Toward Personalized Medicine in Bronchiolitis

Safety and Effectiveness of Inhaling Different Dosage Recombinant Human Interferon α1B for Bronchiolitis in Children: a Systematic Review and Meta-Analysis

Purpose

To systematically evaluate the safety and effectiveness of different dosages of recombinant human interferon α1b (IFNα1b) inhaled for bronchiolitis in children.

Methods

7 databases, including PubMed, EMBASE, Cochrane Library, Web of Science, CNKI, Wanfang Database, and VIP, were searched. The search time was from their inception dates to March 28, 2022. A randomized controlled trial (RCT) of 2 μg/kg IFNα1b (low dosage group) monotherapy or in combination with other drugs vs. 4 μg/kg IFNα1b (high dosage group) monotherapy or in combination with the other drugs was included. The risk of bias 2.0 evaluated the RCT's quality, and the grading of recommendations assessment, development and evaluation (GRADE) tool was used for evaluating the overall quality of the evidence. Then, a meta-analysis was performed by RevMan 5.4.

Results

A total of 13 RCTs with 1719 children were included. The meta-analysis results showed that the high dosage group was significantly shorter than the low dosage group of the duration of hospital stays (MD = -0.40, 95%CI (-0.73, -0.07), P = 0.02) (low quality), three depressions sign disappearing time (MD = -0.60, 95%CI (-1.05, -0.14), P = 0.010) (low quality), and wheeze disappearing time (MD = -0.62, 95%CI (-1.17, -0.06),  = 0.03) (low quality). There was no significant difference between the two groups in coughing disappearing time, pulmonary rales disappearing time, wheezing sound disappearing time, or adverse event rates.

Conclusions

Compared with low dosage IFNα1b, high dosage IFNα1b reduces the duration of hospital stays, the disappearance time of the three depression signs, and the disappearance time of wheeze in the treatment of bronchiolitis in children. Limited by the low quality of the evidence, the conclusions still need to be supported by high-quality studies.

Severe bronchiolitis profiles and risk of asthma development in Finnish children

BACKGROUND

Recent studies support the existence of several entities under the clinical diagnosis of bronchiolitis. Among infants with severe bronchiolitis, distinct profiles have been differentially associated with development of recurrent wheezing by age 3 years. However, their associations with actual asthma remain unclear.

OBJECTIVE

Our aim was to study the association between severe bronchiolitis profiles identified by using a clustering approach and childhood asthma.

METHODS

Among 408 children (aged <2 years) hospitalized with bronchiolitis in Finland (in 2008-2010), latent class analysis identified 3 bronchiolitis profiles: profile A (47%), characterized by history of wheezing and/or eczema, wheezing during acute illness, and rhinovirus infection; profile BC (38%), characterized by severe illness and respiratory syncytial virus infection; and profile D (15%), characterized by the least severely ill children, including mostly children without wheezing and with rhinovirus infection. The children were followed by questionnaire 4 years later (86% [n = 348]) and through a nationwide social insurance database 7 years later (99% [n = 403]). Current asthma at the 4- and 7-year follow-ups was defined by regular use (according to parental report and medical records) or purchase (according to the social insurance database) of asthma control medication.

RESULTS

Compared with risk of current asthma associated with profile BC, we observed increased risk of current asthma associated with profile A both at the 4-year follow-up (age- and sex-adjusted odds ratio = 2.42 [95% CI = 1.23-4.75]) and at the 7-year follow-up (age- and sex-adjusted odds ratio = 3.14 [95% CI = 1.33-7.42]). No significant difference in asthma risk was observed between profile D and profile BC.

CONCLUSION

These longitudinal results provide further support for an association between a distinct severe bronchiolitis profile (characterized by a history of wheezing and/or eczema and rhinovirus infection) and risk of development childhood asthma.

Community Mortality Due to Respiratory Syncytial Virus in Argentina: Population-based Surveillance Study

Background

Many deaths in infants from low-middle income countries (LMICs) occur at home or upon arrival to health facilities. Although acute lower respiratory tract illness plays an important role in community mortality, the accuracy of mortality rates due to respiratory syncytial virus (RSV) remains unknown.

Methods

An active surveillance study among children aged under 5 years old (U5) was performed in Buenos Aires, Argentina, between January and December 2019, to define the burden and role of RSV in childhood community mortality.

Results

A total of 63 families of children U5 participated in the study. Based on a combined approach of tissue sampling, verbal autopsies, and expert’s analysis, RSV infection was found in the causal chain of 11 from 12 cases with positive molecular biology results in respiratory samples. The estimated mortality rate due to RSV among infants was 0.27 deaths/1000 live births. The mean age of RSV-related household deaths was 2.8 months of age (standard deviation [SD] 1.7), and 8/12 were male infants (66.7%). Dying at home from RSV was associated with Streptococcus pneumoniae and/or Moraxella catarrhalis lung coinfection (75%), living in slums and settlement (odds ratio [OR], 17.09; 95% confidence interval [CI], 1.3–219.2), and other underlying comorbidities (OR, 14.87; 95% CI, 1.3–164.6).

Conclusions

Infant community mortality rates due to RSV are higher than those reported in industrialized countries and similar to those reported in hospital-based studies in the same catchment population.

Cost-effectiveness analysis of phenotypic-guided versus guidelines-guided bronchodilator therapy in viral bronchiolitis

OBJECTIVES

Although recent evidence suggests that management of viral bronchiolitis requires something other than guidelines-guided therapy, there is a lack of evidence supporting the economic benefits of phenotypic-guided bronchodilator therapy for treating this disease. The aim of the present study was to compare the cost-effectiveness of phenotypic-guided versus guidelines-guided bronchodilator therapy in infants with viral bronchiolitis.

METHODS

A decision analysis model was developed to compare the cost-effectiveness of phenotypic-guided versus guidelines-guided bronchodilator therapy in infants with viral bronchiolitis. Phenotypic-guided bronchodilator therapy was defined as the administration of albuterol in infants exhibiting a profile of increased likelihood of response to bronchodilators. The effectiveness parameters and costs of the model were obtained from systematic reviews of the literature with meta-analyses and electronic medical records. The main outcome was the avoidance of hospital admission after initial care in the emergency department.

RESULTS

Compared to guidelines-guided strategy, treating patients with viral bronchiolitis with the phenotypic-guided bronchodilator therapy strategy was associated with lower total costs (US$250.99; 95% uncertainty interval [UI]: US$184.37 to $336.51 vs. US$263.46; 95% UI: US$189.81 to $349.19 average cost per patient) and a higher probability of avoidance of hospital admission (0.7902; 95% UI: 0.7315-0.8356 vs. 0.7638; 95% UI: 0.7062-0.8201), thus leading to dominance. Results were robust to deterministic and probabilistic sensitivity analyses.

CONCLUSIONS

Compared to guidelines-guided strategy, treating infants with viral bronchiolitis using the phenotypic-guided bronchodilator therapy strategy is a more cost-effective strategy, because it involves a lower probability of hospital admission at lower total treatment costs.

Identifying pathophysiological bases of disease in COVID-19

COVID-19 is an infectious disease caused by the SARS-CoV-2 virus that can affect lung physiology encompassing a wide spectrum of severities, ranging from asymptomatic and mild symptoms to severe and fatal cases; the latter including massive neutrophil infiltration, stroke and multiple organ failure. Despite many recents findings, a clear mechanistic description underlying symptomatology is lacking. In this article, we thoroughly review the available data involving risk factors, age, gender, comorbidities, symptoms of disease, cellular and molecular mechanisms and the details behind host/pathogen interaction that hints at the existence of different pathophysiological mechanisms of disease. There is clear evidence that, by targeting the angiotensin-converting enzyme II (ACE2) -its natural receptor-, SARS-CoV-2 would mainly affect the renin-angiotensin-aldosterone system (RAAS), whose imbalance triggers diverse symptomatology-associated pathological processes. Downstream actors of the RAAS cascade are identified, and their interaction with risk factors and comorbidities are presented, rationalizing why a specific subgroup of individuals that present already lower ACE2 levels is particularly more susceptible to severe forms of disease. Finally, the notion of endotype discovery in the context of COVID-19 is introduced. We hypothesize that COVID-19, and its associated spectrum of severities, is an umbrella term covering different pathophysiological mechanisms (endotypes). This approach should dramatically accelerate our understanding and treatment of disease(s), enabling further discovery of pathophysiological mechanisms and leading to the identification of specific groups of patients that may benefit from personalized treatments.

Decoding Susceptibility to Respiratory Viral Infections and Asthma Inception in Children

Human Respiratory Syncytial Virus and Human Rhinovirus are the most frequent cause of respiratory tract infections in infants and children and are major triggers of acute viral bronchiolitis, wheezing and asthma exacerbations. Here, we will discuss the application of the powerful tools of systems biology to decode the molecular mechanisms that determine risk for infection and subsequent asthma. An important conceptual advance is the understanding that the innate immune system is governed by a Bow-tie architecture, where diverse input signals converge onto a few core pathways (e.g., IRF7), which in turn generate diverse outputs that orchestrate effector and regulatory functions. Molecular profiling studies in children with severe exacerbations of asthma/wheeze have identified two major immunological phenotypes. The IRF7hi phenotype is characterised by robust upregulation of antiviral response networks, and the IRF7lo phenotype is characterised by upregulation of markers of TGFβ signalling and type 2 inflammation. Similar phenotypes have been identified in infants and children with severe viral bronchiolitis. Notably, genome-wide association studies supported by experimental validation have identified key pathways that increase susceptibility to HRV infection (ORMDL3 and CHDR3) and modulate TGFβ signalling (GSDMB, TGFBR1, and SMAD3). Moreover, functional deficiencies in the activation of type I and III interferon responses are already evident at birth in children at risk of developing febrile lower respiratory tract infections and persistent asthma/wheeze, suggesting that the trajectory to asthma begins at birth or in utero. Finally, exposure to microbes and their products reprograms innate immunity and provides protection from the development of allergies and asthma in children, and therefore microbial products are logical candidates for the primary prevention of asthma.

Phenotypical Sub-setting of the First Episode of Severe Viral Respiratory Infection Based on Clinical Assessment and Underlying Airway Disease: A Pilot Study

Introduction: Viral bronchiolitis is a term often used to group all infants with the first episode of severe viral respiratory infection. However, this term encompasses a collection of different clinical and biological processes. We hypothesized that the first episode of severe viral respiratory infection in infants can be subset into clinical phenotypes with distinct outcomes and underlying airway disease patterns. Methods: We included children (≤2 years old) hospitalized for the first time due to PCR-confirmed viral respiratory infection. All cases were categorized based on primary manifestations (wheezing, sub-costal retractions and hypoxemia) into mild, hypoxemia or wheezing phenotypes. We characterized these phenotypes using lung-X-rays, respiratory outcomes and nasal protein levels of antiviral and type 2 cytokines (IFNγ, IL-10, IL-4, IL-13, IL-1β, and TNFα). Results: A total of 50 young children comprising viral respiratory infection cases (n = 41) and uninfected controls (n = 9) were included. We found that 22% of viral respiratory infection cases were classified as mild (n = 9), 39% as hypoxemia phenotype (n = 16) and 39% as wheezing phenotype (n = 16). Individuals in the hypoxemia phenotype had more lung opacities, higher probability of PICU admission and prolonged hospitalizations. Subjects in the wheezing phenotype had higher probability of recurrent sick visits. Nasal cytokine profiles showed that individuals with recurrent sick visits in the wheezing phenotype had increased nasal airway levels of type 2 cytokines (IL-13/IL-4). Conclusion: Clinically-based classification of the first episode of severe viral respiratory infection into mild, hypoxemia or wheezing phenotypes provides critical information about respiratory outcomes, lung disease patterns and underlying airway immunobiology.

The impact of viral bronchiolitis phenotyping: Is it time to consider phenotype-specific responses to individualize pharmacological management?

Although recent guidelines recommend a minimalist approach to bronchiolitis, there are several issues with this posture. First, there are concerns about the definition of the disease, the quality of the guidelines, the method of administration of bronchodilators, and the availability of tools to evaluate the response to therapies. Second, for decades it has been assumed that all cases of viral bronchiolitis are the same, but recent evidence has shown that this is not the case. Distinct bronchiolitis phenotypes have been described, with heterogeneity in clinical presentation, molecular immune signatures and clinically relevant outcomes such as respiratory failure and recurrent wheezing. New research is critically needed to refine viral bronchiolitis phenotyping at the molecular and clinical levels as well as to define phenotype-specific responses to different therapeutic options.