SARS-CoV-2-related bronchiolitis: a multicentre international study

BACKGROUND

Bronchiolitis is the main acute lower respiratory tract infection in infants. Data regarding SARS-CoV-2-related bronchiolitis are limited.

OBJECTIVE

To describe the main clinical characteristics of infants with SARS-CoV-2-related bronchiolitis in comparison with infants with bronchiolitis associated with other viruses.

SETTING, PATIENTS, INTERVENTIONS

A multicentre retrospective study was conducted in 22 paediatric emergency departments (PED) in Europe and Israel. Infants diagnosed with bronchiolitis, who had a test for SARS-CoV-2 and were kept in clinical observation in the PED or admitted to hospital from 1 May 2021 to 28 February 2022 were considered eligible for participation. Demographic and clinical data, diagnostic tests, treatments and outcomes were collected.

MAIN OUTCOME MEASURES

The main outcome was the need for respiratory support in infants testing positive for SARS-CoV-2 compared with infants testing negative.

RESULTS

2004 infants with bronchiolitis were enrolled. Of these, 95 (4.7%) tested positive for SARS-CoV-2. Median age, gender, weight, history of prematurity and presence of comorbidities did not differ between the SARS-CoV-2-positive and SARS-CoV-2-negative infants. Human metapneumovirus and respiratory syncytial virus were the viruses most frequently detected in the group of infants negative for SARS-CoV-2.Infants testing positive for SARS-CoV-2 received oxygen supplementation less frequently compared with SARS-CoV-2-negative patients, 37 (39%) vs 1076 (56.4%), p=0.001, OR 0.49 (95% CI 0.32 to 0.75). They received less ventilatory support: 12 (12.6%) high flow nasal cannulae vs 468 (24.5%), p=0.01; 1 (1.0%) continuous positive airway pressure vs 125 (6.6%), p=0.03, OR 0.48 (95% CI 0.27 to 0.85).

CONCLUSIONS

SARS-CoV-2 rarely causes bronchiolitis in infants. SARS-CoV-2-related bronchiolitis mostly has a mild clinical course.

Epidemiology, clinical aspects, and management of pediatric drowning

Drowning is the third leading cause of injury death in the pediatric population worldwide, with incidence peaking among those aged 1-4 years and again in adolescence.The purpose of this commentary is to review the basic pathophysiology of drowninginjury and factors that affect the outcome, such as submersion and hypothermia. We also discuss principles of prehospital and in-hospital management, comprising resuscitation and stabilization, administration of oxygen and intravenous liquids, and central reheating.Even though the mortality rate has decreased in recent years, further investments and safety measures are needed to prevent child drowning deaths.

Prevalence of SARS-CoV-2 positivity in infants with bronchiolitis: a multicentre international study

BACKGROUND

Bronchiolitis is the leading acute respiratory tract infection in infants during the winter season. Since the beginning of the SARS-CoV-2 pandemic, a reduction in the number of bronchiolitis diagnoses has been registered.

OBJECTIVE

The present study aimed to describe the incidence and clinical features of bronchiolitis during the 2020-2021 winter season in a large cohort of children in Europe and Israel, and to clarify the role of SARS-CoV-2.

SETTING, PATIENTS, INTERVENTIONS

We conducted a multicentre observational cross-sectional study in 23 paediatric emergency departments in Europe and Israel. Clinical and demographic data about all the cases of infants diagnosed with bronchiolitis from 1 October 2020 to 30 April 2021 were collected. For each enrolled patient, diagnostic tests, treatments and outcomes were reported.

MAIN OUTCOME MEASURES

The main outcome was the prevalence of SARS-CoV-2-positive bronchiolitis.

RESULTS

Three hundred and fourteen infants received a diagnosis of bronchiolitis during the study period. Among 535 infants who tested positive for SARS-CoV-2, 16 (3%) had bronchiolitis. Median age, male sex predominance, weight, history of prematurity and presence of comorbidities did not differ between the SARS-CoV-2-positive and SARS-CoV-2-negative groups. Rhinovirus was the most common involved pathogen, while respiratory syncytial virus (RSV) was detected in one case. SARS-CoV-2 bronchiolitis had a mild clinical course, with one patient receiving oxygen supplementation and none requiring paediatric or neonatal intensive care unit admission.

CONCLUSIONS

During the SARS-CoV-2 pandemic, a marked decrease in the number of bronchiolitis diagnoses and the disappearance of the RSV winter epidemic were observed. SARS-CoV-2-related bronchiolitis was rare and mostly displayed a mild clinical course.

Bone impairment in phenylketonuria is characterized by circulating osteoclast precursors and activated T cell increase

BACKGROUND

Phenylketonuria (PKU) is a rare inborn error of metabolism often complicated by a progressive bone impairment of uncertain etiology, as documented by both ionizing and non- ionizing techniques.

METHODOLOGY

Peripheral blood mononuclear cell (PBMC) cultures were performed to study osteoclastogenesis, in the presence or absence of recombinant human monocyte-colony stimulating factor (M-CSF) and receptor activator of NFκB ligand (RANKL). Flow cytometry was utilized to analyze osteoclast precursors (OCPs) and T cell phenotype. Tumour necrosis factor α (TNF-α), RANKL and osteoprotegerin (OPG) were quantified in cell culture supernatants by ELISA. The effects of RANKFc and anti-TNF-α antibodies were also investigated to determine their ability to inhibit osteoclastogenesis. In addition, bone conditions and phenylalanine levels in PKU patients were clinically evaluated.

PRINCIPAL FINDINGS

Several in vitro studies in PKU patients' cells identified a potential mechanism of bone formation inhibition commonly associated with this disorder. First, PKU patients disclosed an increased osteoclastogenesis compared to healthy controls, both in unstimulated and M-CSF/RANKL stimulated PBMC cultures. OCPs and the measured RANKL/OPG ratio were higher in PKU patients compared to healthy controls. The addition of specific antagonist RANKFc caused osteoclastogenesis inhibition, whereas anti-TNF-α failed to have this effect. Among PBMCs isolated from PKU patients, activated T cells, expressing CD69, CD25 and RANKL were identified. Confirmatory in vivo studies support this proposed model. These in vivo studies included the analysis of osteoclastogenesis in PKU patients, which demonstrated an inverse relation to bone condition assessed by phalangeal Quantitative Ultrasound (QUS). This was also directly related to non-compliance to therapeutic diet reflected by hyperphenylalaninemia.

CONCLUSIONS

Our results indicate that PKU spontaneous osteoclastogenesis depends on the circulating OCP increase and the activation of T cells. Osteoclastogenesis correlates with clinical parameters, suggesting its value as a diagnostic tool for an early assessment of an increased bone resorption in PKU patients.