3-weeks of age, animals were sensitized to ovalbumin (OVA) or physiologic saline (phosphate-buffered saline [PBS]) as a control, followed by three consecutive days of intra-nasal OVA or PBS at 6-weeks of age. We then assessed airway reactivity and allergic-associated cytokine levels. This was followed by single-cell transcriptomic profiling of lung cell populations. In scRNA-seq analysis, we assessed differentially expressed genes, differentially enriched functional pathways, immune cell exhaustion/activation markers, and immune cell secretory products. Our results show that while OVA heightened airway reactivity, CDH suppressed airway reactivity in OVA-challenged and control animals. Through scRNA-seq analysis, we further demonstrate that CDH alters the transcriptional landscape in the lung and alters transcriptional programs in immune cells. These data define CDH-dependent changes in the lung that impact airway reactivity.

Identification of Suitable Reference Genes for Lowlanders Exposed to High Altitude and Ladakhi Highlanders

Sharma, Vandana, Rajeev Varshney, and Niroj Kumar Sethy. Identification of suitable reference genes for lowlanders exposed to high altitude and Ladakhi highlanders. High Alt Med Biol. 23:319-329, 2022. Background: Identifying a stable and reliable reference gene (RG) is a prerequisite for the unbiased and unambiguous analysis of gene expression data. It has become evident that conventionally used housekeeping genes such as beta-actin (ACTB), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and peptidylprolyl Isomerase A (PPIA) exhibit varied expression patterns under hypoxia. Hence, the identification of stable RGs for humans exposed to hypobaric hypoxia can enhance the accuracy of gene expression studies by limiting the negligent use of random housekeeping genes. Methods: Using TaqMan™ array-based quantitative real-time quantitative polymerase chain reaction, we evaluated the expression of 32 commonly used human RGs among lowlanders at Delhi (altitude 216 m, SL), lowlanders at Leh (altitude 3,524 m) after 1 day (HA-D1) and 7 days (HA-D7), as well as indigenous Ladakhi highlanders at the same altitude. The expression stability of the RGs was evaluated using geNorm, NormFinder, BestKeeper, Delta CT method, and RefFinder algorithms. Results: Our studies identify TATA-box binding protein (TBP), proteasome 26S subunit, ATPase 4 (PSMC4), and tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein zeta (YWHAZ) as the most stable human RGs for normalizing human gene expression under hypobaric hypoxia. In addition, we report the combination of TBP and cyclin-dependent kinase inhibitor 1B (CDKN1B) as the most stable RG for studying lowlander gene expression during high-altitude exposure. In contrast, RPL30 and 18S exhibited maximum variation across study groups and were identified as the least stable RGs.

Healthy worker survival effect at a high-altitude mine: prospective cohort observation

Very little is known about the factors of healthy worker survival effect at high-altitude mines. We conducted this cohort observation of the new hires for a high-altitude gold mine in Kyrgyzstan with the aim to ascertain predictors of survival at work. All new hires in 2009 through 2012 for a high-altitude gold mine (3600–4500 m above sea level) were followed up to January 2022. We tested the association of demographic, physiological predictors and diagnoses at the pre-employment screening with non-survival at work in Cox proportional hazards yielding hazard ratios (HR) with their 95% confidence intervals (CI). The cumulative observation time was 5190 person-years. Blood pressure at pre-employment, lung function, the diagnoses of essential hypertension, chronic obstructive pulmonary disease (COPD) or any other analyzed physiological variables were not associated with non-survival at work. However, smoking (HR 1.55; 95% CI 1.10; 2.17) increased the likelihood of non-survival at work, independent of any diagnosis or lowland residence (HR 1.95; 95% CI 1.31; 2.90). Adjusted for covariates and all diagnoses, having chronic rheumatic fever (HR 10.95; 95% CI 2.92; 33.92), hemorrhoids (HR 1.32; 95% CI 1.01; 3.75), adhesive otitis (HR 1.74; 95% CI 1.05; 2.89) or obesity (HR 1.71; 95% CI 1.01; 2.88) were associated with non-survival at work with time. This prospective observation of new hires for a high-altitude mining operation demonstrated that selected diagnoses, smoking and lowland residence elevated the risk of early exit in prospective workers.

Low oxygen levels decrease adaptive immune responses and ameliorate experimental asthma in mice

BACKGROUND

High-altitude therapy has been used as add-on treatment for allergic asthma with considerable success. However, the underlying mechanisms remain unclear. In order to investigate the possible therapeutic effects of high-altitude therapy on allergic asthma, we utilized a new in vivo mouse model.

METHODS

Mice were treated with house dust mite (HDM) extract over 4 weeks and co-exposed to 10% oxygen (Hyp) or room air for the final 2 weeks. Experimental asthma was assessed by airway hyper-responsiveness, mucus hypersecretion and inflammatory cell recruitment. Isolated immune cells from mouse and allergic patients were stimulated in vitro with HDM under Hyp and normoxia in different co-culture systems to analyse the adaptive immune response.

RESULTS

Compared to HDM-treated mice in room air, HDM-treated Hyp-mice displayed ameliorated mucosal hypersecretion and airway hyper-responsiveness. The attenuated asthma phenotype was associated with strongly reduced activation of antigen-presenting cells (APCs), effector cell infiltration and cytokine secretion. In vitro, hypoxia almost completely suppressed the HDM-induced adaptive immune response in both mouse and human immune cells. While hypoxia did not affect effector T-cell responses per-se, it interfered with antigen-presenting cell (APC) differentiation and APC/effector cell crosstalk.

CONCLUSIONS

Hypoxia-induced reduction in the Th2-response to HDM ameliorates allergic asthma in vivo. Hypoxia interferes with APC/T-cell crosstalk and confers an unresponsive phenotype to APCs.

Alpine altitude climate treatment for severe and uncontrolled asthma: An EAACI position paper

Currently available European Alpine Altitude Climate Treatment (AACT) programs combine the physical characteristics of altitude with the avoidance of environmental triggers in the alpine climate and a personalized multidisciplinary pulmonary rehabilitation approach. The reduced barometric pressure, oxygen pressure, and air density, the relatively low temperature and humidity, and the increased UV radiation at moderate altitude induce several physiological and immunological adaptation responses. The environmental characteristics of the alpine climate include reduced aeroallergens such as house dust mites (HDM), pollen, fungi, and less air pollution. These combined factors seem to have immunomodulatory effects controlling pathogenic inflammatory responses and favoring less neuro‐immune stress in patients with different asthma phenotypes. The extensive multidisciplinary treatment program may further contribute to the observed clinical improvement by AACT in asthma control and quality of life, fewer exacerbations and hospitalizations, reduced need for oral corticosteroids (OCS), improved lung function, decreased airway hyperresponsiveness (AHR), improved exercise tolerance, and improved sinonasal outcomes. Based on observational studies and expert opinion, AACT represents a valuable therapy for those patients irrespective of their asthma phenotype, who cannot achieve optimal control of their complex condition despite all the advances in medical science and treatment according to guidelines, and therefore run the risk of falling into a downward spiral of loss of physical and mental health. In the light of the observed rapid decrease in inflammation and immunomodulatory effects, AACT can be considered as a natural treatment that targets biological pathways.

Secondary and Tertiary Prevention: Medical Rehabilitation

Allergies are a major public health burden, and targeted measures are required in terms of prevention and treatment. The most common allergic conditions encompass atopic dermatitis (AD), food allergy (FA), allergic asthma (AA), and allergic rhino-conjunctivitis (AR). Primary prevention aims at preventing the onset of allergic disease, before the disease process begins. Secondary prevention aims at preventing progression and exacerbation of allergic disease whereas tertiary prevention aims at reducing disease burden in patients with established disease, by allergen immunotherapy (AIT) or medical rehabilitation. Rehabilitation programs are used for treatment of AA and AD and usually consist of extensive patient assessment, optimization of treatment management, patient education, and behavioral interventions, ideally involving a multidisciplinary treatment team and sometimes provided in a specific climate, usually alpine or maritime. Similarly, prevention of occupational skin diseases requires interdisciplinary approaches on the level of secondary and tertiary preventive intervention; if this is provided, then prevention programs have proven highly (cost-) effective. Unfortunately, the recently published Minimal Standards of Prevention of these dermatoses, underlining especially the importance of meticulous allergological diagnosis and subsequent multidisciplinary patient education, are so far being adhered to only in very few European countries.

Waterfall Forest Environment Regulates Chronic Stress via the NOX4/ROS/NF-κB Signaling Pathway

Background: Forest therapy has been proven to have beneficial effects on people with depression and anxiety. However, it remains unknown whether the waterfall forest environment (WF) affects the physical and psychological health of patients with chronic fatigue and how the WF regulates chronic stress.

Methods: Twenty-four patients with chronic fatigue were randomly divided into two groups: the WF group and the urban (U) group. Scores on the Hamilton Anxiety Scale (HAMA), Hamilton Depression Scale (HAMD), and Fatigue Scale-14 (FS-14) were evaluated before and after environmental intervention. Detection of physiological indexes and inflammatory factor levels and immunological analysis were also performed. In addition, the chronic stress rat model was constructed, and the effects of the WF on hopelessness and liver damage of rats were investigated.

Results: Patients with chronic fatigue in the WF group showed a significant decrease in FS-14, HAMA, and HAMD scores compared with the U group. The expression levels of glutathione peroxidase and superoxide dismutase were remarkably higher in the WF group than in the U group. However, the expression levels of malondialdehyde and inflammatory factors (IL-1β, TNF-α, IL-6, and IL-10) were remarkably decreased after the intervention of the WF. In addition, animal experiments confirmed that the WF improved hopelessness, liver damage, and excitability of neurons of chronic stress rats. Mechanistically, the WF reduced the liver damage caused by chronic stress in rats by inhibiting the NOX4/ROS/NF-κB signaling pathway.

Conclusions: Collectively, the WF had a positive effect on immune enhancement and physical and psychological health in patients with chronic fatigue and might inhibit chronic stress by regulating the NOX4/ROS/NF-κB signaling pathway.

Effectiveness of pulmonary rehabilitation at high-altitude compared to sea-level in adults with severe refractory asthma

BACKGROUND

Beneficial effects of pulmonary rehabilitation at high-altitude (HAPR) in patients with severe refractory asthma have been reported earlier, but evidence for the effectiveness is limited.

AIM

To investigate the effectiveness of high-altitude pulmonary rehabilitation to comparable treatment at sea-level (LAPR) on patient outcome parameters.

METHODS

Adults with severe refractory asthma living in The Netherlands were included. Treatment consisted of a 12-week personalized multidisciplinary rehabilitation program either at high-altitude (Davos Switzerland) (n = 93) or in a tertiary lung center at sea-level in The Netherlands (n = 45). At baseline, after treatment, and during 12 months follow-up asthma related quality of life (AQLQ), asthma control (ACQ), pulmonary function and OCS-dose were assessed. Patients could not be randomized resulting in different asthma populations. Groups were compared using linear regression analysis (ANCOVA) adjusted for baseline values, in addition to age, atopy, smoking history, BMI and gender.

RESULTS

After treatment, and at 12 months follow-up, improved AQLQ(0.92,p < 0.001 and 0.82,p = 0.001, respectively), ACQ(-0.87,p < 0.001 and -0.69,p = 0.008, respectively) and lower maintenance OCS dose (Unadjusted linear regression analysis-5.29 mg, p = 0.003 and Crude Odds Ratio-1.67, p = 0.003, respectively) were observed in the HAPR-group compared to the LAPR group. Patients receiving HAPR also had less asthma exacerbations (≥1 exacerbation: 20% vs 60%,p < 0.001) and showed improvement in lung function (%predFEV₁ 3.4%,p = 0.014) compared to the LAPR group, but at 12 months no differences between groups were observed.

CONCLUSION

HAPR resulted in a larger improvement in patient outcome parameters compared to LAPR, on the long run the improvement in patient reported symptoms and lower maintenance OCS-dose persists. Underlying factors that explain this observed effect need to be investigated.

Asthma rehabilitation at high vs. low altitude and its impact on exhaled nitric oxide and sensitization patterns: Randomized parallel-group trial

BACKGROUND

Allergens and pollution are reduced at high altitude. We investigated the effect of asthma rehabilitation at high altitude (HA, 3100 m) compared to low altitude (LA, 760 m) on exhaled nitric oxide (FeNO) and on specific IgE levels for house dust mites (HDM,d1) and common pollen (sx1).

METHODS

For this randomized controlled trial adult asthmatics living <1000 m were randomly assigned to a 3-week in-hospital-rehabilitation (education, physical- and breathing-exercises) at either LA or HA. Changes in FeNO, d1 and sx1 from baseline to end-rehabilitation were measured.

RESULTS

50 asthmatics (34 females) were randomized [mean ± standard deviation LA: n = 25, 44 ± 11 years, total IgE 267 ± 365kU/l; HA: n = 25, 43 ± 13 years, total IgE 350 ± 445kU/l]. FeNO significantly improved at HA from 69 ± 56 ppb at baseline to the first day at altitude 23 ± 19 ppb and remained decreased until end-rehabilitation with 37 ± 23 ppb, mean difference 95%CI -31(-50 to -13, p = 0.001) whereas at LA FeNO did not change. A significant decrease in d1 and sx1 at end-rehabilitation was observed in the LA-group [mean difference 95%CI -10.2 kUA/l (-18.9 to -1.4) for d1 and -4.95 kUA/l(-9.69 to -0.21) for sx1] but not in the HA-group. No significant difference between groups [d1 5.9 kUA/l(-4.2 to 16.2) and sx1 4.4 kUA/l(-3.5 to 12.4)] was found.

CONCLUSION

Rehabilitation at HA led to significant FeNO reduction starting from the first day until end-rehabilitation despite unchanged levels of specific IgE. The significant decrease in d1 and sx1 at end-rehabilitation in the LA group might be explained by less HDM in the hospital and/or reduced seasonal pollen, as this decrease was not observed at HA.

Impact of high-altitude therapy on type-2 immune responses in asthma patients

BACKGROUND

Asthma patients present with distinct immunological profiles, with a predominance of type 2 endotype. The aim of this study was to investigate the impact of high-altitude treatment on the clinical and immunological response in asthma.

METHODS

Twenty-six hospitalized asthma patients (nine eosinophilic allergic; EA, nine noneosinophilic allergic; NEA and eight noneosinophilic nonallergic; NN) and nine healthy controls in high altitude for 21 days were enrolled in the study. We assessed eosinophils, T cells, Tregs, and innate lymphoid cells (ILC) from peripheral blood using flow cytometry.

RESULTS

The number of eosinophils (both resting and activated) and chemoattractant receptor homolog expressed on Th2 cells (CRTH2)-expressing CD4⁺ and CD8⁺ T cells decreased significantly in EA patients after altitude treatment. The frequency of CRTH2⁺ Tregs as decreased significantly in all the asthma phenotypes as well as the frequency of ILC2 was significantly reduced in EA after altitude treatment. After 21 days of altitude therapy, CRTH2-expressing ILC2, CD4⁺ and CD8⁺ T cells and Treg cells showed attenuated responses to exogenous PGD2. Furthermore, PGD2 signaling via CRTH2 was found to diminish the suppressive function of CRTH2⁺ Tregs which partially normalized during high-altitude treatment. Improved asthma control was particularly evident in allergic asthma patients and correlated with decreased frequencies of CRTH2⁺ Treg cells in EA patients. Serum IL-5 and IL-13 decreased during climate treatment in asthma patients with high baseline levels.

CONCLUSIONS

Asthma treatment in high altitude reduced the type 2 immune response, corrected the increased CRTH2 expression and its dysregulated functions.

Asthma rehabilitation at high vs. low altitude: randomized parallel-group trial

Background

To investigate the effect of asthma rehabilitation at high altitude (3100 m, HA) compared to low altitude (760 m, LA).

Methods

For this randomized parallel-group trial insufficiently controlled asthmatics (Asthma Control Questionnaire (ACQ) > 0.75) were randomly assigned to 3-week in-hospital rehabilitation comprising education, physical-&breathing-exercises at LA or HA. Co-primary outcomes assessed at 760 m were between group changes in peak expiratory flow (PEF)-variability, and ACQ) from baseline to end-rehabilitation and 3 months thereafter.

Results

50 asthmatics were randomized [median (quartiles) LA: ACQ 2.7(1.7;3.2), PEF-variability 19%(14;33); HA: ACQ 2.0(1.6;3.0), PEF-variability 17%(12;32)].

The LA-group improved PEF-variability by median(95%CI) -7%(− 14 to 0, p = 0.033), ACQ − 1.4(− 2.2 to − 0.9, p < 0.001), and after 3 months by − 3%(− 18 to 2, p = 0.103) and − 0.9(− 1.3 to − 0.3, p = 0.002). The HA-group improved PEF-variability by − 10%(− 21 to − 3, p = 0.004), ACQ − 1.1(− 1.3 to − 0.7, p < 0.001), and after 3 months by − 9%(− 10 to − 3, p = 0.003) and − 0.2(− 0.9 to 0.4, p = 0.177). The additive effect of HA vs. LA directly after the rehabilitation on PEF-variability was − 6%(− 14 to 2), on ACQ 0.3(− 0.4 to 1.1) and after 3 months − 5%(− 14 to 5) respectively 0.4(− 0.4 to 1.1), all p = NS.

Conclusion

Asthma rehabilitation is highly effective in improving asthma control in terms of PEF-variability and symptoms, both at LA and HA similarly.

Trial registration

Clinicaltrials.gov: NCT02741583, Registered April 18, 2016.

Electronic supplementary material

The online version of this article (10.1186/s12890-019-0890-y) contains supplementary material, which is available to authorized users.

Winter Exercise Reduces Allergic Airway Inflammation: A Randomized Controlled Study

Background: Physical exercise is often recommended as additional treatment for people suffering from allergic rhinitis and/or asthma, but less is known about the specific effects of recreational winter outdoor exercise on allergic airway inflammation. Methods: We performed a longitudinal, randomized controlled intervention study to investigate the effects of recreational winter exercise on allergic airway inflammation, quality of life, spirometry and cardiorespiratory fitness in adults suffering from allergic rhinitis and/or asthma. The exercise group participated in a ten-day winter sports program. The control group did not receive any intervention. Results: A significant improvement of fractional oral exhaled nitric oxide (FeNO; p = 0.008, day 10) and a significant decrease in FeNO after a single 4 h hiking tour (p < 0.001, time effect) were observed for the exercise group. The nasal eosinophilic cell count revealed a short-term reduction (p = 0.021, treatment effect) in the exercise group and for the visual analogue scale sustainable improvements in allergic symptoms (p < 0.001, day 60) were found. No adverse effects of outdoor winter exercise were observed. Conclusion: Recreational winter exercise at moderately cold temperatures reduces allergic airway inflammation measured as FeNO, nasal eosinophilic cell count and induces sustainable improvements in allergic symptoms.

The Effect of Pulmonary Rehabilitation in Mountain Environment on Exercise Capacity and Quality of Life in Patients with Chronic Obstructive Pulmonary Disease (COPD) and Chronic Bronchitis

BACKGROUND We aimed to test the effectiveness of the pulmonary rehabilitation in a mountain environment on the pulmonary function, physical performance, dyspnea, affective factors, and quality of life (QoL) in patients with chronic obstructive pulmonary disease (COPD) and chronic bronchitis (CB), as well as to determine predictors of clinical improvement. MATERIAL AND METHODS 128 consecutive patients (90 diagnosed with COPD and 38 diagnosed with CB) underwent comprehensive pulmonary rehabilitation for a duration of 3 weeks in one of 3 mountain health resorts in the High Tatras. The examination included spirometry (FEV1 and FEV1/FVC), 6-minute walk test (6MWT), Borg scale of dyspnea, and assessment of depression (Zung score), anxiety (Beck score), and QoL using the SF-36 scales. RESULTS After the study intervention, all patients in both monitored groups demonstrated significant improvements in objective measurements in which large treatment effect was achieved (for FEV1 η²=0.218, for 6MWT η²=0.771). Similarly, in subjective measurements a large effect was achieved (for the Beck score: η²=0.599, for the Zung score: η²=0.536). QoL improved after the intervention in all the monitored SF-36 scales in both groups (P<0.001 for all). In patients with COPD, the improvement of exercise capacity was positively correlated with baseline 6MWT and FEV1, and negatively with the Beck anxiety score and the Borg dyspnea score, whereas, only improvement in the mental summary component of QoL was negatively correlated with baseline 6MWT and FEV1 (P<0.05 for all). CONCLUSIONS Rehabilitation in a mountain environment has proven to be effective in both the reported diagnoses of COPD and CB. Improvements in both functional and subjective indicators were observed. These findings support the use of this treatment modality.

Randomized study of the safety and pharmacodynamics of inhaled interleukin-13 monoclonal antibody fragment VR942

Background

Interleukin-13 (IL-13) is a key mediator of T-helper-cell-type-2 (Th-2)-driven asthma, the inhibition of which may improve treatment outcomes. We examined the safety, pharmacokinetics, pharmacodynamics, and immunogenicity of VR942, a dry-powder formulation containing CDP7766, a high-affinity anti-human-IL-13 antigen-binding antibody fragment being developed for the treatment of asthma.

Methods

We conducted a phase 1, randomized, double-blind, placebo-controlled, ascending-dose study at Hammersmith Medicines Research, London, UK, which is now complete. Healthy adults aged 18–50 years (n = 40) were randomized 3:1 to a single inhaled dose of VR942 0.5, 1.0, 5.0, 10, or 20 mg, or placebo. Adults aged 18–50 years who were diagnosed with asthma for ≥6 months before screening, and had forced expiratory volume in 1 s (FEV₁) and forced vital capacity (FVC) values ≥70% of the predicted values at screening (n = 45), were randomized to once-daily inhaled VR942 0.5 or 10 mg, or placebo (2:2:1), or VR942 20 mg or placebo (3:2), for 10 days. All participants were randomized to receive VR942 or placebo based on a randomization list prepared by an independent HMR statistician using SAS® software (SAS Institute, Cary, NC). The primary outcome was safety and tolerability of VR942 (safety population, defined as all who received at least one dose of VR942 or placebo). This study is listed on ClinicalTrials.gov (NCT02473939).

Findings

In the VR942 and placebo groups, treatment-emergent adverse events (TEAEs) were reported in 10/30 (33%) and 0/10 (0%) healthy participants, and in 16/29 (55%) and 9/16 (56%) participants with asthma, respectively. Mild intermittent wheezing occurred in 7 participants (VR942 20 mg, n = 4; corresponding placebo, n = 3), resolving spontaneously within 1 h. All TEAEs were mild or moderate; there were no deaths, serious adverse events, or clinically significant changes in vital signs, electrocardiograms, or laboratory parameters. There was no clinically significant immunogenicity, with only one participant with asthma considered positive for treatment-related immunogenicity for CDP7766.

Interpretation

This study, considered to be the only example of a dry powder anti-IL-13 fragment antibody being administered via inhalation, demonstrated that single and repeat doses were well tolerated over a period of up to 10 days in duration. Rapid and durable inhibition of fractional exhaled nitric oxide (FeNO) (secondary outcome) provided evidence of pharmacological engagement with the IL-13 target in the airways of participants diagnosed with mild asthma. These data, together with the numerical improvements observed for predose FEV₁, justify further clinical evaluation of VR942 in a broader population of patients with asthma, and continue to support the development of an inhaled anti-IL-13 antibody fragment as a potential future treatment that is alternative to monoclonal antibodies delivered via the parenteral route.

Funding

Study funding and funding for the medical writing and editorial support for preparation of the manuscript were split equally between the two study co-funders (Vectura Ltd and UCB Pharma).

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Delivery of dry powder VR942 to the lungs of participants with asthma was well tolerated for up to 10 days of dosing.

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There was no detectable systemic exposure to VR942, and no clinically significant anti-drug-antibody effects were observed.

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Pharmacological engagement of VR942 in the lungs was evidenced by dose-related, rapid and sustained reductions in FeNO.

Physiological and Biological Responses to Short-Term Intermittent Hypobaric Hypoxia Exposure: From Sports and Mountain Medicine to New Biomedical Applications

In recent years, the altitude acclimatization responses elicited by short-term intermittent exposure to hypoxia have been subject to renewed attention. The main goal of short-term intermittent hypobaric hypoxia exposure programs was originally to improve the aerobic capacity of athletes or to accelerate the altitude acclimatization response in alpinists, since such programs induce an increase in erythrocyte mass. Several model programs of intermittent exposure to hypoxia have presented efficiency with respect to this goal, without any of the inconveniences or negative consequences associated with permanent stays at moderate or high altitudes. Artificial intermittent exposure to normobaric hypoxia systems have seen a rapid rise in popularity among recreational and professional athletes, not only due to their unbeatable cost/efficiency ratio, but also because they help prevent common inconveniences associated with high-altitude stays such as social isolation, nutritional limitations, and other minor health and comfort-related annoyances. Today, intermittent exposure to hypobaric hypoxia is known to elicit other physiological response types in several organs and body systems. These responses range from alterations in the ventilatory pattern to modulation of the mitochondrial function. The central role played by hypoxia-inducible factor (HIF) in activating a signaling molecular cascade after hypoxia exposure is well known. Among these targets, several growth factors that upregulate the capillary bed by inducing angiogenesis and promoting oxidative metabolism merit special attention. Applying intermittent hypobaric hypoxia to promote the action of some molecules, such as angiogenic factors, could improve repair and recovery in many tissue types. This article uses a comprehensive approach to examine data obtained in recent years. We consider evidence collected from different tissues, including myocardial capillarization, skeletal muscle fiber types and fiber size changes induced by intermittent hypoxia exposure, and discuss the evidence that points to beneficial interventions in applied fields such as sport science. Short-term intermittent hypoxia may not only be useful for healthy people, but could also be considered a promising tool to be applied, with due caution, to some pathophysiological states.

Treatment for moderate to severe atopic dermatitis in alpine and moderate maritime climates differentially affects helper T cells and memory B cells in children

BACKGROUND

Treatment of atopic dermatitis (AD) is focused on topical anti-inflammatory therapy, epidermal barrier repair and trigger avoidance. Multidisciplinary treatment in both moderate maritime and alpine climates can successfully reduce disease activity in children with AD. However, it remains unclear whether abnormalities in B cell and T cell memory normalize and whether this differs between treatment strategies.

OBJECTIVE

To determine whether successful treatment in maritime and alpine climates normalizes B- and T lymphocytes in children with moderate to severe AD.

METHODS

The study was performed in the context of a trial (DAVOS trial, registered at Current Controlled Trials ISCRTN88136485) in which eighty-eight children with moderate to severe AD were randomized to 6 weeks of treatment in moderate maritime climate (outpatient setting) or in the alpine climate (inpatient setting). Before and directly after treatment, disease activity was determined with SA-EASI and serum TARC, and T cell and B cell subsets were quantified in blood.

RESULTS

Both treatment protocols achieved a significant decrease in disease activity, which was accompanied by a reduction in circulating memory Treg, transitional B cell and plasmablast numbers. Alpine climate treatment had a significantly greater effect on disease activity and was accompanied by a reduction in blood eosinophils and increases in memory B cells, CD8+ TemRO, CD4+ Tcm and CCR7+ Th2 subsets.

CONCLUSIONS AND CLINICAL RELEVANCE

Clinically successful treatment of AD induces changes in blood B- and T cell subsets reflecting reduced chronic inflammation. In addition, multidisciplinary inpatient treatment in the alpine climate specifically affects memory B cells, CD8+ T cells and Th2 cells. These cell types could represent good markers for treatment efficacy.

Respiratory Health Benefits and Risks of Living at Moderate Altitude

Grissom, Colin K., and Barbara E. Jones. Respiratory health benefits and risks of living at moderate altitude. High Alt Med Biol 19:109-115, 2018.-The respiratory system plays a critical role in the series of physiologic responses that occur at high altitude and allows individuals to adapt to and tolerate hypobaric hypoxia. Persons with underlying lung disease may have complications, but sometimes derive benefits, related to residence at high altitude. This review will focus on health benefits and risks of patients with underlying asthma, chronic obstructive pulmonary disease, pulmonary hypertension, or obstructive sleep apnea, who live at altitudes of 1500 to 4500 m. We will also discuss maladaptive responses of the respiratory system at high altitude in previously healthy persons, including development of pulmonary hypertension and sleep-disordered breathing.

Does waterfall aerosol influence mucosal immunity and chronic stress? A randomized controlled clinical trial

BACKGROUND

The specific microclimate of alpine waterfalls with high levels of ionized water aerosols has been suggested to trigger beneficial immunological and psychological effects. In the present three-armed randomized controlled clinical study, we focused on effects on (i) immunological reagibility, on (ii) physiological stress responses, and on (iii) stress-related psychological parameters.

METHODS

People with moderate to high stress levels (n = 65) spent an active sojourn with daily hiking tours in the National Park Hohe Tauern (Großkirchheim, Austria). Half of the group was exposed to water aerosol of an alpine waterfall for 1 h/day (first arm, n = 33), whereas the other half spent the same time at a distant site (second arm, n = 32). A third arm (control, n = 26) had no intervention (except vaccination) and stayed at home, maintaining their usual lifestyle. The effect of the interventions on the immune system was tested by oral vaccination with an approved cholera vaccine and measuring specific salivary IgA antibody titers. Lung function was determined by peak expiratory flow measurement. Electric skin conductance, heart rate, and adaption of respiration rate were assessed as physiological stress parameters. Psychological stress-related parameters were analyzed by questionnaires and scales.

RESULTS

Compared to the control group, both intervention groups showed improvement of the lung function and of most physiological stress test parameters. Analysis of the mucosal immune response revealed a waterfall-specific beneficial effect with elevated IgA titers in the waterfall group. In line with these results, exposure to waterfall revealed an additional benefit concerning psychological parameters such as subjective stress perception (measured via visual analog scale), the Global Severity Index (GSI), and the Positive Symptom Total (PST).

CONCLUSIONS

Our study provides new data, which strongly support an "added value" of exposure to waterfall microclimate when combined with a therapeutic sojourn at high altitude including regular physical activity.

No Concentration Decrease of House Dust Mite Allergens With Rising Altitude in Alpine Regions

Purpose

Several studies over the past 4 decades have indicated a significant reduction in house dust mite (HDM) and HDM allergen concentration in areas higher than 1,500 m above sea level. These have served as basis of allergen avoidance therapies for HDM allergy and asthma. However, modern construction techniques used in the insulation, heating, and glazing of buildings as well as global warming have changed the environmental parameters for HDM living conditions. The present study revisits the paradigm of decreasing HDM allergen concentrations with increasing altitude in the alpine region of Germany and Austria.

Methods

A total of 122 dust samples from different abodes (hotels, privates and mountain huts) at different altitudes (400-2,600 m) were taken, and concentrations of HDM allergens were analyzed. Humidity and temperature conditions, and numerous indoor environmental parameters such as fine dust, type of flooring, age of building, and frequency of cleaning were determined.

Results

HDM allergen concentrations did not significantly change with increasing altitude or relative humidity. At the level of indoor parameters, correlations could be found for different flooring types and the concentration of HDM allergens.

Conclusions

In contrast to the widespread view of the relationship between altitude and HDM allergen concentrations, clinically relevant concentrations of HDM allergens could be detected in high-lying alpine regions in Austria and Germany. These results indicate that improvement in conditions of asthmatic patients sensitized against HDMs during a stay at high altitude can no longer be ascribed to decreased levels of HDM allergens, instead, other mechanisms may trigger the beneficial effect.

Low ambient oxygen prevents atherosclerosis

Large population studies have shown that living at higher altitudes, which lowers ambient oxygen exposure, is associated with reduced cardiovascular disease mortality. However, hypoxia has also been reported to promote atherosclerosis by worsening lipid metabolism and inflammation. We sought to address these disparate reports by reducing the ambient oxygen exposure of ApoE-/- mice. We observed that long-term adaptation to 10% O2 (equivalent to oxygen content at ∼5000 m), compared to 21% O2 (room air at sea level), resulted in a marked decrease in aortic atherosclerosis in ApoE-/- mice. This effect was associated with increased expression of the anti-inflammatory cytokine interleukin-10 (IL-10), known to be anti-atherogenic and regulated by hypoxia-inducible transcription factor-1α (HIF-1α). Supporting these observations, ApoE-/- mice that were deficient in IL-10 (IL10-/- ApoE-/- double knockout) failed to show reduced atherosclerosis in 10% oxygen. Our study reveals a specific mechanism that can help explain the decreased prevalence of ischemic heart disease in populations living at high altitudes and identifies ambient oxygen exposure as a potential factor that could be modulated to alter pathogenesis. Key messages: Chronic low ambient oxygen exposure decreases atherosclerosis in mice. Anti-inflammatory cytokine IL-10 levels are increased by low ambient O2. This is consistent with the established role of HIF-1α in IL10 transactivation. Absence of IL-10 results in the loss of the anti-atherosclerosis effect of low O2. This mechanism may contribute to decreased atherosclerosis at high altitudes.

Urbanisation but not biomass fuel smoke exposure is associated with asthma prevalence in four resource-limited settings

BACKGROUND

Urbanisation is an important contributor to the prevalence of asthma worldwide, and the burden of this effect in low-income and middle-income countries undergoing rapid industrialisation appears to be growing. We sought to characterise adult asthma prevalence across four geographically diverse settings in Peru and identify both individual and environmental risk factors associated with adult asthma.

METHODS

We collected sociodemographics, clinical history and spirometry in adults aged ≥35 years. We defined asthma as meeting one of the three criteria: physician diagnosis, self-report of wheezing attack or use of asthma medications. We used multivariable logistic regression to assess individual and environmental factors associated with adult asthma.

RESULTS

We analysed data from 2953 participants (mean age 55 years; 49% male). Overall asthma prevalence was 7.1%, which varied with urbanisation: highest in Lima (14.5%), followed by urban Puno (4.0%), semiurban Tumbes (3.8%) and rural Puno (1.8%). In multivariable analysis, being male (OR=0.60, 95% CI 0.39 to 0.93) and living at high altitude (OR=0.26, 95% CI 0.16 to 0.42) were associated with lower odds of having asthma, whereas living in an urban setting (OR=4.72, 95% CI 3.15 to 7.23) and family history of asthma (OR=1.83, 95% CI 1.19 to 2.73) were associated with higher odds. Current daily exposure to biomass fuel smoke (OR=1.18, 95% CI 0.70 to 1.91) and smoking (OR=0.99, 95% CI 0.73 to 1.22) were not associated with asthma.

CONCLUSIONS

These findings confirm that urbanisation is an environmental risk factor of asthma, questions biomass fuel smoke exposure as an important risk factor and proposes high altitude as possibly protective against the development of asthma.

Responses of peripheral blood mononuclear cells to moderate exercise and hypoxia

The purpose of this study was to analyze the physiological features of peripheral blood mononuclear cells (PBMCs) isolated from healthy female trekkers before and after physical activity carried out under both normoxia (low altitude, < 2000 m a.s.l.) and hypobaric hypoxia (high altitude, > 3700 m a.s.l.). The experimental design was to differentiate effects induced by exercise and those related to external environmental conditions. PBMCs were isolated from seven female subjects before and after each training period. The PBMCs were phenotypically and functionally characterized using fluorimetric and densitometric analyses, to determine cellular activation, and their intracellular Ca(2+) levels and oxidative status. After a period of normoxic physical exercise, the PBMCs showed an increase in fully activated T lymphocytes (CD3(+) CD69(+) ) and a reduction in intracellular Ca(2+) levels. On the other hand, with physical exercise performed under hypobaric hypoxia, there was a reduction in T lymphocytes and an increase in nonactivated B lymphocytes, accompanied by a reduction in O2 (-) levels in the mitochondria. These outcomes reveal that in women, low- to moderate-intensity aerobic trekking induces CD69 T cell activation and promotes anti-stress effects on the high-altitude-induced impairment of the immune responses and the oxidative balance.

A multi-ingredient, pre-workout supplement is apparently safe in healthy males and females

Background

Pre-workout supplements (PWS) have become increasingly popular with recreational and competitive athletes. While many ingredients used in PWS have had their safety assessed, the interactions when combined are less understood.

Objective

The purpose of this study was to examine the safety of 1 and 2 servings of a PWS.

Design

Forty-four males and females (24.4±4.6 years; 174.7±9.3 cm; 78.9±18.6 kg) from two laboratories participated in this study. Subjects were randomly assigned to consume either one serving (G1; n=14) or two servings (G2; n=18) of PWS or serve as an unsupplemented control (CRL; n=12). Blood draws for safety panels were conducted by a trained phlebotomist before and after the supplementation period.

Results

Pooled data from both laboratories revealed significant group×time interactions (p<0.05) for mean corpuscular hemoglobin (MCH; CRL: 30.9±0.8–31.0±0.9 pg; G1: 30.7±1.1–30.2±0.7 pg; G2: 30.9±1.2–30.9±1.1 pg), MCH concentration (CRL: 34.0±0.9–34.4±0.7 g/dL; G1: 34.1±0.9–33.8±0.6 g/dL; G2: 34.0±1.0–33.8±0.8 g/dL), platelets (CRL: 261.9±45.7–255.2±41.2×10³/µL; G1: 223.8±47.7–238.7±49.6×10³/µL; G2: 239.1±28.3–230.8±34.5×10³/µL), serum glucose (CRL: 84.1±5.2–83.3±5.8 mg/dL; G1: 86.5±7.9–89.7±5.6 mg/dL; G2: 87.4±7.2–89.9±6.6 mg/dL), sodium (CRL: 137.0±2.7–136.4±2.4 mmol/L; 139.6±1.4–140.0±2.2 mmol/L; G2: 139.0±2.2–138.7±1.7 mmol/L), albumin (CRL: 4.4±0.15–4.4±0.22 g/dL; G1: 4.5±0.19–4.5±0.13 g/dL; G2: 4.6±0.28–4.3±0.13 g/dL), and albumin:globulin (CRL: 1.8±0.30–1.8±0.28; G1: 1.9±0.30–2.0±0.31; G2: 1.8±0.34–1.8±0.34). Each of these variables remained within the clinical reference ranges.

Conclusions

The PWS appears to be safe for heart, liver, and kidney function in both one-serving and two-serving doses when consumed daily for 28 days. Despite the changes observed for select variables, no variable reached clinical significance.

28 days of creatine nitrate supplementation is apparently safe in healthy individuals

BACKGROUND

Creatine monohydrate has become a very popular nutritional supplement for its ergogenic effects. The safety of creatine monohydrate has previously been confirmed. However with each novel form of creatine that emerges, its safety must be verified. Therefore, the purpose of this study was to examine the safety of a novel form of creatine, creatine nitrate (CN), over a 28 day period.

METHODS

58 young males and females (Pooled: 24.3 ± 3.9 years, 144.9 ± 8.0 cm, 74.2 ± 13.0 kg) participated in this study across two laboratories. Subjects were equally and randomly assigned to consume either 1 g (n = 18) or 2 g (n = 20) of CN or remained unsupplemented (n = 20). Blood draws for full safety panels were conducted by a trained phlebotomist prior to and at the conclusion of the supplementation period.

RESULTS

Pooled data from both laboratories revealed significant group x time interactions for absolute lymphocytes and absolute monocytes (p < 0.05). Analysis of the 1 g treatment revealed lab x time differences for red blood cell distribution width, platelets, absolute monocytes, creatinine, blood urea nitrogen (BUN):creatinine, sodium, protein, and alanine aminotransferase (ALT) (p < 0.05). Analysis of the 2 g treatment revealed lab x time differences for BUN:creatinine and ALT (p < 0.05). BUN and BUN:creatinine increased beyond the clinical reference range for the 2 g treatment of Lab 2, but BUN did not reach statistical significance.

CONCLUSION

Overall, CN appears to be safe in both 1 g and 2 g servings daily for up to a 28 day period. While those with previously elevated BUN levels may see additional increases resulting in post-supplementation values slightly beyond normal physiological range, these results have minor clinical significance and are not cause for concern. Otherwise, all hematological safety markers remained within normal range, suggesting that CN supplementation has no adverse effects in daily doses up to 2 g over 28 days and may be an alternative to creatine monohydrate supplementation.

Influence of alpine mountain climate of Bavaria on patients with atopic diseases: studies at the Environmental Research Station Schneefernerhaus (UFS - Zugspitze) - a pilot study

Mountain and maritime climate therapy takes advantage of specific climatic conditions to treat chronic allergic diseases. It was the aim of the study to investigate effects of a 5 day sojourn on atopic diseases at the highest German mountain. In this pilot study 18 patients with grass pollen-induced rhinoconjunctivitis, atopic ezcema or asthma and 11 non-allergic controls were included. Skin physiology parameters, changes of the respiratory and nasal functions, subjective symptoms and blood parameters were measured during a 5-day observation period in the Environmental Research Station Schneefernerhaus (UFS) at the moderate altitude mountain region (Zugspitze; 2650 m alt.) compared to a low altitude area (Munich; 519 m alt.). Several of the skin physiology parameters changed significantly during the observation period (decrease of skin hydration, increase of skin smoothness, skin roughness, skin scaliness and pH-value). In patients with atopic eczema, the SCORAD (Severity Scoring of Atopic Dermatitis) and the scores of the DIELH (Deutsches Instrument zur Erfassung der Lebensqualität bei Hauterkrankungen) did not change significantly. Histamine induced itch decreased significantly. Parameters of nasal function did not change significantly. Several lung parameters showed a slight, but statistically significant improvement (forced expiratory volume in one second/volume capacity [FEV1/VC], peak expiratory flow [PEF], maximum expiratory flow at 50% of vital capacity [MEF 50], maximal mid-expiratory flow between 25% and 75% of vital capacity [MMFEF 25/75]), whereas the vital capacity (VC) decreased significantly. ECP (eosinophil cationic protein) in the serum and parameters of blood count changed significantly. These results show that the benefit of a moderate altitude mountain climate sojourn over a period of 5 days differs in depending on the atopic disease. Especially asthma parameters and itching of the skin improved. It would be interesting to assess the parameters during longer observation periods in alpine climate.

Problematic severe asthma in children treated at high altitude: tapering the dose while improving control

BACKGROUND

Multidisciplinary treatment at high altitude is a possible treatment option for problematic severe asthma (PSA) in children. This management can result in the tapering of inhaled corticosteroids.

AIM

Our aim was to analyze the effect of multidisciplinary treatment at high altitude, notably the ability to taper corticosteroids. To get an insight into possible factors influencing tapering, we examined whether demographic variables, disease control and quality of life at treatment entrance could predict the tapering of corticosteroids.

METHODS

This prospective open-phase cohort study analyzed the data of 43 children aged 8-17 years referred to a specialized high altitude treatment centre. Lung function (FEV1, FEV1/VC), inflammation (FeNO), medication level, asthma control (ACT) and quality of life [PAQLQ(S)] were evaluated on admission and at discharge.

RESULTS

Thirty-two (74%) children fulfilled PSA criteria. Three (7%) children used daily oral steroids. After 72 ± 30 (mean ± SD) days of treatment, the mean dosage of inhaled corticosteroids (ICS) could be significantly reduced from 1315 μg ± 666 budesonide equivalent to 1132 μg ± 514. Oral steroid maintenance therapy could be stopped in all patients. FeNO, asthma control and quality of life improved (p < 0.001) from admission to discharge; FEV1 was in the normal range on both occasions. Apart from ICS levels at entrance, multiple regression analyses did not show any associated factor predicting the reduction of ICS dosage during treatment.

CONCLUSION

The results indicate that high altitude treatment may be a treatment option for children with PSA, but it is not possible to predict ICS tapering off from health status variables at treatment entrance.

The prospective association between behavioural problems and asthma outcome in young asthma patients

AIM

The aim of this prospective study was to examine the association between behavioural problems and medical and psychological outcomes in clinically treated children and adolescents with asthma.

METHODS

Patients (n = 134) were recruited from two high-altitude asthma clinics in Switzerland and one asthma clinic in the Netherlands. Outcome measures were Asthma Control Test (ACT), Paediatric Asthma Quality of Life Questionnaire (PAQLQ(S)), forced expiratory volume in 1 sec (FEV1 ) and fractional concentration of exhaled nitric oxide (FeNO). Parents completed the Child Behaviour Checklist (CBCL) (predictor variable). Data were collected at the start and end of treatment. Multiple regression analysis was used while adjusting for demographic variables, clinic and length of stay.

RESULTS

More severe internalizing behavioural problems were associated with less improvement of total quality of life (t = -2.26, p = 0.03) and the domains symptoms (t = -2.04, p = 0.04) and emotions (t = -2.3, p = 0.02) after clinical treatment. Behavioural problems were not associated with a change of lung function measurements (FEV1 and FeNO) and asthma control (ACT) during treatment.

CONCLUSION

A focus of healthcare professionals on the treatment of internalizing behavioural problems may optimize the quality of life in clinically treated youth with asthma.

Effects of ionized waterfall aerosol on pediatric allergic asthma

OBJECTIVE

Ionized water aerosols have been suggested to exert beneficial health effects on pediatric allergic asthma. Their effect was evaluated in a randomized controlled clinical trial as part of a summer asthma camp.

METHODS

Asthmatic allergic children (n = 54) spent 3 weeks in an alpine asthma camp; half of the group was exposed to water aerosol of an alpine waterfall for 1 hour per day, whereas the other half spent the same time at a "control site". Immunological analysis, lung function testing, and fractional exhaled nitric oxide (FeNO) testing were performed during the stay, and sustaining effects were evaluated 2 months later. Symptom score testing was done over a period of 140 days.

RESULTS

The water aerosol group showed a significant improvement in all lung function parameters, whereas only the peak expiratory flow improved in the control group. All patients showed a significant improvement in symptom score and a significant decrease in FeNO after the camp. Only the water aerosol group exhibited a long-lasting effect on asthma symptoms, lung function, and inflammation in the follow-up examination. Induction of interleukin (IL)-10 and regulatory T (Treg) cells was measured in both groups, with a pronounced increase in the water aerosol group. IL-13 was significantly decreased in both groups, whereas IL-5 and eosinophil cationic protein were decreased only in the water aerosol group.

CONCLUSIONS

Our findings confirm the induction of Treg cells and reduction in inflammation by climate therapy. They indicate a synergistic effect of water aerosols resulting in a long-lasting beneficial effect on asthma symptoms, lung function, and airway inflammation.

Inpatient paediatric rehabilitation in chronic respiratory disorders

Inpatient pulmonary rehabilitation programs have evolved from tuberculosis sanatoriums to modern medical centres providing standardized comprehensive care in a multidiciplinatory environment. Goals of rehabilitation programs for children and adolescents include restoration of professional activity, improvement of health condition, compliance and disease management as well as restoration of quality of life. Eligibility for an intervention is assessed by defined social and medical criteria. Comprehensive pulmonary rehabilitation programs provide a wide range of health care recourses, including diagnostic procedures, specific medical care, educational interventions and a multiprofessional team. Paediatric rehabilitation programs for chronic respiratory diseases, such as asthma or cystic fibrosis, have been shown to reduce symptoms, increase aerobic fitness and physical strength, improve pulmonary function and inflammation and enhance compliance, self-management, quality of life and psychological symptoms. Regional climatic effects have demonstrated an additional positive effect on the rehabilitation outcome. In addition, first evidence suggests an overall reduction of health care costs.

Current treatment of severe asthma

Severe asthma is considered a heterogeneous disease in which a variety of clinical, physiological and inflammatory markers determine disease severity. Pivotal studies in the last 5 years have led to substantial progress in many areas, ranging from a more accurate definition of truly severe, refractory asthma, to classification of the disease into distinct clinical phenotypes, and introduction of new therapies. This review focuses on three common clinical phenotypes of severe asthma in adults (early onset severe allergic asthma, late onset non-atopic eosinophilic asthma, late onset non-eosinophilic asthma with obesity), and provides an overview of recent developments regarding treatment options that are best suited for each of these phenotypes.

It's time to rethink mite allergen avoidance

The role of allergen exposure in the etiology of allergic sensitization and asthma is complex. Advice on strategies to avoid domestic allergens remains contentious because trials of interventions aimed to prevent asthma or reduce symptoms have often failed to demonstrate benefits. Asthma management guidelines differ widely in their recommendations, while Web-based information often claims benefits associated with products. In this rostrum we argue that although many factors have a role in both the etiology and the exacerbation of asthma, allergen exposure probably remains an important contributor to the manifestations of the disease. Currently, there is no evidence-based framework for effective domestic allergen avoidance interventions to reduce chronic aeroallergen exposure. The development of an effective approach to allergen avoidance requires a better understanding of (a) the physical nature of chronic aeroallergen exposure and methods for measuring and reducing this, (b) the interaction between allergen exposure and innate immune modulators at different disease stages, and (c) markers enabling the identification of individuals who would benefit from this. The strategic risk of overemphasizing other novel mechanisms and approaches to asthma management is that we will prematurely abandon and fail to improve an existing approach that could have a significant impact on the development, progression, and symptoms of the disease.

High-altitude treatment: a therapeutic option for patients with severe, refractory asthma?

High-altitude treatment has been applied for more than a century in the treatment of pulmonary diseases including asthma. Many uncontrolled and controlled studies have shown its beneficial effects in children and adolescents with house dust mite allergic asthma. A recent study also showed an improvement in markers of airway inflammation in adult patients with severe intrinsic asthma, suggesting that factors other than HDM avoidance may contribute to the beneficial influence of the high-altitude climate therapy on asthma. The dry mountain climate not only has decreased levels of mite allergens but also decreased levels of pollens, fungal spores and air pollution, as well as high exposure to UV light with immunomodulatory and anti-inflammatory effects. Treatments targeting environmental control have never been investigated systematically in severe asthma, which is surprising, as environmental factors have been recognized as important contributors to asthma severity for many years and more evidence has been accumulating ever since. Preliminary evidence shows the beneficial effects of high-altitude treatment in patients with severe refractory asthma on symptoms, lung function and oral corticosteroid requirement, irrespective of atopic status. In this narrative review, we will discuss why high-altitude treatment might be a promising therapeutic option for patients who suffer from this disabling disease.

Effect of sustained high altitude on asthma patients

Due to factors such as allergen avoidance and the decrease of air pollution, sustained stays in a high-altitude climate have been recommended for asthma patients for a long time. There are also documented effects and favorable influence on the health of permanent residents at high altitude; for example, the frequency of allergic sensitization to house dust mite in asymptomatic subjects is much lower than at sea level. In the context of this article, 'high altitude' means 1500-2500 m above sea level. The aim of the review is to summarize the available data on the effects of a sustained stay of asthmatic patient data between 1500-1800 m above sea level in alpine altitudes (Europe). Climatic conditions in South America or in Africa are completely different from the altitudes discussed in this review. We conclude that the available evidence suggests a significant benefit of high altitude for asthmatic patients, particularly in steroid-dependent patients.

[Guidelines on asthma in extreme environmental conditions]

Asthma is a highly prevalent chronic disease which, if not properly controlled, can limit the patient's activities and lifestyle. In recent decades, owing to the diffusion of educational materials, the application of clinical guidelines and, most importantly, the availability of effective pharmacological treatment, most patients with asthma are now able to lead normal lives. Significant social changes have also taken place during the same period, including more widespread pursuit of sporting activities and tourism. As a result of these changes, individuals with asthma can now participate in certain activities that were inconceivable for these patients only a few years ago, including winter sports, underwater activities, air flight, and travel to remote places with unusual environmental conditions (deserts, high mountain environments, and tropical regions). In spite of the publication of several studies on this subject, our understanding of the effects of these situations on patients with asthma is still limited. The Spanish Society of Pulmonology and Thoracic Surgery (SEPAR) has decided to publish these recommendations based on the available evidence and expert opinion in order to provide information on this topic to both doctors and patients and to avert potentially dangerous situations that could endanger the lives of these patients.

Prevalence and severity of asthma and allergies in schoolchildren in Lhasa, Tibet

BACKGROUND

The International Study of Asthma and Allergies in Childhood (ISAAC) demonstrated that large variations existed in the prevalence of symptoms of asthma, allergic rhinoconjunctivitis and eczema throughout the world and that environmental factors and lifestyle customs are major determinants of the prevalence and severity of these diseases. However, the relevant data about children living at high-altitude locations were considered to be underreported.

OBJECTIVE

The ISAAC Phase III programme was carried out in Lhasa, the Tibetan Autonomous Region in China, at an elevation of 3658 m above sea level to examine the occurrence of asthma, allergic rhinoconjunctivitis and eczema in schoolchildren aged 13-14 years.

METHODS

All 3196 schoolchildren in eight public junior high schools in urban Lhasa who were confirmed to be 13-14 years old were invited and participated in both written and video questionnaire investigations, among which 3190 pieces of data (49.8% of boys and 50.2% of girls) were validated and analysed.

RESULTS

Among the overall observations, the prevalence of 'having ever experienced wheezing', 'current wheezing' and 'diagnosed to have asthma' was 1.4%, 0.8% and 1.1%, respectively. The prevalence of current exercise-induced asthma and current nocturnal cough was 7.1% and 4.6%, respectively. The current prevalence of allergic rhinoconjunctivitis and eczema was 5.2% and 0.4%, respectively. In addition, the prevalence of rhinoconjunctivitis symptoms during the past 12 months showed no discernable differences throughout the year.

CONCLUSION

The prevalence of asthma, allergic rhinoconjunctivitis and eczema over the past 12 months was the lowest among the centres, that performed ISAAC worldwide.

The dietary habits of non-asthmatic schoolchildren in Lhasa, Tibet

The occurrence of asthma symptoms and food consumption frequencies in 13- to 14-year-old schoolchildren was investigated in Lhasa, Tibet (3,658 meters above sea level). A total of 99.2% of the schoolchildren reported that they had not experienced any wheezing during the prior 12 months. Among these students, more than 50% had consumed rice, meat, fruits, and vegetables at least three times per week in the preceding year. More than 70% of the non-asthmatic students rarely consumed margarine; 50% of these students rarely ate fast food; and 40% only occasionally ate fish during the prior 12 months. The dietary habits of the schoolchildren in Lhasa may have some potential beneficial roles in contributing to the low prevalence of asthma in this high altitude region.