Is oral food challenge test useful for avoiding complete elimination of cow's milk in Japanese patients with or suspected of having IgE-dependent cow's milk allergy?

BACKGROUND: Cow's milk, along with hen's egg, are common causes of food allergies in children worldwide. Accidental ingestion of milk is common and often induces severe allergic reactions. Oral food challenge test (OFC) is usually performed in patients with or suspected of having a food allergy. However, the evidence of whether cow's milk OFC is useful in IgE-dependent cow's milk allergy patients to avoid total elimination is not known. METHODS: After setting the clinical question and outcomes, we performed a systematic review for relevant articles published from January 1, 2000 to August 31, 2019 using PubMed® and Ichushi-Web databases. Each article was then evaluated for the level of evidence. All positive results of the OFC were defined as adverse events. RESULTS: Forty articles were selected in this study. Our review revealed that cow's milk OFC was able to avoid the complete elimination of cow's milk in 66% of the patients with cow's milk allergy. We also found that adverse events occurred frequently (50.5%). CONCLUSIONS: This analysis supports the recommendation of conducting cow's milk OFC to avoid complete elimination of cow's milk, however the test should be conducted with careful consideration of the patient's safety. As the methods of OFC and subjects varied among the articles selected in this study, further studies are needed to obtain higher quality evidence.

[A CASE OF HYPERSENSITIVITY REACTION TO ENOKITAKE (FLAMMULINA VELUTIPES) INGESTION].

We experienced a case of 10-year-old girl who developed hypersensitivity reactions after eating enokitake. The patient had food allergy to egg until 5 years old. When she was 4 years old, she ate enokitake with a hot-pot dish. Later, she felt itching in her mouth. Therefore, she never ate enokitake since that time. At the age of 10, she drank only the soup of enokitake with school lunch. After that she felt discomfort and itching in her oral cavity. The result of enokitake and other mushrooms (siitake, simeji, and eringi) skin prick to prick test were all positive. We performed Western blotting with enokitake extracts and the patient's serum. Enokitake protein's band (75kDa) reacted specifically with the patient's IgE. At the same time Western blotting was performed with the patient's serum of previously reported enokitake anaphylaxis, but a 75kDa band showing specific reaction in this case was not observed. This band we identified was a novel enokitake allergen.

Differential activation of eosinophils by bacteria associated with asthma.

BACKGROUND: It has been suggested that there is a complex interaction between microbiota and various human diseases. Some bacteria have been reported to be involved in the inception and progression of asthma, and others in the protection against asthma. We know very little about the mechanisms by which bacteria do harm or good with regard to asthma. This study investigated whether bacteria exert differential effects on the functions of eosinophils, major effector cells in airway inflammation in asthma. METHODS: Eosinophils were purified from healthy adult volunteers by Percoll density gradient centrifugation and negative immunomagnetic bead selection using anti-CD16 microbeads. Three kinds of heat-killed bacteria that have been implicated in asthma, namely Staphylococcus aureus (SA), Haemophilus influenzae (HI) and a Prevotella sp. (PS), were tested for their effects on the secretion of eosinophil-derived neurotoxin (EDN), the generation of superoxides and the production of cytokines/chemokines. RESULTS: SA, but not HI or PS, induced significant EDN release in a dose-dependent manner. Superoxide generation was significantly enhanced by each of the bacterial species, but most strongly by SA, which induced significantly greater TNF-α production by eosinophils than either HI or PS. Conversely, interleukin 10, an anti-inflammatory cytokine, was more strongly induced by HI and PS than by SA. CONCLUSIONS: Bacteria exert differential effects on eosinophils. Based on these results, SA may be involved in the exacerbation of, and HI and PS in the inhibition of, eosinophilic inflammation in asthma.

Case report of a child who may have developed anaphylaxis after ingesting raw horse meat by cross-reactivity of horse and cat pelt.

Pork-cat syndrome can occur in children younger than 10 years. A history of contact with animals since infancy and history of severe atopic dermatitis, which can promote epicutaneous sensitization to animal serum albumin, may be helpful in diagnosis.

Parents' Fears about Hospital Visits and Trait Anxiety in the COVID-19 Pandemic.

Anxiety in parents of children with allergic diseases during the COVID-19 pandemic may impact hospital visits. This study explored the effect of the pandemic on parents' fears about hospital visits and their relationship with their personality traits. A cross-sectional, questionnaire-based study was conducted between September 2020 and March 2021, with parents of children aged 0-15 years, who regularly visited 24 outpatient facilities for allergic disease. The survey included patient information, fears about hospital visits, desired information, and the State-Trait Anxiety Inventory. Responses were compared between parents with high and low trait anxiety. The response rate was 97.6% (2439/2500). The most common fear was "Fear of getting medical care as usual (85.2%)" and "Fear of COVID-19 infection during hospital visits (87.1%)". High trait anxiety showed a significant association with "Fear of worsening of children's allergies" (adjusted OR: 1.31, 95%CI: 1.04 to 1.65, p = 0.022), and "Fear of worsening of COVID-19 due to allergy" (adjusted OR: 1.52, 95%CI: 1.27 to 1.80, p < 0.01). Healthcare professionals should share updates on COVID-19 and healthcare system to reduce parents' fear. Subsequently, they should communicate the importance of continuing treatment to prevent worsening of COVID-19 and avoid emergency visits, considering parental trait anxiety.

Pediatric allergies in Japan: Coronavirus disease pandemic-related risk factors.

Background: The coronavirus disease 2019 (COVID-19) pandemic impacted various parts of society, including Japanese children with allergies. Objective: This study investigated risk factors for pediatric allergic diseases associated with the state of emergency owing to the COVID-19 pandemic in Japan, including during school closures. Methods: Parents of pediatric patients (0-15 years) with allergies were enrolled and queried regarding the impact of school closure on pediatric allergies compared to that before the COVID-19 pandemic. Results: A valid response was obtained from 2302 parents; 1740 of them had children with food allergies. Approximately 4% (62/1740) of the parents reported accidental food allergen ingestion was increased compared to that before the COVID-19 pandemic. Accidental ingestion during school closures was associated with increased contact with meals containing allergens meant for siblings or other members of the family at home. The exacerbation rate during the pandemic was highest for atopic dermatitis at 13% (127/976), followed by allergic rhinitis at 8% (58/697), and bronchial asthma at 4% (27/757). The main risk factors for worsening atopic dermatitis, allergic rhinitis, and bronchial asthma were contact dermatitis of the mask area (34/120 total comments); home allergens, such as mites, dogs, and cats (15/51 total comments); and seasonal changes (6/25 total comments), respectively. Conclusion: The main factors affecting allergic diseases were likely related to increased time at home, preventive measures against COVID-19, and refraining from doctor visits. Children with allergies were affected by changes in social conditions; however, some factors, such as preventing accidental ingestion and the management of allergens at home, were similar to those before the COVID-19 pandemic. Patients who had received instructions on allergen avoidance at home before the pandemic were able to manage their disease better even when their social conditions changed.

1,25-Dihydroxyvitamin D3 upregulates functional C-x-C chemokine receptor type 4 expression in human eosinophils.

BACKGROUND: Epidemiological studies suggest that vitamin D may be protective against the inception and exacerbation of allergic diseases. However, the direct effect of vitamin D on eosinophils, the major effector cells in allergic inflammation, is not known. It has been reported that C-X-C chemokine receptor type 4 (CXCR4) in eosinophils is induced in non-Th2 cytokine milieu or in response to glucocorticoids, recruiting the cell to noninflammatory sites. OBJECTIVES: To test whether 1,25-dihydroxyvitamin D(3) [1,25-(OH)(2)D(3) or calcitriol], the active metabolite of vitamin D, acts directly on eosinophils to induce upregulation of CXCR4. METHODS: Peripheral blood eosinophils from normal volunteers were isolated by CD16 immunomagnetic beads. Vitamin D receptor (VDR) expression was detected by RT-PCR. Eosinophils were cultured with 1,25-(OH)(2)D(3) and the survival and expression of CXCR4 on eosinophils were measured by flowcytometry. Eosinophil migration by CXCL-12/SDF-1 in the presence of 1,25-(OH)(2)D(3) was also analyzed. RESULTS: Eosinophils expressed VDR. 1,25-(OH)(2)D(3) prolonged eosinophil survival and upregulated eosinophil surface expression of CXCR4 in a concentration-dependent manner. Interleukin (IL)-5 significantly reduced CXCR4 expression and migration induced by the ligand CXCL-12/SDF-1. 1,25-(OH)(2)D(3) reversed the negative effects of IL-5 on the CXCR4-CXCL12 pathway. CONCLUSION: 1,25-(OH)(2)D(3) regulates CXCR4 expression in eosinophils. The mechanism may be involved in eosinophil recruitment to noninflammatory sites where the ligand of CXCR4 is constitutively expressed.

Vaccine-induced anaphylaxis in a child with cow's milk allergy: Lactose hydrate was the culprit.

Lactose hydrate was the cause of vaccine-induced anaphylaxis in a child with severe milk allergy. Although the amount of milk protein in lactose-containing vaccines is extremely small, physicians administering such a vaccine must be prepared for the potential risk of severe milk allergy.

Inhibition of eosinophil activation mediated by a Toll-like receptor 7 ligand with a combination of procaterol and budesonide.

BACKGROUND: Viral respiratory tract infections play an important role in the inception and exacerbation of asthma. Eosinophils, major effector cells in asthma, often accumulate in the airways during viral infections and are possibly activated by respiratory RNA viruses through Toll-like receptor (TLR) 7. We investigated the effect of a ß(2)-agonist, i.e. procaterol, and a corticosteroid, i.e. budesonide, that are commonly used for viral-induced asthma, on TLR7 ligand-induced activation of eosinophils in vitro. METHODS: Purified peripheral blood eosinophils were incubated with procaterol and/or budesonide and stimulated with a TLR7 ligand, i.e. R-837. Expression of CD11b was analyzed by flow cytometry. Superoxide generation was measured via the cytochrome C reduction method. IL-8 in the supernatants was assayed by ELISA. RESULTS: Although procaterol or budesonide alone did not inhibit R-837-induced CD11b expression, combinations of the 2 drugs significantly inhibited CD11b. Likewise, the combinations significantly inhibited O(2)(-) generation at low concentrations. Budesonide significantly inhibited R-837-induced IL-8 production in a concentration-dependent manner, and procaterol potentiated inhibition by budesonide although single-agent procaterol had no effect. CONCLUSION: A combination of procaterol and budesonide inhibits the TLR7-mediated effector function of eosinophils, indicating their possible anti-inflammatory effect for virus-induced asthma.

Progress of Home-Based Food Allergy Treatment during the Coronavirus Disease Pandemic in Japan: A Cross-Sectional Multicenter Survey.

The coronavirus disease 2019 (COVID-19) pandemic's impact on food allergy treatment such as home-based oral immunotherapy (OIT) is not known. This cross-sectional, questionnaire-based anonymized survey screened 2500 parents of children with allergic diseases and was conducted in the pediatric outpatient clinics of 24 hospitals. Basic clinical data of the children were collected along with the degree of allergy control, parental anxiety about emergency visits, and the risk of COVID-19 in the first state of emergency. A total of 2439 (97.6%) questionnaires were collected, and 1315 parents who were instructed to initiate home-based OIT for their children were enrolled (OIT group). Subjective OIT progress compared to before the COVID-19 pandemic was ascertained as "Full", "Middle", "Low", "Little", and "Stop" in 264 (20.1%), 408 (31.0%), 384 (29.2%), 203 (15.4%), and 56 (4.3%) participants, respectively. Anxiety about emergency visits and the risk of COVID-19 were negatively associated with the subjective OIT progress. In Japan, approximately half of the children continued smoothly the home-based OIT during the COVID-19 pandemic. Parents with high levels of anxiety about the disruption of the medical care system due to COVID-19 and the risk of COVID-19 did not experience a smooth continuation of home-based OIT.

Differential activation of eosinophils by 'probiotic' Bifidobacterium bifidum and 'pathogenic' Clostridium difficile.

BACKGROUND: Recent studies suggest that probiotics alleviate pathophysiological processes of allergic diseases and inflammatory bowel diseases, whereas 'non-probiotic' microflora has negative effects. However, the underlying mechanisms are not well known, especially in relation to eosinophils, the major effector cells of these inflammatory diseases. OBJECTIVE: To investigate the effects of probiotic Bifidobacterium bifidum (BB) on human eosinophil functions compared with pathogenic Clostridium difficile (CD). METHODS: Peripheral human eosinophils were cultured with heat-killed BB or CD. FISH-labeled CD and BB were incubated with eosinophils visualized by confocal laser scanning microscopy. Superoxide generation and degranulation of eosinophils were measured with the cytochrome c reduction method and the eosinophil-derived neurotoxin (EDN) release assay, respectively. RESULTS: Confocal microscopy revealed that Cy3-labeled CD and BB were apparently ingested by eosinophils. Both bacteria induced minimal superoxide generation. However, CD elicited significantly higher EDN release than BB. GM-CSF significantly enhanced EDN release by CD but not by BB. Bacterial-induced EDN release was calcium dependent. CONCLUSION: The beneficial effect of probiotic BB might be explained, at least in part, by its ability to decrease EDN release from eosinophils compared with 'pathogenic' CD.

Serum measurement of thymus and activation-regulated chemokine/CCL17 in children with atopic dermatitis: elevated normal levels in infancy and age-specific analysis in atopic dermatitis.

Elevated blood levels of thymus and activation-regulated chemokine (TARC)/CCL17 have been observed in atopic dermatitis (AD) and may serve as a new biomarker for AD. However, the normal levels, especially in children, have not been well determined. We sought to establish an efficient enzyme-linked immunosorbent assay (ELISA) with a wide range of detection that would be suitable for measurement of serum TARC/CCL17 and to determine the normal ranges of this chemokine in different age groups and its diagnostic usefulness for AD. A sensitive specific ELISA for TARC/CCL17, which we previously reported, was modified to accommodate the wide range of TARC/CCL17 values often found in sera. Twenty-seven children with AD under 6 yr of age and 25 age-matched normal non-atopic controls, and 18 patients with AD and 27 controls who were 6 yr and older were enrolled. The severity of AD was evaluated using the SCORAD index. The serum levels of TARC/CCL17 were measured with the ELISA, and the serum levels of IP-10/CXCL10 were also measured. With the novel ELISA system, the assayable range of TARC/CCL17 was 14-8000 pg/ml, and the coefficient of variation at various concentrations ranged from 2.3% to 5.0%. The serum levels of TARC/CCL17 in normal individuals were significantly higher in young children, especially in the age group of 0-1 yr. The cut-off values of TARC/CCL17 for the diagnosis of AD were 1431 pg/ml for 0-1 yr group, 803 pg/ml for 2-5 yr group and 510 pg/ml for the 6 yr and older group, with high sensitivity and specificity of 0.83 and 0.93, 0.83 and 0.92, 0.85 and 0.96, respectively. The magnitude of the decrease in the SCORAD index after treatment with topical steroids correlated significantly with the decrease in serum TARC/CCL17. There was no difference in the serum levels of IP-10/CXCL10 between AD and the controls. The TARC/CCL17:IP-10/CXCL10 ratio tended to be higher in the control children aged 0-1 yr than in those aged 2-5 yr. The serum level of TARC/CCL17 reflects the severity and therapeutic response in AD. The high normal levels in infants should be taken into account when assaying TARC/CCL17.

Antigen-induced expression of CD203c on basophils predicts IgE-mediated wheat allergy.

BACKGROUND: For in vitro diagnosis of wheat allergy, specific IgE to wheat is known to be a poor predictive marker. Oral food challenge, the gold standard for the diagnosis, is accompanied by a risk of severe induced reactions. Reliable in vitro tests are needed to be developed for safe indication for oral challenge. OBJECTIVE: We examined the utility of a basophil activation marker, CD203c, for the diagnosis of IgE-mediated wheat allergy. METHODS: Fifty-eight children with suspected wheat allergy with positive CAP-FEIA to wheat were enrolled. On 70 occasions, the clinical distinction between patients with wheat allergy (WA) and patients tolerant to wheat (TW) was made by means of an oral food challenge test or recent history of immediate allergic reactions or tolerance after ingestion of wheat. Twelve replicate evaluations were performed in 9 patients over more than a 6-month interval. Thirty two patients on 43 occasions were diagnosed with WA and 27 were confirmed to be TW. One patient had both diagnoses 18 months apart. Peripheral blood was incubated with fractionated wheat extracts, purified native omega-5 gliadin (nOG5) and recombinant omega-5 gliadin (rOG5). Expression of CD203c on basophils was then analyzed by flow cytometry using a commercial kit. RESULTS: All wheat proteins induced concentration-dependent enhancement of CD203c expression in WA, but did not in TW. The analysis of receiver operating characteristics (ROC) showed that nOG5-induced CD203c(high)% values provided the best power for discriminating between WA and TW, with a sensitivity of 85.0% and specificity of 77.0% at the cut-off level of 14.4%. AUC for CD203c with nOG5 were significantly higher than that for conventional CAP-FEIA, 0.89 and 0.73, respectively (p < 0.01). CONCLUSIONS: Measurement of nOG-induced enhancement of CD203c on basophils is useful for the diagnosis of immediate wheat allergy in children.

Biomarkers for allergen immunotherapy in cedar pollinosis.

To initiate, monitor, and complete effective immunotherapy, biomarkers to predict and visualize the immune responses are needed. First, we need to identify the right candidate for immunotherapy. Secondly, the immune responses induced by immunotherapy should be monitored. For the first objective, analysis of polymorphisms of candidate genes may be helpful, but still be in development. Regarding biomarkers for immune responsese, there are numerous reports that evaluate immunotherapy-induced immune changes such as suppression of effector cells, deviation to Th1 cytokine production, and induction of regulatory T cells. No standardized methods, however, have been established. Among them, a functional assay of blocking IgG activity, the IgE-facilitated allergen binding assay, may be useful. We quantitated induced expression of an activation marker, CD203c, on basophils and found that the assay efficiently predicts sensitivity to particular allergen and severity of the allergen-induced symptoms. In patients who received rush immunotherapy for Japanese cedar pollinosis, reduction in CD203c expression after the therapy was observed, suggesting the utility of the test for monitoring immunotherapy.

[Factors related to recurrent wheezing after hospitalization with RSV infection with the children who were aged three years old or younger: a questionnaire survey].

Respiratory syncytial virus (RSV) infections in infancy have been related to the subsequent recurrent wheezing and asthma. However, there are a few reports about the relationship between RSV infection and subsequent wheezing in Japan. We sought to determine the contributing factors for wheezing illness after RSV infection in 99 Japanese patients with RSV-associated hospitalizations by questionnaire and follow up survey. Fifty eight patients, who were aged three years old or younger on admission and could be followed up more than one year, were analyzed. The mean duration from discharge to last survey were 703.6+/-105.5 days (432-950 days), the mean age on admission were 9.4+/-8.8 months (0-30 months). Wheezing episodes after discharge were reported in 29 of the subjects (50.0%). Univariable and multivariable analysis identified that the subsequent wheezing after RSV infection were related with the history of wheezing before admission and attending a daycare. The patient's age on admission, the patient's atopic profile, history of continuous nocturnal cough before admission, gestational ages, birth weight, length of hospital stay, perinatal abnormality, environmental tobacco smoke, parental history of allergy and asthma, presence of sibling and sibling history of allergy and asthma were not associated with subsequent wheezing. These results suggest that some host factors susceptible to wheezing and chance of infection due to attending a daycare may be related to recurrent wheezing possibly onset of bronchial asthma, after RSV infection.

Neutrophil Proteases Activate Eosinophil Function in vitro.

BACKGROUND: Recent evidence suggests that both neutrophilic and eosinophilic inflammation persist in the airways of patients with severe asthma. Mechanisms for interaction between neutrophils and eosinophils are still to be understood. Since eosinophils express protease-activated receptor 2, neutrophil-derived serine proteases may activate eosinophils. OBJECTIVE: We investigated the effect of neutrophil serine proteases on eosinophil effector functions. METHODS: Peripheral blood eosinophils were stimulated with elastase, cathepsin G and proteinase 3. Superoxide generation was quantitated with the cytochrome C reduction method. A panel of cytokines and chemokines in the culture supernatants were measured with a multiplex beads array system. Effects of an elastase inhibitor, sivelestat, and a serine protease inhibitor, PMSF, on the protease-induced reactions were also tested. RESULTS: Neutrophil proteases significantly induced superoxide production from eosinophils. Elastase was the most potent among them. Sivelestat and PMSF inhibited the reaction. The proteases induced production of IL-6, IL-8, TNF-alpha and GRO-alpha, that have a possible connection with neutrophilic inflammation. CONCLUSION: Neutrophil proteases activate eosinophils to produce superoxide, proinflammatory cytokines and neutrophilotactic chemokines and may further aggravate airway inflammation in patients with severe asthma.

Allergen-induced basophil CD203c expression as a biomarker for rush immunotherapy in patients with Japanese cedar pollinosis.

BACKGROUND: Rush immunotherapy (RIT) can confer rapid clinical benefit on patients with allergic rhinitis or asthma. However, biomarkers representing mechanisms for the efficacy of RIT are still to be established. CD203c is a basophil activation marker known to be upregulated by cross-linking of the FcepsilonRIalpha receptor and may serve as a useful marker. OBJECTIVE: We sought to investigate the changes in allergen-induced CD203c expression in patients with Japanese cedar pollen (JCP) pollinosis who received RIT. METHODS: Nine patients treated with RIT were enrolled in the study. Whole blood was incubated with various concentrations of JCP extract. CD203c expression on basophils was quantitated by means of flow cytometry. JCP-specific IgG4 levels in sera were measured with ELISA. Basophil histamine release, CAP-RAST to JCP (JCP-IgE) and total IgE were also examined. The biomarkers listed above were evaluated before and sequentially after RIT. Symptom and quality of life scores were obtained during pre- and posttreatment pollen seasons. RESULTS: All patients showed significant improvement in symptom and quality of life scores after RIT. Serum JCP-specific IgG4 titers were significantly elevated at 1 month and remained at high levels 12 months after the treatment. Stimulation with JCP extract induced enhancement of basophil CD203c expression in a concentration-dependent manner except for 2 subjects in whom no increase in CD203c by an anti-IgE antibody was observed (nonresponders). Significant reductions in the responses were observed in 4 subjects after RIT (reduction in CD203c expression, RCE) whereas no changes were seen in 3 subjects (non-RCE). RCE subjects were older than non-RCE counterparts, with mean ages of 20 and 12 years, respectively. No significant changes in JCP-specific IgE and total IgE levels were seen before and after RIT. CONCLUSION: Allergen-induced CD203c expression in basophils may represent, at least in part, the cellular mechanism for the therapeutic responses to RIT for JCP pollinosis. However, further larger-scale studies to confirm the utility of the test are necessary.

Blocking antibody is generated in allergic rhinitis patients during specific immunotherapy using standardized Japanese cedar pollen extract.

BACKGROUND: Japanese cedar pollen is by far the most important cause of allergic rhinitis in Japan. In this study, we assessed the induction of blocking antibody during specific immunotherapy (SIT) using a recently standardized allergen extract from Japanese cedar pollen. METHODS: Basophils from nonallergic subjects were passively sensitized with serum samples prepared from pollinosis patients before and after SIT; all patients showed good clinical efficacy. The cells were then stimulated with the standardized allergen, and histamine release was measured. In most experiments, the basophil stimulation buffer contained 1% serum. RESULTS: Pollinosis patients' sera obtained both before and after SIT showed essentially similar sensitizing capacity for basophils. Basophil degranulation in response to a relatively low concentration of pollen extract was effectively suppressed by addition of post-SIT serum samples, indicating the presence of blocking antibody. The blocking antibody was IgG, and its potency varied widely among the donor patients. CONCLUSIONS: The standardized allergen extract from Japanese cedar pollen is useful not only for clinical application in SIT, but also for testing for induction of blocking antibody during SIT.