Chronic Intermittent Hypoxia Reduces the Effects of Glucosteroid in Asthma via Activating the p38 MAPK Signaling Pathway.

AIMS: Obstructive sleep apnea (OSA) is a risk factor for steroid-resistant (SR) asthma. However, the underlying mechanism is not well defined. This study aimed to investigate how chronic intermittent hypoxia (CIH), the main pathophysiology of OSA, influenced the effects of glucocorticoids (GCs) on asthma. MAIN METHODS: The effects of dexamethasone (Dex) were determined using the ovalbumin (OVA)-challenged mouse model of asthma and transforming growth factor (TGF)-ß treated airway smooth muscle cells (ASMCs), with or without CIH. The p38 MAPK signaling pathway activity was then detected in the mouse (n = 6) and ASMCs models (n = 6), which were both treated with the p38 MAPK inhibitor SB239063. KEY FINDINGS: Under CIH, mouse pulmonary resistance value, inflammatory cells in bronchoalveolar lavage fluid (BALF), and inflammation scores increased in OVA-challenged combined with CIH exposure mice compared with OVA-challenged mice (p < 0.05). These indicators were similarly raised in the OVA + CIH + Dex group compared with the OVA + Dex group (P < 0.05). CIH exposure enhanced the activation of the p38 MAPK pathway, oxidative stress injury, and the expression of NF-κB both in lung tissue and ASMCs, which were reversed by treatment with Dex and SB239063. In the in vitro study, treatment with Dex and SB239063 decreased ASMCs proliferation induced by TGF-ß combined with CIH and suppressed activation of the p38 MAPK pathway, oxidative stress injury, and NF-κB nuclear transcription (p < 0.05). SIGNIFICANCE: These results indicated that CIH decreased GC sensitivity by activating the p38 MAPK signaling pathway.

Effect of PIFR-based optimised inhalation therapy in patients recovering from acute exacerbation of chronic obstructive pulmonary disease: protocol of a prospective, multicentre, superiority, randomised controlled trial.

INTRODUCTION: Acute exacerbation (AE) is a major cause of disease progression and death in patients with chronic obstructive pulmonary disease (COPD), accounting for majority of medical expenditures. Correct inhalation therapy is effective in preventing AE attacks. However, inappropriate usage of dry powder inhaler, partially due to the unrecovered peak inhalation flow rate (PIFR) after acute exacerbation of COPD (AECOPD), results in increased risk of early treatment failure. Therefore, we designed a multicentre, randomised clinical trial to determine whether PIFR-based optimised inhalation therapy and training on inhaler usage at discharge could effectively reduce early treatment failure events. METHODS AND ANALYSIS: A total of 416 hospitalised patients just recovering from AECOPD will be recruited and equally randomised into the PIFR group and the control group at a 1:1 ratio. The PIFR group will receive additive support before discharge, including choice of PIFR-guided inhaler and education on its usage. PIFR is measured by InCheck DIAL. In comparison, the control group will receive inhalers based on judgement of the respiratory physician. The primary outcome of the study is 30-day treatment failure rate. Other endpoints include PIFR, error rate of inhalation device use, satisfaction with inhalation devices, 30-day mortality, 90-day mortality, symptoms and quality of life of patients, and COPD-related treatment costs. ETHICS AND DISSEMINATION: The trial has been approved by the Ethics Committee of Zhongshan Hospital of Fudan University (B2019-142). Participants will be screened and enrolled from hospitalised patients with AECOPD by clinicians, with no public advertisement for recruitment. After the trial has completed, the results will be reported to the public through conference presentations and peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT04000958.

Synergistic effects of temperature and humidity on the symptoms of COPD patients.

This panel study investigates how temperature, humidity, and their interaction affect chronic obstructive pulmonary disease (COPD) patients' self-reported symptoms. One hundred and six COPD patients from Shanghai, China, were enrolled, and age, smoking status, St. George Respiratory Questionnaire (SGRQ) score, and lung function index were recorded at baseline. The participants were asked to record their indoor temperature, humidity, and symptoms on diary cards between January 2011 and June 2012. Altogether, 82 patients finished the study. There was a significant interactive effect between temperature and humidity (p < 0.0001) on COPD patients. When the indoor humidity was low, moderate, and high, the indoor temperature ORs were 0.969 (95% CI 0.922 to 1.017), 0.977 (0.962 to 0.999), and 0.920 (95% CI 0.908 to 0.933), respectively. Low temperature was a risk factor for COPD patients, and high humidity enhanced its risk on COPD. The indoor temperature should be kept at least on average at 18.2 °C, while the humidity should be less than 70%. This study demonstrates that temperature and humidity were associated with COPD patients' symptoms, and high humidity would enhance the risk of COPD due to low temperature.

An increased ratio of Th2/Treg cells in patients with moderate to severe asthma.

BACKGROUND: Recent studies have shown that T helper type-2 (Th2) cells can induce the apoptosis of CD4+CD25+ Treg cells or resist the immunosuppressive effect of Treg cells. We hypothesize that an imbalance of Th2/Treg is present in patients with allergic asthma. METHODS: Twenty-two patients with mild asthma, 17 patients with moderate to severe asthma, and 20 healthy donors were enrolled. All patients were allergic to house dust mites. The proportion of peripheral blood CD4+CD25+ Treg cells and Th2 cells were determined by flow cytometry. The concentration of interleukin (IL)-10, transforming growth factor (TGF)-ß and IL-4 in plasma was determined by enzyme linked immunosorbent assay. In these subjects, peripheral blood mononuclear cells from 17 mild asthmatic patients, 13 moderate to severe asthmatic patients and 14 healthy donors were acquired and expression of forkhead box P3 (Foxp3) and GATA-3 mRNA was detected by reverse-transcriptase polymerase chain reaction. RESULTS: Compared with healthy donors and patients with mild asthma, the percent of CD4+CD25+ Treg cells and plasma IL-10 levels were decreased in patients with moderate to severe asthma. There were no significant differences in Foxp3 mRNA expression among three groups, but a downward trend seen among patients with asthma. However, the percent of Th2 cells, IL-4 levels and expression of GATA-3 mRNA was markedly higher in patients with mild and moderate to severe asthma than in the control group. The ratio of Th2/Treg and their cytokines was increased in allergic asthma, especially for moderate to severe asthma. The ratio of GATA-3/Foxp3 mRNA was also increased in allergic asthma. In patients with moderate to severe asthma, the percentage of peripheral blood Treg cells was negatively correlated to the percentage of Th2 cells and IL-4 levels. CONCLUSIONS: The decline of CD4+CD25+ Treg cells in patients with moderate to severe asthma may play an important role in progress of the disease. Furthermore, the deficiency of CD4+CD25+ Treg cells was associated with the over-expression of Th2 response.

Coexistence of Th1/Th2 and Th17/Treg imbalances in patients with allergic asthma.

BACKGROUND: Recent recognition is that Th2 response is insufficient to fully explain the aetiology of asthma. Other CD4(+) T cells subsets might play a role in asthma. We investigated the relative abundance and activities of Th1, Th2, Th17 and CD4(+)CD25(+) Treg cells in patients with allergic asthma. METHODS: Twenty-two patients with mild asthma, 17 patients with moderate to severe asthma and 20 healthy donors were enrolled. All patients were allergic to house dust mites. Plasma total IgE, pulmonary function and Asthma Control Questionnaire were assessed. The proportions of peripheral blood Th1, Th2, Th17 and CD4(+)CD25(+) Treg cells were determined by flow cytometry. The expression of cytokines in plasma and in the culture supernatant of peripheral blood mononuclear cells was determined by enzyme linked, immunosorbent assay. RESULTS: The frequency of blood Th2 cells and IL-4 levels in plasma and culture supernatant of peripheral blood mononuclear cells were increased in all patients with allergic asthma. The frequency of Th17 cells and the plasma and culture supernatant levels of IL-17 were increased, whereas the frequency of CD4(+)CD25(+) Treg cells and plasma IL-10 levels were decreased in patients with moderate to severe asthma. Dermatophagoides pteronyssinus specific IgE levels were positively correlated with the percentage of blood Th2 cells and plasma IL-4 levels. Forced expiratory volume in the first second was negatively correlated with the frequency of Th17 cells and plasma IL-17 levels, and positively correlated with the frequency of Treg cells. However, mean Asthma Control Questionnaire scores were positively correlated with the frequency of Th17 cells and plasma IL-17 levels, and negatively correlated with the frequency of Treg cells. CONCLUSIONS: Imbalances in Th1/Th2 and Th17/Treg were found in patients with allergic asthma. Furthermore, elevated Th17 cell responses, the absence of Tregs and an imbalance in Th17/Treg levels were associated with moderate to severe asthma.