Postinfectious bronchiolitis obliterans in children: the South American contribution

Low-dose heparin sodium as a protective factor against bronchiolitis obliterans formation after adenovirus infection

BACKGROUND

Adenovirus (ADV) pneumonia in children is a significant contributor to the occurrence of post-infectious bronchiolitis obliterans (BO). Heparin sodium has known anti-inflammatory, immunomodulatory, and tissue repair properties. However, its role in treating BO after ADV infection remains unclear.

METHODS

A retrospective analysis was conducted on 793 children diagnosed with ADV pneumonia and hospitalized in the southern region from January 2019 to December 2019. Among them, 307 cases were classified as single ADV pneumonia. We utilized directed acyclic graphs to analyze the causal relationships between various variables, which further helped us identify the independent and confounding variables for constructing our regression model. Propensity score matching (PSM) was also employed to control for confounding variables that could not be intervened in this study, ensuring baseline level equilibrium and correction. We utilized univariate logistic regression analysis to explore the factors influencing BO development after ADV pneumonia.

RESULTS

Among the 793 children diagnosed with ADV pneumonia, 86 cases (10.84%) progressed to BO. The proportion of heparin use was higher in the non-BO group than in the BO group after PSM. The univariate regression analysis revealed that acute respiratory failure, neurological involvement and fibrinogen (FIB) were risk factors for the development of BO in ADV pneumonia cases (OR > 1, p < 0.05), but low-dose heparin sodium treatment and hemoglobin (OR < 1, p < 0.05) exhibited protective effects against BO formation. Among the 307 children with single ADV pneumonia (excluding confounding factors), 33 cases (10.75%) developed BO. The univariate regression analysis further indicated that fever duration, acute respiratory failure and FIB were risk factors for the development of BO in single ADV pneumonia (OR > 1, p < 0.05), while low-dose heparin sodium treatment (OR < 1, p < 0.05) was protective against BO formation after a single ADV pneumonia.

CONCLUSION

Low-dose heparin sodium treatment may be a protective factor against the development of BO after ADV pneumonia infection.

High-level adenovirus-neutralizing antibodies plasma beneficial for adenovirus type 7 (Adv7) induced pediatric severe ARDS

Objective

Respiratory failure and acute respiratory distress syndrome (ARDS) caused by adenovirus pneumonia (AVP) present significant challenges for pediatricians. High-level adenovirus-neutralizing antibody plasma (HL-ANAP), containing elevated levels of neutralizing antibodies (NAbs), might represent a valuable passive immunotherapy option. To assess the therapeutic effects, we investigated three cases diagnosed with adenovirus type 7 (Adv7)-induced severe ARDS, which required combined therapy with extracorporeal membrane oxygenation (ECMO) and HL-ANAP.

Methods

Blood samples from three patients with Adv7-induced ARDS were collected before HL-ANAP administration, and at 6, 12, 24, 48, and 72 hours, and 7, 21, and 28 days after treatment. We measured Adv7 viral load, NAb titers, and cytokine levels in the serum, describing the observed trends.

Results and discussion

All patients survived. Before HL-ANAP transfusion, Adv7 viral loads exceeded 1∗10^7. Adv7 viral loads gradually decreased within 72 hours after HL-ANAP transfusion, accompanied by a rising trend in NAb titers. IL-6 and IL-8 levels decreased sharply during the first 24 hours post-HL-ANAP transfusion, followed by a slower decline.

Conclusion

HL-ANAP may be effective in treating ARDS induced by severe type-7 adenoviral pneumonia in children. This approach may reduce adenovirus load, decrease systemic inflammation, and improve clinical outcomes. The neutralizing antibody's activity against the virus may occur within 24-72 hours post-infusion in vivo.

Risk factors for bronchiolitis obliterans development in children after Mycoplasma pneumoniae pneumonia: a retrospective study of 981 patients

BACKGROUND

Bronchiolitis obliterans (BO) is a rare and severe chronic pulmonary condition in children following an injury to lower respiratory tract lesion. Mycoplasma pneumoniae (M. pneumoniae) is the second etiology of post-infectious bronchiolitis obliterans (PIBO). The aim of this study was to determine risk factors for PIBO development in children after M. pneumoniae pneumonia.

METHODS

This retrospective study enrolled 981 children admitted to Beijing children's hospital due to M. pneumoniae pneumonia between January 2016 and December 2022. The medical records of the PIBO and non-PIBO groups, including demographic, clinical, radiologic, and laboratory data were analyzed by multivariate logistic regression to reveal PIBO development-associated risk factors.

RESULTS

Seventy-two of the study patients developed PIBO after M. pneumoniae pneumonia. Multivariate analysis showed that large lobar consolidation (OR 4.06, 95% CI 1.18-14.03), diffuse bronchiolitis (OR 11.78, 95% CI 3.28-42.22), co-infection (OR 3.65, 95% CI 1.60-8.33), atopic conditions (OR 12.32, 95% CI 5.2-29.11), bronchial mucus plug (OR 2.48, 95% CI 1.10-5.58), CPR (OR 1.01, 95% CI 1.00-1.02), mechanical ventilation (OR 2.95, 95% CI 1.00-8.67), and duration of fever (OR 1.19, 95% CI 1.05-1.37) were significantly associated with development of PIBO after M. pneumoniae pneumonia.

CONCLUSIONS

In children with M. pneumoniae pneumonia, large lobar consolidation, diffuse bronchiolitis, co-infections, atopic conditions, bronchial mucus plug, CRP, mechanical ventilation, and duration of fever appeared as prominent independent risk factors for PIBO. Timely application of HRCT could provide a basis for the early prediction of PIBO development in children.

Clinical features and risk factors for development of post-infectious bronchiolitis obliterans in children

BACKGROUND

Post-infectious bronchiolitis obliterans (PIBO) is a severe form of chronic obstructive lung disease secondary to severe respiratory tract infections. Knowledge of pediatric PIBO development-associated risk factors may improve selection of appropriate early therapeutic interventions.

OBJECTIVE

The aim of this study was to describe the clinical characteristics of children diagnosed with PIBO, and identify the risk factors for development of PIBO after adenovirus pneumonia.

METHODS

First, a retrospective observational study was performed of 308 pediatric patients with PIBO (ages < 5 years) that revealed high frequencies of non-invasive/invasive ventilation, co-infection, and atopic conditions. Subsequently, we retrospectively reviewed 131 patients (ages < 5 years) with adenovirus pneumonia who developed BO (included among the 308 children) or not. Logistic regression analysis revealed PIBO development-associated risk factors.

RESULTS

Respiratory symptoms of 308 patients (median age of 18 months, range: 12-54 months; male predominance of 3.7:1) included wheezing (71%), dyspnea (66%), tachypnea (23%), and hypoxemia (18%). Etiologic agents (predominantly adenovirus, Mycoplasma pneumoniae) were detected in 236 patients, of whom 137 had co-infections. Notably, atopic disease history (of patients and/or family members) was associated with 78% of patients, and 15% of patients diagnosed with asthma before, at the time of PIBO diagnosis. In a subsequent study of 131 adenovirus pneumonia patients, multivariate analysis showed that co-infection (OR 4.20, 95% CI 1.29 to 13.63), atopic conditions (OR 29.67, 95% CI 12.16 to 81.67), and duration of fever (OR 1.42, 95% CI 1.10 to 1.83) were independent risk factors for PIBO development following adenovirus pneumonia.

CONCLUSIONS

Atopic conditions, co-infections, and duration of fever were identified as risk factors for pediatric post-infectious BO development following adenovirus pneumonia, and PIBO may overlap with asthma, warranting early aggressive treatment and further research to elucidate roles of atopic conditions in BO development.

Empowering caregivers of children with bronchiolitis obliterans: The effectiveness of an internet-based follow-up platform

OBJECTIVE

Limited evidence on home care and need for long-term individualized follow-up highlight the importance of developing an Internet-based follow-up platform to support caregivers of children with Bronchiolitis Obliterans (BO). This Study aims to explore and test the potential benefits of this platform by comparing family management, medication compliance and clinical systems.

STUDY DESIGN AND METHODS

A two-arm, single-blind randomized controlled trial was conducted on 168 children with BO and their families from January 2022 to October 2022. Families were randomly divided into Internet-based follow-up group and conventional follow-up group with a ratio of 1:1. Scores of family management measures (FaMM), 8-item of Morisky Medication Adherence (8-MMAS) and BO clinical symptoms of both groups were collected at three points of time: the day of discharge (T1), 3 months after discharge (T2), and 6 months after discharge (T3). The changes of each group due to intervention were compared by repeated-measures ANOVA.

RESULTS

90 families completed the trial, including 48 in the Internet-based follow-up group and 42 in the conventional follow-up group. The results showed a significant difference in the group-by-time interaction on the scores of Child's Daily Life, Condition Management Ability and Parental Mutuality (p < 0.05). No group-by-time effect was found on the scores of View of Condition Impact and Family Life Difficulty. Scores of BO clinical symptoms and MMAS-8 showed intra-group, inter-group, and group-by-time effects.

CONCLUSIONS

The Internet-based follow-up platform can empower caregivers in enhancing effective family management, improving medication compliance in children with BO, and relieving patients' clinical symptoms.

TRIAL REGISTRATION

Chinese Clinical Trials Registry of ChiCTR2200065121 (04/28/2022).

Post-infectious bronchiolitis obliterans in children: Clinical and radiological evaluation and long-term results

BACKGROUND AND OBJECTIVE

This study aims to evaluate clinical and radiological findings and treatment outcomes of the patients with PIBO.

METHODS

One hundred fourteen children were enrolled. Initial demographic and clinical findings were evaluated. Pre- and post-treatment clinical and radiological findings were compared.

RESULTS

The median age of the patients at initial pulmonary injury was 7,2 months, the median age at diagnosis was 17.5 months. Persistent wheezing was the most common complaint. Thirty-five patients had mechanical ventilation history. 82,5% of patients had clinical improvement. Bronchiectasis, atelectasis, hyperinflation and air trapping in HRCT improved significantly with treatment. Post-treatment Bhalla scores decreased from 8.3 to 6.5 (p= 0,001). Improvement was observed in radiological and clinical findings after treatment.

CONCLUSIONS

This study is one of the largest studies in the literature and one of the few studies that evaluate clinical and radiological outcomes of patients with PIBO.

Lung hyperinflation quantitated by chest CT in children with bronchiolitis obliterans syndrome following allogeneic hematopoietic cell transplantation

OBJECTIVES

Bronchiolitis obliterans syndrome (BOS) diagnosis in children following allogeneic hematopoietic stem cell transplantation (post-HSCT) is based on detection of airway obstruction on spirometry and air-trapping, small airway thickening or bronchiectasis on chest CT. We assessed the relationship between spirometry indices and low-attenuation lung volume at total lung capacity (TLC) on CT.

METHODS

Data of children post-HSCT with and without BOS were analyzed. An age-specific, low-attenuation threshold (LAT) was defined as average of (mean-1SD) lung parenchyma attenuation of 5 control subjects without lung disease matched to each age subgroup of post-HSCT patients. % CT lung volume at TLC with attenuation values <LAT was calculated. Association between % lung volume with low attenuation and FEV₁/FVC was assessed.

RESULTS

Twenty-nine children post-HSCT were referred to exclude BOS and 12 of them had spirometry and an analyzable chest CT. We studied: (i) 6 children post-HSCT/BOS (median age: 8.5 years [IQR 7, 15]; median FEV₁/FVC z-score: -2.60 [IQR -2.93, -2.14]); (ii) 6 children post-HSCT/no BOS (age: 13.5 years [9.8, 16.3]; FEV₁/FVC z-score: 0.44 [-0.30, 2.10]); and (iii) 40 controls without lung disease (age:11 years [8.3, 15.8]). Patients post-HSCT/BOS had significantly higher % lung volume with low attenuation than patients post-HSCT/no BOS: median % volume 16.4% (7.1%, 37.2%) vs. 0.61% (0.34%, 2.79%), respectively; P = .004. An exponential model described the association between % CT lung volume below LAT and FEV₁/FVC z-score (r² = 0.76; P < .001).

CONCLUSION

In children post-HSCT with BOS, low-attenuation lung volume on chest CT is associated with airway obstruction severity as expressed by FEV₁/FVC z-score.

Clinical analysis of adenovirus postinfectious bronchiolitis obliterans and nonadenovirus postinfectious bronchiolitis obliterans in children

Background and Objective:

Postinfectious bronchiolitis obliterans (PIBO) is an uncommon and severe form of chronic obstructive lung disease in children. Adenovirus (ADV) is the main pathogen of PIBO in children. However, the risk factors of ADV-PIBO are not fully understood. This study aims to analyze the clinical characteristics of PIBO caused by ADV and compared with non-ADV-PIBO.

Materials and Methods:

A retrospective study of children under the age of 14 years diagnosed PIBO was performed in 56 ADV-PIBO cases, 29 non-ADV-PIBO, and 39 healthy controls to determine clinical characteristics of PIBO.

Results:

There was no difference between ADV-PIBO and non-ADV-PIBO cases in gender, age, individual and family atopy or history of asthma, and previous history of wheezing and no difference in the clinical manifestations and signs between the two groups. However, the hospital stay, duration of ventilator use, and multifocal pneumonia incidence of ADV-PIBO group have a significant differences compared with non-ADV-PIBO. Notably, inflammatory markers lactic dehydrogenase (LDH), interleukin 8 (IL-8), and interferon-gamma (IFN-γ) were significantly increased in PIBO patients, and those expressed in ADV-PIBO patients were higher than those in non-ADV-PIBO patients. In addition, ADV-PIBO children required a longer duration of oral prednisone and azithromycin than non-ADV-PIBO cases.

Conclusions:

Compared with non-ADV-PIBO, ADV-PIBO has a longer hospital stay, longer duration of ventilator use, increased LDH, IL-8, and IFN-γ expressions, and longer duration of oral prednisone and azithromycin treatment. Further research is needed to determine why PIBO caused by ADVs are more severe than those caused by other pathogens.

Health-related quality of life in patients with bronchiolitis obliterans

INTRODUCTION

Bronchiolitis obliterans (BO) is mainly caused by infections and hematopoietic stem cell transplantation (HSCT). This study aimed to investigate the health-related quality of life (HRQOL) of children with BO compared to the healthy children and also to assess the HRQOL according to the etiology.

METHODS

Postinfectious (group 1) and post-HSCT BO (group 2) patients and healthy children were included in the study. HRQOL was assessed by the Short Form-36 (SF-36) and St George's Respiratory Questionnaire (SGRQ). Correlations between demographic and clinical characteristics, pulmonary function tests, high-resolution chest tomography scores, and HRQOL were assessed.

RESULTS

Thirty-seven postinfectious and post-HSCT BO patients and 34 healthy children were included in the study. Mean age was 13.8 ± 0.7 years. Mean forced vital capacity and forced expiratory volume₁ were 60.7 ± 2.7% predicted, and 49.8 ± 3.1% predicted, respectively. The SF-36 scores were lower in BO patients compared to healthy children (P < .01). Patients with better lung functions had higher SF-36 scores, but lower SGRQ. The number of inhaled therapies, acute exacerbations, hospitalizations were inversely correlated with SF-36. A positive correlation was found between these parameters and total SGRQ scores (r = .507, P = .02; r = .409, P = .12; r = .326, P = .049, respectively). SF-36 scores were better in group 1 for subscales of physical role functioning and social role functioning compared to group 2. (P = .01, P = .01, respectively).

CONCLUSION

The HRQOL of patients with BO measured by SF-36 was low compared to healthy children. SF-36 scores were more affected in post-HSCT BO patients. HRQOL of children with chronic lung disease should be taken into consideration in the management of these patients.

Les séquelles de virose en pneumopédiatrie

L’immaturité du système immunitaire explique une part de la vulnérabilité aux pathogènes respiratoires durant l’enfance. Une infection virale respiratoire aiguë chez l’enfant peut être secondaire à 1 des 200 virus génétiquement différents et identifiables par les outils moléculaires. Les cellules ciliées distribuées tout au long de l’épithélium des voies respiratoires sont la cible des virus. Les études épidémiologiques rapportent une diminution de la fonction respiratoire chez l’adulte indépendamment de facteurs confondants lorsqu’une pneumonie est survenue avant l’âge de 2 voire 7 ans. Cette réduction de la fonction respiratoire est le reflet probable de l’atteinte initiale malgré les processus de réparation (altération potentielle de croissance pulmonaire) et à l’âge adulte d’une accélération du déclin physiologique des capacités ventilatoires. Les études portant sur l’origine des dilatations des bronches retrouvent des antécédents de pneumopathies infectieuses plus d’une fois sur deux. Les infections à adénovirus sont particulièrement en cause. Une bronchiolite obstructive post-infectieuse peut survenir même chez l’enfant immunocompétent ; le tableau initial est très souvent pseudo-grippal, puis est marqué par une dissociation entre des signes fonctionnels importants et un examen clinique pauvre. L’évolution au long cours est peu prévisible mais peut conduire à l’insuffisance respiratoire chronique létale. Les pneumopathies infiltratives diffuses sont caractérisées par une infiltration diffuse de la charpente conjonctivale du poumon par des cellules inflammatoires et de la fibrose. Le rôle des virus dans son développement a été évoqué en raison de la présence d’inclusions cellulaires évoquant des particules virales dans le poumon d’enfants atteints. Enfin la plupart des études épidémiologiques soulignent l’association entre une symptomatologie sifflante secondaire à une agression virale durant l’enfance et le risque ultérieur de développement d’un asthme.

Postinfectious bronchiolitis obliterans masked by misdiagnosis as asthma

OBJECTIVES

Asthma and postinfectious bronchiolitis obliterans (PIBO) have similar clinical findings, and PIBO may be misdiagnosed with asthma. This study aimed to determine the clinical features of PIBO in children and the causes of delay in its diagnosis.

METHODS

We retrospectively evaluated all patients diagnosed with PIBO in four pediatric pulmonology centers between 2007 and 2018. In total, 64 PIBO patients were retrospectively reviewed. We compared the clinical and laboratory differences between PIBO patients who had initially been misdiagnosed with asthma and correctly diagnosed with PIBO.

RESULTS

Of the 64 patients, 22 (34.4%) had initially been misdiagnosed with asthma. Adenovirus was the most common infectious agent in children. The age upon diagnosis was older, and the symptom duration was significantly longer in patients misdiagnosed with asthma (P < .05). There were no statistical differences in terms of sex, history of prematurity, duration of hospitalization, treatment, history of oxygen or mechanical ventilation support, pulmonary function test (PFT) results and asthma-predisposing findings between the two groups (P > .05).

CONCLUSIONS

Patients with PIBO who had initially been misdiagnosed with asthma were correctly diagnosed at older ages and had longer symptom duration. Asthma may mask PIBO diagnosis by the similarity of symptoms and the clinical response to inhaled β2-agonist or steroid treatment. PFTs may not help clinicians because of the age of children. The delay in the diagnosis of PIBO is probably attributable to the fact that some clinicians fail to include PIBO in the differential diagnosis when there is no clinical response to asthma medication.

Health-related quality of life in post-infectious bronchiolitis obliterans: agreement between children and their proxy

OBJECTIVE

To assess the level of agreement in health-related quality of life between children with Post-infectious Bronchiolitis Obliterans and their parent (so-called proxy).

METHODS

Participants aged between 8and 17 years who had been previously diagnosed with Post-infectious Bronchiolitis Obliterans were regularly followed up at a pediatric pulmonology outpatient clinic. Parents or legal guardians (caregivers) of these patients were also recruited for the study. A validated and age-appropriate version of the Pediatric Quality of Life Inventory 4.0 was used for the assessment of health-related quality of life. Caregivers completed the corresponding proxy versions of the questionnaire. The correlation between self and proxy reports of health-related quality of life was determined by intra-class correlation coefficient and dependent t-tests.

RESULTS

The majority of participants were males (79.4%), and the average age was 11.8 years. Intra-class correlations between each of the Pediatric Quality of Life Inventory 4.0 domains and the total score were all lower than 0.6, with a range between 0.267 (poor) and 0.530 (fair). When the means of each domain and the total score of the questionnaires were compared, caregivers were observed to have a significantly lower health-related quality of life score than children, with the exception of the social domain in which the difference was not significant. However, the differences in score exceeded the critical threshold difference of four points in all other domains.

CONCLUSION

Proxies of children and adolescents with Post-infectious Bronchiolitis Obliterans appear to consistently perceive their children as having lower health-related quality of life than how the patients perceive themselves.

Clinical features of postinfectious bronchiolitis obliterans in children undergoing long-term nebulization treatment

BACKGROUND

Limited data are available in relation to the clinical features of PIBO undergoing prolonged nebulization treatment with budesonide, terbutaline and ipratropium bromide. This retrospective study aimed to outline the features of clinical, high-resolution computed tomography (HRCT) and pulmonary function test (PFT) of PIBO, undergoing maintenance therapy utilizing a triple nebulization treatment and to determine the factors associated with prognosis.

METHODS

Children diagnosed with PIBO were followed up between April 2014 and March 2017. The clinical features after maintenance nebulization treatment for 12 months were thereafter summarized.

RESULTS

Thirty patients, 21 boys and 9 girls, were enrolled in the study. The median age of patients was 17.4 months, with a range between 3.0 and 33 months. Persistent coughing and wheezing were detected whilst wheezing and crackles were the common manifestations presented. HRCT scans revealed patchy ground and glass opacity, while PFT showed fixed airway obstruction in all patients. Four patients were lost during follow-up. After treatment, the clinical symptoms were improved greatly in all patients (P < 0.01). The mean increase in the percentage of TPEF%TE and VPEF%VE were improved greatly (P < 0.01). Images of the HRCT scan indicated marked improvements in 18 patients (81.8%) in comparison with scans obtained pre-treatment.

CONCLUSIONS

Our data suggest a potential role of long-term nebulization treatment of budesonide, terbutaline, ipratropium bromide on PIBO, due to its efficacy as indicated in the improved clinical symptoms, pulmonary functions and CT manifestations identified in the children. New prospective and controlled studies are required to confirm this proposition.

Health-related quality of life in patients with bronchiolitis obliterans

OBJECTIVE

To evaluate the overall health-related quality of life in patients with bronchiolitis obliterans.

METHODS

Participants with a diagnosis of post-infectious bronchiolitis obliterans, who were being followed-up at two specialized outpatient clinics of Pediatric Pulmonology in Porto Alegre, Brazil, and controls aged between 8 and 17 years, of both genders, were included in the study. Controls were paired by gender, age, and socioeconomic level in relation to the group of participants with post-infectious bronchiolitis obliterans. The version of the Pediatric Quality of Life Inventory (PedsQ) tool validated for Brazil was applied for the assessment of Health-related Quality of Life, through an interview. The comparison of the Health-related Quality of Life means between the groups was performed using Student's t-test for independent samples and the chi-squared test, for categorical variables.

RESULTS

34 patients diagnosed with post-infectious bronchiolitis obliterans and 34 controls participated in the study. The mean age of the children included in the study was 11.2±2.5 years, and 49 (72%) of them were males. The groups showed no significant differences in relation to these variables. The quality of life score was significantly and clinically lower in the post-infectious bronchiolitis obliterans group when compared with controls in the health (72.36±15.6, 81.06±16.4, p=0.031) and school domains (62.34±20.7, 72.94±21.3, p=0.043), as well as in the total score (69.53±14.9, 78.02±14.8, p=0.024), respectively.

CONCLUSION

Patients with post-infectious bronchiolitis obliterans presented lower health-related quality of life scores when compared with healthy individuals in the total score and in the health and school domains.

Lung Clearance Index and Quantitative Computed Tomography of Post-Infectious Bronchiolitis Obliterans in Infants

Post-infectious bronchiolitis obliterans (BO) could be diagnosed via spirometry and chest computed tomography (CT); however, these tests are limited in infants. We aimed to evaluate the utility of lung clearance index (LCI) and air-trapping lung volume from chest CT in infants. This prospective study included 20 infants (mean age, 10.9 ± 6.3 months) diagnosed with post-infectious BO between 2009 and 2016. All subjects underwent multiple breath washout tests. For quantitative analysis of chest CT, the mean lung area attenuation value was used as an individual cutoff to determine the air-trapping lung volume. The mean cutoff lung attenuation value was −659 Hounsfield units, the mean total lung volume was 265 ml, and the mean air-trapping lung volume percentage was 22.9%. Functional residual capacity correlated with total lung volume and normal attenuation lung volume (p < 0.02). LCI (p < 0.02) and moment ratio (MR) 1 (p < 0.05) correlated with the air-trapping lung volume percentage. The concordance indices of LCI (0.659, p = 0.025) and MR1 (0.642, p = 0.046) were significantly correlated with the air-trapping lung volume percentage from CT. LCI and quantitative air-trapping lung volume from chest CT are feasible, complimentary tools for assessing infants with post-infectious BO.

Risk factors for morbidities and mortality in children following pneumonectomy

BACKGROUND AND OBJECTIVE

Pneumonectomy (PNE) is a procedure infrequently performed in children. A high morbidity/mortality rate associated with PNE has been described. Few series have been published in the last 15 years. Risk factors associated with morbidity/mortality after PNE were evaluated. Indications, course, survival and complications of PNE in children were also analized.

METHODS

In a case series of 51 children who underwent PNE, death within 30 days of surgery, pneumonia, empyema, sepsis, adult respiratory distress syndrome, bronchopleural fistula, bleeding, pneumothorax and post-PNE syndrome were considered major morbidities. Scoliosis, wound infection and atelectasis were considered minor morbidities.

RESULTS

Median age at PNE was 7.4 years; 45% were males. Indications of pneumonectomy were postinfectious bronchiectasis (61%), tumours (17%), pulmonary malformations (17%), aspiration syndrome (14%), cystic fibrosis (6%), immunodeficiency (4%) and trauma (2%). Mortality rate was 4% at 1 month. Major and minor morbidities were present in 23% and 27% of patients, respectively. Risk factors for development of morbidities after PNE were age ≤ 3 years (OR: 16.7; 95% CI: 2.4-117) and the need for mechanical ventilation for at least 4 days (OR: 8; 95% CI: 1.5-43.6).

CONCLUSION

Children are at high risk of death, major and minor morbidities following PNE. Caution is recommended for this group of patients.

Evaluating bronchodilator response in pediatric patients with post-infectious bronchiolitis obliterans: use of different criteria for identifying airway reversibility

OBJECTIVE

Post-infectious bronchiolitis obliterans (PIBO) is a clinical entity that has been classified as constrictive, fixed obstruction of the lumen by fibrotic tissue. However, recent studies using impulse oscillometry have reported bronchodilator responses in PIBO patients. The objective of this study was to evaluate bronchodilator responses in pediatric PIBO patients, comparing different criteria to define the response.

METHODS

We evaluated pediatric patients diagnosed with PIBO and treated at one of two pediatric pulmonology outpatient clinics in the city of Porto Alegre, Brazil. Spirometric parameters were measured in accordance with international recommendations.

RESULTS

We included a total of 72 pediatric PIBO patients. The mean pre- and post-bronchodilator values were clearly lower than the reference values for all parameters, especially FEF25-75%. There were post-bronchodilator improvements. When measured as mean percent increases, FEV1 and FEF25-75%, improved by 11% and 20%, respectively. However, when the absolute values were calculated, the mean FEV1 and FEF25-75% both increased by only 0.1 L. We found that age at viral aggression, a family history of asthma, and allergy had no significant effects on bronchodilator responses.

CONCLUSIONS

Pediatric patients with PIBO have peripheral airway obstruction that is responsive to treatment but is not completely reversible with a bronchodilator. The concept of PIBO as fixed, irreversible obstruction does not seem to apply to this population. Our data suggest that airway obstruction is variable in PIBO patients, a finding that could have major clinical implications.

OBJETIVO

A bronquiolite obliterante pós-infecciosa (BOPI) é uma entidade clínica que tem sido classificada como obstrução fixa e constritiva do lúmen por tecido fibrótico. Entretanto, estudos recentes utilizando oscilometria de impulso relataram resposta ao broncodilatador em pacientes com BOPI. O objetivo deste estudo foi avaliar a resposta broncodilatadora em pacientes pediátricos com BOPI, comparando critérios diferentes para a definição da resposta.

MÉTODOS

Foram avaliados pacientes pediátricos com diagnóstico de BOPI tratados em um de dois ambulatórios de pneumologia pediátrica na cidade de Porto Alegre (RS). Parâmetros espirométricos foram medidos de acordo com recomendações internacionais.

RESULTADOS

Foram incluídos 72 pacientes pediátricos com BOPI no estudo. As médias dos valores pré- e pós-broncodilatador foram claramente inferiores aos valores de referência para todos os parâmetros, especialmente FEF25-75%. Houve uma melhora pós-broncodilatador. Quando medidos como aumentos percentuais médios, VEF1 e FEF25-75% melhoraram em 11% e 20%, respectivamente. Entretanto, quando os valores absolutos foram calculados, as médias de VEF1 e FEF25-75% aumentaram somente em 0,1 l. Verificamos que a idade da agressão viral, história familiar de asma e alergia não tiveram efeitos significativos na resposta ao broncodilatador.

CONCLUSÕES

Pacientes pediátricos com BOPI têm uma obstrução das vias aéreas periféricas que responde ao tratamento, mas não uma reversão completa com o broncodilatador. O conceito de BOPI como obstrução fixa e irreversível parece não se aplicar a essa população. Nossos dados sugerem que a obstrução de vias aéreas em pacientes com BOPI é variável, e esse achado pode ter importantes implicações clínicas.

Post-infectious bronchiolitis obliterans and mannose-binding lectin insufficiency in Argentinean children

BACKGROUND AND OBJECTIVE

Post-infectious bronchiolitis obliterans (PIBO) is a severe disorder following acute lower pulmonary infection in young children, especially caused by adenovirus. Mannose-binding lectin (MBL) deficiency arising from polymorphisms in the coding and non-coding region on the MBL2 gene has been associated with more frequent and severe respiratory infections. Our aim was to evaluate the influence of MBL variants in the susceptibility and evolution of children with PIBO.

METHODS

One hundred eleven children with PIBO diagnosis were studied. The coding A, B, D and X promoter variants of MBL2 gene were assessed by PCR-RFLP. B and D alleles were pooled as O. The combined genotypes A/A and YA/O were grouped as sufficient MBL (sMBL), and O/O and XA/O as insufficient MBL (iMBL) groups. To evaluate the frequency of MBL2 polymorphisms in the general population, we studied DNA samples from 127 healthy donors from the blood bank of the hospital (control group).

RESULTS

iMBL variants were significantly more frequent in PIBO children compared with controls (21.6% vs 10.2%, P = 0.01). PIBO patients with iMBL required intensive care unit (P = 0.001) and mechanical assistance at the moment of viral injury (P = 0.001) more frequently than those with sMBL.

CONCLUSIONS

Insufficiency of MBL was more common in PIBO children than in healthy controls. This genetic condition was significantly associated with more severe initial disease, illustrating the relevance of innate immune defence factors prior to the maturation of the adaptative immune system.

Efficacy of pulse methylprednisolone in a pediatric case of postinfectious bronchiolitis obliterans

Postinfectious bronchiolitis obliterans is a chronic incapacitating disease with persistent airway inflammation. However, the efficacy of systemic corticosteroids has never been studied systematically. In the presented case, serial spirometry, plethysmography measurements, and nocturnal oximetry demonstrated progressive decline in lung hyperinflation and air-trapping and improvement in expiratory function and nocturnal oxygenation during and after six three-day courses of high-dose methylprednisolone (30 mg/kg/day). At four months post treatment, most gain in lung function was lost suggesting the need for sustained immunosuppression. Randomized, controlled trials using serial plethysmography measurements, spirometry, and nocturnal oximetry could provide evidence for the management of postinfectious bronchiolitis obliterans.