Exosomes Derived from Human Umbilical Cord Mesenchymal Stem Cells Alleviate Diffuse Alveolar Hemorrhage Associated with Systemic Lupus Erythematosus in Mice by Promoting M2 Macrophage Polarization via the microRNA-146a-5p/NOTCH1 Axis.

Systemic lupus erythematosus (SLE)-associated diffuse alveolar hemorrhage (DAH) is a rare but extremely harmful condition. The current study sought to dissect the mechanisms underlying the effects of human umbilical cord mesenchymal stem cell (HUCMSC)-derived exosomes on M2 macrophage polarization in SLE-associated DAH via the microRNA (miR)-146a-5p/NOTCH1 axis. A DAH mouse model was established using pristane. Exosomes were isolated from HUCMSCs transfected or untransfected with the miR-146a-5p antagonist or agonist and their NCs and then injected into DAH mice. Additionally, miR-146a-5p was overexpressed in macrophages. Expression of miR-146a-5p, NOTCH1, M1 macrophage markers, and M2 macrophage markers was measured in mice and macrophages, and inflammatory factor levels were detected. Mouse lung injuries were evaluated, so was the binding of miR-146a-5p to NOTCH1. Rescue experiments were conducted in mice and macrophages using NOTCH1 shRNA and pcDNA3.1-NOTCH1, respectively. NOTCH1 expression was enhanced in DAH mice. HUCMSC-derived exosomes reduced NOTCH1 expression, bleeding, inflammation, and M1 macrophage polarization but elevated M2 macrophage polarization in lung tissues of DAH mice. Mechanistically, NOTCH1 is negatively targeted by miR-146a-5p. miR-146a-5p overexpression diminished M1 marker and inflammatory factor levels but enhanced M2 marker levels in macrophages, which was nullified by NOTCH1 overexpression. HUCMSC-derived exosomes with miR-146a-5p inhibition increased NOTCH1 expression, worsened bleeding and inflammation, and augmented M1 macrophage polarization while decreasing M2 macrophage polarization in lung tissues of DAH mice, which was abrogated by silencing NOTCH1. HUCMSC-derived exosomes diminished NOTCH1 expression to accelerate M2 macrophage polarization via delivery of miR-146a-5p, thus alleviating SLE-associated DAH in mice.

sRAGE Inhibits the Mucus Hypersecretion in a Mouse Model with Neutrophilic Asthma.

BACKGROUND: Neutrophilic asthma (NA) may result in irreversible airflow limitations. Soluble advanced glycosylation receptor (sRAGE) has been shown to be associated with neutrophilic airway inflammation. However, the association between sRAGE and mucus hypersecretion in NA remains unknown. This study aims to assess the function of sRAGE on mucus hypersecretion. METHODS: A NA mouse model was established and treated with adeno-associated virus 9 (AAV9)-sRAGE and inhibitors. Collagen deposition and goblet cell hyperplasia in the lungs were evaluated by periodic acid-Schiff (PAS) and Masson staining. sRAGE and mucin levels in bronchoalveolar lavage fluid were measured by ELISA. Pathway molecule expression levels were determined by RT-qPCR and western blotting. RESULTS: The results showed that the NA mouse model exhibited airway mucus hypersecretion. Mice can be effectively transfected by AAV9-sRAGE via tail-vein injection and intranasal drip. AAV9-sRAGE increased the sRAGE levels but it inhibited the collagen deposition, the PAS score, as well as the expression of MUC5AC and MUC5B. Inhibitors of high-mobility group protein 1 (HMGB1), receptor for advanced glycation end product (RAGE) and phosphatidylinositol 3-kinase (PI3K) suppressed the MUC5AC levels in NA mice as well as in cultured HMGB1-induced human bronchial epithelial cells. Furthermore, the phospho- extracellular signal-regulated kinase (ERK) protein in NA was increased while the sRAGE intervention inhibited this elevation. CONCLUSIONS: These results suggest that sRAGE may be a potential target for the treatment of mucus hypersecretion in NA.

[Advances in application of Jurkat cell model in research on infectious diseases].

Infectious diseases can be caused by multiple pathogens, which can produce specific immune response in human body. The immune response produced by T cells is cellular immunity, which plays an important role in the anti-infection process of human body, and can participate in immunological protection and cause immunopathology. The outcome of various infectious diseases is closely related to cellular immune function, especially the function of T cells. Jurkat cells belong to the human acute T lymphocyte leukemia cell line. Jurkat cell model can simulate the function T lymphocytes, so it is widely used in the in vitro studies of T cell signal transduction, cytokines, and receptor expression, and can provide reference and guidance for the treatment of various infectious diseases and the research on their pathogenesis. The Jurkat cell model has been widely used in the in vitro studies of viral diseases and atypical pathogens, but parasitic infection studies using the Jurkat cell model are still rare. This article reviews advances in the application of Jurkat cell model in the research on infectious diseases.

[Role of programmed death-1 in viral infectious diseases].

The research on the immunoregulatory effect of programmed death-1 (PD-1) in infectious diseases mainly focuses on chronic viral infection, but there are few studies on acute viral infection. In chronic viral infection, PD-1 is highly expressed on the surface of CD8+ T cells, which is a sign of CD8+ T cell depletion. Recent studies have shown that in chronic viral infection, PD-1 is also highly expressed on the surface of regulatory T cells and binds to programmed death-ligand 1 (PD-L1) on the surface of exhausted CD8+ T cells, resulting in a stronger inhibitory effect on CD8+ T cell immunity. Blocking the PD-1/PD-L1 signaling pathway between exhausted CD8+ T cells and regulatory T cells can significantly reverse the depletion of CD8+ T cells and greatly improve the antiviral effect of CD8+ T cells. However, the role of the PD-1/PD-L1 signaling pathway in acute viral infection remains unknown. This article summarizes the latest research on PD-1 in infectious diseases and discusses its role in acute and chronic viral infection.

Are Chinese pediatricians missing the opportunity to help parents quit smoking?

BACKGROUND: Secondhand smoke (SHS) exposure of children due to parental tobacco use is a particularly prevalent health issue and is associated with adverse health outcomes. Following the US Clinical Practice guidelines, pediatricians in the United States deliver 5A's (ask, advise, assess, assist, and arrange) counseling to smoking parents which has proven to be effective. We examined Chinese pediatricians' adherence to the clinical practice guidelines for smoking cessation (i.e. 5A's counseling practices) with smoking parents, and identified factors associated with these practices. METHODS: A cross-sectional paper-and-pencil survey of pediatricians was conducted in twelve conveniently selected southern Chinese hospitals. Factors associated with any of the 5A's smoking cessation counseling practices were identified by logistic regression. RESULTS: Of respondents (504/550), only 26 % routinely provided 5A's smoking cessation counseling to smoking parents. More than 80 % of pediatricians didn't receive formal training in smoking cessation and had not read China smoking cessation guidelines; 24 % reported being "very confident" in discussing smoking or SHS reduction with parents. Pediatricians who had never smoked (OR: 2.29, CI:1.02-5.12), received training in smoking cessation (OR: 2.50, CI:1.40-4.48), had read China smoking cessation guidelines (OR: 2.17, CI:1.10-4.26), and felt very (OR: 7.12, CI:2.45-20.70) or somewhat (OR: 3.05, CI:1.11-8.37) confident in delivering cessation counseling were more likely to practice 5A's. Pediatricians who reported "it is hard to find a time to talk with parents" (OR: 0.32, CI: 0.11-0.92) or "lack of a standard of care requiring pediatricians to provide smoking cessation or SHS exposure reduction intervention" (OR: 0.45, CI: 0.21-0.98) as a barrier were less likely to follow the 5A's guidelines. CONCLUSIONS: Smoking cessation counseling to address parental smoking is infrequent among Chinese pediatricians. There is a need to develop and test intervention strategies to improve the delivery of 5A's smoking cessation counseling to parental smokers.

[Expression and role of Tc17 cells in mice with neutrophilic asthma].

OBJECTIVE: To determine the proportion of Tc17 cells in the lungs of mice with neutrophilic(NEU) asthma, and to investigate the role of Tc17 cells in the pathogenesis of NEU asthma. METHODS: Thirty-two C57/B6 mice of clean grade were randomly divided into two groups: NEU asthma and control. The mice in the NEU asthma group were sensitized by airway instillation of ovalbumin (OVA) and lipopolysaccharide (LPS), and challenged with an aerosol of OVA, while those in the control group were sensitized and challenged with normal saline. At 24 hours after the final challenge, bronchoalveolar lavage fluid (BALF) was collected, and the total number and differential counts of nucleated cells and percentage of each type were determined. The lung tissues were separated and hematoxylin-eosin staining was performed to observe the pathological changes of lungs; flow cytometry was applied to determine the percentages of Tc17 and Th17 cells in the lung tissues. Enzyme-linked immunosorbent assay was applied to determine the levels of interleukin-6 (IL-6), transforming growth factor β (TGF-β), and interleukin-17 (IL-17) in BALF. RESULTS: The NEU asthma group had a significantly higher total number of nucleated cells, a significantly higher percentage of eosinophils, and a significantly higher percentage of neutrophils in BALF than the control group (P<0.01). The NEU asthma group also had significantly higher percentages of Tc17 and Th17 cells than the control group (P<0.01). In the NEU asthma group, the percentage of Tc17 cells was positively correlated with that of Th17 cells (P<0.05). The NEU asthma group had significantly higher concentrations of IL-6, TGF-β, and IL-17 in BALF than the control group (P<0.05). CONCLUSIONS: The expression of Tc17 cells in the lung tissues increases in mice with NEU asthma, and the increased number of Tc17 cells may be involved in the pathogenesis of NEU asthma. Tc17 cells may play an important role in NEU asthma through IL-17.

Secondhand smoke exposure assessment and counseling in the Chinese pediatric setting: a qualitative study.

BACKGROUND: Assisting smoking parents to quit smoking and eliminating the secondhand smoke (SHS) exposure of their children is a global health priority. Engaging healthcare workers in developing countries to address this priority has been a challenge. This study intends to explore issues around current practice related to SHS exposure assessment and counseling and identify barriers to SHS exposure reduction counseling in the Chinese pediatric setting. METHODS: We conducted qualitative interviews (11 focus groups discussions (FGDs) with pediatricians, 6 FGDs with pediatric nurses and 11 in-depth interviews (IDIs) with hospital administrators) among 101 health-care professionals (HCP) from 5 hospitals in four major cities of Guangxi Province, China. All FGDs/ IDIs were audio recorded and analysed thematically. RESULTS: The findings suggest that few Chinese pediatricians routinely address the SHS exposure of children in their usual practice. All HCPs felt the need for clinical interventions to promote SHS exposure reduction for children. Primary barriers to SHS exposure reduction counseling in the Chinese pediatric setting included: lack of skills and training in tobacco use reduction and cessation counseling; time constraints and heavy workloads, uncertainty about the usefulness of smoking cessation interventions and lack of hospital-wide systems requiring pediatricians to record tobacco use or SHS exposure information. Ideas for overcoming these barriers were building capacity of pediatricians, collaboration with international organization to initiate training, engaging top level leaders in the effort and ensuring financial resources to support the program. CONCLUSIONS: This study among hospital administrators and service providers in China demonstrated a high level of interest in delivering SHS exposure reduction interventions in the pediatric setting. The findings can inform the creation and delivery of clinical interventions in China to promote SHS exposure reduction to children in the pediatric setting.

Leukotriene receptor antagonists for small-airway abnormalities in asthmatics: a systematic review and meta-analysis.

BACKGROUND: Airway inflammation that occurs in asthma is mainly distributed in the small airways. Leukotriene receptor antagonists (LTRAs) are systemically active drugs that may act on the small airways. OBJECTIVES: The aim of our study was to assess the efficacy of LTRAs for small-airway abnormalities in asthmatics. METHODS: We searched the databases of Cochrane Central, MEDLINE, and EMBASE from the time of the establishment of the databases to December 2012. The data were extracted using a pooled mean difference (MD) or standardized mean difference (SMD) with a 95% confidence interval (CI). RESULTS: Eight studies were included. The outcomes were the conventional parameters for the detection of small-airway abnormalities. Eight studies were included. The outcomes were the conventional parameters for the detection of small-airway abnormalities. LTRAs compared to placebo improved small-airway abnormalities, as indicated by a number of radiological and physiological parameters, such as lung attenuation (MD, 61.00; 95% CI, 26.32 to 95.68) and residual volume (SMD, -0.85; 95% CI, -1.29 to -0.42). Conventional inhaled corticosteroids (ICSs) compared to LTRAs improved small-airway abnormalities, as indicated by the reactance area (p = 0.028). Compared with conventional treatment alone, a combination of LTRAs and conventional treatment improved small-airway abnormalities, as indicated by a number of radiological and physiological parameters, such as airway wall thickness (p < 0.05), alveolar nitric oxide concentration (p = 0.04), a decrease in resistance from 5 to 20 hertz (p = 0.032), reactance area (p = 0.014), eosinophil cationic protein levels (p = 0.045) and number of eosinophils (p = 0.035) in the late-phase induced sputum. However, there was no significant improvement in forced expiratory flow between 25% and 75% of forced vital capacity in any of the comparisons. CONCLUSIONS: LTRAs may improve most of the conventional parameters for the detection of small-airway abnormalities in asthmatics. However, there is no evidence of the superiority of LTRAs over ICSs in improving functional parameters related to the small airways.

Chinese Guideline on Allergen Immunotherapy for Allergic Rhinitis: The 2022 Update.

In the last few decades, there has been a progressive increase in the prevalence of allergic rhinitis (AR) in China, where it now affects approximately 250 million people. AR prevention and treatment include allergen avoidance, pharmacotherapy, allergen immunotherapy (AIT), and patient education, among which AIT is the only curative intervention. AIT targets the disease etiology and may potentially modify the immune system as well as induce allergen-specific immune tolerance in patients with AR. In 2017, a team of experts from the Chinese Society of Allergy (CSA) and the Chinese Allergic Rhinitis Collaborative Research Group (C2AR2G) produced the first English version of Chinese AIT guidelines for AR. Since then, there has been considerable progress in basic research of and clinical practice for AIT, especially regarding the role of follicular regulatory T (TFR) cells in the pathogenesis of AR and the use of allergen-specific immunoglobulin E (sIgE) in nasal secretions for the diagnosis of AR. Additionally, potential biomarkers, including TFR cells, sIgG4, and sIgE, have been used to monitor the incidence and progression of AR. Moreover, there has been a novel understanding of AIT during the coronavirus disease 2019 pandemic. Hence, there was an urgent need to update the AIT guideline for AR by a team of experts from CSA and C2AR2G. This document aims to serve as professional reference material on AIT for AR treatment in China, thus improving the development of AIT across the world.

[Causes of chronic cough in children: an analysis of 111 cases].

OBJECTIVE: To investigate the causes of chronic cough in children. METHODS: A prospective cohort study was performed on 111 children with chronic cough who were referred to the First Affiliated Hospital of Guangxi Medical University between December 2008 and January 2011. The causes of chronic cough were investigted. RESULTS: Cough variant asthma (45 cases, 40.5%) was the most common cause of chronic cough, followed by upper airway cough syndrome (34 cases, 30.6%), postinfectious cough (19 cases, 17.1%), allergic cough (5 cases, 4.5%), Tourette's syndrome (4 cases, 3.6%), psychogenic cough (1 case, 0.9%) and endobronchial tuberculosis (1 case, 0.9%). The causes were not identified in 2 cases (1.8%). A single cause for chronic cough was noted in 60 patients (54.1%), and multiple potential causes were noted in 49 patients (44.1%), including two coexisting causes in 47 patients (42.3%) and three in 2 patients (1.8%). CONCLUSIONS: The top three causes of chronic cough in children are cough variant asthma, upper airway cough syndrome and postinfectious cough.

Geleophysic dysplasia caused by a mutation in FBN1: A case report.

BACKGROUND: Geleophysic dysplasia (GD) presents the characterized clinical manifestations of acromelic dysplasia, including extremely short stature, short limbs, small hands and feet, stubby fingers and toes, joint stiffness and others. It is clinically distinct from the other acromelic dysplasia in terms of symptoms such as cardiac valvular abnormalities, progressive hepatomegaly and tracheal stenosis. CASE SUMMARY: We report on a Chinese 9-year-old girl with GD with the c.5243G>T (p.C1748F) mutation in FBN1 (fibrillin 1, OMIM 134797). She was born in Guangxi Zhuang Autonomous Region of China. The patient presented with typical clinical features of GD and recurrent respiratory tract infections over 6 years. Laboratory studies and chest computed tomography (CT) scan indicated bronchopneumonia. Her echocardiography revealed mild mitral valve thickening with regurgitation. Laryngopharyngeal CT and electronic bronchoscopy revealed severe glottic stenosis. Echocardiography examination displayed mild mitral valve thickening and regurgitation. Ophthalmic examination did not reveal myopia or lens dislocation. Treated with ceftriaxone sodium and methylprednisolone sodium succinate for injection as well as methylprednisolone orally, patient's symptoms had improved. CONCLUSION: GD is a rare genetic condition that can cause life-threatening cardiovascular and respiratory problems. This study also found that the identified genotype of GD could be related to different clinical phenotypes.

miR­29a­3p regulates the epithelial­mesenchymal transition via the SPARC/ERK signaling pathway in human bronchial epithelial cells.

Neutrophilic asthma (NA) is a subtype of asthma that responds poorly to corticosteroid treatment. In certain diseases, microRNA (miR)­29a­3p is considered to be a key regulatory molecule for remodeling of the extracellular matrix. However, the effect of miR­29a­3p on airway remodeling is unknown. The present study aimed to investigate the role of miR­29a­3p in NA. A mouse model of NA was established and these animals were compared to normal controls. Both groups of mice were subjected to lung function tests and histopathological analysis. Human bronchial epithelial cells (16HBE) were grown in culture and incubated with secreted protein acidic rich in cysteine (SPARC) and a miR­29a­3p mimic. The expression of miR­29a­3p, SPARC and epithelial­mesenchymal transition (EMT)­related markers were measured using reverse transcription­quantitative PCR and western blotting. Luciferase reporter assay was performed to identify the direct regulatory relationship between miR­29a­3p and SPARC. miR­29a­3p expression was significantly decreased, while SPARC expression was increased in the NA mouse model with a phenotype of EMT. Overexpression of SPARC downregulated the expression of E­cadherin, while it increased the expression of vimentin in 16HBE cells. miR­29a­3p administration reversed the SPARC­induced effects on E­cadherin and vimentin expression. Luciferase assays confirmed that SPARC was the target gene for miR­29a­3p. Furthermore, SPARC overexpression increased the protein expression of phosphorylated (p)­ERK, while transfection with miR­29a­3p mimics significantly inhibited this increase. The data suggested that EMT in the NA mouse model was associated with decreased levels of miR­29a­3p and elevated SPARC. Furthermore, SPARC could induce the formation of EMT in 16HBE cells in vitro and this was directly targeted by miR­29a­3p and mediated by p­ERK, suggesting that miR­29a­3p may participate in the airway remodeling of NA.

Relationship between Th17-mediated immunity and airway inflammation in childhood neutrophilic asthma.

BACKGROUND: The pathogenetic mechanisms of neutrophilic asthma are not well understood now. Whether T helper (Th)17-mediated immunity contributes to the pathogenesis of neutrophilic asthma in human is still under investigation. The aim of this study was to explore the relationship between Th17-mediated immunity and airway inflammation in childhood neutrophilic asthma. METHODS: Twenty-eight children with exacerbated asthma and without using any glucocorticoids were divided into three groups: eosinophilic asthma (EA, n = 12) group, neutrophilic asthma (NA, n = 10) group and paucigranulocytic asthma (PGA, n = 6) group according to the induced sputum cytology. Ten healthy children were recruited as healthy control (HC, n = 10) group. Peripheral Th17 and Th2 cells, and the expression of Ki-67 in peripheral Th17 cells were detected by flow cytometry. The mRNA expression of retinoic acid-related orphan receptor γt (RORγt) in peripheral blood mononuclear cells (PBMCs) was detected by qRT-PCR. The concentrations of IL-17, IL-8 and IL-5 in sputum, as well as IL-17 in plasma and culture supernatant of activated PBMCs were measured by ELISA. RESULTS: The percentage of Th17 cells in peripheral Th cells, and the concentrations of IL-17, IL-8 in sputum, as well as IL-17 in culture supernatant of activated PBMCs were all increased in NA group, and positively correlated with neutrophil level in sputum and with each other. Also, the mRNA expression of RORγt in PBMCs and Ki-67 positivity in peripheral Th17 cells were both increased in NA group. The percentage of Th2 cells in peripheral Th cells, and the concentration of IL-5 in sputum were both increased in EA group, and positively correlated with eosinophil level in sputum and with each other. CONCLUSIONS: Both Th17- and Th2-mediated immunity are involved in the pathogenesis of childhood asthma. There is predominance of Th17-mediated immunity and Th17 cells proliferation in childhood neutrophilic asthma.

Exosomes Derived from Human Umbilical Cord Mesenchymal Stem Cells Regulate Macrophage Polarization to Attenuate Systemic Lupus Erythematosus-Associated Diffuse Alveolar Hemorrhage in Mice.

BACKGROUND AND OBJECTIVES: To investigate the effect and the underlying mechanism of exosomes secreted by human umbilical cord mesenchymal stem cells (hUCMSCs) on diffuse alveolar hemorrhage (DAH) in murine lupus. METHODS AND RESULTS: Exosomes were extracted from cultured hUCMSCs by ultracentrifugation. The expressions of exosome markers (Alix, CD63 and TSG101) were measured for identification of hUCMSC-derived exosomes (hUCMSC-exosomes). The alveolar hemorrhage of DAH mice was revealed by H&E staining. The primary alveolar macrophages were isolated from bronchoalveolar lavage fluid (BALF) of DAH mice. The expressions of M1 macrophage markers (iNOS, IL-6, TNF-α and IL-1ß) and M2 macrophage markers (Arg1, IL-10, TGF-ß and chi3l3) were detected. Flow cytometry measured the ratio of M1/M2 macrophages. ELISA measured the secretion of pro-inflammatory cytokines (IL-6 and TNF-α) and anti-inflammatory cytokines (IL-10 and TGF-ß). DAH mice had hemorrhage and small-vessel vasculitis in the lung, with neutrophil and monocyte infiltration observed around the capillary and small artery. Furthermore, increases of IL-6 and TNF-α, and decreases of IL-10 and TGF-ß were detected in the BALF of DAH mice. M1 makers were overexpressed in alveolar macrophages of DAH mice while M2 makers were lowly expressed. DAH mice had a higher proportion of M1 macrophages than M2 macrophages. After hUCMSC-exosome or methylprednisolone treatment in DAH mice, the alveolar injuries and inflammatory responses were attenuated, and the proportion of M2 macrophages was increased. CONCLUSIONS: hUCMSC-exosomes attenuate DAH-induced inflammatory responses and alveolar hemorrhage by regulating macrophage polarization.

Efficacy and safety of interferon α-2b spray for herpangina in children: A randomized, controlled trial.

OBJECTIVES: The treatment of acute herpangina is inconsistent. We aim to evaluate the effectiveness and safety of interferon α-2b spray versus Ribavirin for this disease. METHODS: A randomized, controlled trial was conducted in eight hospitals in China between 2016 and 2018. 668 patients (1-7 years old) were randomized into an experimental group (treated with Interferon α-2b spray) or control group (received Ribavirin Aerosol). Body temperature returning to normal within 72 h and remaining so for 24 h was the primary outcome; release of oral herpes and adverse events were the secondary outcomes. RESULTS: (1) The average age of onset was 2.5 years old. (2) After 72 h treatment, body temperature of 98.5% patients in experimental group and 94.3% in control group returned to normal and remained so for 24 h (P = 0.004). The differences were greater at 48 h treatment (95.2% vs. 85.9%, P < 0.001) and at 24 h (77.5% vs. 66.5%, P = 0.001). (3) The rate of improved oral herpes in the experimental group was higher than that in control group (46.7% vs.37.1%, P = 0.011). No adverse reaction occurred. CONCLUSIONS: Local application of recombinant interferon α-2b spray showed better efficacy for acute herpangina in children. It was safe for use.

Prosurvival activity for airway neutrophils in severe asthma.

BACKGROUND: Airway neutrophilia is a recognised feature of chronic severe asthma, but the mechanisms that underlie this phenomenon are unknown. Evidence for factors present in airway secretions that prolong neutrophil survival has been sought and it has been hypothesised that these might be augmented in neutrophilic asthma. METHODS: Non-smoking subjects with severe asthma (SA) or mild asthma (MA) and healthy control subjects (HC) underwent sputum induction. The SA group was subdivided into subjects with neutrophil counts above (SA-high) and those within the normal range (SA-low). Apoptotic neutrophils were enumerated in the cellular phase while the fluid phase was assessed for its ability to prolong the in vitro survival of blood-derived neutrophils using morphometric and flow cytometric analyses. RESULTS: There was a significant difference between all four subject groups with respect to the percentage of apoptotic sputum neutrophils (Kruskal-Wallis, p=0.042). Cuzick test showed a highly significant (p=0.008) trend towards decreasing numbers of apoptotic neutrophils across the four groups with increasing asthma severity and neutrophil count. The sputum antiapoptotic activity was also different between the groups (p=0.039), with a highly significant (p=0.005) decreasing trend across the four groups. The survival effect could not be inhibited by blocking selective chemotaxin receptors, neutralising neutrophil survival factors, inhibiting phosphatidylinositol-3-kinase (using LY294002) or with pertussis toxin pretreatment. Similarly, it could not be explained by lipopolysaccharide contamination or by the presence of inhaled corticosteroids in sputum. CONCLUSIONS: These data demonstrate the capacity of as yet unidentified factor(s) in the airways of subjects with asthma to delay human neutrophil apoptosis and extend their lifespan as a potential mechanism contributing to unresolving airways neutrophilia in severe asthma.

[Primary immunodeficiency diseases in children: clinical analysis of 35 cases].

OBJECTIVE: To summarize clinical features of primary immunodeficiency diseases (PID) in children. METHODS: The clinical data of 35 children with PID from September 2005 to December 2008 were studied retrospectively, including illness history, birth history, family history, clinical manifestations, laboratory findings, diagnosis, treatment and outcome. RESULTS: Of the 35 cases of PID, 6 cases were confirmed with combined T- and B-cell immunodeficiency, 4 cases with X-linked agammaglobulinaemia, 22 cases with selective IgG subclass deficiency, 1 case with common variable immunodeficiency and 2 cases with chronic granulomatous disease. All cases had fever and recurrent infections. Respiratory and digestive tract infections were the most common clinical manifestation. Some of the PID cases lagged behind the normal children of the same age in growth and development. Human gamma-globulin transfusion and anti-infection therapy were administered. Two patients discontinued the therapy, one was transferred to the other hospital and the other 32 patients were discharged following improvement in clinical symptoms. CONCLUSIONS: PID should be considered in children who suffer from recurrent infections and autoimmune diseases or do not respond to long-term use of antibiotics. Immunologic tests should be done as early as possible for the children.

Effect of IL­7 on Th17 cell responses in a mouse model of neutrophilic asthma.

Neutrophilic asthma (NA) is characterized by neutrophil­mediated inflammation and the presence of Th17 cells. However, the mechanisms underlying Th17 cell responses in NA remain unknown. The aim of the present study was to examine the effects of interleukin (IL)­7 on Th17 cell responses in NA. A NA mouse model was sensitized by airway delivery of ovalbumin (OVA) and lipopolysaccharide and challenged with 1% OVA aerosol from day 21 for 3 consecutive days. Airway resistance was then measured to assess airway hyper­responsiveness (AHR). Cells from bronchoalveolar lavage fluid (BALF) underwent Diff­Quick and hematoxylin and eosin staining for classification. The levels of IL­17 in the BALF were determined by ELISA. The effects of IL­7 administration and STAT5 inhibition on Th17 cells were also characterized in vitro using splenic CD4+ T cells. Ki­67, Bcl­2 and activated caspase­3 expression in differentiated Th17 cells were analyzed by flow cytometry. The mouse model of NA was characterized by increased AHR, elevated levels of IL­17, high neutrophil counts in BALF, accumulated inflammatory cells in the lung and Th17 cell responses. IL­7 promoted the expression of Ki­67 and Bcl­2 while reducing caspase­3 expression. STAT5 inhibitor treatment decreased the levels of Ki­67 and Bcl­2, and resulted in increased expression of caspase­3. These results suggested that the IL­7/JAK/STAT5 signaling pathway may be involved in Th17 cell responses in NA.

Update on protracted bacterial bronchitis in children.

BACKGROUND: Chronic cough is a common symptom in children and protracted bacterial bronchitis (PBB) is one of the causes of chronic cough. However, the understanding of this disease remains limited. The present study aims to update PBB in children. METHODS: The clinical data of children with PBB from 2014 to 2018 were retrospectively analyzed, and PBB clinical features of published studies were summarized. Electronic databases were searched in May 2019. Clinical studies were included in the present study. Reviews were undertaken in duplicate. RESULTS: Totally 712 cases were analyzed in this study, including 52 cases in our center and 660 cases from 14 studies. In the 52 cases, 88.5% of patients with PBB were less than 6 years old and all of them complained of wet cough. Three cases were confirmed with laryngomalacia, and microbiologically-based-PBB were identified in 13 cases (9 Streptococcus pneumonia, 3 Staphylococcus aureus, and 1 Pseudomonas aeruginosa). Twenty cases were completely remitted after treatment. In the 14 studies, the patients with PBB were typically younger than 3 years old, accompanying wheezing and airway malacia. Co-infection was common in most western cases, Streptococcus pneumonia, Haemophilus influenza and Moraxella catarrhalis were the top three pathogens. Symptoms were improved in most patients, whereas some cases with comorbidities required prolonged antibiotics treatment. CONCLUSIONS: PBB is common in male infants with chronic wet cough and accompanied by wheezing and airway deformities. Most cases are clinically diagnosed PBB in China and microbiologically-based-PBB is common in western countries. Co-infection could be found, Streptococcus pneumoniae and Haemophilus influenza were the most frequent etiology in China and western countries, respectively. Patients with comorbidities may need extended antibiotics treatment for more than 2 weeks.