High incidence of acute lung injury in children with Down syndrome

Risk Factors for Poor Outcomes in Children Hospitalized With Virus-associated Acute Lower Respiratory Infections: A Systematic Review and Meta-analysis

BACKGROUND

Acute lower respiratory infection (ALRI) caused by respiratory viruses is among the most common causes of hospitalization and mortality in children. We aimed to identify risk factors for poor outcomes in children <5 years old hospitalized with ALRI caused by respiratory syncytial virus (RSV), influenza and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

METHODS

We searched Embase, Medline and Global Health databases and included observational studies reporting risk factors for poor outcomes (defined as use of supplemental oxygen, mechanical ventilation, intensive care unit admission, prolonged hospital stay and mortality) published between January 2011 and January 2023. Two authors independently extracted data on study characteristics, outcomes and risk factors. Due to limited data, meta-analyses were only conducted for RSV-ALRI poor outcome risk factors using random effects model when there were at least 3 studies.

RESULTS

We included 30 studies. For RSV-related ALRI, significant risk factors based on meta-analysis were: neurological disease [odds ratio (OR): 6.14; 95% confidence intervals (CIs): 2.39-15.77], Down's syndrome (5.43; 3.02-9.76), chronic lung disease (3.64; 1.31-10.09), immunocompromised status (3.41; 1.85-6.29), prematurity (2.98; 1.93-4.59), congenital heart disease (2.80; 1.84-4.24), underlying disease (2.45; 1.94-3.09), age <2 months (2.29; 1.78-2.94), age <6 months (2.08; 1.81-2.39), viral coinfection (2.01; 1.27-3.19), low birth weight (1.88; 1.19-2.95) and being underweight (1.80; 1.38-2.35). For influenza-related ALRI, chronic conditions and age 6-24 months were identified as risk factors for poor outcomes. Cardiovascular disease, immunosuppression, chronic kidney disease, diabetes and high blood pressure were reported as risk factors for mortality due to SARS-CoV-2 associated ALRI.

CONCLUSIONS

These findings might contribute to the development of guidelines for prophylaxis and management of ALRI caused by RSV, influenza and SARS-CoV-2.

Death of children with Down syndrome by gestational age and cause

BACKGROUND

We often encounter preterm infants with Down syndrome (DS) who die in the neonatal intensive care unit (NICU). In this study, we examined survival until NICU discharge and assessed the developmental prognosis of preterm infants with DS.

METHODS

We retrospectively reviewed 416 infants with DS hospitalized during the past 27 years at our NICU.

RESULTS

Death occurred in 8/20 (40%) infants at <32 weeks' gestation, 11/23 (48%) at 32-33 weeks, 9/99 (9%) at 34-36 weeks, and 9/274 (3%) at >36 weeks. In total, 84% of infants who died and 25% of those who survived had a non-reassuring fetal status (p < 0.001). Sex, small-for-gestational-age status, and postnatal transport were not associated with death. The main causes of death were bronchopulmonary dysplasia in 4/8 (50%) infants at <32 weeks' gestation, transient abnormal myelopoiesis in 11/20 (55%) and lymphatic dysplasia in 6/20 (30%) at 32-36 weeks, and varied causes at >36 weeks. Among survivors born at <34 weeks' gestation, 6/19 (32%) aged >2 years had moderate or severe cerebral palsy.

CONCLUSIONS

These data on the high mortality and morbidity of preterm infants with DS may be useful for patient treatment and parent counseling in NICUs treating critically ill infants.

IMPACT

Most infants with Down syndrome born at <34 weeks' gestation are born by cesarean section because of the non-reassuring fetal status. The mortality rate before discharge for infants with Down syndrome born at <34 weeks' gestation was 40%, and 30% of survivors developed moderate or severe cerebral palsy. The risk of death due to bronchopulmonary dysplasia and pulmonary hypertension was high in very preterm infants with Down syndrome despite the absence of chorioamnionitis. Infants with Down syndrome were born 1-2 weeks earlier than unaffected controls.

The Impact of Altitude at Birth on Perinatal Respiratory Support for Neonates with Trisomy 21

OBJECTIVE

Both high altitude and trisomy 21 (T21) status can negatively impact respiratory outcomes. The objective of this study was to examine the association between altitude and perinatal respiratory support in neonates with T21 compared with those without T21.

STUDY DESIGN

This retrospective cohort study used the United States all-county natality files that included live, singleton, in-hospital births from 2015 to 2019. Descriptive statistics for neonates with and without the primary outcome of sustained assisted ventilation (>6 hours) were compared using t-tests and Chi-squared analyses. Multivariable logistic regression was used to determine the association between respiratory support and the presence of T21, and included an interaction term to determine whether the association between respiratory support and the presence of T21 was modified by elevation at delivery.

RESULTS

A total of 17,939,006 neonates, 4,059 (0.02%) with T21 and 17,934,947 (99.98%) without, were included in the study. The odds of requiring sustained respiratory support following delivery were 5.95 (95% confidence interval [CI]: 5.31, 6.66), 4.06 (95% CI: 2.39, 6.89), 2.36 (95% CI: 1.64, 3.40), and 5.04 (95% CI: 1.54, 16.54) times as high for neonates with T21 than without T21 when born at low, medium, high, and very high elevations, respectively. The odds of requiring immediate ventilation support following delivery were 5.01 (95% CI: 4.59, 5.46), 5.90 (95% CI: 4.16, 8.36), 2.86 (95% CI: 2.15, 3.80), and 12.08 (95% CI: 6.78, 21.51) times as high for neonates with T21 than without T21 when born at low, medium, high, and very high elevation, respectively.

CONCLUSION

Neonates with T21 have increased odds of requiring respiratory support following delivery when compared with neonates without T21 at all categories of altitude. However, the odds ratios did not increase monotonically with altitude which indicates additional research is critical in understanding the effects of altitude on neonates with T21.

KEY POINTS

· Neonates with T21 have an increased need for perinatal respiratory support at all altitudes.. · The odds of needing perinatal respiratory support did not increase monotonically with elevation.. · Additional research is critical to understanding the effects of altitude on neonates with T21..

Excessive negative regulation of type I interferon disrupts viral control in individuals with Down syndrome

Down syndrome (DS) is typically caused by triplication of chromosome 21. Phenotypically, DS presents with developmental, neurocognitive, and immune features. Epidemiologically, individuals with DS have less frequent viral infection, but when present, these infections lead to more severe disease. The potent antiviral cytokine type I Interferon (IFN-I) receptor subunits IFNAR1 and IFNAR2 are located on chromosome 21. While increased IFNAR1/2 expression initially caused hypersensitivity to IFN-I, it triggered excessive negative feedback. This led to a hypo-response to subsequent IFN-I stimuli and an ensuing viral susceptibility in DS compared to control cells. Upregulation of IFNAR2 expression phenocopied the DS IFN-I dynamics independent of trisomy 21. CD14+ monocytes from individuals with DS exhibited markers of prior IFN-I exposure and had muted responsiveness to ex vivo IFN-I stimulation. Our findings unveil oscillations of hyper- and hypo-response to IFN-I in DS, predisposing individuals to both lower incidence of viral disease and increased infection-related morbidity and mortality.

Pulmonary complications in children with Down syndrome: A scoping review

CONTEXT

Down syndrome (DS) is a prevalent chromosomal disorder associated with a wide range of congenital anomalies and other health problems.

OBJECTIVES

To give a scoping overview of encountered lower airway problems (both infectious and non-infectious) in DS children.

DATA SOURCES

We systematically searched the MEDLINE and PubMed databases for relevant publications.

STUDY SELECTION

Studies were eligible if they were original studies about pediatric airway problems in DS and were evaluated by the PRISMA guidelines.

DATA EXTRACTION

Data concerning patient characteristics, study methods and outcomes were critically reviewed.

RESULTS

Sixty papers were included. These were reviewed and summarized by topic, i.e. airway anomalies, dysphagia and aspiration, lower respiratory tract infections (and bronchiolitis in particular), pulmonary hypertension and other. Respiratory problems are proven to be a frequent and a major health burden in DS children. Airway anomalies (both single and multiple) are more prevalent and require a specific approach. A large proportion of DS children have (often silent) aspiration, resulting in protracted and difficult-to-treat symptoms. Respiratory tract infections are usually more severe and associated with an increased need for (prolonged) hospitalization. Pulmonary hypertension, wheeze and some other rare conditions are more commonly encountered in DS.

LIMITATIONS

Large number of studies and high levels of study heterogeneity.

CONCLUSIONS

Several lower airway problems are more frequent and more complex in children with DS. These findings emphasize the need for a multidisciplinary approach by an experienced team allowing for a prompt diagnosis, proper management and improved long term outcome.

Dihydrotanshinone Attenuates LPS-Induced Acute Lung Injury in Mice by Upregulating LXRα

Dihydrotanshinone (DIH) is an extract of Salvia miltiorrhiza Bunge. It has been reported that DIH could regulate NF-κB signaling pathway. The aim of this study was to investigate whether DIH could protect mice from lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice. In this study, sixty mice were randomly divided into five groups, one group as blank control group, the second group as LPS control group, and the last three groups were pre-injected with different doses of DIH and then inhaled LPS for experimental comparison. After 12 h of LPS treatment, the wet-dry ratio, histopathlogical changes, and myeloperoxidase (MPO) activity of lungs were measured. In addition, ELISA kits were used to measure the levels of TNF-α and IL-1β inflammatory cytokines in bronchoalveolar lavage fluids (BALF), and western blot analysis was used to measure the activity of NF-κB signaling pathway. The results demonstrated that DIH could effectively reduce pulmonary edema, MPO activity, and improve the lung histopathlogical changes. Furthermore, DIH suppressed the levels of inflammatory cytokines in BALF, such as TNF-α and IL-1β. In addition, DIH could also downregulate the activity of NF-κB signaling pathway. We also found that DIH dose-dependently increased the expression of LXRα. In addition, DIH could inhibit LPS-induced IL-8 production and NF-κB activation in A549 cells. And the inhibitory effects were reversed by LXRα inhibitor geranylgeranyl pyrophosphate (GGPP). Therefore, we speculate that DIH regulates LPS-induced ALI in mice by increasing LXRα expression, which subsequently inhibiting NF-κB signaling pathway.

Diffuse alveolar hemorrhage in children with trisomy 21

BACKGROUND

Respiratory conditions are the leading cause of hospitalization and death in children with Trisomy 21 (T21). Diffuse alveolar hemorrhage (DAH) occurs at higher frequency in children with T21; yet, it is not widely studied nor is there a standardized approach to diagnosis or management. The objective of this study was to identify children with T21 and DAH in order to understand contributing factors and identify opportunities to improve outcomes. We identified 5 children with T21 at a single institution with histology-proven DAH over 10 years and discuss their presentation, evaluation, management, and outcomes. We also reviewed the cases in the literature.

CASE PRESENTATION

Patient 1 died at age seven due to secondary hemophagocytic lymphohistiocytosis. DAH was seen on autopsy. Patient 2 was a three-year-old with systemic-onset juvenile idiopathic arthritis diagnosed with DAH after presenting for hypoxia. Patient 3 was diagnosed with DAH at age nine after presenting with recurrent suspected pneumonia and aspiration. Patient 4 was diagnosed with DAH at age eight after presenting with pallor and fatigue. She had additional ICU admissions for DAH with infections. Patient 5 developed hemoptysis at age three and had recurrent DAH for 10 years. Four patients responded positively to immune-modulation such as intravenous immunoglobulin, glucocorticoids, and rituximab. Of the 19 patients identified in the literature, only one was from the United States. The majority had anemia, respiratory distress, autoantibodies, and recurrences. Very few patients had hemoptysis. Idiopathic pulmonary hemosiderosis was the most common diagnosis. Almost all received glucocorticoids with or without additional immunosuppression. The majority of our patients and those in the literature had positive auto-antibodies such as anti-neutrophil cytoplasmic antibodies and anti-nuclear antigen antibodies. Diagnostic clues included respiratory distress, hypoxia, anemia, recurrent pneumonia, and/or ground glass opacities on imaging. We identified four contributors to DAH: structural lung abnormalities, pulmonary arterial hypertension, infection/aspiration, and autoimmune disease/immune dysregulation.

CONCLUSION

These cases demonstrate the need for an increased index of suspicion for DAH in children with T21, particularly given the low frequency of hemoptysis at presentation, enrich the understanding of risk factors, and highlight the favorable response to immunosuppressive therapies in this vulnerable population.

Down syndrome and congenital heart disease: perioperative planning and management

Approximately 50% of newborns with Down syndrome have congenital heart disease. Non-cardiac comorbidities may also be present. Many of the principles and strategies of perioperative evaluation and management for patients with congenital heart disease apply to those with Down syndrome. Nevertheless, careful planning for cardiac surgery is required, evaluating for both cardiac and noncardiac disease, with careful consideration of the risk for pulmonary hypertension. In this manuscript, for children with Down syndrome and hemodynamically significant congenital heart disease, we will summarize the epidemiology of heart defects that warrant intervention. We will review perioperative planning for this unique population, including anesthetic considerations, common postoperative issues, nutritional strategies, and discharge planning. Special considerations for single ventricle palliation and heart transplantation evaluation will also be discussed. Overall, the risk of mortality with cardiac surgery in pediatric patients with Down syndrome is no more than the general population, except for those with functional single ventricle heart defects. Underlying comorbidities may contribute to postoperative complications and increased length of stay. A strong understanding of cardiac and non-cardiac considerations in children with Down syndrome will help clinicians optimize perioperative care and long-term outcomes.

Trisomy 21 and Coronavirus Disease 2019 in Pediatric Patients

We present 4 pediatric patients with trisomy 21 (T21) and associated comorbidities who developed coronavirus disease 2019 requiring hospitalization. A review of the literature revealed that comorbidities associated with T21 may predispose patients to severe disease. Children with T21 should be considered high risk and monitored carefully if infected with severe acute respiratory syndrome coronavirus 2.

Individuals with Down syndrome hospitalized with COVID-19 have more severe disease

PURPOSE

Rare genetic conditions like Down syndrome (DS) are historically understudied. Infection is a leading cause of mortality in DS, along with cardiac anomalies. Currently, it is unknown how the COVID-19 pandemic affects individuals with DS. Herein, we report an analysis of individuals with DS who were hospitalized with COVID-19 in New York, New York, USA.

METHODS

In this retrospective, dual-center study of 7246 patients hospitalized with COVID-19, we analyzed all patients with DS admitted in the Mount Sinai Health System and Columbia University Irving Medical Center. We assessed hospitalization rates, clinical characteristics, and outcomes.

RESULTS

We identified 12 patients with DS. Hospitalized individuals with DS are on average ten years younger than patients without DS. Patients with DS have more severe disease than controls, particularly an increased incidence of sepsis and mechanical ventilation.

CONCLUSION

We demonstrate that individuals with DS who are hospitalized with COVID-19 are younger than their non-DS counterparts, and that they have more severe disease than age-matched controls. We conclude that particular care should be considered for both the prevention and treatment of COVID-19 in these patients.

Effects of Pidotimod on recurrent respiratory infections in children with Down syndrome: a retrospective Italian study

BACKGROUND

Children with Down syndrome (DS) show a high susceptibility to recurrent infections (RI), caused by immune defects and abnormalities of the airways. Our goal was to investigate the effects of Pidotimod on RI prevention in children with DS, comparing immune and clinical parameters before (T0) and after (T1) the treatment with Pidotimod.

METHODS

The study was conducted at the Down syndrome outpatient Center of Bambino Gesù Children's Hospital, in Rome. We reviewed the medical records of all children with a positive history for RI and who received oral prophylaxis of Pidotimod from September 2016 to February 2017.

RESULTS

Thirty-three children met the inclusion criteria (males: 51.5%; average age: 6 years ±SD: 3). We found a significant decrease in the number of children with upper respiratory infections (82% at T0 vs 24% at T1; p = 0,0001) and with lower respiratory infections (36% at T0 vs 9% at T1; p = 0.003) after treatment with Pidotimod. We also demonstrated a significant decrease in the number of children hospitalized for respiratory infections (18% at T0 vs 3% at T1; p = 0.03). We measured T and B cells in the peripheral blood and B cell function in vitro at T0 and T1. We found that the response to CpG improved at T1. A significant increase of B cell frequency (p = 0.0009), B cell proliferation (p = 0.0278) and IgM secretion (p = 0.0478) were observed in children with DS after treatment.

CONCLUSIONS

Our results provided evidence that Pidotimod may be able to prevent RI in children with Down syndrome.

Clinical implications of immune-mediated diseases in children with Down syndrome

Children with Down syndrome have changes in their innate and adaptive immunity, which contribute to increased rates of infections, autoimmune diseases, and haematological malignancies. While improved care for congenital heart disease has decreased mortality and morbidity, complications related to immune-mediated diseases continue to limit the life expectancy in Down syndrome. Infectious diseases are common and have a significant effect on development, behaviour and quality of life. Infection frequency and severity are influenced by various anatomical and physiological alterations in addition to immunological changes in Down syndrome. Thus, prevention of respiratory tract infections requires a multifactorial approach. This could include additional active and/or passive immunizations, prophylactic antibiotics, immunoglobulin replacement and ear, nose and throat surgical interventions. Autoimmune conditions like coeliac disease, type I diabetes mellitus and thyroid disease are classically mentioned in the context of Down syndrome. However, autoinflammatory conditions are more prevalent as well. Screening for autoimmune diseases is required and immunosuppression has to be used with caution. Future studies should address optimal screening programmes for immune-mediated diseases in individuals with Down syndrome, as well as the effect of immune modulation, to further decrease morbidity and mortality, and improve the quality of life of individuals with Down syndrome.

The evaluation and management of respiratory disease in children with Down syndrome (DS)

Children with Down syndrome (DS) have wide range of respiratory problems. Although underlying abnormalities in the respiratory system are important causes of morbidity and mortality in children with DS, particularly in the young, abnormalities in other organ systems may also impact respiratory function. A comprehensive evaluation of the child with DS and respiratory disease may prevent short-term morbidity and mortality, and reduce the incidence of complications in the long term. This review provides an overview of the various causes of respiratory disease, and insight into some of the newer therapies available to treat obstructive sleep apnea, in this population.

What people with Down Syndrome can teach us about cardiopulmonary disease

Down syndrome is the most common chromosomal abnormality among live-born infants. Through full or partial trisomy of chromosome 21, Down syndrome is associated with cognitive impairment, congenital malformations (particularly cardiovascular) and dysmorphic features. Immune disturbances in Down syndrome account for an enormous disease burden ranging from quality-of-life issues (autoimmune alopecia) to more serious health issues (autoimmune thyroiditis) and life-threatening issues (leukaemia, respiratory tract infections and pulmonary hypertension). Cardiovascular and pulmonary diseases account for ∼75% of the mortality seen in persons with Down syndrome. This review summarises the cardiovascular, respiratory and immune challenges faced by individuals with Down syndrome, and the genetic underpinnings of their pathobiology. We strongly advocate increased comparative studies of cardiopulmonary disease in persons with and without Down syndrome, as we believe these will lead to new strategies to prevent and treat diseases affecting millions of people worldwide.

Age-related alterations of the CD19 complex and memory B cells in children with Down syndrome

Children with Down syndrome (DS) have a high incidence of recurrent respiratory tract infections, leukaemia and autoimmune disorders, suggesting immune dysfunction. The present study evaluated the role of the CD19 complex and memory B cells in the pathogenesis of immunodeficiency in children with DS. The expression levels (median fluorescein intensity-MFI) of CD19, CD21 and CD81 molecules on the surface of B cells and memory B cell subsets were studied in 37 patients and 39 healthy controls. Twenty-nine of the DS group had congenital cardiac disease. The B cell count was significantly low in children with DS compared with healthy age-matched controls for all three age groups (under 2 years; 2-6 years and older than 6 years). The MFI of CD19 was reduced in all the age groups, whereas that of CD21 was increased in those older than 2 years with DS. The expression level of CD81 was significantly increased in those older than 6 years. Age-related changes were also detected in memory B cell subsets. The frequency of CD27⁺IgD⁺IgM⁺ natural effector B cells was reduced in children with DS who had needed hospitalisation admission due to infections. The observed intrinsic defects in B cells may be responsible for the increased susceptibility of children with DS to severe respiratory tract infections.

Children with Down syndrome: Clinical course and mortality-associated factors in a French medical paediatric intensive care unit

AIM

To investigate clinical course and mortality-associated factors in children with Down syndrome (DS) managed in a medical paediatric intensive care unit.

METHODS

A single-centre, retrospective study conducted between 2001 and 2010 in DS children aged 1 month to 16 years.

RESULTS

Sixty-six patients with a median age of 24 months (1-192) and a male/female ratio of 1.5 were analysed. Patients presented with history of congenital heart disease (n = 52, 78.8%), mechanical ventilation (n = 40, 60.6%) and chronic upper airway obstruction (n = 10, 15.1%). The primary reason for admission was respiratory failure (n = 56, 84.8%). Pulmonary arterial hypertension (PAH) (n = 19, 28.8%), acute respiratory distress syndrome (ARDS) (n = 18, 27.2%) and sepsis (n = 14, 21.2%) were observed during their clinical course. Twenty-six patients died (39.4%). Mortality-associated factors included the following: (i) baseline characteristics: history of mechanical ventilation, chronic upper airway obstruction and congenital heart disease; (ii) clinical course during paediatric intensive care unit stay: sepsis, catecholamine support, ARDS, PAH and nosocomial infection. In multivariate logistic analysis, history of mechanical ventilation, ARDS and PAH remained independently associated with death.

CONCLUSIONS

The mortality rate in critically ill DS children admitted for medical reasons is high and is predominantly associated with respiratory conditions.

A protracted course of Pneumocystis pneumonia in the setting of an immunosuppressed child with GMS-negative bronchoalveolar lavage

We report a case of Pneumocystis pneumonia in a 5-year-old male with Trisomy 21 and acute lymphoblastic leukemia. The lack of response to trimethoprim-sulfamethoxazole raised concerns for antimicrobial resistance. Further, diagnosis of Pneumocystis in this patient was complicated by a GMS-negative bronchoalveolar lavage despite molecular evidence of Pneumocystis infection.

Atractylenolide I protects mice from lipopolysaccharide-induced acute lung injury

Atractylenolide I (AO-I), one of the major bioactive components isolated from Rhizoma Atractylodes macrocephala, has been reported to have anti-inflammatory effects. In the present study, we investigated the protective effects of AO-I on acute lung injury (ALI) using LPS-induced ALI mouse model. Lung injury was assessed by histological study. Inflammatory cytokines TNF-α, IL-6 and IL-1β production were detected by ELISA. TLR4 expression and NF-κB activation were measured by western blot analysis. The results showed that treatment of AO-I significantly attenuated LPS-induced lung wet-to-dry weight ratio and MPO activity. Meanwhile, treatment of AO-I significantly inhibited the production of TNF-α, IL-6, IL-1β, IL-13, and MIF production in bronchoalveolar lavage fluid (BALF), as well as neutrophils and macrophages in BALF. AO-1 could up-regulate the production of IL-10 in BALF. Besides, LPS-induced TLR4 expression and NF-κB activation were suppressed by treatment of AO-I. In conclusion, the current study suggested that AO-I protected mice acute lung injury induced by LPS via inhibition of TLR4 expression and NF-κB activation.

Hematopoietic stem cell transplantation for patients with acute lymphoblastic leukemia and Down syndrome

BACKGROUND

Hematopoietic stem cell transplantation (HSCT) is one curable option for high-risk acute lymphoblastic leukemia (ALL); however, transplant-related toxicities might be severe in patients with Down syndrome and ALL (DS-ALL).

PROCEDURE

HSCTs performed in patients with DS-ALL were identified in the Japan Society for Hematopoietic Cell Transplantation registry.

RESULTS

In the registry data, 11 patients with DS-ALL were identified. The median age at HSCT was 9 years (range: 6-22 years). Six patients underwent HSCT at non-remission status. Allogeneic grafts were utilized in all patients, including eight patients who received HSCT from unrelated donors. Reduced intensity conditioning regimens were used in three patients. All patients achieved neutrophil engraftment by a median of day 18 (range: day 11-61). Ten patients experienced grade 3 or more infectious episodes. Six patients experienced complications of the respiratory system. The incidences of II-IV or III-IV acute GVHD were nine (81.8%) or seven patients (63.6%), respectively. Chronic GVHD was observed in five (55.6%) out of nine evaluable patients. Seven patients died at a median of 6 months (range: 0-24 months) after HSCT. Two-year relapse-free and overall survival were 33.3% (95% CI: 2.5-64.1%) or 37.5% (95% CI: 5.9-69.1%), respectively. The causes of death were relapse (n = 2), infection (n = 2), bleeding (n = 1), thrombotic microangiopathy (n = 1), and chronic GVHD (n = 1).

CONCLUSIONS

Therapy-related mortality accounted for five out of seven deceased patients in this case series. Attempts to reduce toxicities should be considered in HSCT for patients with DS-ALL.

Risk factors associated with death in patients with severe respiratory syncytial virus infection

BACKGROUND

Respiratory syncytial virus (RSV) infection is an important cause of viral respiratory tract infection in children. This retrospective study describes the clinical characteristics of severe RSV infection and determines the risk factors for death.

METHODS

Patients were identified through a review of all patients discharged with a diagnosis of RSV lower respiratory tract infection and admitted to hospital in the pediatric intensive care unit (PICU) of a tertiary medical center between July 1, 2001 and June 30, 2010. The medical and demographic variables were recorded and analyzed.

RESULTS

The 186 RSV-positive patients admitted to the PICU had a median age of 5.3 months (interquartile range 2.3-12.4 months) and included 129 boys and 57 girls. Among them, 134 had at least one underlying disease: prematurity in 92, neurological disease in 57, bronchopulmonary dysplasia in 40, congenital heart disease in 26, hematological malignancies in 11, and Down's syndrome in nine patients. The 10 patients who died from RSV-related causes had a median age of 20.8 months (interquartile range 6.6-89.2 months) and all had a comorbidity. In multivariate analysis, the risk factors for death in severe RSV infection were Down's syndrome (odds ratio 7.20, 95% confidence interval 1.13-45.76; p = 0.036) and nosocomial RSV infection (odds ratio 4.46, 95% confidence interval 1.09-18.27; p = 0.038).

CONCLUSION

Down's syndrome and nosocomial RSV infection are significantly associated with death in severe RSV infections. Clinicians should be alert to these conditions.

The distribution and frequency of pulmonary neuroendocrine cells in Down syndrome fetal lungs

The pulmonary neuroendocrine cells (PNEC) are located in the epithelial lining of the airways and consist of solitary neuroendocrine cells (NEC) and NEC clusters, the neuroepithelial bodies (NEB). During fetal life, PNEC are the first to differentiate within the primitive airway epithelium, and bombesin expression favors branching of the respiratory tree. We investigated PNEC in Down syndrome (DS), where the lungs often show enlarged and reduced number of alveoli. Immunohistochemistry for bombesin and synaptophysin, PNEC markers, was evaluated in fetal lungs from 15 cases of DS and 11 age-matched controls from the 17th to 23rd week of gestation. Morphometric analysis assessed PNEC in the mucosal lining of each lung, expressed as number/mm. Nonparametric Mann-Whitney U test showed no statistical difference in frequency of PNEC in DS and controls. Our findings suggest that, at least in late second trimester, the distribution and frequency of PNEC in DS fetuses is not altered.

Early postoperative outcomes following surgical repair of complete atrioventricular septal defects: is down syndrome a risk factor?

OBJECTIVE

To evaluate the impact of Down syndrome on the early postoperative outcomes of children undergoing complete atrioventricular septal defect repair.

DESIGN

Retrospective cohort study.

SETTING

Single tertiary pediatric cardiac center.

PATIENTS

All children admitted to PICU following biventricular surgical repair of complete atrioventricular septal defect from January 2004 to December 2009.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A total of 107 children, 67 with Down syndrome, were included. Children with Down syndrome were operated earlier: 4 months (interquartile range, 3.5-6.6) versus 5.7 months (3-8.4) for Down syndrome and non-Down syndrome groups, respectively (p < 0.01). There was no early postoperative mortality. There was no significant difference in the prevalence of dysplastic atrioventricular valve between the two groups. Two children (2.9%) from Down syndrome and three children (7.5%) from non-Down syndrome group required early reoperation (p = 0.3). Junctional ectopic tachycardia was the most common arrhythmia, and the prevalence of junctional ectopic tachycardia was similar between the two groups (9% and 10% in Down syndrome and non-Down syndrome, respectively, p = 1). One patient from each group required insertion of permanent pacemaker for complete heart block. Children with Down syndrome had significantly higher prevalence of noncardiac complications, that is, pneumothorax, pleural effusions, and infections (p < 0.01), than children without Down syndrome. There was a trend for longer duration of mechanical ventilation in children with Down syndrome (41 hr [20-61 hr] vs 27.5 hr [15-62 hr], p = 0.2). However, there was no difference in duration of PICU stay between the two groups (2 d [1.3-3 d] vs 2 d [1-3 d], p = 0.9, respectively).

CONCLUSIONS

In our study, we found no difference in the prevalence of atrioventricular valve dysplasia between children with and without Down syndrome undergoing complete atrioventricular septal defect repair. This finding contrasts with previously published data, and further confirmatory studies are required. Although clinical outcomes were similar, children with Down syndrome had a significantly higher prevalence of noncardiac complications in the early postoperative period than children without Down syndrome.

Effect of rowing on pulmonary functions in children with Down syndrome

PURPOSE

To examine effects of a rowing exercise regimen versus a chest physical therapy program on pulmonary function in children with Down syndrome.

METHODS

Twenty-nine participants of both sexes, between 8 to 12 years of age, participated in this study. They were assigned randomly into 2 study groups. The first group (A) received a chest physical therapy program, while the second group (B) received an aerobic exercise regimen using a rowing ergometer. Vital capacity, forced vital capacity, forced expiratory volume after 1 second, and peak expiratory flow rate were measured before and after 12 successive weeks of treatment.

RESULTS

Significant improvements in all measured variables were found posttreatment in both study groups. No significant difference between the 2 groups was found posttreatment.

CONCLUSION

Rowing exercise could be effective in improving pulmonary functions in children with Down syndrome.

An overview of respiratory problems in children with Down's syndrome

Respiratory disease is a common cause of morbidity and mortality in children with Down's syndrome (DS). Causes range from those problems common to many children with DS, such as a narrow airway or impaired immunity, to rare structural lesions, such as tracheal bronchus. Additionally, other organ systems or extrinsic factors may play a role. A thorough understanding of the range of potential problems will aid in the evaluation and management of children with DS and respiratory symptoms.

Down syndrome and hospitalizations due to respiratory syncytial virus: a population-based study

OBJECTIVE

To assess the risk estimates for respiratory syncytial virus (RSV) hospitalization in children with Down syndrome (DS) and the clinical features and severity of RSV lower respiratory tract infection (LRTI) in hospitalized children.

STUDY DESIGN

Statewide hospitalization data for children with DS for 1995 through 2006 from the Colorado Health and Hospital Association database were combined with birth data from the Colorado Department of Public Health and Environment to obtain population-based estimates of RSV LRTI hospitalization for children with DS in the first 2 years of life. RSV hospitalization data for children with DS at the Children's Hospital Colorado for 2000 through 2006 were used to compare the course and severity of hospitalization of DS LRTI admissions with those of matched control subjects.

RESULTS

There were 85 RSV LRTI hospitalizations in 630 children born with DS in Colorado, with 50 having no concurrent underlying conditions identified. Children with DS had a significantly higher risk than did those without DS for being hospitalized with RSV LRTI (OR, 5.99; 95% CI, 6.68-5.38), even in the absence of other underlying conditions (OR 3.5; 95% CI, 3.10-4.12). In the case-control study, children with DS hospitalized for RSV presented more frequently with fever (P = .005), had consolidation reported more often on chest radiography (P = .003), and were given bronchodilator therapy more often during the hospital stay (P = .002).

CONCLUSIONS

Children with DS have a higher risk of being hospitalized with RSV LRTI even in the absence of coexisting risk factors. They present more often with fever and more often have radiographic consolidation detected on chest radiography.

Pulmonary epithelial apoptosis in fetal down syndrome: not higher than normal

Children with Down syndrome (DS) are at high risk for acute lung injury (ALI). Pulmonary epithelial apoptosis is an important factor in the pathophysiology of ALI. Whether the risk of ALI in DS is associated with a high level of pulmonary epithelial apoptosis is not known. We hypothesized that the percentage of apoptotic epithelial cells is higher in DS than in control lungs. Lung tissue sections from autopsies of 21 fetuses with DS and 12 controls were stained with antibodies against the epithelial marker pan-cytokeratin (CK) and apoptosis marker activated caspase-3 (aC3). Spectral imaging software was used to quantify the mean percentage of pixels that showed colocalization of CK and aC3. Mean (standard deviation [SD]) gestational age in weeks was 18.7 (1.4) in DS and 18.9 (2.0) in controls (P  =  0.67). The mean (SD) percentage of CK-positive pixels was 27.2% (4.7%) in DS compared to 27.1% (6.2%) in controls (P  =  0.97). The median (interquartile range [IQR]) percentage of CK-positive pixels that showed colocalization of aC3 was 0.16% (0.18%) in DS compared to 0.27% (0.24%) in controls (P  =  0.45). The mean (SD) number of CK-positive pixels increased from 22.5% (5.2%) to 30.4% (4.6%) with the appearance of saccular morphology in controls but not in DS (P  =  0.01). The percentage of apoptotic epithelial cells in DS fetal lungs does not differ from that in controls. However, we did find a difference in the development of epithelial structures between DS and controls that may be associated with anomalies in alveolar development found at birth in DS.

Infections and immunodeficiency in Down syndrome

Down syndrome (DS) is the most common genetic disease and presents with cognitive impairment, cardiac and gastrointestinal abnormalities, in addition to other miscellaneous clinical conditions. DS individuals may have a high frequency of infections, usually of the upper respiratory tract, characterized by increased severity and prolonged course of disease, which are partially attributed to defects of the immune system. The abnormalities of the immune system associated with DS include: mild to moderate T and B cell lymphopenia, with marked decrease of naive lymphocytes, impaired mitogen-induced T cell proliferation, reduced specific antibody responses to immunizations and defects of neutrophil chemotaxis. Limited evidence of genetic abnormalities secondary to trisomy of chromosome 21 and affecting the immune system is available, such as the potential consequences of gene over-expression, most significantly SOD1 and RCAN1. Secondary immunodeficiency due to metabolic or nutritional factors in DS, particularly zinc deficiency, has been postulated. Non-immunological factors, including abnormal anatomical structures (e.g. small ear canal, tracheomalacia) and gastro-oesophageal reflux, may play a role in the increased frequency of respiratory tract infections. The molecular mechanisms leading to the immune defects observed in DS individuals and the contribution of these immunological abnormalities to the increased risk of infections require further investigation. Addressing immunological and non-immunological factors involved in the pathogenesis of infectious diseases may reduce the susceptibility to infections in DS subjects.