Effects of Probiotics on the Immune System and Allergic Diseases

ABSTRACTIntestinal microbiota play a crucial role in the development of mucosal tolerance and adaptation. Perturbations in microbiota composition are strongly associated with allergies and asthma in westernized countries. There has been accumulating evidence that the administration of probiotics, “live microbial supplements that exert a beneficial effect on human health,” may be effective in the treatment and/or prevention of allergic diseases. Although it has been shown that part of the effect of probiotics arises from its interaction with the host immune system, the precise mechanisms remain to be determined. In addition, future studies are necessary to define appropriate species and strains, optimum dose, frequency, and duration for the treatment of allergic diseases

Reactivity of IgE in fish-allergic patients to fish muscle collagen

ABSTRACTBackground: In addition to parvalbumin, the well- known major allergen in fish, collagen was recently identified as a new allergen in the muscle of bigeye tuna and in the skin of several species of fish. The aim of the present study was to evaluate fish muscle colla- gens for their reactivity with IgE in fish-allergic patients and antigenic cross-reactivity.Methods: Collagen was purified from the white muscle of five species of fish (Japanese eel, alfonsin, mackerel, skipjack and bigeye tuna) by acid extraction and salt precipitation, whereas parvalbumin was purified from bigeye tuna by gel filtration and reverse- phase HPLC. The IgE reactivities to collagen and parvalbumin were examined by ELISA, whereas antigenic cross-reactivity among fish muscle collagens was investigated by ELISA inhibition experiments.Results: When 15 sera from fish-allergic patients were subjected to ELISA using bigeye tuna collagen and parvalbumin, 10 sera reacted only to parvalbumin, two reacted only to collagen, two reacted to both collagen and parvalbumin and one reacted to neither collagen nor parvalbumin. The sera containing specific IgE to bigeye tuna collagen also reacted to collagens from the other four species of fish. In the ELISA inhibition experiments, bigeye tuna collagen inhibited the binding of IgE not only to bigeye tuna collagen, but also to that from the other four species of fish, suggesting cross-reactivity among the collagens from five species of fish.Conclusions: These results demonstrate that some Japanese fish-allergic patients have specific IgE to fish muscle collagen and that fish muscle collagen is a cross-reactive allergen among various species of fish

Relationship between RANTES Polymorphisms and Respiratory Syncytial Virus Bronchiolitis in a Japanese Infant Population

SUMMARY: Respiratory syncytial virus (RSV) is the most important virus associated with bronchiolitis in infants and young children. The regulated upon activation, normal T-cell expressed and secreted protein (RANTES, also known as CCL5) appears to be a key player in the etiology of RSV-infected airway inflammation. In this study, we genotyped three single-nucleotide polymorphisms in the RANTES gene: -403G/A, -28C/G, and In1.1T/C in 59 infants with severe RSV bronchiolitis and 201 control subjects. The frequencies of the -403G/A ＋ A/A, -28C/G ＋ G/G, and In1.1T/C ＋ C/C genotypes were significantly lower in patients with severe RSV bronchiolitis than in control subjects, and the frequencies of the -403A, -28G, and In1.1C alleles were significantly lower in RSV patients than in control subjects. The present results suggest that RANTES polymorphisms may confer risk for severe RSV bronchiolitis. Respiratory syncytial virus (RSV) is the most important pathogen causing lower respiratory tract infection in infants and young children (1-3). Bronchiolitis is an important disease in infancy and early childhood, and the development of severe bronchiolitis is closely related to RSV infection. Previous studies have implicated cellular immunity in airway inflammation after RSV infection (4,5). Multiple proinflammatory cytokines and chemokines released by alveolar macrophages and epithelial cells are involved in the activation of cellular immunity after RSV infection (6). Regulated upon activation, normal T-cell expressed and secreted protein (RANTES, also known as CCL5) is a chemokine that attracts monocytes, eosinophils, basophils, and memory T lymphocytes (7-11). RANTES is generated by macrophages, CD8

Japanese guidelines for atopic dermatitis 2020.

Atopic dermatitis (AD) is a disease characterized by relapsing eczema with pruritus as a primary lesion, which is frequently encountered in clinical practice. Skin barrier dysfunction leads to enhanced skin irritability to non-specific stimuli and epicutaneous sensitization. In the lesion site, a further inflammation-related reduction in skin barrier function, enhanced irritability and scratching-related stimuli deteriorate eczema, leading to vicious cycle of inflammation. The current strategies to treat AD in Japan from the perspective of evidence-based medicine consist of three primary measures: (i) the use of topical corticosteroids and tacrolimus ointment as the main treatment for the inflammation; (ii) topical application of emollients to treat the cutaneous barrier dysfunction; and (iii) avoidance of apparent exacerbating factors, psychological counseling and advice about daily life. The guidelines present recommendations to review clinical research articles, evaluate the balance between the advantages and disadvantages of medical activities, and optimize medical activity-related patient outcomes with respect to several important points requiring decision-making in clinical practice

Skin care interventions in infants for preventing eczema and food allergy

BackgroundEczema and food allergy are common health conditions that usually begin in early childhood and often occur together in the same people. They can be associated with an impaired skin barrier in early infancy. It is unclear whether trying to prevent or reverse an impaired skin barrier soon after birth is effective in preventing eczema or food allergy.ObjectivesPrimary objectiveTo assess effects of skin care interventions, such as emollients, for primary prevention of eczema and food allergy in infantsSecondary objectiveTo identify features of study populations such as age, hereditary risk, and adherence to interventions that are associated withthe greatest treatment benefit or harm for both eczema and food allergy.Search methodsWe searched the following databases up to July 2020: Cochrane Skin Specialised Register, CENTRAL, MEDLINE, and Embase. We searched two trials registers and checked reference lists of included studies and relevant systematic reviews for further references to relevant randomised controlled trials (RCTs). We contacted field experts to identify planned trials and to seek information about unpublished or incomplete trials.Selection criteriaRCTs of skin care interventions that could potentially enhance skin barrier function, reduce dryness, or reduce subclinical inflammation in healthy term (> 37 weeks) infants (0 to 12 months) without pre‐existing diagnosis of eczema, food allergy, or other skin condition were included. Comparison was standard care in the locality or no treatment. Types of skin care interventions included moisturisers/emollients; bathing products; advice regarding reducing soap exposure and bathing frequency; and use of water softeners. No minimum follow‐up was required.Data collection and analysisThis is a prospective individual participant data (IPD) meta‐analysis. We used standard Cochrane methodological procedures, and primary analyses used the IPD dataset. Primary outcomes were cumulative incidence of eczema and cumulative incidence of immunoglobulin (Ig)E‐mediated food allergy by one to three years, both measured by the closest available time point to two years. Secondary outcomes included adverse events during the intervention period; eczema severity (clinician‐assessed); parent report of eczema severity; time to onset of eczema; parent report of immediate food allergy; and allergic sensitisation to food or inhalant allergen.Main resultsThis review identified 33 RCTs, comprising 25,827 participants. A total of 17 studies, randomising 5823 participants, reported information on one or more outcomes specified in this review. Eleven studies randomising 5217 participants, with 10 of these studies providing IPD, were included in one or more meta‐analysis (range 2 to 9 studies per individual meta‐analysis).Most studies were conducted at children's hospitals. All interventions were compared against no skin care intervention or local standard care. Of the 17 studies that reported our outcomes, 13 assessed emollients. Twenty‐five studies, including all those contributing data to meta‐analyses, randomised newborns up to age three weeks to receive a skin care intervention or standard infant skin care. Eight of the 11 studies contributing to meta‐analyses recruited infants at high risk of developing eczema or food allergy, although definition of high risk varied between studies. Durations of intervention and follow‐up ranged from 24 hours to two years.We assessed most of this review's evidence as low certainty or had some concerns of risk of bias. A rating of some concerns was most often due to lack of blinding of outcome assessors or significant missing data, which could have impacted outcome measurement but was judged unlikely to have done so. Evidence for the primary food allergy outcome was rated as high risk of bias due to inclusion of only one trial where findings varied when different assumptions were made about missing data.Skin care interventions during infancy probably do not change risk of eczema by one to two years of age (risk ratio (RR) 1.03, 95% confidence interval (CI) 0.81 to 1.31; moderate‐certainty evidence; 3075 participants, 7 trials) nor time to onset of eczema (hazard ratio 0.86, 95% CI 0.65 to 1.14; moderate‐certainty evidence; 3349 participants, 9 trials). It is unclear whether skin care interventions during infancy change risk of IgE‐mediated food allergy by one to two years of age (RR 2.53, 95% CI 0.99 to 6.47; 996 participants, 1 trial) or allergic sensitisation to a food allergen at age one to two years (RR 0.86, 95% CI 0.28 to 2.69; 1055 participants, 2 trials) due to very low‐certainty evidence for these outcomes. Skin care interventions during infancy may slightly increase risk of parent report of immediate reaction to a common food allergen at two years (RR 1.27, 95% CI 1.00 to 1.61; low‐certainty evidence; 1171 participants, 1 trial). However, this was only seen for cow’s milk, and may be unreliable due to significant over‐reporting of cow’s milk allergy in infants. Skin care interventions during infancy probably increase risk of skin infection over the intervention period (RR 1.34, 95% CI 1.02 to 1.77; moderate‐certainty evidence; 2728 participants, 6 trials) and may increase risk of infant slippage over the intervention period (RR 1.42, 95% CI 0.67 to 2.99; low‐certainty evidence; 2538 participants, 4 trials) or stinging/allergic reactions to moisturisers (RR 2.24, 95% 0.67 to 7.43; low‐certainty evidence; 343 participants, 4 trials), although confidence intervals for slippages and stinging/allergic reactions are wide and include the possibility of no effect or reduced risk.Preplanned subgroup analyses show that effects of interventions were not influenced by age, duration of intervention, hereditary risk, FLG mutation, or classification of intervention type for risk of developing eczema. We could not evaluate these effects on risk of food allergy. Evidence was insufficient to show whether adherence to interventions influenced the relationship between skin care interventions and risk of developing eczema or food allergy.Authors' conclusionsSkin care interventions such as emollients during the first year of life in healthy infants are probably not effective for preventing eczema, and probably increase risk of skin infection. Effects of skin care interventions on risk of food allergy are uncertain.Further work is needed to understand whether different approaches to infant skin care might promote or prevent eczema and to evaluate effects on food allergy based on robust outcome assessments