Peanut Sensitivity and Allergic Rhinitis in Young Children are Associated with Attention-Deficit Hyperactivity Disorder Symptoms in Adolescence

Pathways of atopic disease and neurodevelopmental impairment: assessing the evidence for infant antibiotics

INTRODUCTION

Epidemiologic studies are starting to report associations between antibiotic use in early life and neurodevelopmental disorders. Through mechanisms within the gut microbiota-brain axis, indeed, it is plausible that infant antibiotic treatment plays a role in the development of atopic disease and neurodevelopmental disorders.

AREAS COVERED

This narrative review summarizes and interprets published evidence on infant antibiotic use in future outcomes of atopic disease, and neurodevelopmental delay and disorders, including attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD). To this end, we critically assess study bias from 2 main confounding factors, maternal/infant infection and infant feeding status. We also discuss common mechanisms that link atopy and neurodevelopment, and propose hypotheses related to immune activation and the gut microbiome.

EXPERT OPINION

Atopic disease and neurodevelopmental disorders share many risk factors and biological pathways. Infant antibiotic use has been linked to both disorders and is likely a marker for prenatal or infant infection. The mediating role of breastfeeding can also not be discounted. The exploration of causal pathways along the gut-brain axis leading towards neurodevelopmental impairment is evolving and of future interest.

Two meta-analyses of the association between atopic diseases and core symptoms of attention deficit hyperactivity disorder

Studies in the field of neuroscience and psychology have hypothesized that a causal association exists between atopic diseases and attention-deficit/hyperactivity disorder (ADHD). Previous systematic reviews and meta-analyses have reported a higher risk of ADHD in children with atopic diseases; however, the relationship between ADHD symptoms and atopic diseases remains unclear. We systematically reviewed observational cross-sectional and longitudinal studies to investigate the relationship between atopic diseases and ADHD symptom severity (hyperactivity/impulsivity and inattention). The majority of studies showed a statistically significant association between atopic diseases and both ADHD symptoms, with substantial heterogeneity in the outcome of hyperactivity/impulsivity. Remarkably decreased heterogeneity and statistical significance were observed in the second meta-analysis of ADHD-related behavior symptoms in atopic patients without ADHD. Our study indicated that atopic diseases not only associated with ADHD but also ADHD symptoms severity. This association was even observed in children with subthreshold ADHD, indicating that atopic diseases may play a role in the spectrum of ADHD symptom severity. Trial registration: This study was registered on PROSPERO (registration ID: CRD42020213219).

Sex-specific associations among infant food and atopic sensitizations and infant neurodevelopment

INTRODUCTION

Food sensitization is a first and strong indicator of immune deviation in the progression to other allergic conditions. Sensitization to food or other allergens and related inflammation during critical windows of infant development may adversely affect neurodevelopmental milestones. However, additional research is needed to test this association further.

METHODS

Associations between atopic (any food or aeroallergen) or food sensitization (specific to egg, soybean, peanut, and milk) at age 1 year and neurodevelopment up to 2 years of age were evaluated in the national CHILD Cohort Study, with a secondary aim examining whether these associations were sex-specific. Food and atopic sensitization were assessed by skin prick tests (SPT) in 1-year-old infants, with neurodevelopment assessed using the cognitive, language, motor, and social-emotional subscales of the Bayley Scales of Infant Development (BSID-III) administered at 1 and 2 years of age.

RESULTS

Atopic sensitization was present among 16.4% of infants, while 13.4% had food sensitizations. Only socioemotional scores reached statistical significance among the four BSID-III domains. Both atopic and food sensitization at 1 year of age was associated with lower social-emotional scores, independent of the infant's ethnicity. These findings were sex-specific and only observed among boys, among whom social-emotional scores were lowered by 5 points if atopic sensitization was present (-5.22 [95% CI: -9.96, -0.47], p = 0.03) or if food sensitization was present (-4.85 [95% CI: -9.82,0.11], p = 0.06). Similar results were observed using the standard SPT cut-off of ≥3 mm - for atopic sensitization (-5.17 [95% CI: -11.14, -0.80], p = 0.09) and for food sensitization (-4.61 [95% CI: -10.96, 1.74], p = 0.15).

CONCLUSION

In our study of term infants, we found an inverse, cross-sectional association between atopic and food sensitization status and social-emotional development scores in male children but not female children.

Overexpression of miR-224-5p alleviates allergic rhinitis in mice via the TLR4/MyD88/NF-κB pathway

Inflammatory allergic reaction is the main cause of allergic rhinitis (AR). Previous studies indicated that miR-224-5p was downregulated in the nasal mucosa of patients with AR, while the function of miR-224-5p in AR remains unclear. To explore this issue, AR mouse model was established using ovalbumin (OVA). For treatment group, lentivirus (LV)-miR-224-5p or its control was intranasally administrated to AR mice. miR-224-5p expression was detected by reverse transcription-quantitative PCR, followed by assessing the immunoglobulin E (IgE) level. Pathological alterations in nasal mucosa were detected using Hematoxylin-Eosin staining and Sirius red staining, followed by assessing the levels of inflammatory cells and factors. The NLRP3 inflammasome and TLR4/MyD88/NF-κB pathway were measured by Western blot, and then the relationship between miR-224-5p and toll-like receptor 4 (TLR4) was verified. The results showed that miR-224-5p was significantly decreased in nasal mucosa of AR mice. AR mice exhibited increased sneezing and nasal rubbing events, IgE level in serum, and pathological alterations in nasal mucosa, while overexpression of miR-224-5p markedly attenuated these changes. The levels of inflammatory cells in nasal lavage fluid and pro-inflammatory factors in serum and nasal mucosa were significantly increased in AR mice, which were reduced by miR-224-5p overexpression. Of note, LV-miR-224-5p treatment remarkably suppressed the activations of NLRP3 inflammasome and the TLR4/MyD88/NF-κB pathway in AR mice. Furthermore, miR-224-5p could bind to 3'-untranslated region (3'-UTR) of TLR4 and negatively regulate TLR4 level. Overall, we conclude that miR-224-5p may relieve AR by negatively regulating TLR4/MyD88/NF-κB pathway, indicating that miR-224-5p may be a promising target for AR treatment.

A National Population Cohort Study Showed That Exposure to General Anesthesia in Early Childhood Is Associated with an Increase in the Risk of Developmental Delay

This study investigated the relationship between exposure to general anesthesia (GA) and the risk of cognitive and mental disorders. This study has thus investigated the relationships between exposure to GA before the age of 3 and subsequent cognitive and mental disorders in a national-wide research sample. We obtained our subjects from the National Health Insurance Research Database (NHIRD) of Taiwan, which was based on the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM). Children in the hospital aged less than 3 years old were included if there was GA exposure or not during the period of year 1997 to 2008. Cox proportional hazard regression models adjusted for potential confounding factors were used to estimate the relative magnitude of the risk associated with GA exposure. The cohort contained 2261 subjects with GA and 4522 children without GA as a comparison group. GA exposure group had a higher rate of developmental delay than in the without GA group (hazard ratio 1.46, p < 0.0001). There was no significant difference in the overall incidence of ADHD, autism and intellectual disability between the GA-exposed group and the comparison cohort. In conclusion, this study reported that children exposed to GA early before the age of three had a small association with increased risk of development delay thereafter.

Changes in Resting-State Spontaneous Brain Activity in Patients With Allergic Rhinitis: A Pilot Neuroimaging Study

BACKGROUND

Allergic rhinitis (AR) is an inflammatory disorder of the nose caused by immunoglobulin E (IgE)-mediated immune response to allergens. Apart from the typical symptoms of sneezing, itching, rhinorrhea, and nasal congestion, behavioral complications were also reported to be associated with the progression of AR, such as cognitive deficits, mood changes, memory decline, attention deficiency, poor school performance, anxiety, and depression. Recent human studies have suggested that alterations in brain function caused by allergen exposure may precipitate high levels of anxiety and emotional reactivity in asthma patients. But until now, there is no direct evidence of the relationship between brain activity and allergic rhinitis.

METHODS

Resting-state functional magnetic resonance imaging (rs-fMRI) was used to excavate whether there remain functional changes of brain activity in AR patients. We measured the amplitude of low-frequency fluctuation (ALFF) and the z conversion of ALFF (zALFF) in 20 patients with AR and 20 age- and sex-matched healthy controls (HCs) using the rs-fMRI data.

RESULTS

Compared with healthy controls, AR patients exhibited lower ALFF values in the precuneus (PCUN) and higher ALFF values in the anterior cingulate cortex (ACC). The ALFF values of these features were significantly correlated with the visual analog scale (VAS) scores, the Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) scores, the subscales of RQLQ, and specific IgE, partly.

CONCLUSION

We found changes in resting-state spontaneous brain activity in AR patients with hypoactivity in the PCUN and hyperactivity of the ACC. The brain-related symptoms of AR might be another potential clinical intervention target for improving the life quality of AR patients. Further attention to brain activity is essential for a deeper understanding of AR.