The 'hygiene hypothesis' for autoimmune and allergic diseases: an update

Allergic disease and sensitization disparity in urban and rural China: A EuroPrevall-INCO study

BACKGROUND

Studies in comparison with allergic diseases and sensitization between rural and urban environments in westernized countries might be biased and not adequately reflect countries undergoing rapid transition.

METHODS

A total of 5542 schoolchildren from urban area and 5139 from rural area were recruited for the EuroPrevall-INCO survey. A subsequent case-control sample with 196 children from urban area and 202 from rural area was recruited for a detailed face-to-face questionnaire and assessment of sensitization. Skin prick tests and serum-specific IgE measurements were used to assess sensitizations against food and aeroallergens. Logistic regression analysis was used to determine associations between risk/protective factors, food adverse reactions (FAR), allergic diseases, and sensitizations.

RESULTS

Prevalence of self-reported allergic diseases, including asthma (6.6% vs.2.5%), rhinitis (23.2% vs.5.3%), and eczema (34.1% vs.25.9%), was higher in urban than in rural children. Urban children had a significantly higher prevalence of FAR and related allergic diseases, and lower food/inhalation allergen sensitization rate, than those of rural children. In urban children, frequent changing places of residency (odds ratio 2.85, 95% confidence interval: 1.45-5.81) and antibiotic usage (3.54, 1.77-7.32) in early life were risk factors for sensitization, while sensitization and family history of allergy were risk factors for allergic diseases. In rural children, exposure to rural environments in early life was protective against both allergen sensitizations (0.46, 0.21-0.96) and allergic diseases (0.03, 0.002-0.19).

CONCLUSION

We observed a disparity in rates of allergic diseases and allergen sensitization between rural and urban children. In addition to family history, the development of allergic diseases and allergen sensitization were associated with specific urban/rural environmental exposures in early life.

The hygiene hypothesis for allergy - conception and evolution

In 1989, a short paper entitled "Hay fever, hygiene and household size" observed that British children from larger families were less likely to develop hay fever and suggested that this could be because early exposure to infection prevents allergy. This sibship size association for hay fever, since replicated many times in Britain and other affluent countries and confirmed by objective measures of atopy, prompted what has come to be known as the "hygiene hypothesis for allergy", although that term was not specifically used in the 1989 paper. The present paper reviews the historical roots of the "hygiene hypothesis" and charts its development over more than 30 years. Initial scepticism among immunologists turned to enthusiasm in the mid-1990s as the Th1/Th2 paradigm for allergic sensitisation emerged from animal experiments and the concept of "immunological old friends" became popular from the early 2000s. From the late 1990s, observations of reduced allergy risk among children of anthroposophic families and those brought up on farms suggested that the sibship size effects formed part of a broader range of "hygiene-related" determinants of allergy. Children from large families with farming exposure have approximately sixfold reduction in prevalence of hay fever, indicating the potential strength and epidemiological importance of these environmental determinants. During the 21st century, a wide range of specific microbial, environmental and lifestyle factors have been investigated as possible underlying mechanisms, but sadly none have emerged as robust explanations for the family size and farming effects. Thus, while the "hygiene hypothesis" led to a fundamental reappraisal of our relationship with our microbial environment and to the concept that early exposure, rather than avoidance, is beneficial for developing a healthy immune system, the underlying mechanism for variations in allergy prevalence with family size remains, in Churchillian terms, "a riddle wrapped in a mystery inside an enigma".

Effects of high fat diet-induced obesity on pathophysiology, immune cells, and therapeutic efficacy in systemic lupus erythematosus

Prior studies have suggested a strong link between obesity and autoimmune diseases. This study aimed to evaluate the effects of high fat diet (HFD)-induced obesity on the disease pathogenesis, immune cell infiltration, and therapeutic efficacy in systemic lupus erythematosus (SLE). Treatment with methylprednisolone significantly increased the survival in the control diet group, but not in the HFD group. An HFD significantly increased the incidence of severe proteinuria and glucose intolerance. Regardless of the diet, treatment with methylprednisolone significantly decreased the serum levels of anti-dsDNA antibodies, IL-2, IL-10, and interferon γ-induced protein 10 (IP-10), and improved the renal pathology scores. Treatment with methylprednisolone significantly lowered the serum levels of IL-6, MCP-1, and TNF-α in the control diet group, but not in the HFD group. HFD significantly increased the proportions of CD45⁺ and M1 cells and significantly decreased the proportion of M2 cells in white adipose tissue; methylprednisolone treatment significantly rescued this effect. In the HFD group, methylprednisolone treatment significantly decreased the M1:M2 and increased the Foxp3⁺:RORγt⁺ cell in the spleen compared with the untreated group. These data improve our understanding of the effect of HFD on the therapeutic efficacy of corticosteroids in SLE treatment, which could have clinical implications.

Does latent Toxoplasma infection have a protective effect against developing multiple sclerosis? Evidence from an updated meta-analysis

Previous epidemiologic evidence suggests a protective effect of Toxoplasma gondii infection against multiple sclerosis (MS) development; however, inconsistent findings have been reported in this regard. Therefore, we performed an updated meta-analysis of observational studies to investigate the association of To. gondii infection with MS development. We searched all articles published in PubMed, Scopus, Embase and Web of Science databases as of 20 December 2021. A random effects meta-analysis model was used to generate the pooled OR at 95% CIs. The heterogeneity between studies was assessed using I2 and Cochran's Q statistics. Moreover, the likelihood of publication bias was determined by Egger's regression test. A total of 11 studies were eligible for meta-analysis, including 1172 MS cases and 1802 controls. Our findings indicated that 29.8% (95% CI 22.8 to 37.2%) of MS patients were seropositive for To. gondii infection, compared with 34.2% (95% CI 21.9 to 47.6%) of control subjects. The estimated pooled OR was 0.79 (95% CI 0.49 to 1.26), suggesting a non-significant negative association between To. gondii infection and MS development (p>0.05). The current study does not support the significant protective role of To. gondii infection on MS development. Our findings imply that further well-designed epidemiological and mechanistic studies are warranted to ascertain the possible association between To. gondii infection and MS and to exclude the potential confounders.

The Role of Brain-Derived Neurotrophic Factor in Immune-Related Diseases: A Narrative Review

Brain-derived neurotrophic factor (BDNF) is a neurotrophin regulating synaptic plasticity, neuronal excitability, and nociception. It seems to be one of the key molecules in interactions between the central nervous system and immune-related diseases, i.e., diseases with an inflammatory background of unknown etiology, such as inflammatory bowel diseases or rheumatoid arthritis. Studies show that BDNF levels might change in the tissues and serum of patients during the course of these conditions, e.g., affecting cell survival and modulating pain severity and signaling pathways involving different neurotransmitters. Immune-related conditions often feature psychiatric comorbidities, such as sleep disorders (e.g., insomnia) and symptoms of depression/anxiety; BDNF may be related as well to them as it seems to exert an influence on sleep structure; studies also show that patients with psychiatric disorders have decreased BDNF levels, which increase after treatment. BDNF also has a vital role in nociception, particularly in chronic pain, hyperalgesia, and allodynia, participating in the formation of central hypersensitization. In this review, we summarize the current knowledge on BDNF's function in immune-related diseases, sleep, and pain. We also discuss how BDNF is affected by treatment and what consequences these changes might have beyond the nervous system.

Visualizing the knowledge domains and research trends of childhood asthma: A scientometric analysis with CiteSpace

Background

Asthma is one of the most common chronic diseases in children globally. In recent decades, advances have been made in understanding the mechanism, diagnosis, treatment and management for childhood asthma, but few studies have explored its knowledge structure and future interests comprehensively.

Objective

This scientometric study aims to understand the research status and emerging trends of childhood asthma.

Methods

CiteSpace (version 5.8.R3) was used to demonstrate national and institutional collaborations in childhood asthma, analyze research subjects and journal distribution, review research keywords and their clusters, as well as detect research bursts.

Results

A total of 14,340 publications related to childhood asthma were extracted from Web of Science (core database) during January 2011 to December 2021. The results showed that academic activities of childhood asthma had increased steadily in the last decade. Most of the research was conducted by developed countries while China, as a developing country, was also actively engaged in this field. In addition to subjects of allergy and immunology, both public health aspects and ecological environmental impacts on the disease were emphasized recently in this research field. Keywords clustering analysis indicated that research on asthma management and atopy was constantly updated and became the two major research focuses recently, as a significant shift in research hotspots from etiology and diagnosis to atopic march and asthma management was identified. Subgroup analysis for childhood asthma management and atopy suggested that caregiver- or physician-based education and interventions were emerging directions for asthma management, and that asthma should be carefully studied in the context of atopy, together with other allergic diseases.

Conclusions

This study presented a comprehensive and systematic overview of the research status of childhood asthma, provided clues to future research directions, and highlighted two significant research trends of asthma management and atopy in this field.

Longitudinal disease-associated gut microbiome differences in infants with food protein-induced allergic proctocolitis

BACKGROUND

Complex interactions between the gut microbiome and immune cells in infancy are thought to be part of the pathogenesis for the marked rise in pediatric allergic diseases, particularly food allergies. Food protein-induced allergic proctocolitis (FPIAP) is commonly the earliest recognized non-immunoglobulin E (IgE)-mediated food allergy in infancy and is associated with atopic dermatitis and subsequent IgE-mediated food allergy later in childhood. Yet, a large prospective longitudinal study of the microbiome of infants with FPIAP, including samples prior to symptom onset, has not been done.

RESULTS

Here, we analyzed 954 longitudinal samples from 160 infants in a nested case-control study (81 who developed FPIAP and 79 matched controls) from 1 week to 1 year of age by 16S rRNA ribosomal gene sequencing as part of the Gastrointestinal Microbiome and Allergic Proctocolitis (GMAP) study. We found key differences in the microbiome of infants with FPIAP, most strongly a higher abundance of a genus of Enterobacteriaceae and a lower abundance of a family of Clostridiales during the symptomatic period. We saw some of these significant taxonomic differences even prior to symptom onset. There were no consistent longitudinal differences in richness or stability diversity metrics between infants with FPIAP and healthy controls.

CONCLUSIONS

This study is the first to identify differences in the infant gut microbiome in children who develop FPIAP, some even before they develop symptoms, and provides a foundation for more mechanistic investigation into the pathogenesis of FPIAP and subsequent food allergic diseases in childhood. Video abstract.

Biodiversity Effects on Human Mental Health via Microbiota Alterations

The biodiversity hypothesis postulates that the natural environment positively affects human physical and mental health. We evaluate the latest evidence and propose new tools to examine the halobiont environment. We chose to target our review at neuropsychiatric disorders, including depression, anxiety, autism, dementia, multiple sclerosis, etc. because a green prescription (exposure to green spaces) was shown to benefit patients with neuropsychiatric disorders. Specifically, our review consists of three mini reviews on the associations exploring: (1) ecological biodiversity and human microbiota; (2) human microbiota and neuropsychiatric disorders; (3) ecological biodiversity and neuropsychiatric disorders. We conclude that the environment could directly transfer microbes to humans and that human studies support the gut microbiota as part of the pathophysiology of neuropsychiatric disorders. Overall, the results from the three mini reviews consistently support the biodiversity hypothesis. These findings demonstrated the plausibility of biodiversity exerting mental health effects through biophysiological mechanisms instead of psychological mechanisms alone. The idea can be further tested with novel biodiversity measurements and research on the effects of a green prescription.

Eosinophilic oesophagitis in Denmark: Population‐based incidence and prevalence in a nationwide study from 2008 to 2018

Background

Eosinophilic oesophagitis (EoE) is a chronic immune‐mediated or antigen‐mediated oesophageal disease characterised by symptoms related to oesophageal dysfunction and eosinophil‐predominant inflammation.

Objective

We aimed to estimate the incidence and prevalence of EoE in Denmark during the period 2008–2018.

Methods

Based on data from nationwide registers we identified cases of EoE using two definitions: a broad definition based solely on oesophageal biopsies registered in the Danish Pathology Register and a narrow definition also including symptoms of oesophageal dysfunction registered in the Danish National Patient Registry. The annual incidence and prevalence were standardised by sex and age in 5‐year intervals to the 2013 study population.

Results

From 2008 to 2011, the standardised incidence of EoE was stable, but from 2011 to 2018 it increased from 3.9 (95% CI 3.3–4.4) to 11.7 (95% CI 10.8–12.6) per 100,000 person‐years. Similar temporal trends were observed when using the narrow EoE definition. The increase in incidence was most pronounced in men and in individuals above 40 years of age. In children, the EoE incidence was a fourth of the incidence in adults aged 40–64 years: 4.4 (95% CI 3.2–5.6) versus 17.6 (95% CI 15.7–19.5) per 100,000 person‐years. The EoE incidence varied substantially across the five regions in Denmark. Overall, the biopsy rate as well as the proportion of oesophageal biopsies with detected eosinophilia increased during the study period.

Conclusion

This study of the entire population of Denmark during the period 2008 to 2018 shows that the incidence and prevalence of EoE is not yet plateauing and that EoE could be severely underdiagnosed, especially in children.

Cysteine protease of Clonorchis sinensis alleviates DSS-induced colitis in mice

Background

Currently, inflammatory bowel disease (IBD) has become a global chronic idiopathic disease with ever-rising morbidity and prevalence. Accumulating evidence supports the IBD-hygiene hypothesis that helminths and their derivatives have potential therapeutic value for IBD. Clonorchis sinensis (C. sinensis) mainly elicit Th2/Treg-dominated immune responses to maintain long-term parasitism in the host. This study aimed to evaluate the therapeutic effects of cysteine protease (CsCP) and adult crude antigen (CsCA) of C. sinensis, and C. sinensis (Cs) infection on DSS-induced colitis mice.

Methods

BALB/c mice were given 5% DSS daily for 7 days to induce colitis. During this period, mice were treated with rCsCP, CsCA or dexamethasone (DXM) every day, or Cs infection which was established in advance. Changes in body weight, disease activity index (DAI), colon lengths, macroscopic scores, histopathological findings, myeloperoxidase (MPO) activity levels, regulatory T cell (Treg) subset levels, colon gene expression levels, serum cytokine levels, and biochemical indexes were measured.

Results

Compared with Cs infection, rCsCP and CsCA alleviated the disease activity of acute colitis more significant without causing abnormal blood biochemical indexes. In comparison, rCsCP was superior to CsCA in attenuating colonic pathological symptoms, enhancing the proportion of Treg cells in spleens and mesenteric lymph nodes, and improving the secretion of inflammatory-related cytokines (e.g., IL-2, IL-4, IL-10 and IL-13) in serum. Combined with RNA-seq data, it was revealed that CsCA might up-regulate the genes related to C-type lectin receptor and intestinal mucosal repair related signal pathways (e.g., Cd209d, F13a1 and Cckbr) to reduce colon inflammation and benefit intestinal mucosal repair. Dissimilarly, rCsCP ameliorated colitis mainly through stimulating innate immunity, such as Toll like receptor (TLR) signaling pathway, down-regulating the expression of inflammatory cytokines (e.g., IL-12b, IL-23r and IL-7), thereby restraining the differentiation of Th1/Th17 cells.

Conclusions

Both rCsCP and CsCA showed good therapeutic effects on the treatment of acute colitis, but rCsCP is a better choice. rCsCP is a safe, effective, readily available and promising therapeutic agent against IBD mainly by activating innate immunity and regulating the IL-12/IL-23r axis.

Risk factor analysis in women who underwent trial of labor after cesarean section: a multicenter study in Germany

Objective

Rising caesarean delivery (CD) rates throughout the world are accompanied with high rates of severe maternal complications. The aim of the present study was to analyze the outcome of trial of labor after caesarean section (TOLAC) in a Western population and identify factors associated with the success of vaginal birth after caesarean section (VBAC).

Material and Methods

A retrospective study was performed at two large obstetric departments in Germany from 2008 to 2018. Women with singleton pregnancies, a history of only one previous CD with a low transverse incision, a viable fetus in cephalic presentation, and gestational age >32 weeks were included in the study. The characteristics and outcome of successful VBAC and failed TOLAC were compared. A subgroup analysis addressed gestational age, interpregnancy interval, fetal macrosomia, body mass index, and maternal age.

Results

Of 1,546 patients, 62.3% achieved VBAC while 37.7% had a secondary CD. Independent factors associated with the success of TOLAC were a history of vaginal birth in previous pregnancies (p<0.001) and the use of oxytocin (p<0.001), whereas preterm birth between gestational week 32 and 37 signified a higher risk of failed TOLAC (p=0.04). The success of VBAC did not differ significantly for patients older than 40 years of age, those with a shorter interpregnancy interval than 12 months, and fetal macrosomia with birth weight exceeding 4000 grams. Maternal and neonatal outcomes were poorer in women with failed TOLAC.

Conclusion

Nearly two thirds of women with a history of CD achieve VBAC in Germany. Previous vaginal birth and the augmentation of labor with oxytocin are positively associated with the achievement of VBAC and no major perinatal complications. The decision to have a TOLAC should be encouraged in the majority of patients. Further studies are needed to evaluate the feasibility of TOLAC in preterm delivery.

Association of maternal low-carbohydrate-diet score during pregnancy with allergic diseases at 2 years of age

BACKGROUND

We prospectively evaluated the association between low-carbohydrate-diet (LCD) score during pregnancy and the risk of allergic diseases in infants up to 2 years.

METHODS

Participants were from a prospective mother-offspring cohort study in Wuhan, China. LCD score was calculated according to the percentage of dietary energy intake from carbohydrate, protein, and fat assessed in late pregnancy using validated food frequency questionnaires. Allergic diseases, including immunoglobulin E (IgE)-mediated allergic diseases, allergic contact dermatitis, and food allergy, were recorded at 3, 6, 12, and 24 months postpartum follow-up. Poisson regression models were used to calculate relative risks (RRs) and 95% confidence intervals (CIs).

RESULTS

Among 1636 mother-infant pairs included in the present analysis, 230 infants (14.1%) with IgE-mediated allergic diseases, 77 (4.7%) with allergic contact dermatitis, and 488 (29.8%) with food allergy were, respectively, reported. Independent of total energy intake and other potential confounders, both the lowest quintile (RR, 1.77; 95% CI, 1.13-2.77) and the highest quintile (RR, 1.72; 95% CI, 1.22-2.63), were associated with the risk of IgE-mediated allergic diseases compared with the middle quintile. Among high-carbohydrate-diet pregnant women, substituting 5% of energy from either protein or fat for carbohydrate was associated with a lower risk of IgE-mediated allergic diseases. While among low-carbohydrate-diet pregnant women, substituting 5% of energy from carbohydrate, especially high-quality carbohydrate, for fat was associated with a lower risk of IgE-mediated allergic diseases.

CONCLUSION

Maternal low carbohydrate-high protein and fat, and high carbohydrate-low protein and fat diet were both associated with an increased risk of allergic diseases in the infants up to 2 years. This study may provide an intervention strategy for allergy prevention in early childhood.

Biomolecular Mechanisms of Autoimmune Diseases and Their Relationship with the Resident Microbiota: Friend or Foe?

The use of innovative approaches to elucidate the pathophysiological mechanisms of autoimmune diseases, as well as to further study of the factors which can have either a positive or negative effect on the course of the disease, is essential. In this line, the development of new molecular techniques and the creation of the Human Genome Program have allowed access to many more solutions to the difficulties that exist in the identification and characterization of the microbiome, as well as changes due to various factors. Such innovative technologies can rekindle older hypotheses, such as molecular mimicry, allowing us to move from hypothesis to theory and from correlation to causality, particularly regarding autoimmune diseases and dysbiosis of the microbiota. For example, Prevotella copri appears to have a strong association with rheumatoid arthritis; it is expected that this will be confirmed by several scientists, which, in turn, will make it possible to identify other mechanisms that may contribute to the pathophysiology of the disease. This article seeks to identify new clues regarding similar correlations between autoimmune activity and the human microbiota, particularly in relation to qualitative and quantitative microbial variations therein.

Rejuvenating the human gut microbiome

Industrial advances have caused significant loss of diversity in our gut microbiome, potentially increasing our susceptibility to many diseases. Recently, rewilding the human gut microbiome - that is, bringing it back to an ancestral or preindustrial state (e.g., by transplanting stool material from donors in nonindustrial societies) - has been hotly debated from medical, ethical, and evolutionary perspectives. Here we propose an alternative solution: rejuvenating the human gut microbiome by stool banking and autologous fecal microbiota transplantation, that is, collecting the hosts' stool samples at a younger age when they are at optimal health, and cryopreserving the samples in a stool bank for the hosts' own future use. In this article we discuss the motivation, applications, feasibility, and challenges of this solution.

A plausible contributor to multiple sclerosis; presentation of antigenic myelin protein epitopes by major histocompatibility complexes

BACKGROUND

Multiple sclerosis (MS) can be induced upon successful presentation of myelin antigens by MHC I/II. Antigenic similarity between the myelin and viral proteins may worsen the immunological responses.

METHODOLOGY

Antigenic regions within myelin proteins; PLP1, MBP, MOG, and MAG were analyzed using SVMTrip and EMBOSS. Homology search identified sequence similarity between the predicted host epitopes and viral proteins. NetMHCpan predicted MHC I/II binding followed by peptide-protein docking through the HPEPDOCK server. Thereafter we analyzed conformational flexibility and stability of 15 protein-peptide complexes based on high docking scores. The binding free energy was calculated using conventional (MD) and Gaussian accelerated molecular dynamics simulation.

RESULTS

PLP1, MBP, MAG and MOG contained numerous antigenic epitopes. MBP and MOG epitopes had sequence similarity to HHV-6 BALF5; EBNA1 and CMV glycoprotein M (gM), and EBV LMP2B, gp350/220; HHV-8 ORFs respectively. Many herpes virus proteins like tegument, envelope glycoproteins, and ORFs of EBV, CMV, HHV-6, and HHV-8 demonstrated sequence similarity with MAG and PLP1. Some antigenic peptides were also linear B-cell epitopes and influenced cytokine production by T-cell. MHC I allele HLA-B*57:01 bound to PLP1 peptide and HLA-A*68:02 bound to a MAG peptide strongly. MHC II alleles HLA-DRB1*04:05 and HLA-DR1*01:01 associated with MAG- and MOG-derived peptides, respectively, demonstrating high HPEPDOCK scores. MD simulations established stable binding of certain peptides with the MHC namely HLA-B*51:01-MBP(DYKSAHKGFKGVDAQGTLSKIFKL), HLA-B*57:01-PLP1(PDKFVGITYALTVVWLLVFACSAVPVYIYF), HLA-DR1*01:01-MOG(VEDPFYWVSPGVLVLLAVLPVLLLQITVGLVFLCLQYR) and HLA-DRB1*04:05-MAG(TWVQVSLLHFVPTREA).

CONCLUSIONS

Cross-reactivity between self-antigens and pathogen derived immunodominant epitopes may induce MS. Our study supported the role of specific MHC alleles as a contributing MS risk factor.

Laundry detergent promotes allergic skin inflammation and esophageal eosinophilia in mice

The prevalence of allergic diseases is on the rise, yet the environmental factors that contribute to this increase are still being elucidated. Laundry detergent (LD) that contains cytotoxic ingredients including microbial enzymes continuously comes into contact with the skin starting in infancy. An impaired skin barrier has been suggested as a route of allergic sensitization. We hypothesized that exposure of skin to LD damages the skin barrier resulting in systemic sensitization to allergens that enter through the impaired skin barrier. Mouse skin samples exposed in vitro to microbial proteases or LD exhibited physical damage, which was more pronounced in neonatal skin as compared to adult skin. Exposure of the skin to microbial proteases in vitro resulted in an increase in the levels of interleukin (IL)-33 and thymic stromal lymphopoietin (TSLP). BALB/c wild type mice epicutaneously exposed to LD and ovalbumin (OVA) showed an increase in levels of transepidermal water loss, serum OVA-specific immunoglobulin (Ig) G1 and IgE antibodies, and a local increase of Il33, Tslp, Il4 and Il13 compared with LD or OVA alone. Following intranasal challenge with OVA, mice epicutaneously exposed to LD showed an increase in allergen-induced esophageal eosinophilia compared with LD or OVA alone. Collectively, these results suggest that LD may be an important factor that impairs the skin barrier and leads to allergen sensitization in early life, and therefore may have a role in the increase in allergic disease.

Cow Farmers’ Homes Host More Diverse Airborne Bacterial Communities Than Pig Farmers’ Homes and Suburban Homes

Living on a farm has been linked to a lower risk of immunoregulatory disorders, such as asthma, allergy, and inflammatory bowel disease. It is hypothesized that a decrease in the diversity and composition of indoor microbial communities is a sensible explanation for the upsurge in immunoregulatory diseases, with airborne bacteria contributing to this protective effect. However, the composition of this potentially beneficial microbial community in various farm and suburban indoor environments is still to be characterized. We collected settled airborne dust from stables and the associated farmers’ homes and from suburban homes using electrostatic dust collectors (EDCs) over a period of 14 days. Then, quantitative PCR (qPCR) was used to assess bacterial abundance. The V3–V4 region of the bacterial 16S rRNA gene was amplified and sequenced using Ilumina MiSeq in order to assess microbial diversity. The Divisive Amplicon Denoising Algorithm (DADA2) algorithm was used for the inference of amplicon sequence variants from amplicon data. Airborne bacteria were significantly more abundant in farmers’ indoor environments than in suburban homes (p < 0.001). Cow farmers’ homes had significantly higher bacterial diversity than pig farmers’ and suburban homes (p < 0.001). Bacterial taxa, such as Firmicutes, Prevotellaceae, Lachnospiraceae, and Lactobacillus were significantly more abundant in farmers’ homes than suburban homes, and the same was true for beneficial intestinal bacterial species, such as Lactobacillus amylovorus, Eubacterium hallii, and Faecalibacterium prausnitzii. Furthermore, we found a higher similarity between bacterial communities in individual farmers’ homes and their associated cow stables than for pig stables. Our findings contribute with important knowledge on bacterial composition, abundance, and diversity in different environments, which is highly valuable in the discussion on how microbial exposure may contribute to the development of immune-mediated diseases in both children and adults.

Vaginal birth after cesarean section: Experience from a regional hospital

OBJECTIVE

Trial of labor after cesarean section (TOLAC) is an option for women with previous cesarean section. However, few women choose this option because of safety concerns. We evaluate the safety and risks associated with TOLAC and the success rate of vaginal birth after cesarean delivery (VBAC).

MATERIAL AND METHODS

We reviewed all patients with a history of previous cesarean section that underwent elective repeat cesarean section (ERCS) or TOLAC in a regional teaching hospital from Nov, 2013 to May, 2018. Maternal basic clinical information, intrapartum management, postpartum complications, and neonatal outcomes were analyzed.

RESULTS

199 pregnant women with a history of at least one previous cesarean section were enrolled. 156 women received ERCS and 43 women (21.6%) underwent TOLAC, with 37 (86.0%) who underwent successful VBAC. The VBAC rate was 18.6%. Higher success rate was found in women with previous vaginal birth than in women without vaginal birth (100% vs. 81.8%). One case (2.3%) in the VBAC group was complicated with uterine rupture and inevitable neonatal death during second stage of labor. The uterus was repaired without maternal complications. In another case, the newborn's condition was complicated with low APGAR score (<7) at birth due to maternal chorioamnionitis. Among indications for previous cesarean section, cephalo-pelvic disproportion (CPD) was associated with TOLAC failure and uterine rupture after VBAC.

CONCLUSION

VBAC is a feasible and safe option. Modes of delivery should be thoroughly discussed when considering TOLAC for women with history of previous cesarean section due to CPD, considering its association with TOLAC failure in second stage of labor.

Insights into the underlying mechanisms and clinical management of microscopic colitis in relation to other gastrointestinal disorders

Microscopic colitis (MC) is a chronic inflammatory disease of the large intestine and as a relatively late recognized condition, its relationship with other disorders of the gastrointestinal tract is gradually being understood and investigated. As a multifactorial disease, MC interacts with inflammatory bowel disease, celiac disease, and irritable bowel syndrome through genetic overlap, immunological factors, and gut microflora. The risk of colorectal cancer was significantly lower in MC, gastrointestinal infections increased the risk of developing MC, and there was an inverse association between Helicobacter pylori infection and MC. A variety of associations are found between MC and other gastrointestinal disorders, where aspects such as genetic effects, resemblance of immunological profiles, and intestinal microecology are potential mechanisms behind the relationships. Clinicians should be aware of these connections to achieve a better understanding and management of MC.

Targeting the PI3K/Akt signaling pathway in pancreatic β-cells to enhance their survival and function: An emerging therapeutic strategy for type 1 diabetes

Type 1 diabetes (T1D) is an autoimmune disease caused by the destruction of the insulin-producing β-cells within the pancreas. Islet transplantation represents one cure; however, during islet preparation and post transplantation significant amounts of β-cell death occur. Therefore, prevention and cure of T1D is dependent upon the preservation of β-cell function and the prevention of β-cell death. Phosphoinositide 3-kinase (PI3K)/Akt signaling represents a promising therapeutic target for T1D due to its pronounced effects on cellular survival, proliferation, and metabolism. A growing amount of evidence indicates that PI3K/Akt signaling is a critical determinant of β-cell mass and function. Modulation of the PI3K/Akt pathway, directly (via the use of highly specific protein and peptide-based biologics, excretory/secretory products of parasitic worms, and complex constituents of plant extracts) or indirectly (through microRNA interactions) can regulate the β-cell processes to ultimately determine the fate of β-cell mass. An important consideration is the identification of the specific PI3K/Akt pathway modulators that enhance β-cell function and prevent β-cell death without inducing excessive β-cell proliferation, which may carry carcinogenic side effects. Among potential PI3K/Akt pathway agonists, we have identified a novel parasite-derived protein, termed FhHDM-1 (Fasciola hepatica helminth defense molecule 1), which efficiently stimulates the PI3K/Akt pathway in β-cells to enhance function and prevent death without concomitantly inducing proliferation unlike several other identified stimulators of PI3K/Akt signaling . As such, FhHDM-1 will inform the design of biologics aimed at targeting the PI3K/Akt pathway to prevent/ameliorate not only T1D but also T2D, which is now widely recognized as an inflammatory disease characterized by β-cell dysfunction and death. This review will explore the modulation of the PI3K/Akt signaling pathway as a novel strategy to enhance β-cell function and survival.

Bate palmas mutant mice as a model of Kabuki syndrome: Higher susceptibility to infections and vocalization impairments?

The recessive mutant mouse bate palmas (bapa) arose from N-ethyl-N-nitrosourea mutagenesis. Previous studies of our group revealed some behavioral impairments and a mutation in the lysine (K)-specific methyltransferase 2D (Kmt2d) gene. Because mutations in the KMT2D gene in humans are mainly responsible for Kabuki syndrome, this study was proposed to validate bapa mice as a model of Kabuki syndrome. Besides other symptoms, Kabuki syndrome is characterized by increased susceptibility to infections and speech impairments, usually diagnosed in the early childhood. Thus, juvenile male and female bapa mice were studied in different developmental stages (prepubertal period and puberty). To induce sickness behavior and to study infection susceptibility responses, lipopolysaccharide (LPS) was used. To study oral communication, ultrasonic vocalizations were evaluated. Behavioral (open-field test) and central (astrocytic glial fibrillary acidic protein [GFAP] and tyrosine hydroxylase [TH]) evaluations were also performed. Control and bapa female mice emitted 31-kHz ultrasounds on prepubertal period when exploring a novel environment, a frequency not yet described for mice, being defined as 31-kHz exploratory vocalizations. Males, LPS, and puberty inhibited these vocalizations. Bapa mice presented increased motor/exploratory behaviors on prepubertal period due to increased striatal TH expression, revealing striatal dopaminergic system hyperactivity. Combining open-field behavior and GFAP expression, bapa mice did not develop LPS tolerance, that is, they remained expressing signs of sickness behavior after LPS challenge, being more susceptible to infectious/inflammatory processes. It was concluded that bapa mice is a robust experimental model of Kabuki syndrome.

The Role of Airway Epithelial Cell Alarmins in Asthma

The airway epithelium is the first line of defense for the lungs, detecting inhaled environmental threats through pattern recognition receptors expressed transmembrane or intracellularly. Activation of pattern recognition receptors triggers the release of alarmin cytokines IL-25, IL-33, and TSLP. These alarmins are important mediators of inflammation, with receptors widely expressed in structural cells as well as innate and adaptive immune cells. Many of the key effector cells in the allergic cascade also produce alarmins, thereby contributing to the airways disease by driving downstream type 2 inflammatory processes. Randomized controlled clinical trials have demonstrated benefit when blockade of TSLP and IL-33 were added to standard of care medications, suggesting these are important new targets for treatment of asthma. With genome-wide association studies demonstrating associations between single-nucleotide polymorphisms of the TSLP and IL-33 gene and risk of asthma, it will be important to understand which subsets of asthma patients will benefit most from anti-alarmin therapy.

The Intestinal Microbiota May Be a Potential Theranostic Tool for Personalized Medicine

The human intestine is colonized by a huge number of microorganisms from the moment of birth. This set of microorganisms found throughout the human body, is called the microbiota; the microbiome indicates the totality of genes that the microbiota can express, i.e., its genetic heritage. Thus, microbiota participates in and influences the proper functioning of the organism. The microbiota is unique for each person; it differs in the types of microorganisms it contains, the number of each microorganism, and the ratio between them, but mainly it changes over time and under the influence of many factors. Therefore, the correct functioning of the human body depends not only on the expression of its genes but also on the expression of the genes of the microorganisms it coexists with. This fact makes clear the enormous interest of community science in studying the relationship of the human microbiota with human health and the incidence of disease. The microbiota is like a unique personalized "mold" for each person; it differs quantitatively and qualitatively for the microorganisms it contains together with the relationship between them, and it changes over time and under the influence of many factors. We are attempting to modulate the microbial components in the human intestinal microbiota over time to provide positive feedback on the health of the host, from intestinal diseases to cancer. These interventions to modulate the intestinal microbiota as well as to identify the relative microbiome (genetic analysis) can range from dietary (with adjuvant prebiotics or probiotics) to fecal transplantation. This article researches the recent advances in these strategies by exploring their advantages and limitations. Furthermore, we aim to understand the relationship between intestinal dysbiosis and pathologies, through the research of resident microbiota, that would allow the personalization of the therapeutic antibiotic strategy.

Clinical characteristics and risk factors for mortality among COVID-19 hospitalized patients in UAE: Does ethnic origin have an impact

Background

The relationship between COVID-19 patient’s clinical characteristics and disease manifestation remains incompletely understood. The impact of ethnicity on mortality of patients with COVID-19 infection is poorly addressed in the literature. Emerging evidence suggests that many risk factors are related to symptoms severity and mortality risk, emphasizing the necessity of fulfilling this knowledge gap that may help reducing mortality from COVID-19 infections through tackling the risk factors.

Aims

To explore epidemiological and demographic characteristics of hospitalized COVID-19 patients from different ethnic origins living in the UAE, compare them to findings reported across the globe and determine the impact of these characteristics and ethnicity on mortality during hospitalization.

Methods

A single center, retrospective chart review study of hospitalized COVID-19 patients was conducted in a large COVID-19 referral hospital in UAE. The following outcomes were assessed: patients’ clinical characteristics, disease symptoms and severity, and association of ethnicity and other risk factors on 30-day in hospital mortality.

Results

A total of 3296 patients were recruited in this study with an average age of 44.3±13.4 years old. Preliminary data analysis indicated that 78.3% (n = 2582) of cases were considered mild. Average duration of hospital stay was 6.0±7.3 days and 4.3% (n = 143) were admitted to ICU. The most frequently reported symptoms were cough (32.6%, n = 1075) and fever (22.2%, n = 731). The 30-day mortality rate during hospitalization was 2.7% (n = 90). Many risk factors were associated with mortality during hospitalization including: age, respiratory rate (RR), creatinine, and C-reactive protein, oxygen saturation (SaO₂), hemoglobin, hematocrit, ferritin, creatinine, C-reactive protein, anemia, COPD, Chronic kidney disease, dyslipidemia, Vitamin-D Deficiency, and ethnic origin (p <0.05). Multiple logistic regression analysis showed that higher mortality rates during hospitalization was associated with anemia, chronic obstructive pulmonary disease (COPD), chronic kidney disease, and Middle Eastern origin (p<0.05).

Conclusion

The results indicated that most COVID-19 cases were mild and morality rate was low compared to worldwide reported mortality. Mortality rate during hospitalization was higher in patients from Middle East origin with preexisting comorbidities especially anemia, COPD, and chronic kidney disease. Due to the relatively small number of mortality cases, other identified risk factors from univariate analysis such as age, respiratory rate, and Vitamin-D (VitD) deficiency should also be taken into consideration. It is crucial to stratify patients on admission based on these risk factors to help decide intensity and type of treatment which, possibly, will reduce the risk of death.

Effect of inactivated nature‐derived microbial composition on mouse immune system

Introduction

The hygiene hypothesis suggests that decrease in early life infections due to increased societal‐level hygiene standards subjects one to allergic and autoimmune diseases. In this report, we have studied the effect of sterilized forest soil and plant‐based material on mouse immune system and gut microbiome.

Methods

Inbred C57Bl/6 mice maintained in normal sterile environment were subjected to autoclaved forest soil‐derived powder in their bedding for 1 h a day for 3 weeks. Immune response was measured by immune cell flow cytometry, serum cytokine enzyme‐linked immunoassay (ELISA) and quantitative polymerase chain reaction (qPCR) analysis. Furthermore, the mouse gut microbiome was analyzed by sequencing.

Results

When compared to control mice, mice treated with soil‐derived powder had decreased level of pro‐inflammatory cytokines namely interleukin (IL)−17F and IL‐21 in the serum. Furthermore, splenocytes from mice treated with soil‐derived powder expressed less IL‐1b, IL‐5, IL‐6, IL‐13, and tumor necrosis factor (TNF) upon cell activation. Gut microbiome appeared to be stabilized by the treatment.

Conclusions

These results provide insights on the effect of biodiversity on murine immune system in sterile environment. Subjecting mice to soil‐based plant and microbe structures appears to elicit immune response that could be beneficial, for example, in type 2 inflammation‐related diseases, that is, allergic diseases.

The Ability of Resveratrol to Attenuate Ovalbumin-Mediated Allergic Asthma Is Associated With Changes in Microbiota Involving the Gut-Lung Axis, Enhanced Barrier Function and Decreased Inflammation in the Lungs

Asthma is a chronic respiratory disease highly prevalent worldwide. Recent studies have suggested a role for microbiome-associated gut-lung axis in asthma development. In the current study, we investigated if Resveratrol (RES), a plant-based polyphenol, can attenuate ovalbumin (OVA)-induced murine allergic asthma, and if so, the role of microbiome in the gut-lung axis in this process. We found that RES attenuated allergic asthma with significant improvements in pulmonary functions in OVA-exposed mice when tested using plethysmography for frequency (F), mean volume (MV), specific airway resistance (sRaw), and delay time(dT). RES treatment also suppressed inflammatory cytokines in the lungs. RES modulated lung microbiota and caused an abundance of Akkermansia muciniphila accompanied by a reduction of LPS biosynthesis in OVA-treated mice. Furthermore, RES also altered gut microbiota and induced enrichment of Bacteroides acidifaciens significantly in the colon accompanied by an increase in butyric acid concentration in the colonic contents from OVA-treated mice. Additionally, RES caused significant increases in tight junction proteins and decreased mucin (Muc5ac) in the pulmonary epithelium of OVA-treated mice. Our results demonstrated that RES may attenuate asthma by inducing beneficial microbiota in the gut-lung axis and through the promotion of normal barrier functions of the lung.

Concurrent allergy and helminthiasis in underprivileged urban South African adults previously residing in rural areas

This study investigated whether prior exposure to helminths (Ascaris IgE, Ascaris eggs and Trichuris eggs) either in childhood or in adulthood, and residence in rural and resource‐limited urban areas influence allergy outcomes (asthma, rhinitis, IgE atopy and food allergy) in a South African population. Participants historical and present allergies data were collected through questionnaires and clinical record files. Coproscopy and immunoassays (ImmunoCAP^TM Phadiatop, total IgE and allergen‐specific fx3 IgE immunoassays and Ascaris IgE radioallergosorbent [RAST] tests) were used for active helminthiasis and allergy screens respectively. Data were analysed using logistic regression analysis, and models were adjusted for age, gender and locality. High Ascaris IgE was significantly associated with asthma (adjusted odds ratio [aOR] = 2.20, p = .047), IgE atopy (aOR = 18.18, p < .0001) and food allergy (aOR = 14.47, p < .0001). Asthma was significantly less likely among participants with Ascaris eggs (aOR = 0.43, p = .048) and Trichuris eggs (aOR = 0.36, p = .024). The findings of co‐occurrent helminthiasis and allergic disorders in a population that has resided both in rural and peri‐urban informal settlements both oppose and agree with two main notions of the hygiene hypothesis that (i) individuals residing in rural settings with poor sanitation and geohelminth infection are less prone to allergy, and (ii) helminth infections protect against allergy respectively. Further research is warranted.

Amoxicillin does not affect the development of cow’s milk allergy in a Brown Norway rat model

The use of antibiotics as well as changes in the gut microbiota have been linked to development of food allergy in childhood. It remains unknown whether administration of a single clinically relevant antibiotic directly promotes food allergy development when administrated during the sensitisation phase in an experimental animal model. We investigated whether the antibiotic amoxicillin affected gut microbiota composition, development of cow's milk allergy (CMA) and frequencies of allergic effector cells and regulatory T cells in the intestine. Brown Norway rats were given daily oral gavages of amoxicillin for six weeks and whey protein concentrate (WPC) with or without cholera toxin three times per week for the last five weeks. Microbiota composition in faeces and small intestine was analysed by 16S rRNA sequencing. The development of CMA was assessed by WPC‐specific IgE in serum, ear swelling response to WPC and body hypothermia following oral gavage of WPC. Allergic effector cells were analysed by histology, and frequencies of regulatory and activated T cells were analysed by flow cytometry. Amoxicillin administration reduced faecal microbiota diversity, reduced the relative abundance of Firmicutes and increased the abundance of Bacteroidetes and Proteobacteria. Despite these effects, amoxicillin did not affect the development of CMA, nor the frequencies of allergic effector cells or regulatory T cells. Thus, amoxicillin does not carry a direct risk for food allergy development when administrated in an experimental model of allergic sensitisation to WPC via the gut. This finding suggests that confounding factors may better explain the epidemiological link between antibiotic use and food allergy.

The Study of Microbe–Host Two-Way Communication

Back-and-forth intercommunication in host–pathogen interactions has long been recognized to play an important role in commensalism and microbial pathogenesis. For centuries, we have studied these microbes in our surroundings, yet many questions about the evolutionary cross-talk between host and microbe remain unanswered. With the recent surge in research interest in the commensal microbiome, basic immunological questions have returned to the fore, such as, how are vast numbers of microbes capable of coexisting within animals and humans while also maintaining a healthy functional immune system? How is the evasion and subversion of the immune system achieved by some microbes but not others? The intricate and important-to-remember two-way interaction and coevolution of host and microbe is the communication network we must tap into as researchers to answer these questions.

Association of exposure to artificial light at night with atopic diseases: A cross-sectional study in college students

The impact of artificial light at night (ALAN) exposure on health has become increasingly prominent. However, little is known about the effect of ALAN exposure on atopic diseases. In this study, a cross-sectional analysis of incoming students was conducted in 5 geographically disperse universities which locate in Changsha (south), Wuhan (central), Xiamen (east), Urumchi (west), and Hohhot (north), respectively. All incoming students who consented to participate were recruited, followed by a health examination and a questionnaire survey. Prevalent atopic diseases were diagnosed by clinicians. Mean ALAN (nanoWatts/cm²/sr) during their adolescence was obtained from the remote sensing observed nighttime light data matching with their residence information, which was obtained from survey. Mixed generalized linear models (log-binomial) were used to estimate the associations, in terms of prevalence ratio (PR) with 95% confidence interval (CI). A total of 20106 participants were included in the analysis. Based on previous work, we chose factors including socioeconomic status, behavioural factors, major air pollutants, and air climatic parameters for adjustment. After full adjustment, the PR for atopic diseases was 1.35 (95% CI: 1.27-1.42; P < 0.001). The effect size of ALAN was the largest for asthma (PR = 1.80; 95% CI: 1.48-2.19; P < 0.001), followed by atopic rhinitis (PR = 1.42; 95% CI: 1.33-1.51; P < 0.001), and atopic dermatitis (PR = 1.20; 95% CI: 1.06-1.35; P = 0.003). Subgroup analyses by covariates showed consistent results. This study revealed that exposure to ALAN during adolescence may contribute to a higher risk of atopic diseases in young adulthood.

Use of helminth therapy for management of ulcerative colitis and Crohn's disease: a systematic review

The incidence rate of inflammatory bowel diseases is increasing in developed countries. As such there is an increasing demand for new therapies. The aim of this systematic review was to investigate whether there is evidence to support the use of helminth therapy for the management of Crohn's disease and ulcerative colitis. Four databases (PubMed, Embase, Medline and the Cochrane Central Register of Control Trials) were searched for primary evidence in the form of clinical studies. Nine studies were suitable for inclusion: five double-blind randomized control trials and four open-label studies. This review divided the results of the studies into two categories: (a) the efficacy of helminth therapy and (b) the safety of helminth therapy. Results regarding the efficacy were mixed and a conclusive answer could not be reached, as there was not enough evidence to rule out a placebo effect. More research is needed, particularly studies with control groups to address the possibility of a placebo effect. Despite this, all nine studies concluded helminth therapy was safe and tolerable, and therefore there is currently no evidence against further exploration of this treatment option.

Immunological insights of selectins in human disease mechanism

Selectin enzymes are glycoproteins and are an important adhesion molecule in the mammalian immune system, especially in the inflammatory response and the healing process of tissues. Selectins play an important role in a variety of biological processes, including the rolling of leukocytes in endothelial cells, a process known as the adhesion cascade. It has recently been discovered and reported that the selectin mechanism plays a role in cancer and thrombosis disease. This process begins with non-covalent interactions-based selectin-ligand binding and the glycans play a role as a connector between cancer cells and the endothelium in this process. The selectin mechanism is critical for the immune system, but it is also involved in disease mechanisms, earning the selectins the nickname "Selectins-The Two Dr. Jekyll and Mr. Hyde Faces". As a result, the drug for selectins should have a multifaceted role and be a dynamic molecule that targets the disease mechanism specifically. This chapter explores the role of selectins in the disease mechanism at the mechanism level that provides the impact for identifying the selectin inhibitors. Overall, this chapter provides the molecular level insights on selectins, their ligands, involvement in normal and disease mechanisms.

Deep Functional Profiling of Wild Animal Microbiomes Reveals Probiotic Bacillus pumilus Strains with a Common Biosynthetic Fingerprint

The biodiversity of microorganisms is maintained by intricate nets of interactions between competing species. Impaired functionality of human microbiomes correlates with their reduced biodiversity originating from aseptic environmental conditions and antibiotic use. Microbiomes of wild animals are free of these selective pressures. Microbiota provides a protecting shield from invasion by pathogens in the wild, outcompeting their growth in specific ecological niches. We applied ultrahigh-throughput microfluidic technologies for functional profiling of microbiomes of wild animals, including the skin beetle, Siberian lynx, common raccoon dog, and East Siberian brown bear. Single-cell screening of the most efficient killers of the common human pathogen Staphylococcus aureus resulted in repeated isolation of Bacillus pumilus strains. While isolated strains had different phenotypes, all of them displayed a similar set of biosynthetic gene clusters (BGCs) encoding antibiotic amicoumacin, siderophore bacillibactin, and putative analogs of antimicrobials including bacilysin, surfactin, desferrioxamine, and class IId cyclical bacteriocin. Amicoumacin A (Ami) was identified as a major antibacterial metabolite of these strains mediating their antagonistic activity. Genome mining indicates that Ami BGCs with this architecture subdivide into three distinct families, characteristic of the B. pumilus, B. subtilis, and Paenibacillus species. While Ami itself displays mediocre activity against the majority of Gram-negative bacteria, isolated B. pumilus strains efficiently inhibit the growth of both Gram-positive S. aureus and Gram-negative E. coli in coculture. We believe that the expanded antagonistic activity spectrum of Ami-producing B. pumilus can be attributed to the metabolomic profile predetermined by their biosynthetic fingerprint. Ultrahigh-throughput isolation of natural probiotic strains from wild animal microbiomes, as well as their metabolic reprogramming, opens up a new avenue for pathogen control and microbiome remodeling in the food industry, agriculture, and healthcare.

Diet and Hygiene in Modulating Autoimmunity During the Pandemic Era

The immune system is an efficiently toned machinery that discriminates between friends and foes for achieving both host defense and homeostasis. Deviation of immune recognition from foreign to self and/or long-lasting inflammatory responses results in the breakdown of tolerance. Meanwhile, educating the immune system and developing immunological memory are crucial for mounting defensive immune responses while protecting against autoimmunity. Still to elucidate is how diverse environmental factors could shape autoimmunity. The emergence of a world pandemic such as SARS-CoV-2 (COVID-19) not only threatens the more vulnerable individuals including those with autoimmune conditions but also promotes an unprecedented shift in people's dietary approaches while urging for extraordinary hygiene measures that likely contribute to the development or exacerbation of autoimmunity. Thus, there is an urgent need to understand how environmental factors modulate systemic autoimmunity to better mitigate the incidence and or severity of COVID-19 among the more vulnerable populations. Here, we discuss the effects of diet (macronutrients and micronutrients) and hygiene (the use of disinfectants) on autoimmunity with a focus on systemic lupus erythematosus.

Incidence of celiac disease autoimmunity and associations with maternal tuberculosis and pediatric Helicobacter pylori infections in 4-year-old Ethiopian children followed up in an HLA genotyped birth cohort

BACKGROUND

The prevalence of celiac disease in the general population is mainly unknown in most of sub-Saharan African countries. The aim of this study was to determine the incidence of celiac disease autoimmunity (CDA) and its associations with latent Mycobacterium tuberculosis (LMTB) and Helicobacter pylori (HP) infections in Ethiopian children aged 4 years in an HLA genotyped cohort study.

METHODS

Of 1,389 recruited children between 2018 and 2022, 1,046 (75.3%) had been screened at least twice for celiac disease between the ages of 2 and 4 years using a tissue transglutaminase autoantibody (tTGA) ELISA kit. Tissue TGA-positive children were retested using radio-binding assays. CDA was defined as persistent-confirmed tTGA positivity in two consecutive samples. Associations of CDA with LMTB and HP were tested in a subpopulation of 752 children born to mothers who were previously tested for LMTB with IFN-γ and anti-HP antibodies in samples collected at a mean age of 49.3 ± 5.3 months.

RESULTS

Screening detected 38 out of 1,046 (3.6%) IgA-tTGA-positive children. Ten (1.0%) were confirmed to be positive, with six (0.6%) children diagnosed with CDA. The incidence of CDA at 4 years of age was 1.2 per 1,000 person-years. LMTB was found in 4 of 6 (66.7%) mothers with CDA children compared with 340 of 734 (46.3%) mothers of children without CDA (p = 0.424), while HP was found in 3 of 6 (50.0%) CDA children compared with 315 of 746 (42.2%) children without CDA (p = 0.702).

CONCLUSION

The incidence of CDA in Ethiopian children is lower than the pooled global incidence. Neither LMTB nor HP infections are associated with CD in Ethiopian children.

<i>Helicobacter pylori</i>-associated comorbidity

Helicobacter pylori (H. pylori) infection is known to lead to various diseases such as gastric and duodenal ulcers, chronic gastritis and malignant diseases, including MALT lymphoma and stomach cancer. To date, various factors of pathogenicity and virulence of the H. pylori bacterium have been studied. The interaction of infection with host cells leads to the induction of inflammatory responses through the release of cytokines, activation of apoptosis or proliferation, which leads to inflammation and dysfunction of the epithelial barrier. This process can facilitate the movement of H. pylori virulence factors and inflammatory mediators into the bloodstream and promote or enhance the development of a systemic inflammatory response and the possible clinical effects of H. pylori infections outside the stomach. The purpose of this review is to clarify the available data on H. pylori-associated comorbidity with diseases of the cardiovascular, nervous, endocrine systems, autoimmune diseases and some other pathologies outside the digestive system.

Helminth-induced CD9+ B-cell subset alleviates obesity-associated inflammation via IL-10 production

It has been shown that helminth infection can protect against obesity and improve insulin sensitivity to a certain extent, based on epidemiological investigations and animal experiments. Meanwhile, helminths induce a network of regulatory immune cells, including regulatory B cells (Bregs). However, the molecule characteristics and function of these Bregs in improving whole-body metabolic homeostasis remains largely unclear. We established a mouse model with chronic Schistosoma japonicum infection, and compared the differences in B10 cells (CD19⁺CD5⁺CD1d^hi) and B10^- cells (CD19⁺CD5^-CD1d^-) from splenic B cells of infected mice using RNA-seq. A unique Breg population was identified. Furthermore, these Bregs were evaluated for their ability to produce inhibitory cytokines in vitro and suppress obesity when adoptively transferred into mice on a high-fat diet. We found that schistosome infection could expand Breg cell populations in mice. CD9 was demonstrated to be a key surface marker for most murine IL-10⁺ B cells in spleen. CD19⁺CD9⁺ B cells produced more IL-10 than conventional B10 cells. Adoptive transfer of CD9⁺ B cells had the capacity to alleviate obesity-associated inflammation via promoting Tregs, Th2 cells and decreasing Th1, Th17 cells in high-fat diet mice. In conclusion, schistosome infection can induce regulatory CD9⁺ B cell production, which plays a critical role in the regulation of metabolic disorders through IL-10 production.

Dermatology for the internist: optimal diagnosis and management of atopic dermatitis

Internists are front-line health care providers that commonly provide the first encounter to patients for dermatological conditions, especially atopic dermatitis (AD). Internists need to be comfortable with managing mild-moderate AD in their practices. Criteria and guidelines established in dermatology literature are available to help the general practitioner diagnose and treat AD. AD is a systemic disease associated with multiple cutaneous and extra-cutaneous comorbidities that warrant screening by internists, especially mental health conditions. Environmental factors may play a role in the development or worsening of AD; however, there is currently no strong evidence to guide specific population- or clinic-based interventions for their avoidance. While food allergies are common in AD patients, the role of food allergens as an exacerbating factor for AD is controversial. Before starting any dietary modifications, careful evaluation should be performed by an allergist. If the patient is not well-controlled despite adequate topical therapies or is experiencing severe/worsening disease, early referral to dermatology is warranted to rule out confounding diagnoses and/or escalation to systemic therapies. Finally, it is important to recognise the racial disparities present in AD and address these when formulating treatment plans.Key messages:Confounding dermatoses, either instead of or in addition to AD, should be considered in treatment-refractory AD, and the appropriate workup may be initiated while awaiting dermatology referral.AD patients have multiple cutaneous and extra-cutaneous comorbidities that warrant screening by internists, especially mental health conditions.

Positive QuantiFERON test and the severity of COVID-19 disease: A prospective study

Background

A strong negative correlation is reported between the Bacille Calmette Guerin (BCG) index and COVID-19 mortality. The present study explored if frequent exposure to strong Th1 antigens like Mycobacteria or Salmonella have any effect on the progression of the disease in COVID-19 patients.

Methods

This prospective comparative study comprised of 3 groups of 20 each of mild or asymptomatic COVID-19 patients (A), severely ill patients (S) and healthy volunteers with a COVID Negative report (H).

Results

QuantiFERON TB Gold (QFT) which is interferon gamma release assay (IGRA) against Mtb antigen was used to quantify immunity status of patients against the tuberculosis. Group S showed positive QFT in only 15% patients as against 50% QFT positive patients in group A and H. All fourteen patients in group S with QFT negative report died while 5 of six survived patients showed positive QFT report either on initial or repeat testing done at 6 weeks. The sixth survived patient was QFT negative but showed high antibody titre against H antigen (TH) on Widal test. All severely ill group S patients showed huge reduction of IGRA even to the mitogen stimulus thus suggesting gross general unresponsiveness of T cells. Presence of BCG scar showed no correlation with prevalence or progression of the disease.

Conclusion

Population in an endemic area of tuberculosis and typhoid with good community exposure to these antigen is likely to withstand COVID -19 better and show reduced mortality following it.

How to Tackle the Relationship between Autoimmune Diseases and Diet: Well Begun Is Half-Done

Nutrition and immunity are closely related, and the immune system is composed of the most highly energy-consuming cells in the body. Much of the immune system is located within the GI tract, since it must deal with the huge antigenic load introduced with food. Moreover, the incidence of immune-mediated diseases is elevated in Westernized countries, where “transition nutrition” prevails, owing to the shift from traditional dietary patterns towards Westernized patterns. This ecological correlation has fostered increasing attempts to find evidence to support nutritional interventions aimed at managing and reducing the risk of immune-mediated diseases. Recent studies have described the impacts of single nutrients on markers of immune function, but the knowledge currently available is not sufficient to demonstrate the impact of specific dietary patterns on immune-mediated clinical disease endpoints. If nutritional scientists are to conduct quality research, one of many challenges facing them, in studying the complex interactions between the immune system and diet, is to develop improved tools for investigating eating habits in the context of immunomediated diseases.

High-fat diet prevents the development of autoimmune diabetes in NOD mice

AIMS

Type 1 diabetes (T1D) has a strong genetic predisposition and requires an environmental trigger to initiate the beta-cell autoimmune destruction. The rate of childhood obesity has risen in parallel to the proportion of T1D, suggesting high-fat diet (HFD)/obesity as potential environmental triggers for autoimmune diabetes. To explore this, non-obese diabetic (NOD) mice were subjected to HFD and monitored for the development of diabetes, insulitis and beta-cell stress.

MATERIALS AND METHODS

Four-week-old female NOD mice were placed on HFD (HFD-NOD) or standard chow-diet. Blood glucose was monitored weekly up to 40 weeks of age, and glucose- and insulin-tolerance tests performed at 4, 10 and 15 weeks. Pancreata and islets were analysed for insulin secretion, beta-cell mass, inflammation, insulitis and endoplasmic reticulum stress markers. Immune cell levels were measured in islets and spleens. Stool microbiome was analysed at age 4, 8 and 25 weeks.

RESULTS

At early ages, HFD-NOD mice showed a significant increase in body weight, glucose intolerance and insulin resistance; but paradoxically, they were protected from developing diabetes. This was accompanied by increased insulin secretion and beta-cell mass, decreased insulitis, increased splenic T-regulatory cells and altered stool microbiome.

CONCLUSIONS

This study shows that HFD protects NOD mice from autoimmune diabetes and preserves beta-cell mass and function through alterations in gut microbiome, increased T-regulatory cells and decreased insulitis. Further studies into the exact mechanism of HFD-mediated prevention of diabetes in NOD mice could potentially lead to interventions to prevent or delay T1D development in humans.

Pathogenesis, clinical features of asthma COPD overlap (ACO), and therapeutic modalities

Both asthma and COPD are heterogeneous diseases identified by characteristic symptoms and functional abnormalities, with airway obstruction common in both diseases. Asthma COPD overlap (ACO) does not define a single disease but is a descriptive term for clinical use that includes several overlapping clinical phenotypes of chronic airways disease with different underlying mechanisms. This literature review was initiated to describe published studies, identify gaps in knowledge, and propose future research goals regarding the disease pathology of ACO, especially the airway remodelling changes and inflammation aspects. Airway remodelling occurs in asthma and COPD, but there are differences in the structures affected and the prime anatomic site at which they occur. Reticular basement membrane thickening and cellular infiltration with eosinophils and T-helper (CD4+) lymphocytes are prominent features of asthma. Epithelial squamous metaplasia, airway wall fibrosis, emphysema, bronchoalveolar lavage (BAL) neutrophilia and (CD8+) T-cytotoxic lymphocyte infiltrations in the airway wall are features of COPD. There is no universally accepted definition of ACO, nor are there clearly defined pathological characteristics to differentiate from asthma and COPD. Understanding etiological concepts within the purview of inflammation and airway remodelling changes in ACO would allow better management of these patients.

Environmental Determinants of Type 1 Diabetes: From Association to Proving Causality

The rising incidence of type 1 diabetes (T1D) cannot be ascribed to genetics alone, and causative environmental triggers and drivers must also be contributing. The prospective TEDDY study has provided the greatest contributions in modern time, by addressing misconceptions and refining the search strategy for the future. This review outlines the evidence to date to support the pathways from association to causality, across all stages of T1D (seroconversion to beta cell failure). We focus on infections and vaccinations; infant growth and childhood obesity; the gut microbiome and the lifestyle factors which cultivate it. Of these, the environmental determinants which have the most supporting evidence are enterovirus infection, rapid weight gain in early life, and the microbiome. We provide an infographic illustrating the key environmental determinants in T1D and their likelihood of effect. The next steps are to investigate these environmental triggers, ideally though gold-standard randomised controlled trials and further prospective studies, to help explore public health prevention strategies.

Mixed evidence on the relationship between socioeconomic position and atopic dermatitis: A systematic review

BACKGROUND

Lower socioeconomic position usually portends worse health outcomes, but multiple studies have found that atopic dermatitis is associated with higher socioeconomic position. The nature of this relationship remains unclear.

OBJECTIVE

To systematically review the literature on socioeconomic position and atopic dermatitis and determine whether the association varies by patient or study characteristics.

METHODS

A literature search was conducted in the PubMed and Embase databases. Individual-level studies addressing the association between all measures of socioeconomic position and the prevalence or incidence of atopic dermatitis were eligible for inclusion. Two independent reviewers screened all texts and extracted all data for qualitative synthesis.

RESULTS

Eighty-eight studies met the inclusion criteria. Of the 88 studies, 42% (37) found a positive association between atopic dermatitis and socioeconomic position, 15% (13) found a negative association, and 43% (38) found a null or inconsistent association. Studies conducted in Europe, among children, and based on self-report of eczema were more likely to find a positive association with socioeconomic position.

LIMITATIONS

Studies varied both in terms of the measurement of socioeconomic position and the definition of atopic dermatitis, limiting quantitative synthesis.

CONCLUSION

The evidence of a positive association between atopic dermatitis and socioeconomic position is not consistent.

Gut Microbiota-Modulated Metabolomic Profiling Shapes the Etiology and Pathogenesis of Autoimmune Diseases

Autoimmunity is a complex and multifaceted process that contributes to widespread functional decline that affects multiple organs and tissues. The pandemic of autoimmune diseases, which are a global health concern, augments in both the prevalence and incidence of autoimmune diseases, including type 1 diabetes, multiple sclerosis, and rheumatoid arthritis. The development of autoimmune diseases is phenotypically associated with gut microbiota-modulated features at the molecular and cellular levels. The etiology and pathogenesis of autoimmune diseases comprise the alterations of immune systems with the innate and adaptive immune cell infiltration into specific organs and the augmented production of proinflammatory cytokines stimulated by commensal microbiota. However, the relative importance and mechanistic interrelationships between the gut microbial community and the immune system during progression of autoimmune diseases are still not well understood. In this review, we describe studies on the profiling of gut microbial signatures for the modulation of immunological homeostasis in multiple inflammatory diseases, elucidate their critical roles in the etiology and pathogenesis of autoimmune diseases, and discuss the implications of these findings for these disorders. Targeting intestinal microbiome and its metabolomic associations with the phenotype of autoimmunity will enable the progress of developing new therapeutic strategies to counteract microorganism-related immune dysfunction in these autoimmune diseases.

Higher educational level in patients with eosinophilic esophagitis: a comparative analysis

BACKGROUND

Eosinophilic esophagitis is a chronic inflammatory gastrointestinal disease with a high prevalence in younger, atopic males. In our clinical practice, we observed a striking preponderance of patients having a high educational background. The purposes of this study were first to assess the level of education of eosinophilic esophagitis patients and second to compare the findings to patients with inflammatory bowel disease, another chronic immune-mediated condition of the gastrointestinal tract, and with the Swiss general population.

METHODS

Using a questionnaire, we assessed the educational level of adult patients who have attended Swiss Eosinophilic Esophagitis Clinics in the past. In addition, the educational level of the parents was assessed as well. We calculated the proportions of patients and parents who have obtained a higher educational level. Data from the Swiss Inflammatory Bowel Disease Cohort Study and from the Swiss general population served as confirmation and as comparison, respectively.

RESULTS

A total of 277 successfully contacted patients (response rate 69.1%; mean age 51.1 years, 73% male) participated. A significantly higher proportion of surveyed eosinophilic esophagitis patients had a high International Standard Classification of Education level (66.8%, P < 0.001) compared with inflammatory bowel disease patients (n = 2534; 34.2%, P < 0.001) and to the Swiss general population (n = 6,066,907; 30.5% P < 0.001).

CONCLUSION

Our analysis confirms the clinical observation that eosinophilic esophagitis patients have a significantly higher educational level compared with the general population and to patients with other chronic inflammatory diseases of the gastrointestinal tract. As a limitation, this impressive finding remains on a purely descriptive level.