Molecular evolution of human coronavirus-NL63, -229E, -HKU1 and -OC43 in hospitalized children in China.

Human coronaviruses (HCoVs) HCoV-NL63, HCoV-229E, HCoV-HKU1 and HCoV-OC43 have been circulated in the human population worldwide, and they are associated with a broad range of respiratory diseases with varying severity. However, there are neither effective therapeutic drugs nor licensed vaccines available for the treatment and prevention of infections by the four HCoVs. In this study, we collected nasopharyngeal aspirates of children hospitalized for respiratory tract infection in China during 2014-2018 and conducted next-generation sequencing. Sequences of four HCoVs were then selected for an in-depth analysis. Genome sequences of 2 HCoV-NL63, 8 HCoV-229E, 2 HCoV-HKU1, and 6 HCoV-OC43 were obtained. Based on the full-length S gene, a strong temporal signal was found in HCoV-229E and the molecular evolutionary rate was 6 × 10-4 substitutions/site/year. Based on the maximum-likelihood (ML) phylogenetic tree of complete S gene, we designated H78 as a new sub-genotype C2 of HCoV-HKU1, and the obtained P43 sequence was grouped into the reported novel genotype K of HCoV-OC43 circulating in Guangzhou, China. Based on the complete genome, potential recombination events were found to occur as two phenomena, namely intraspecies and interspecies. Moreover, we observed two amino acid substitutions in the S1 subunit of obtained HCoV-NL63 (G534V) and HCoV-HKU1 (H512R), while residues 534 and 512 are important for the binding of angiotensin-converting enzyme 2 and neutralizing antibodies, respectively. Our findings might provide a clue for the molecular evolution of the four HCoVs and help in the early diagnosis, treatment and prevention of broad-spectrum HCoV infection.

A rare pathogen causing pulmonary infection and liver dysfunction in a 46-day-old infant: Rhizobium radiobacter.

Rhizobium radiobacter is an aerobic, motile, oxidase-positive, non-spore-forming Gram-negative tumorigenic plant pathogen which rarely infects humans. A 46-day-old girl was admitted to hospital with a 10-day history of fever and cough. She had pneumonia and liver dysfunction owing to infection by R. radiobacter. After 3 days of treatment with ceftriaxone, (compound glycyrrhizin and ambroxol), her body temperature returned to normal and the pneumonia improved, but liver enzyme levels continued to rise. After treatment with meropenem (glycyrrhizin and reduced glutathione), her condition stabilised and she recovered with no liver damage, and was discharged after 15 days. R. radiobacter has low virulence and antibiotics are highly sensitive, but, rarely, severe organ dysfunction can occur and result in multi-system damage in vulnerable children.

Plastic bronchitis associated with influenza A virus in children with asthma.

Plastic bronchitis (PB) is a rare and potentially fatal disease characterized by acute progressive dyspnea caused by bronchial casts in the bronchial tree. We analyzed two children with asthma and PB who presented with high fever, cough and dyspnea. Both cases showed acute onset and rapid disease progression. Laboratory examination revealed that both children were infected with influenza A virus. Emergency fiberoptic bronchoscopy was performed within 20 hours of admission. Immediately after removing the bronchial casts, their dyspnea symptoms improved significantly, and they recovered after comprehensive treatment with antiviral drugs, antibiotics and glucocorticoids. When children with asthma have acute progressive and difficult-to-relieve dyspnea after infection with influenza A virus, clinicians should be aware of the possibility of PB and perform bronchoscopy as soon as possible to facilitate early diagnosis and treatment and improve patient prognosis.

The effect of recombinant human interferon α1b treatment of infants hospitalized with lower respiratory tract infection on subsequent wheezing

Abstract Objective: To investigate the impact of recombinant human interferon α1b (rhIFNα1b) treatment in infants hospitalized with lower respiratory tract infections on subsequent wheezing. Methods: The clinical data of infants (n = 540) with viral pneumonia, wheezy bronchitis, or bronchiolitis hospitalized in 19 Chinese hospitals from June 2009 to June 2015 were retrospectively analyzed. The parameters relevant to wheezing episodes within the last year were collected by telephone and questionnaires. The rhIFNα1b treatment group (n = 253) and control group (n = 287) were compared in terms of wheezing episodes within the last year. Moreover, the wheezing group (95 cases) and non-wheezing group (445 cases) were compared. Results: Out of 540 cases, 95 (17.6%) experienced wheezing episodes, 13.8% (35/253) cases treated with rhIFNα1b, and 20.9% (60/287) cases without rhIFNα1b experienced wheezing episodes within the last year. The rhIFNα1b treatment significantly improved wheezing episodes within the last year, compared with the control peers (p = 0.031). Single-factor regression showed statistically significant differences between the wheezing and non-wheezing groups in terms of age, rhIFNα1b use, childhood and family history of allergy, housing situation, and feeding history (p < 0.05). Binary logistic regression showed a childhood history of allergy (OR = 2.14, p = 0.004), no rhIFNα1b use (OR = 1.70, p = 0.028), and living in a crowded house (OR = 1.92, p = 0.012) might be risk factors of subsequent wheezing. Accordingly, breastfeeding (OR = 0.44, p = 0.008) and hospitalization age of 1-year-old (OR = 0.58, p = 0.024) were protective factors. Conclusions: Early use of rhIFNα1b in infants hospitalized with lower respiratory tract infections and breastfeeding could prevent subsequent wheezing. Living in a crowded house could promote subsequent wheezing.

Efficacy of Huaiqihuang granules as adjuvant therapy for bronchial asthma in children: a real-world study. / æ§æžé»„é¢—ç²’è¾ åŠ©æ²»ç–—å„¿ç«¥æ”¯æ°”ç®¡å“®å–˜ç–—æ•ˆçš„çœŸå®žä¸–ç•Œç ”ç©¶.

OBJECTIVES: To study the efficacy of Huaiqihuang granules as adjuvant therapy for bronchial asthma in children. METHODS: A multicenter, prospective, and registered real-world study was performed for the children, aged 2-5 years, who had a confirmed diagnosis of bronchial asthma in the outpatient service of 21 hospitals in China. Among these children, the children treated with medications for long-term asthma control (inhaled corticosteroid and/or leukotriene receptor antagonist) without Huaiqihuang granules were enrolled as the control treatment group, and those treated with medications for long-term asthma control combined with Huaiqihuang granules were enrolled as the combined treatment group. The medical data of all children were collected. Outpatient or telephone follow-up was performed at weeks 4, 8, 12, 20, 28, and 36 after treatment, including asthma attacks and rhinitis symptoms. A statistical analysis was performed for the changes in these indices. RESULTS: There was no significant difference in the frequency of asthma attacks or rhinitis attacks between the two groups before treatment (P>0.05). After treatment, the combined treatment group had significantly lower frequencies of asthma attacks, severe asthma attacks, and rhinitis attacks compared with the control treatment group (P<0.05). There was no signification difference in the incidence rate of adverse reactions between the two groups (P=0.667). CONCLUSIONS: Huaiqihuang granules in addition to medications for long-term asthma control can alleviate the symptoms of bronchial asthma and rhinitis and improve the level of asthma control in children with bronchial asthma, with good safety and little adverse effect. Citation.

Comprehensive Description of Pathogens and Antibiotic Treatment Guidance in Children With Community-Acquired Pneumonia Using Combined Mass Spectrometry Methods.

The objective of this study was to evaluate the value of molecular methods in the management of community-acquired pneumonia (CAP) in children. Previously developed mass spectrometry (MS)-based methods combined with quantitative real-time PCR (combined-MS methods) were used to describe the aetiology and evaluate antibiotic therapy in the enrolled children. Sputum collected from 302 children hospitalized with CAP were analyzed using the combined-MS methods, which can detect 19 viruses and 12 bacteria related to CAP. Based on the results, appropriate antibiotics were determined using national guidelines and compared with the initial empirical therapies. Respiratory pathogens were identified in 84.4% of the patients (255/302). Co-infection was the predominant infection pattern (51.7%, 156/302) and was primarily a bacterial-viral mixed infection (36.8%, 111/302). Compared with that using culture-based methods, the identification rate for bacteria using the combined-MS methods (61.8%, 126/204) increased by 28.5% (p <0.001). Based on the results of the combined-MS methods, the initial antibiotic treatment of 235 patients was not optimal, which mostly required switching to ß-lactam/ß-lactamase inhibitor combinations or reducing unnecessary macrolide treatments. Moreover, using the combined-MS methods to guide antibiotic therapy showed potential to decrease the length of stay in children with severe CAP. For children with CAP, quantitative molecular testing on sputum can serve as an important complement to traditional culture methods. Early aetiology elucidated using molecular testing can help guide the antibiotic therapy.

A multi-center study on Molecular Epidemiology of Human Respiratory Syncytial Virus from Children with Acute Lower Respiratory Tract Infections in the Mainland of China between 2015 and 2019.

Human respiratory syncytial virus (RSV) is a major pathogen of acute lower respiratory tract infection among young children. To investigate the prevalence and genetic characteristics of RSV in China, we performed a molecular epidemiological study during 2015-2019. A total of 964 RSV-positive specimens were identified from 5529 enrolled patients during a multi-center study. RSV subgroup A (RSV-A) was the predominant subgroup during this research period except in 2016. Totally, 535 sequences of the second hypervariable region (HVR-2) of the G gene were obtained. Combined with 182 Chinese sequences from GenBank, phylogenetic trees showed that 521 RSV-A sequences fell in genotypes ON1 (512), NA1 (6) and GA5 (3), respectively; while 196 RSV-B sequences fell in BA9 (193) and SAB4 (3). ON1 and BA9 were the only genotypes after December 2015. Genotypes ON1 and BA9 can be separated into 10 and 7 lineages, respectively. The HVR-2 of genotype ON1 had six amino acid changes with a frequency more than 10%, while two substitutions H258Q and H266L were co-occurrences. The HVR-2 of genotype BA9 had nine amino acid substitutions with a frequency more than 10%, while the sequences with T290I and T312I were all from 2018 to 2019. One N-glycosylation site at 237 was identified among ON1 sequences, while two N-glycosylation sites (296 and 310) were identified in the 60-nucleotide duplication region of BA9. To conclusion, ON1 and BA9 were the predominant genotypes in China during 2015-2019. For the genotypes ON1 and BA9, the G gene exhibited relatively high diversity and evolved continuously.

Molecular Characteristics of Human Adenovirus Type 3 Circulating in Parts of China During 2014-2018.

Human adenoviruses (HAdVs) are important pathogens causing respiratory infections; 3.5-11% of childhood community-acquired pneumonia is associated with HAdV infection. Human adenovirus type 3 (HAdV-3), leading to severe morbidity and mortality, is one of the most prevalent genotype among adenoviruses responsible for acute respiratory infections (ARIs) in children in China. To identify the genetic variation of HAdV-3 in children with ARIs in China, a molecular epidemiological study was conducted. A total of 54 HAdV-3 isolated strains were obtained from children with ARIs in Beijing, Wenzhou, Shanghai, Shijiazhuang, Hangzhou, Guangzhou, and Changchun from 2014 to 2018. Thirty-two strains of which were selected for whole-genome sequencing, while the hexon, penton base, and fiber genes were sequenced for remaining strains. Bioinformatics analysis was performed on the obtained sequences. The phylogenetic analyses based on whole-genome sequences, major capsid protein genes (hexon, penton base, and fiber), and early genes (E1, E2, E3, and E4) showed that the HAdV-3 strains obtained in this study always clustered together with the reference strains from Chinese mainland, while the HAdV-3 prototype strain formed a cluster independently. Compared with the prototype strain, all strains possessed nine amino acid (AA) substitutions at neutralization antigenic epitopes of hexon. The homology models of the hexon protein of the HAdV-3 prototype and strain BJ20160214 showed that there was no evident structural change at the AA mutation sites. Two AA substitutions were found at the Arg-Gly-Asp (RGD) loop and hypervariable region 1 (HVR1) region of the penton base. A distinct AA insertion (20P) in the highly conserved PPPSY motif of the penton base that had never been reported before was observed. Recombination analysis indicated that partial regions of protein IIIa precursor, penton base, and protein VII precursor genes among all HAdV-3 strains in this study were from HAdV-7. This study showed that the genomes of the HAdV-3 strains in China were highly homologous. Some AA mutations were found at antigenic sites; however, the significance needs further study. Our data demonstrated the molecular characteristics of HAdV-3 circulating in China and was highly beneficial for further epidemiological exploration and the development of vaccines and drugs against HAdV-3.

The effect of recombinant human interferon α1b treatment of infants hospitalized with lower respiratory tract infection on subsequent wheezing.

OBJECTIVE: To investigate the impact of recombinant human interferon α1b (rhIFNα1b) treatment in infants hospitalized with lower respiratory tract infections on subsequent wheezing. METHODS: The clinical data of infants (n=540) with viral pneumonia, wheezy bronchitis, or bronchiolitis hospitalized in 19 Chinese hospitals from June 2009 to June 2015 were retrospectively analyzed. The parameters relevant to wheezing episodes within the last year were collected by telephone and questionnaires. The rhIFNα1b treatment group (n=253) and control group (n=287) were compared in terms of wheezing episodes within the last year. Moreover, the wheezing group (95 cases) and non-wheezing group (445 cases) were compared. RESULTS: Out of 540 cases, 95 (17.6%) experienced wheezing episodes, 13.8% (35/253) cases treated with rhIFNα1b, and 20.9% (60/287) cases without rhIFNα1b experienced wheezing episodes within the last year. The rhIFNα1b treatment significantly improved wheezing episodes within the last year, compared with the control peers (p=0.031). Single-factor regression showed statistically significant differences between the wheezing and non-wheezing groups in terms of age, rhIFNα1b use, childhood and family history of allergy, housing situation, and feeding history (p<0.05). Binary logistic regression showed a childhood history of allergy (OR=2.14, p=0.004), no rhIFNα1b use (OR=1.70, p=0.028), and living in a crowded house (OR=1.92, p=0.012) might be risk factors of subsequent wheezing. Accordingly, breastfeeding (OR=0.44, p=0.008) and hospitalization age of ≤1-year-old (OR=0.58, p=0.024) were protective factors. CONCLUSIONS: Early use of rhIFNα1b in infants hospitalized with lower respiratory tract infections and breastfeeding could prevent subsequent wheezing. Living in a crowded house could promote subsequent wheezing.

Genetic Analysis of Human Adenovirus Type 7 Strains Circulating in Different Parts of China.

To investigate the molecular epidemiology and genetic variation of human adenovirus type 7 (HAdV-7) in children with acute respiratory infections (ARI) in China. HAdV-7-positive respiratory samples collected from children with ARI in Beijing, Shijiazhuang, Wenzhou and Guangzhou from 2014-2018 were selected for gene amplification and sequence analysis. Fifty-seven HAdV-7 clinical strains with hexon, penton base and fiber gene sequences were obtained. Meanwhile 17 strains were selected randomly from different cities for whole genome sequencing. Phylogenetic and variation analyses were performed based on the obtained sequences, HAdV-7 prototype strain Gomen (AY594255), vaccine strains (AY495969 and AY594256) and representative sequences of strains. The phylogenetic trees constructed based on whole genome sequences, major capsid protein genes (hexon, penton base and fiber) and the early genes (E1, E2, E3 and E4) were not completely consistent. The HAdV-7 strains obtained in this study always clustered with most of the circulating strains worldwide from the 1980s to the present. Compared with the HAdV-7 prototype strain Gomen (AY594255), some amino acid mutations in loop1 and loop2 of hexon and the RGD loop region of the penton base gene were observed. Recombination analysis showed that partial regions of 55 kDa protein and 100 kDa hexon-assembly associated protein genes among all HAdV-7 strains in this study were from HAdV-16 and HAdV-3, respectively. Our study demonstrated the molecular evolution characteristics of HAdV-7 strains circulating in China and provided basic reference data for the prevention, control and vaccine development of HAdV-7.

Familial Interstitial Lung Disease Caused by Mutation of the STING1 Gene.

Mutations that affect the STING1 (TMEM173) gene cause a rare autoinflammatory syndrome, which is known as STING-associated vasculopathy with onset in infancy (SAVI) and which was initially described in 2014 (1). Thus far, only four reports have been conducted regarding families affected with SAVI in the literature. In this article, the clinical, laboratory, and genetic characteristics of two generations (three cases) of SAVI are described. Unlike previously reported cases that were caused by STING1 mutation, the initial and major clinical manifestations of the mentioned cases are largely identified in the lungs with interstitial lung disease (ILD), and the evidence of typical extrapulmonary symptoms of early-onset systemic inflammation (e.g., cutaneous vasculopathy) were minimal except for the proband, who was diagnosed with arthritis 8 years after onset. In addition, a younger sibling showed no symptoms. Such reports are rarely related to mutations in STING1. The proband was examined with bronchoscopy and alveolar lavage to determine the cause. This study emphasizes that, in the clinical assessment of interstitial pneumonia in children, the possibility of STING1 mutation should be considered, especially in patients with arthritis in addition.

CYSLTR1 promotes adenoid hypertrophy by activating ERK1/2.

Cysteinyl leukotriene receptor 1 (CYSLTR1) serves a pivotal role in allergic reactions, which is one of the main causes of adenoid hypertrophy. The present study aimed to investigate the function of CYSLT1 within adenoid hypertrophy. A total of 40 patients with adenoid hypertrophy were recruited between January 2014 and January 2016 at the Children's Hospital of Hebei Province, China. The patients were divided into either the mild-moderate group or the severe group according to their disease severity. The expression of CYSLT1 in the adenoid tissue and whole blood of all patients and healthy controls was detected by reverse transcription-quantitative polymerase chain reaction. Associations between the expression level of CYSLT1 and the clinical characteristics of patients were analyzed. Primary human adenoid epithelial cells (HAECs) with CYSLT1 knockdown and overexpression were constructed. The levels of extracellular signal-regulated kinase (ERK)2 and phosphorylated-ERK1/2 in adenoid tissue and HAECs were detected by western blot analysis. The expression of CYSLT1 in adenoid tissue and whole blood of all patients with adenoid hypertrophy was significantly higher compared with the healthy controls (P<0.05). In addition, the expression level of CYSLT1 was significantly higher in the severe group compared with the mild-moderate group (P<0.05). The highest level of p-ERK1/2 in adenoid tissue was observed in the severe group, followed by the mild-moderate group and then the control group (P<0.05). CYSLT1 expression was positively associated with the severity of disease. CYSLT1 knockdown significantly decreased the level of p-ERK1/2 in HAECs (P<0.05), while CYSLT1 overexpression significantly increased the level of p-ERK1/2. It was concluded that CYSLT1 may contribute to the progression of adenoid hypertrophy by activating ERK1/2.

Genetic variations in the fusion protein of respiratory syncytial virus isolated from children hospitalized with community-acquired pneumonia in China.

To identify the variations in fusion (F) protein gene of RSV in China, a molecular epidemiological study was conducted. A total of 553 RSV positive specimens were collected from 2338 pediatric patients hospitalized with community-acquired pneumonia during a multi-center study conducted during 2014-2016. A total of 252 samples (183 RSV A, 69 RSV B) were selected for F gene sequencing, and analyzed together with 142 F gene sequences downloaded from GenBank. The result showed that all the Chinese RSV A and RSV B strains could be divided respectively into three branches. Compared with RSV A/B prototype sequences respectively, there were significant amino acid (AA) mutations at multiple antigenic sites. For RSV A, changes were found at AA residues 122, 124, 125, 276 and 384, and for RSV B at AA residues 45, 116, 125, 172, 173 and 202. Variations in human histocompatibility leukocyte antigen-restricted CTL epitopes were also observed. In total, 56 amino acid differences for the complete F protein were found between the RSV A and B groups in China, while several mutations were only found in the RSV B strains during 2015-2016. The RSV F gene is relatively conserved in China, however, limited mutations are still occurring with time.

[Detection of respiratory viruses in children with acute lower respiratory tract infection: an analysis of 5,150 children].

OBJECTIVE: To investigate the distribution of respiratory viruses on throat swabs in hospitalized children with acute lower respiratory tract infection (ALRTI). METHODS: A total of 5,150 children with ALRTI who were admitted to Hebei Children's Hospital between March 2014 and February 2015 were enrolled to investigate the distribution of respiratory viruses in children with ALRTI. Direct immunofluorescence assay was performed for throat swabs from these children to detect influenza virus A (FA), influenza virus B (FB), adenovirus (ADV), respiratory syncytial virus (RSV), and parainfluenza virus types 1, 2, and 3 (PIV-1, PIV-2, and PIV-3). RESULTS: Of all the 5,150 throat swabs from hospitalized children, 2,155 (41.84%) had positive virus detection results. RSV had the highest detection rate (1,338 cases/25.98%), followed by PIV-3 (439 cases/8.52%) and FA (166 cases/3.22%), and 29 patients had mixed infection with 2 viruses. With the increasing age, the detection rates of viruses tended to decrease (χ2=279.623; P<0.01). The positive rate of RSV increased gradually from September, and reached the peak value (60.09%) in November; the lowest positive rate occurred in June (1.51%). The positive rate of PIV-3 was the highest in May (21.38%) and the lowest in November (1.77%). CONCLUSIONS: The distribution of viruses in children with ALRTI varies with age and season, with RSV prevalence in autumn and winter and PIV-3 prevalence in spring and summer. RSV is the most common viral pathogen that causes ALRTI in hospitalized children.

[Prognostic judgment of children with Mycoplasma pneumoniae pneumonia associated with airway mucous plug formation].

OBJECTIVE: To investigate the clinical characteristics and treatment defects in slow-to-recover children with Mycoplasma pneumoniae pneumonia (MPP) associated with airway mucous plug formation, and to provide a basis for prognostic judgment and therapeutic guidance. METHODS: A retrospective analysis was performed on the clinical data of 67 children with MPP who were admitted between May 2012 and May 2014 and showed airway mucous plug formation in fiberoptic bronchoscope examinations. Based on the results of re-examinations using imaging methods, all patients were classified into a slow-to-recover group (n=30) and a control group (n=37). Comparisons of clinical outcomes, laboratory indices, imaging findings, and treatment methods were performed between the two groups. The receiver operating characteristic (ROC) curves were drawn to analyze the indices with significant differences. RESULTS: The percentage of neutrophils, levels of C-reactive protein (CRP), lactic dehydrogenase (LDH), fibrinogen (FIB), and IgM in peripheral blood, and incidence of pleural effusion were significantly higher in the slow-to-recover group than in the control group (P<0.05). The fever duration and treatment time of azithromycin and fiberoptic bronchoscope for the first time were significantly longer in the slow-to-recover group than in the control group (P<0.05). The results of ROC curve analysis showed that the optimal cut-off points of fever duration, percentage of neutrophils, levels of CRP and FIB, and treatment time of fiberoptic bronchoscope for the first time were 11.5 days, 70.7%, 57 mg/L, 4.7 g/L, and 13.5 days, respectively, with sensitivity and specificity higher than 0.643 and 0.727. CONCLUSIONS: The fever duration, percentage of neutrophils, level of CRP, level of FIB, and treatment time of fiberoptic bronchoscope for the first time can predict a recovery time longer than two months in children with MPP associated with mucous plug formation.

[Correlation of fractional exhaled nitric oxide with peripheral blood eosinophils and lung function in 1-3-year-old children with asthma].

OBJECTIVE: To examine fractional exhaled nitric oxide (FeNO) values in 1-3-year-old children with asthma and analyze the correlation of FeNO with peripheral blood eosinophils (EOS) and lung function in these children. METHODS: A total of 111 children aged 1-3 years with asthma were enrolled. The children were classified into acute exacerbation (n=62) and remission groups (n=49) according to their symptoms. FeNO values, lung function, and peripheral blood EOS count were measured in these children. Sixty age-matched healthy children were enrolled as the control group. RESULTS: FeNO values were significantly higher in the acute exacerbation group (24.4 ppb) than in the remission group (18.0 ppb) and the control group (13.7 ppb) (P<0.05). The FeNO values in the remission group were significantly higher than in the control group (P<0.05). FeNO values were not significantly correlated with peripheral blood EOS count and lung function parameters (PEF, TEF25, TEF50, and TEF75). CONCLUSIONS: Measurement of FeNO is useful to evaluate the disease activity in children with asthma aged 1 to 3 years, but the FeNO values are not correlated with peripheral blood EOS count and lung function.

[Utility of fractional exhaled nitric oxide in children with asthma].

OBJECTIVE: To study the utility of fractional exhaled nitric oxide (FeNO) in young children at different stages of asthma. METHODS: Fifty-eight children with newly diagnosed asthma (aged 1-3 years) at the acute exacerbation stage between April and June, 2014 were recruited. After 3 months' treatment, the children switched into the chronic persistent stage (n=34) or remission stage (n=24). Thirty aged-matched healthy children served as controls. FeNO levels and lung function were measured for all subjects. The best cut-off value of FeNO for the diagnosis of asthma was evaluated by receiver operating characteristic (ROC) curve. RESULTS: The FeNO levels in children with asthma at various stages were higher than controls (P<0.05). The FeNO levels in the acute exacerbation stage were highest, followed by the chronic persistent stage (P<0.05). FeNO level was correlated to the stages of asthma (r=-0.382, P<0.001). The cut-off value of FeNO for the diagnosis of asthma was 22.75 ppb by ROC curve, with the sensitivity of 0.933 and the specificity of 0.388. CONCLUSIONS: The children with asthma at different stages have different FeNO levels. Measurement of FeNO is useful in the diagnosis of asthma in young children.

[Comparative analysis of conventional pulmonary function test results in children with asthma or cough variant asthma].

OBJECTIVE: To compare the conventional pulmonary function test results of children with asthma or cough variant asthma (CVA). METHODS: A total of 140 children, who were diagnosed with asthma or CVA from May 2010 to May 2011, were divided into acute asthma attack (n=50), asthma remission (n=50) and CVA groups (n=40); 30 healthy children were included as a control group. The forced vital capacity (FVC), forced expiratory volume in one second (FEV1), peak expiratory flow (PEF), forced expiratory flow after 25% of vital capacity has been expelled (FEF25), forced expiratory flow after 50% of vital capacity has been expelled (FEF50), forced expiratory flow after 75% of vital capacity has been expelled (FEF75) and maximal midexpiratory flow (MMEF75/25) were measured. RESULTS: The mean percent predicted values of all the above indices were lower than 80% in the acute asthma attack group, with FEF50, FEF75 and MMEF75/25 declining markedly; the mean percent predicted values of FEF75 and MMEF75/25 were lower than 80% in the CVA group. All the pulmonary function indices in the acute asthma attack group were lower than those in the control group. The mean percent predicted values of FVC, FEV1, FEF25 and MMEF75/25 in the asthma remission and CVA groups were lower than in the control group. All the pulmonary function indices in the acute asthma attack group were lower than in the asthma remission and CVA groups, but there were no significant differences between the asthma remission and CVA groups. CONCLUSIONS: There is small and large airway dysfunction, particularly small airway dysfunction, in children with acute asthma attack. Children with CVA present mainly with mild small airway dysfunction, as do those with asthma in remission.