Project description:AimLinks between respiratory syncytial virus bronchiolitis and asthma are well known, but few studies have dealt with wheezing following bronchiolitis induced by other viruses. We assessed the risk factors for recurrent wheezing in infants hospitalised for acute viral bronchiolitis.MethodsWe followed 313 infants for three years after they were hospitalised for bronchiolitis, caused by 14 different viruses, to identify risk factors for recurrent wheezing. Parents provided feedback on wheezing episodes during telephone interviews 12 (n = 266), 24 (n = 242) and 36 (n = 230) months after hospitalisation.ResultsThe frequency of wheezing episodes diminished during the follow-up period: 137 children (51.7%) at 12 months, 117 (48.3%) at 24 months and 93 (40.4%) at 36 months. The risk of wheeze after three years was OR = 7.2 (95% CI 3.9-13.3) if they had episodes of wheezing during the first year after bronchiolitis, 16.8 (8.7-32.7) if they had episodes of wheezing during the second year and 55.0 (22.7-133.2) if they wheezed during both years. Blood eosinophils >400 cells/μL (OR 7.7; CI 1.4-41.8) and rhinovirus infections (3.1; 1.0-9.4) were the major risk factors for recurrent wheezing.ConclusionRecurrent wheezing 36 months after infant bronchiolitis was associated with rhinoviruses and blood eosinophilia.
Project description:BackgroundBronchiolitis is associated with a greater risk of developing recurrent wheezing, but with currently available tools, it is impossible to know which infants with bronchiolitis will develop this condition. This preliminary prospective study aimed to assess whether urine metabolomic analysis can be used to identify children with bronchiolitis who are at risk of developing recurrent wheezing.MethodsFifty-two infants <1 year old treated in the emergency department at University Hospital of Padova for acute bronchiolitis were enrolled (77% tested positive for respiratory syncytial virus [RSV]). Follow-up visits were conducted for 2 years after the episode of bronchiolitis. Untargeted metabolomic analyses based on mass spectrometry were performed on urine samples collected from infants with acute bronchiolitis. Data modeling was based on univariate and multivariate data analyses.ResultsWe distinguished children with and those without postbronchiolitis recurrent wheeze, defined as ≥3 episodes of physician-diagnosed wheezing. Pathway overrepresentation analysis pointed to a major involvement of the citric acid cycle (P < .001) and some amino acids (lysine, cysteine, and methionine; P ≤ .015) in differentiating between these 2 groups of children.ConclusionThis is the first study showing that metabolomic profiling of urine specimens from infants with bronchiolitis can be used to identify children at increased risk of developing recurrent wheezing.
Project description:BackgroundTo better understand the role of human rhinovirus-associated wheeze as a risk factor for childhood recurrent wheezing, a cohort of young children experiencing their first wheezing episode was followed until school age.MethodsAll 111 hospitalized wheezing children (median age, 12 months) were initially participated in a randomized, double-blind, placebo-controlled, parallel trial on the efficacy of oral prednisolone. In this 7-yr follow-up, risk factors for recurrent wheezing were analysed, and then, the efficacy of prednisolone was evaluated overall and in pre-specified subgroups post-hoc. The main outcome was time to recurrent wheezing.ResultsThe strongest independent risk factor for recurrent wheezing was rhinovirus detection (hazard ratio 3.54; 95% confidence interval 1.51-8.30) followed by sensitization (3.47; 1.55-8.30, respectively) age <1 yr (2.45; 1.29-4.65) and eczema (2.33; 1.11-4.90). Overall, prednisolone did not prevent recurrent wheezing. In subgroup analysis, prednisolone was associated with less recurrent wheezing in children affected by rhinovirus (0.32; 0.12-0.90, adjusted to sensitization, young age, viral aetiology and parental asthma) and/or with eczema (0.27; 0.08-0.87, adjusted respectively).ConclusionsOur data strengthen the role of rhinovirus-associated wheeze as an important risk factor for recurrent wheezing and asthma in young first-time wheezing children. Prospective randomized trials on the efficacy of corticosteroids in rhinovirus-associated early wheezing are warranted. (ClinicalTrials.gov number, NCT 00494624).
Project description:BackgroundInfections caused by human rhinoviruses (HRVs) are important triggers of wheezing in young children. Wheezy illness has increasingly been recognised as an important cause of morbidity in African children, but there is little information on the contribution of HRV to this. The aim of this study was to determine the role of HRV as a cause of acute wheezing in South African children.MethodsTwo hundred and twenty children presenting consecutively at a tertiary children's hospital with a wheezing illness from May 2004 to November 2005 were prospectively enrolled. A nasal swab was taken and reverse transcription PCR used to screen the samples for HRV. The presence of human metapneumovirus, human bocavirus and human coronavirus-NL63 was assessed in all samples using PCR-based assays. A general shell vial culture using a pool of monoclonal antibodies was used to detect other common respiratory viruses on 26% of samples. Phylogenetic analysis to determine circulating HRV species was performed on a portion of HRV-positive samples. Categorical characteristics were analysed using Fisher's Exact test.ResultsHRV was detected in 128 (58.2%) of children, most (72%) of whom were under 2 years of age. Presenting symptoms between the HRV-positive and negative groups were similar. Most illness was managed with ambulatory therapy, but 45 (35%) were hospitalized for treatment and 3 (2%) were admitted to intensive care. There were no in-hospital deaths. All 3 species of HRV were detected with HRV-C being the most common (52%) followed by HRV-A (37%) and HRV-B (11%). Infection with other respiratory viruses occurred in 20/128 (16%) of HRV-positive children and in 26/92 (28%) of HRV-negative samples.ConclusionHRV may be the commonest viral infection in young South African children with acute wheezing. Infection is associated with mild or moderate clinical disease.
Project description:Rhinoviruses may be pathogens contributing to the development of childhood wheezing. However, their role in low risk infants without an asthmatic predisposition is unknown. Knowing which healthy, low risk children are at increased risk for childhood wheezing after rhinovirus wheezing illness (RV-WI) in infancy, might help in developing prevention and treatment strategies for childhood wheezing. The aim of this study was to determine the association of medically attended wheezing at the age of three with RV-WI in the first year of life in low risk children without parental asthma. In a low risk, prospective birth cohort study, we followed 181 healthy born children from birth through the third year of life. We considered children 'low risk' if neither parent had a doctor's diagnosis of asthma. We determined infant RV-WI by parent-reported wheezing (based on daily logs) and simultaneous molecular rhinovirus detection in the first year of life. Respiratory function and blood eosinophil count were both measured in the first month of life. The primary outcome, third year wheezing, was defined as the use of prescribed inhaled asthma medications together with a doctor's visit for respiratory symptoms in the third year of life. We calculated the association of RV-WI with medically attended third year wheezing and other known possible risk factors for wheezing at the age of three. Among low risk children, third year wheezing was observed in 7 out of 18 (39%) children with versus 10 out of 163 (6%) children without infant RV-WI (OR 9.7, 95% CI 3.1-33.5, P < 0.0001). The association between RV-WI and third year wheezing was unchanged after adjustment for potential confounders such as eosinophilia and atopic eczema. RV-WI is a robust and independent risk factor for third year wheezing in low risk children without parental asthma. Future research will identify and protect those children at increased risk for RV-WI.
Project description:MDA5 is a cytosolic sensor of double-stranded RNA (ds)RNA including viral byproducts and intermediates. We studied a child with life-threatening, recurrent respiratory tract infections, caused by viruses including human rhinovirus (HRV), influenza virus, and respiratory syncytial virus (RSV). We identified in her a homozygous missense mutation in IFIH1 that encodes MDA5. Mutant MDA5 was expressed but did not recognize the synthetic MDA5 agonist/(ds)RNA mimic polyinosinic-polycytidylic acid. When overexpressed, mutant MDA5 failed to drive luciferase activity from the IFNB1 promoter or promoters containing ISRE or NF-κB sequence motifs. In respiratory epithelial cells or fibroblasts, wild-type but not knockdown of MDA5 restricted HRV infection while increasing IFN-stimulated gene expression and IFN-β/λ. However, wild-type MDA5 did not restrict influenza virus or RSV replication. Moreover, nasal epithelial cells from the patient, or fibroblasts gene-edited to express mutant MDA5, showed increased replication of HRV but not influenza or RSV. Thus, human MDA5 deficiency is a novel inborn error of innate and/or intrinsic immunity that causes impaired (ds)RNA sensing, reduced IFN induction, and susceptibility to the common cold virus.
Project description:Asthma is one of the most common chronic diseases affecting children's health, and recurrent wheezing in infants is closely related to childhood asthma. However, up to now, there is a lack of unified diagnostic criteria and interventions for recurrent wheezing in infants. By analyzing and discussing the risk factors of recurrent wheezing in infants and related intervention measures, we aim to take individualized treatment for different children and reduce the occurrence of recurrent wheezing in infants. From January 2017 to December 2020, children under 3 years old who were admitted to the Department of Pediatric Respiratory of Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine with the chief complaint of wheezing for the first time and were clinically diagnosed with bronchiolitis, asthmatic bronchopneumonia and asthmatic bronchitis were retrospectively analyzed through telephone questionnaires. These children were divided into two groups based on whether the wheezing occurred again after discharge. The demographic characteristics, clinical treatment, imaging characteristics, and related interventions and outcomes after discharge were analyzed in both groups. Among the 523 children under 3 years old who were hospitalized due to wheezing, 264 (50.5%) did not have wheezing after discharge, and 259 (49.5%) still had wheezing after discharge. Both chi-squared test and multivariate analysis showed that male, history of eczema, history of rhinitis, history of wheezing before hospitalization, family smoke exposure, mycoplasma infection and inhalation allergen sensitization were risk factors for recurrent wheezing in infants and young children (P<0.05). Simultaneously, Cox survival curve showed that different intervention time and intervention methods would lead to different prognosis. (I) Male, with a history of eczema, rhinitis, wheezing before hospitalization, family environment smoke exposure, mycoplasma infection and a history of inhalation allergy are high risk factors for recurrent wheezing in the recurrent wheezing group, and are more likely to have recurrent wheezing after discharge, with shorter days of wheezing control; (II) there was a significant interaction between mycoplasma infection and a history of inhalation allergy in infants with the risk of recurrent wheezing; (III) long-term intervention for children with wheezing for 4 weeks or more after discharge can reduce the probability of recurrent wheezing; (IV) for children of male, with a history of eczema or rhinitis, the most effective intervention to reduce the probability of recurrent wheezing is long-term inhaled corticosteroids (ICS) treatment after discharge.
Project description:Few studies have investigated the disease burden and genetic diversity of human rhinoviruses (HRVs) in developing countries.To assess the burden of HRV in Amman, Jordan, and to characterise clinical differences between HRV groups.We prospectively studied children <5 years, hospitalised with respiratory symptoms and/or fever in Amman, Jordan. Viruses were identified by real-time reverse transcriptase polymerase chain reaction (RT-PCR). VP4/VP2 gene sequencing was performed on HRV-positive specimens.Of the 728 enrolled children, 266 (37%) tested positive for picornaviruses, 240 of which were HRV. Of the HRV-positive samples, 62 (26%) were of the recently identified group HRVC, 131 (55%) were HRVA and seven (3%) were HRVB. The HRVC strains clustered into at least 19 distinct genotypes. Compared with HRVA-infected children, children with HRVC were more likely to require supplemental oxygen (63% vs. 42%, p=0.007) and, when co-infections were excluded, were more likely to have wheezing (100% vs. 82%, p=0.016).There is a significant burden of HRV-associated hospitalisations in young children in Jordan. Infection with the recently identified group HRVC is associated with wheezing and more severe illness.
Project description:BackgroundIn severe bronchiolitis, it is unclear if delayed clearance or sequential infection of respiratory syncytial virus (RSV) or rhinovirus (RV) is associated with recurrent wheezing.MethodsIn a 17-center severe bronchiolitis cohort, we tested nasopharyngeal aspirates (NPA) upon hospitalization and 3 weeks later (clearance swab) for respiratory viruses using PCR. The same RSV subtype or RV genotype in NPA and clearance swab defined delayed clearance (DC); a new RSV subtype or RV genotype at clearance defined sequential infection (SI). Recurrent wheezing by age 3 years was defined per national asthma guidelines.ResultsAmong 673 infants, RSV DC and RV DC were not associated with recurrent wheezing, and RSV SI was rare. The 128 infants with RV SI (19%) had nonsignificantly higher risk of recurrent wheezing (hazard ratio [HR], 1.31; 95% confidence interval [CI], .95-1.80; P = .10) versus infants without RV SI. Among infants with RV at hospitalization, those with RV SI had a higher risk of recurrent wheezing compared to children without RV SI (HR, 2.49; 95% CI, 1.22-5.06; P = .01).ConclusionsAmong infants with severe bronchiolitis, those with RV at hospitalization followed by a new RV infection had the highest risk of recurrent wheezing.
Project description:Human rhinovirus (HRV) contains a 7.2 kb messenger-sense RNA genome which is the template for reproducing progeny viruses after it enters the cytoplasm of a host cell. Reverse genetics refers to the regeneration of progeny viruses from an artificial cDNA copy of the RNA genome of an RNA virus. It has been a powerful molecular genetic tool for studying HRV and other RNA viruses because the artificial DNA stage makes it practical to introduce specific mutations into the viral RNA genome. This chapter uses HRV-16 as the model virus to illustrate the strategy and methods for constructing and cloning the artificial cDNA copy of a full-length HRV genome, identifying the infectious cDNA clone isolates, and selecting the most vigorous cDNA clone isolate to serve as the standard parental clone for future molecular genetic study of the virus.