Suppression of IFN-γ Production in Murine Splenocytes by Histamine Receptor Antagonists

Differences of gut microbiota and behavioral symptoms between two subgroups of autistic children based on γδT cells-derived IFN-γ Levels: A preliminary study

Background

Autism Spectrum Disorders (ASD) are defined as a group of pervasive neurodevelopmental disorders, and the heterogeneity in the symptomology and etiology of ASD has long been recognized. Altered immune function and gut microbiota have been found in ASD populations. Immune dysfunction has been hypothesized to involve in the pathophysiology of a subtype of ASD.

Methods

A cohort of 105 ASD children were recruited and grouped based on IFN-γ levels derived from ex vivo stimulated γδT cells. Fecal samples were collected and analyzed with a metagenomic approach. Comparison of autistic symptoms and gut microbiota composition was made between subgroups. Enriched KEGG orthologues markers and pathogen-host interactions based on metagenome were also analyzed to reveal the differences in functional features.

Results

The autistic behavioral symptoms were more severe for children in the IFN-γ-high group, especially in the body and object use, social and self-help, and expressive language performance domains. LEfSe analysis of gut microbiota revealed an overrepresentation of Selenomonadales, Negatiyicutes, Veillonellaceae and Verrucomicrobiaceae and underrepresentation of Bacteroides xylanisolvens and Bifidobacterium longum in children with higher IFN-γ level. Decreased metabolism function of carbohydrate, amino acid and lipid in gut microbiota were found in the IFN-γ-high group. Additional functional profiles analyses revealed significant differences in the abundances of genes encoding carbohydrate-active enzymes between the two groups. And enriched phenotypes related to infection and gastroenteritis and underrepresentation of one gut-brain module associated with histamine degradation were also found in the IFN-γ-High group. Results of multivariate analyses revealed relatively good separation between the two groups.

Conclusions

Levels of IFN-γ derived from γδT cell could serve as one of the potential candidate biomarkers to subtype ASD individuals to reduce the heterogeneity associated with ASD and produce subgroups which are more likely to share a more similar phenotype and etiology. A better understanding of the associations among immune function, gut microbiota composition and metabolism abnormalities in ASD would facilitate the development of individualized biomedical treatment for this complex neurodevelopmental disorder.

Effectiveness of Cimetidine as Adjuvant Therapy in the Treatment of Acute-Extrinsic Atopic Dermatitis: A Double-Blind Randomized Controlled Trial

Introduction

Acute extrinsic atopic dermatitis (AD) requires long-term treatment. Cimetidine could be used as an adjuvant therapy for acute-extrinsic AD due to immunomodulatory effects. This study aims to assess the effectiveness of cimetidine as an adjuvant to standard treatment in acute extrinsic AD.

Methods

This is a double-blind randomized controlled trial involving 26 AD patients aged 12–60 years from 2017 to 2020. Effectiveness of cimetidine was assessed by comparing SCORing Atopic Dermatitis (SCORAD) and objective SCORAD changes in both groups at week 2, 4, 6, and 8. Serum levels of immunoglobulin E (IgE), interferon (IFN)-γ, interleukin (IL)-12, and IL-4 were also documented.

Results

Significant differences were observed in SCORAD changes at week 2, 4, 6, and 8 (p = 0.004; p = 0.001; p < 0.001; and p < 0.001 respectively), objective SCORAD changes at week 2, 4, 6, and 8 (p = 0.004, p = 0.001, p < 0.001, and p < 0.001 respectively), and IgE level changes at week 8 (p = 0.002) between the two groups. However, there were no significant changes in IFN-γ, IL-12, and IL-4 levels between the two groups.

Conclusion

Cimetidine is a safe and effective adjuvant therapy for acute-extrinsic AD.

Trial Registration

NCT04018131.