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

Clinical practice - latest insights in optimizing the care of children with Down syndrome

An essential part of the care of children with Down syndrome is secondary screening for comorbidity. It is well known that comorbidity frequently occurs in these children. A new update of the Dutch Down syndrome medical guideline was developed to create a sound evidence base for several of these conditions. We present the latest insights and recommendations from this Dutch medical guideline which are based on the most relevant literature currently available and developed with rigorous methodology. The main focus of this revision of the guideline was on obstructive sleep apnea and other airway problems and hematologic disorders, such as transient abnormal myelopoiesis, leukemia, and thyroid disorders. Conclusion: This is a short summary of the latest insights and recommendations from the updated Dutch medical guideline for children with Down syndrome.

Flexible bronchoscopy in pediatric patients with Down syndrome: A case-control study of the indications, findings, and complications

BACKGROUND

Children with Down syndrome (DS) often undergo flexible bronchoscopies (FB) due to common respiratory symptoms.

OBJECTIVE

To examine the indications, findings, and complications of FB in pediatric DS patients.

METHODS

A retrospective case-control study on FB performed in DS pediatric patients between 2004 and 2021 in a tertiary center. DS patients were matched to controls (1:3) based on age, gender, and ethnicity. Data collected included demographics, comorbidities, indications, findings, and complications.

RESULTS

Fifty DS patients (median age 1.36 years, 56% males) and 150 controls (median age 1.27 years, 56% males), were included. Evaluation for obstructive sleep apnea and oxygen dependence were more common indications among DS (38% vs. 8%, 22% vs. 4%, p < 0.01, respectively). Normal bronchoscopy was less frequent in DS compared with controls (8% vs. 28%, p = 0.01). Soft palate incompetence and tracheal bronchus were more frequent in DS (12% vs. 3.3%, p = 0.024, 8% vs. 0.7%, p = 0.02, respectively). Complications were more frequent in DS (22% vs. 9.3%, incidence rate ratio [IRR] 2.36, p = 0.028). In DS, cardiac anomalies (IRR 3.96, p < 0.01), pulmonary hypertension (IRR 3.76, p = 0.006), and pediatric intensive care unit (PICU) hospitalization before the procedure (IRR 4.2, p < 0.001) were associated with higher complication rates. In a multivariate regression model, history of cardiac disease and PICU hospitalization before the procedure, but not DS, were independent risk factors for complications with an IRR of 4 and 3.1, respectively (p = 0.006, p = 0.05).

CONCLUSION

DS pediatric patients undergoing FB are a unique population with specific indications and findings. DS pediatric patients with cardiac anomalies and pulmonary hypertension are at the highest risk for complications.

Heart Rate Variability in Individuals with Down Syndrome: A Scoping Review with Methodological Considerations

Individuals with Down syndrome (DS) present similar heart rate variability (HRV) parameters at rest but different responses to selected movement maneuvers in comparison to individuals without DS, which indicates reduced vagal regulation. The present study undertakes a scoping review of research on HRV in individuals with DS, with special attention paid to the compliance of the studies with standards and methodological paper guidelines for HRV assessment and interpretation. A review was performed using PubMed, Web of Science and CINAHL databases to search for English language publications from 1996 to 2020 with the MESH terms "heart rate variability" and "down syndrome", with the additional inclusion criteria of including only human participants and empirical investigations. From 74 studies, 15 were included in the review. None of the reviewed studies met the recommendations laid out by the standards and guidelines for providing the acquisition of RR intervals and necessary details on HRV analysis. Since authors publishing papers on this research topic do not adhere to the prescribed standards and guidelines when constructing the methodology, results of the research papers on the topic are not directly comparable. Authors need to design the study methodology more robustly by following the aforementioned standards, guidelines and recommendations.

Down Syndrome: A Review of Key Perioperative Implications

Down syndrome (DS) is the most common chromosomal abnormality in humans that is compatible with life. This syndrome occurs when there is an extra copy of the 21st chromosome. Down syndrome is associated with numerous comorbidities that can pose challenges for the perioperative nurse caring for a patient with DS undergoing surgery. These challenges can affect the patient assessment, communication with the patient, and patient safety (eg, preventing complications). As the life expectancy of people with DS has increased, so too have the chances that perioperative nurses will care for a patient with this disorder. This article reviews the pathophysiology of DS, discusses common comorbidities that may directly affect perioperative care, and reviews an exemplar case study that demonstrates how personnel with knowledge of DS can positively influence surgical team decision making for these patients in the perioperative setting.

Increased rate of respiratory symptoms in children with Down syndrome: a 2-year web-based parent-reported prospective study

To compare the incidence of respiratory symptoms and short-term consequences between children with Down syndrome and children from the general population, we conducted a prospective parent-reported observational study. Children with Down syndrome (≤ 18 years) were included between March 2012 and June 2014. Caregivers received a baseline questionnaire with follow-up 1-2 years after inclusion. Caregivers received a weekly questionnaire about respiratory symptoms, fever, antibiotic prescriptions, doctor's visits, and consequences for school and work attendance. Children with Down syndrome were compared to a cohort of the general population ("Kind en Ziek" study) with similar weekly questionnaires. A total of 9,011 childweeks were reported for 116 participants with Down syndrome (75% response rate). The frequency of respiratory symptoms was higher in children with Down syndrome than in children from the general population (30% vs 15.2%). In addition, symptoms subsided later (around 8 vs 5 years of age). The seasonal influence was limited, both in children with Down syndrome and children from the general population. Consequences of respiratory disease were significant in children with Down syndrome compared to children from the general population, with a higher rate of doctor's visits (21.3% vs 11.8%), antibiotic prescriptions (47.8% vs 26.3%), and absenteeism from school (55.5% vs 25.4%) and work (parents, 9.4% vs 8.1%).  Conclusion: Children with Down syndrome have a higher frequency of respiratory symptoms and symptoms last until a later age, confirming the impression of professionals and caregivers. Individualized treatment plans might prevent unfavorable consequences of chronic recurrent respiratory disease in children with Down syndrome. What is Known: • Children with Down syndrome have an altered immune system and are prone to a more severe course of respiratory tract infections. • The overall conception is that patients with Down syndrome suffer from respiratory tract infections more often. What is New: • Children with Down syndrome suffer from respiratory symptoms more frequently than children from the general population. • The respiratory symptoms in children with Down syndrome subside at a later age compared to children from the general population.

Lower airway microbiota in children with Down syndrome compared to controls with similar respiratory symptomatology

BACKGROUND

Children with Down syndrome (DS) often present with chronic or recurrent respiratory symptoms and generally have a more severe and prolonged disease course in case of infection. This can be caused by anatomical and/or immunological predisposition. With this study, we aim to compare microbial composition in the lower airways of patients with DS versus controls, to see if we can explain the difference in disease course.

METHODS

All endoscopic procedures under general anesthesia in patients with DS were reviewed retrospectively. We compared the microbiological data from bronchoalveolar lavage fluid (BALF) cultures (when available) to a cohort of children with chronic respiratory symptoms but without any other relevant medical history.

RESULTS

Endoscopic data were available for 65 DS patients, BAL cultures for 47 out of 65 patients (72%). The "control" group consisted of 150 children without significant underlying disease, who were matched for age and sex. BAL culture results were available for 135 out of 150 patients (90%). Microorganisms were categorized and compared between both groups, with no statistical differences. Among the microorganisms tested, the most frequently reported were typical bacteria such as Haemophilus influenzae, Moraxella catarrhalis, Streptococci and Staphylococci.

CONCLUSIONS

No significant differences in lower airways microbial composition of children with DS and chronic respiratory symptoms were found when compared to controls presenting similar symptomatology. A suggestion for future research may be to investigate possible differences in drug sensitivity.

Efficacy and adherence of noninvasive ventilation treatment in children with Down syndrome

OBJECTIVE

Children with Down syndrome (DS) have an increased prevalence of obstructive sleep apnea (OSA). Noninvasive ventilation (NIV) is a common modality of OSA treatment in this cohort. This study aimed to measure adherence and efficiency of NIV delivery in children with DS.

STUDY DESIGN

This was a retrospective cohort study involving 106 children with confirmed OSA and home NIV with downloadable data capacity. Children were divided into DS (n = 44) and non-DS cohorts (n = 62). Adherence, clinical outcomes apnea-hypopnoea index (AHI), positive airway pressure delivery, and leakage were recorded and compared between DS and non-DS cohorts and within the DS cohort based on past surgical history.

RESULTS

Significantly greater NIV usage was observed in the DS cohort, they showed more consistent use with an increased percentage of days used relative to their non-DS counterparts (78.95 ± 2.26 vs. 72.11 ± 2.14, p = .031). However, despite greater usage, poorer clinical outcomes in the form of increased AHI (p = .0493) was observed in the DS cohort, where significantly greater leakage was also shown 41.00 ± 1.61 L/min versus 36.52 ± 1.18 L/min (p = .022). Twenty children with DS had prior cardiac surgery; compliance across all parameters was significantly reduced relative to those without.

CONCLUSION

These data confirm that satisfactory NIV adherence is achievable in children with DS. However, we have identified excessive system leak at the machine-patient interface as a factor, which could undermine NIV efficacy in children with DS.

Respiratory and otolaryngological disorders in Down syndrome from one center in Brazil

Down syndrome (DS) is the most common chromosomal condition. Anatomical and functional variations in the upper and lower airways are component manifestations of the syndrome and increase the risk of various medical problems. The objective of this study was to determine the prevalence of otorhinolaryngological and respiratory diseases in a DS outpatient clinic over a 3-year period. Medical records data from 1207 patients were retrospectively reviewed. Newborn Hearing Screening was positive in 7.1% of patients. Brainstem auditory evoked potential was performed in 1101 children and showed a hearing loss of 19.8% in the first year. It was positive in 21% of 1021 exams. Audiometry was altered in 64 of 994 exams (6.4%), showing a conductive loss in 90%. Adenotonsillectomy was performed in 308 (25.5%) patients, and 169 (14.0%) required serous otitis ventilation tubes. Asthma was observed in 140 (11.6%) patients, and allergic rhinitis in 544 (56.6%). There were hospitalizations for invasive infection in 480 (39.8%) children, and two (0.2%) patients had severe septicemia from pulmonary focus. Five (0.4%) infants had laryngotracheomalacia, and one patient had anomalous right tracheal bronchus. Recognizing the prevalence of respiratory and otorhinolaryngological disorders in patients with DS allows the promotion of optimal follow-up and early treatment, preventing the development of sequelae.

Tracheal anomalies associated with Down syndrome: A systematic review

INTRODUCTION

Airway anomalies are accountable for a substantial part of morbidity and mortality in children with Down syndrome (DS). Although tracheal anomalies occur more often in DS children, a structured overview on the topic is lacking. We systematically reviewed the characteristics of tracheal anomalies in DS children.

METHODS

A MEDLINE and EMBASE search for DS and tracheal anomalies was performed. Tracheal anomalies included tracheal stenosis, complete tracheal ring deformity (CTRD), tracheal bronchus, tracheomalacia, tracheal web, tracheal agenesis or atresia, laryngotracheoesophageal cleft type 3 or 4, trachea sleeve, and absent tracheal rings.

RESULTS

Fifty-nine articles were included. The trachea of DS children is significantly smaller than non-DS children. Tracheomalacia and tracheal bronchus are seen significantly more often in DS children. Furthermore, tracheal stenosis, CTRD, and tracheal compression by vascular structures are seen regularly in children with DS. These findings are reflected by the significantly higher frequency of tracheostomy and tracheoplasty performed in DS children.

CONCLUSION

In children with DS, tracheal anomalies occur more frequently and tracheal surgery is performed more frequently than in non-DS children. When complaints indicative of tracheal airway obstruction like biphasic stridor, dyspnea, or wheezing are present in children with DS, diagnostic rigid laryngotracheobronchoscopy with special attention to the trachea is indicated. Furthermore, imaging studies (computed tomography, magnetic resonance imaging, and ultrasound) play an important role in the workup of DS children with airway symptoms. Management depends on the type, number, and extent of tracheal anomalies. Surgical treatment seems to be the mainstay in severe cases.

Hospitalisations due to respiratory syncytial virus infection in children with Down syndrome before and after palivizumab recommendation in Japan

AIM

Down syndrome has been considered an independent risk factor for respiratory syncytial virus (RSV) infection. Palivizumab, an anti-RSV humanised monoclonal antibody, was currently approved for all children with Down syndrome in Japan. To investigate the change in RSV-associated hospitalisation (RSVH) rates before and after the universal approval of palivizumab in Japan in 2013, we conducted a nationwide retrospective survey.

METHODS

We conducted a nationwide, retrospective, questionnaire survey across paediatric institutions in Japan. The recruited children with Down syndrome were divided into two groups: those born April 2010 to March 2013 (2010-2012 cohort) and those born April 2013 to March 2016 (2013-2015 cohort).

RESULTS

Of the 664 institutions, 321 (48.3%) replied, and a total of 3929 children with Down syndrome were registered. The percentage of children who received palivizumab increased from 49.2% to 82.2%. The cumulative RSVH rate showed a decreased trend in the 2013-2015 cohort (OR, 0.83; 95%CI, 0.63-1.10), while the rate of these children (without CHD and born at a gestational age ≥ 36 weeks) was significantly decreased in the 2013-2015 cohort (OR, 0.56; 95%CI, 0.34-0.92).

CONCLUSION

The cumulative RSVH rate tended to be decreased after approval for all children with Down syndrome although the result was not significant.

Neurodevelopmental Disorders Commonly Presenting with Sleep Disturbances

There are multiple disorders of neurodevelopment that present with co-occurring sleep disturbances. Many of these neurodevelopmental disorders (NDD) include sleep disturbances in their diagnostic criteria. Neurobiological, genetic, and environmental factors overlap to cause different sleep disorders in individuals with NDD. Caregivers often present reporting either insomnia or hypersomnia, and based on the clinical history and findings from diagnostic tests, an appropriate diagnosis can be made. It is crucial that clinicians understand the different presentations of sleep disturbances in individuals with NDD.

Universal palivizumab prophylaxis for children with Down syndrome in Japan: analysis with interrupted time-series

Down syndrome (DS) is an independent risk factor for severe respiratory syncytial virus (RSV) infection. Palivizumab - passive immunization for RSV - is the only pharmacological measure for preventing severe disease. In most countries, palivizumab is indicated in young children with congenital heart disease, premature birth, and chronic lung disease. In Japan, since 2013, children with DS, but without such "standard" risk factors, have been able to receive insurance-covered palivizumab prophylaxis, but its effectiveness of policy is unknown. From a nationwide database, we extracted data of children with DS who hospitalized for RSV-related lower respiratory infections (LRTIs), from April 2010 to January 2019. Using an interrupted time-series design, we analyzed data from before and after the introduction of the universal palivizumab prophylaxis program for DS children in Japan. As a result, we identified a total of 152 RSV-related LRTIs in 147 children hospitalized with DS. With time-series analysis, we did not observe a significant change in both level (-1.07, P = .11) and slope (0.26 per 12 months, P = .30), before and after 2013. In summary, the expansion of the palivizumab prophylaxis program to all children with DS in Japan was not associated with a reduction in RSV-related hospitalization in these children.

Multiorgan involvement and management in children with Down syndrome

AIM

To review multiorgan involvement and management in children with Down syndrome (DS).

METHODS

A literature review of articles from 1980 to 2019 using the MEDLINE interface of PubMed was performed using the following search terms- [Down syndrome] or [Trisomy 21] AND [Cardiology] or [Respiratory] or [neurodevelopment] or [epilepsy] or [musculoskeletal] or [immune system] or [haematological] or [endocrine] or [gastrointestinal] or [ophthalmological] or [Ear Nose Throat] or [dermatology] or [renal].

RESULTS

Congenital heart disease particularly septal defects occur in over 60% of infants with DS and 5%-34% of infants develop persistent pulmonary hypertension of the newborn irrespective of a diagnosis of congenital heart disease. Early recognition and management of aspiration, obstructive sleep apnoea and recurrent lower respiratory tract infections (LRTI) could reduce risk of developing pulmonary hypertension in later childhood. Children with DS have an increased risk of autistic spectrum disorder, attention deficit disorder and epilepsy particularly infantile spasms, which are associated with poor neurodevelopmental outcomes. Congenital anomalies of the gastrointestinal and renal system as well as autoimmune diseases, coeliac disease, arthropathy, thyroid dysfunction fold diabetes mellitus and dermatological conditions are more common. Hearing and visual anomalies are also well recognised association with DS (Table 1).

CONCLUSION

Children with DS are at an increased risk of multiorgan comorbidities. Organ-specific health surveillance may provide holistic care for the children and families with DS throughout childhood.

Airway Ciliary Beating Affected by the Pcp4 Dose-Dependent [Ca2+]i Increase in Down Syndrome Mice, Ts1Rhr

In Ts1Rhr, a Down syndrome model mouse, the airway ciliary beatings are impaired; that is, decreases in ciliary beat frequency (CBF) and ciliary bend angle (CBA, an index of ciliary beat amplitude)). A resumption to two copies of the Pcp4 gene on the Ts1Rhr trisomic segment (Ts1Rhr:Pcp4^+/+/-) rescues the decreases in CBF and CBA that occur in Ts1Rhr. In airway cilia, upon stimulation with procaterol (a β₂-agonist), the CBF increase is slower over the time course than the CBA increase because of cAMP degradation by Ca²⁺/calmodulin-dependent phosphodiesterase 1 (PDE1) existing in the metabolon regulating CBF. In Ts1Rhr, procaterol-stimulated CBF increase was much slower over the time course than in the wild-type mouse (Wt) or Ts1Rhr:Pcp4^+/+/-. However, in the presence of 8MmIBMX (8-methoxymethyl isobutylmethyl xanthine, an inhibitor of PDE1) or calmidazolium (an inhibitor of calmodulin), in both Wt and Ts1Rhr, procaterol stimulates CBF and CBA increases over a similar time course. Measurements of cAMP revealed that the cAMP contents were lower in Ts1Rhr than in Wt or in Ts1Rhr:Pcp4^+/+/-, suggesting the activation of PDE1A that is present in Ts1Rhr airway cilia. Measurements of the intracellular Ca²⁺ concentration ([Ca²⁺]_i) in airway ciliary cells revealed that temperature (increasing from 25 to 37 °C) or 4αPDD (a selective transient receptor potential vanilloid 4 (TRPV4) agonist) stimulates a larger [Ca²⁺]_i increase in Ts1Rhr than in Wt or Ts1Rhr:Pcp4^+/+/-. In airway ciliary cells of Ts1Rhr, Pcp4-dose dependent activation of TRPV4 appears to induce an increase in the basal [Ca²⁺]_i. In early embryonic day mice, a basal [Ca²⁺]_i increased by PCP4 expressed may affect axonemal regulatory complexes regulated by the Ca²⁺-signal in Ts1Rhr, leading to a decrease in the basal CBF and CBA of airway cilia.

The Pattern of Malignancies in Down Syndrome and Its Potential Context With the Immune System

The immune surveillance theory of cancer posits that the body's immune system detects and destroys randomly occurring malignant cells. This theory is based on the observation of the increased frequency of malignancies in primary and secondary immunodeficiencies, and is supported by the successful demonstration of immune augmentation in current oncological immune therapy approaches. We review this model in the context of Down syndrome (DS), a condition with a unique tumor profile and various immune defects. Children and adults with DS are more prone to infections due to anatomical reasons and a varying degree of T- and B-cell maturation defects, NK cell dysfunction, and chemotactic or phagocytic abnormalities. However, despite an increased incidence of lymphoblastic and myeloblastic leukemia of infants and children with DS, individuals with DS have a globally decreased incidence of solid tumors as compared to age-adjusted non-DS controls. Additionally, cancers that have been considered “proof of immune therapy principles,” such as renal carcinoma, small cell lung carcinoma, and malignant melanoma, are less frequent in adults with DS compared to the general population. Thus, despite the combination of an increased risk of leukemia with detectable immune biological abnormalities and a clinical immunodeficiency, people with DS appear to be protected against many cancers. This observation does not support the immune surveillance theory in the context of DS and indicates a potential tumor-suppressive role for trisomy 21 in non-hematological malignancies.

Dysregulated miR-155 and miR-125b Are Related to Impaired B-cell Responses in Down Syndrome

Children with Down Syndrome (DS) suffer from immune deficiency with a severe reduction in switched memory B cells (MBCs) and poor response to vaccination. Chromosome 21 (HSA21) encodes two microRNAs (miRs), miR-125b, and miR-155, that regulate B-cell responses. We studied B- and T- cell subpopulations in tonsils of DS and age-matched healthy donors (HD) and found that the germinal center (GC) reaction was impaired in DS. GC size, numbers of GC B cells and Follicular Helper T cells (T_FH) expressing BCL6 cells were severely reduced. The expression of miR-155 and miR-125b was increased in tonsillar memory B cells and miR-125b was also higher than expected in plasma cells (PCs). Activation-induced cytidine deaminase (AID) protein, a miR-155 target, was significantly reduced in MBCs of DS patients. Increased expression of miR-155 was also observed in vitro. MiR-155 was significantly overexpressed in PBMCs activated with CpG, whereas miR-125b was constitutively higher than normal. The increase of miR-155 and its functional consequences were blocked by antagomiRs in vitro. Our data show that the expression of HSA21-encoded miR-155 and miR-125b is altered in B cells of DS individuals both in vivo and in vitro. Because of HSA21-encoded miRs may play a role also in DS-associated dementia and leukemia, our study suggests that antagomiRs may represent pharmacological tools useful for the treatment of DS.