Efficacy of sequential fecal-marker examination for evaluating gastrointestinal inflammation in solid food protein-induced enterocolitis syndrome.

BACKGROUND: Food protein-induced enterocolitis syndrome caused by solid foods (Solid-FPIES) is a non-immunoglobulin E-mediated allergic disease characterized by delayed gastrointestinal symptoms. An oral food challenge (OFC) test, although necessary, can be inconclusive in cases with mild symptoms. Moreover, limited diagnostic marker availability highlights the need for novel surrogate markers. We aimed to examine the efficacy of fecal hemoglobin (FHb), lactoferrin (FLf), and calprotectin (FCp) over time in evaluating gastrointestinal inflammation degree in Solid-FPIES. METHODS: This observational study included 40 patients and 42 episodes at Juntendo University Hospital and affiliated hospitals between October 2020 and March 2024 categorized into FPIES (12 patients with 11 egg yolk, 1 fish, and 1 soybean episodes), control (14 patients with 15 episodes), and remission (14 patients). Fecal tests were performed for 7 days following antigen exposure. The ratios of each value were divided by the baseline value and analyzed over time course. RESULTS: The FPIES group had significantly higher peak ratios of all fecal markers than the control group (p < 0.01). The median FHb, FLf, and FCp ratios were 3.25, 9.09, and 9.79 in the FPIES group and 1.08, 1.29, and 1.49 in the control group, respectively. In the remission group, several patients had fluctuating fecal markers despite negative OFC, and one patient was diagnosed with FPIES by OFC with increased load. Receiver operating characteristic curve analyses revealed high diagnostic performance for each fecal marker in FPIES. CONCLUSIONS: Sequential fecal marker examination proved valuable in diagnosing Solid-FPIES and evaluating the degree of gastrointestinal inflammation.

A retrospective study of SARS-CoV-2 antibodies in children with allergies.

BACKGROUND: The dynamics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in children are continually changing. We conducted a survey of pediatric allergy patients attending our department to determine the prevalence of antibodies against SARS-CoV-2 in children. METHODS: A retrospective study was performed among children aged <11 years, referred to a pediatric allergy department between February 2020 and January 2022 with a chief complaint of allergy. The data of children with blood examination findings were retrospectively studied. Qualitative testing for anti-SARS-CoV-2 IgG and IgM antibodies was performed using a SARS-CoV-2 rapid antibody test. Participants were retested 1 year later to evaluate changes in antibody levels. RESULTS: In total, 310 patients with a median age of 26 months (interquartile range: 11.6-58.4 months) and male/female ratio of 1.31 were included. A total of 32 patients tested positive for anti-SARS-CoV-2 IgG or IgM antibodies. No differences were observed in the severity of allergic disease. The prevalence of antibodies was higher among children enrolled in preschool or school (odds ratio: 13.19, 95% confidence interval; 2.30-249.7). A total of 66.7% of patients underwent follow-up testing. The antibody positivity rate increased between the first and second testing, but this was not related to the number of medical visits or the severity of allergic disease. CONCLUSION: Antibody prevalence in children was low but increased during the study period. The majority of children who tested positive for SARS-CoV-2 antibodies did not have a history of coronavirus disease 2019, suggesting that most infections were subclinical.

Murine model identifies tropomyosin as IgE cross-reactive protein between house dust mite and coho salmon that possibly contributes to the development of salmon allergy.

Background: Recently, we have developed a method to identify IgE cross-reactive allergens. However, the mechanism by which IgE cross-reactive allergens cause food allergy is not yet fully understood how. In this study, we aimed to understand the underlying pathogenesis by identifying food allergens that cross-react with house dust mite allergens in a murine model. Material and methods: Allergenic protein microarray analysis was conducted using serum from mice intraperitoneally injected with Dermatophagoides pteronyssinus (Der p) extract plus alum or alum alone as controls. Der p, Dermatophagoides farinae (Der f), coho salmon extract-sensitized and control mice were analyzed. Serum levels of IgE against Der p, Der f, coho salmon extract, protein fractions of coho salmon extract separated by ammonium sulfate precipitation and anion exchange chromatography, and recombinant coho salmon tropomyosin or actin were measured by an enzyme-linked immunosorbent assay. A murine model of cutaneous anaphylaxis or oral allergy syndrome (OAS) was established in Der p extract-sensitized mice stimulated with coho salmon extract, tropomyosin, or actin. Results: Protein microarray analysis showed that coho salmon-derived proteins were highly bound to serum IgE in Der p extract-sensitized mice. Serum IgE from Der p or Der f extract-sensitized mice was bound to coho salmon extract, whereas serum IgE from coho salmon extract-sensitized mice was bound to Der p or Der f extract. Analysis of the murine model showed that cutaneous anaphylaxis and oral allergic reaction were evident in Der p extract-sensitized mice stimulated by coho salmon extract. Serum IgE from Der p or Der f extract-sensitized mice was bound strongly to protein fractions separated by anion exchange chromatography of coho salmon proteins precipitated with 50% ammonium sulfate, which massively contained the approximately 38 kDa protein. We found that serum IgE from Der p extract-sensitized mice was bound to recombinant coho salmon tropomyosin. Der p extract-sensitized mice exhibited cutaneous anaphylaxis in response to coho salmon tropomyosin. Conclusion: Our results showed IgE cross-reactivity of tropomyosin between Dermatophagoides and coho salmon which illustrates salmon allergy following sensitization with the house dust mite Dermatophagoides. Our method for identifying IgE cross-reactive allergens will help understand the underlying mechanisms of food allergies.

Evidence of off-label inhalation therapy on pediatric asthma practice in Japan.

BACKGROUND: In Japan, many asthma inhalers do not have formal approval for use in the pediatric population because of the lack of domestic data. In real-world settings, however, numerous off-label medications are prescribed. Currently, the nature of off-label prescriptions of asthma inhalers on pediatric patients in Japan remains unclear. METHODS: Using public open-source national medical claims data, we investigated the real-world descriptive epidemiology of off-label prescriptions for asthma inhalers for pediatric patients. We obtained the number of off-label prescriptions of formulations for patients aged 0-14 years from anonymously summarized prescription data for a 7-year period starting from April 2014. The actual prescription numbers and their chronology over time were then analyzed. RESULTS: In 2019, 143,439 asthma inhalers were used off label in children and adolescents. Overall, 96.1% were inhaled corticosteroids (ICSs) or long-acting beta stimulants (LABAs), and 3.9% were high-dose ICS. Of ICSs and LABAs, 18.8% were off-label prescriptions. The total number of off-label ICS/LABA prescriptions and their percentage relative to the overall formulations gradually decreased but a notable disparity was observed among inhaler types. CONCLUSIONS: There was a surprisingly large number of off-label prescriptions of asthma inhalers in the pediatric population in Japan. The proper use of ICSs/LABAs and expansion of insurance coverage should be advocated to reduce off-label use.

Staphylococcus aureus δ-toxin present on skin promotes the development of food allergy in a murine model.

Background: Patients with food allergy often suffer from atopic dermatitis, in which Staphylococcus aureus colonization is frequently observed. Staphylococcus aureus δ-toxin activates mast cells and promotes T helper 2 type skin inflammation in the tape-stripped murine skin. However, the physiological effects of δ-toxin present on the steady-state skin remain unknown. We aimed to investigate whether δ-toxin present on the steady-state skin impacts the development of food allergy. Material and methods: The non-tape-stripped skins of wild-type, KitW-sh/W-sh, or ST2-deficient mice were treated with ovalbumin (OVA) with or without δ-toxin before intragastric administration of OVA. The frequency of diarrhea, numbers of jejunum or skin mast cells, and serum levels of OVA-specific IgE were measured. Conventional dendritic cell 2 (cDC2) in skin and lymph nodes (LN) were analyzed. The cytokine levels in the skin tissues or culture supernatants of δ-toxin-stimulated murine keratinocytes were measured. Anti-IL-1α antibody-pretreated mice were analyzed. Results: Stimulation with δ-toxin induced the release of IL-1α, but not IL-33, in murine keratinocytes. Epicutaneous treatment with OVA and δ-toxin induced the local production of IL-1α. This treatment induced the translocation of OVA-loaded cDC2 from skin to draining LN and OVA-specific IgE production, independently of mast cells and ST2. This resulted in OVA-administered food allergic responses. In these models, pretreatment with anti-IL-1α antibody inhibited the cDC2 activation and OVA-specific IgE production, thereby dampening food allergic responses. Conclusion: Even without tape stripping, δ-toxin present on skin enhances epicutaneous sensitization to food allergen in an IL-1α-dependent manner, thereby promoting the development of food allergy.

A Case of Neonate with Split Cord Malformation Presenting with Hypoplasia of the Left Lower Extremity.

The frequency of split cord malformation (SCM) is approximately 1 in 5000 births; however, patients are rarely diagnosed with SCM in the neonatal period. Moreover, there have been no reports of SCM with hypoplasia of the lower extremities at birth. A 3-day-old girl was transferred to our hospital for a thorough examination of hypoplasia of the left lower extremity and lumbosacral abnormalities detected after birth. The spinal magnetic resonance imaging (MRI) revealed a split spinal cord in a single dural tube. Based on the MRI findings, the patient was diagnosed with SCM type II. Following discussions with the parents, pediatricians, neurosurgeons, psychologists, and social workers, we decided to perform untethering to prevent further neurological impairment after achieving a sufficient body weight. The patient was discharged on day 25 of life. Early diagnosis and intervention may improve the neurological prognosis in terms of motor function, bladder and bowel function, and superficial sensation; thus, clinicians should report infrequent findings that may lead to SCM diagnosis. SCM should be differentiated in patients with left-right differences in the appearance of the lower extremity, particularly in those with lumbosacral abnormalities.

Development of mouse model for oral allergy syndrome to identify IgE cross-reactive pollen and food allergens: ragweed pollen cross-reacts with fennel and black pepper.

Oral allergy syndrome (OAS) is an IgE-mediated immediate food allergy that is localized to the oral mucosa. Pollen food allergy syndrome (PFAS), a pollinosis-associated OAS, is caused by cross-reactivity between food and pollen allergens. However, we need to more precisely understand the underlying pathogenesis of OAS/PFAS. In the present study, we developed a method to comprehensively identify cross-reactive allergens by using murine model of OAS and protein microarray technology. We focused on lip angioedema, which is one of the most common symptoms of OAS, and confirmed that mast cells reside in the tissues inside the lower lip of the mice. Interestingly, when the food allergen ovalbumin (OVA) was injected inside the lower lip of mice with high levels of OVA-specific IgE followed by an intravenous injection of the Evans blue dye, we found immediate dye extravasation in the skin of the neck in a mast cell-dependent manner. In addition, the degree of mast cell degranulation in the oral cavity, reflecting the severity of oral allergic responses, can be estimated by measuring the amount of extravasated dye in the skin. Therefore, we used this model of OAS to examine IgE cross-reactive allergens in vivo. Protein microarray analysis showed that serum IgE from mice intraperitoneally sensitized with ragweed pollen, one of the major pollens causing pollinosis, bound highly to protein extracts from several edible plants including black peppercorn and fennel. We confirmed that the levels of black pepper-specific IgE and fennel-specific IgE were significantly higher in the serum from ragweed pollen-sensitized mice than in the serum from non-sensitized control mice. Importantly, analysis of murine model of OAS showed that the injection of black pepper or fennel extract induced apparent oral allergic responses in ragweed pollen-sensitized mice. These results indicate IgE cross-reactivity of ragweed pollen with black pepper and fennel. In conclusion, we developed mouse model of OAS to identify IgE cross-reactive pollen and food allergens, which will help understand the pathogenesis of OAS/PFAS.

A COL4A1 variant in a neonate with multiple intracranial hemorrhages and congenital cataracts.

A 2-day-old neonate presented with seizures, multiple intracranial hemorrhages, and bilateral congenital cataracts. Targeted next-generation sequencing of the collagen type IV alpha 1 chain (COL4A1) gene revealed a heterozygous de novo missense variant (NM_001845.6:c.2291G>A/p.Gly764Asp). This missense variant adds to the compendium of COL4A1 variants and is associated with a COL4A1-related disorder.

Gender disparities in the pediatric allergy-related guidelines in Japan.

BACKGROUND: Inclusion of female authors has been noted as potentially beneficial in the development of medical guidelines. Japanese professional committees representing allergic subspecialties develop practical guidelines with recommendations to caregivers, but these committees may be influenced by their gender composition. The objective of our study was to examine the influence of gender in developing pediatric allergic disease guidelines in Japan from 1999 to 2020. METHODS: We examined the gender parities among the guideline committee members in allergic rhinitis, atopic dermatitis, bronchial asthma, and food allergy guidelines in Japan. We examined the gender composition of the committees, annual trends, and differences in guideline content. RESULTS: The median proportion of women members among the 22 guidelines committees was 6.6% (range: 0%-27.3%). The analysis of the quadrant period did not show a significant increase in the proportion of female members. The food allergy group had a significantly higher proportion of female members than other guidelines (P < 0.01), but the proportion decreased from 25% to 14.3% during the observation period. For the pediatric asthma guidelines, the proportion of female committee members decreased from 5.3% in the 2000 version to 0% in the most recent revision in 2017. CONCLUSIONS: The proportion of women on the committees that develop pediatric guidelines continues to be low and has not improved over the past 20 years.

Notch signaling contributes to the establishment of sustained unresponsiveness to food allergens by oral immunotherapy.

BACKGROUND: Oral immunotherapy (OIT) aims to establish desensitization and sustained unresponsiveness (SU) in patients with food allergy by ingestion of gradually increasing doses of specific food allergens. However, little is known about the mechanisms by which OIT induces SU to specific allergens. OBJECTIVES: We investigated the role of Notch signaling, which controls cell fate decisions in many types of immune cells in the induction of SU by OIT treatment. METHODS: Two types of mouse models, ovalbumin-induced food allergy and OIT, were generated. To elucidate the role of Notch signaling in OIT-induced SU, mice were intraperitoneally injected with the Notch signaling inhibitor N-[(3,5-difluorophenyl)acetyl]-l-alanyl-2-phenylglycine-1,1-dimethylethyl ester during the OIT treatment period. RESULTS: Ovalbumin-sensitized mice were desensitized and also had SU induced by OIT treatment, whereas repeated challenges with ovalbumin caused the development of severe allergic reactions in ovalbumin-sensitized mice. Administration of N-[(3,5-difluorophenyl)acetyl]-l-alanyl-2-phenylglycine-1,1-dimethylethyl ester to mice during the OIT treatment period inhibited the establishment of SU to ovalbumin but did not affect the induction of desensitization. OIT induced a systemic expansion of IL-10-producing CD4+ T cells, including TH2 cells, and myeloid-derived suppressor cells (MDSCs), particularly the monocytic MDSC subpopulation. Inhibition of Notch signaling prevented the OIT-induced expansion of those cells. In vitro cultures of bone marrow cells showed that Notch signaling directly promoted the generation of monocytic MDSCs. In addition, the contribution of MDSCs to OIT-induced SU was confirmed by MDSC depletion with the anti-Gr1 antibody. CONCLUSION: Notch signaling contributes to the establishment of SU induced by OIT through systemic expansion of immunosuppressive cells, such as IL-10-producing CD4+ T cells and MDSCs.

The phytosphingosine-CD300b interaction promotes zymosan-induced, nitric oxide-dependent neutrophil recruitment.

Zymosan is a glucan that is a component of the yeast cell wall. Here, we determined the mechanisms underlying the zymosan-induced accumulation of neutrophils in mice. Loss of the receptor CD300b reduced the number of neutrophils recruited to dorsal air pouches in response to zymosan, but not in response to lipopolysaccharide (LPS), a bacterial membrane component recognized by Toll-like receptor 4 (TLR4). An inhibitor of nitric oxide (NO) synthesis reduced the number of neutrophils in the zymosan-treated air pouches of wild-type mice to an amount comparable to that in CD300b-/- mice. Treatment with clodronate liposomes decreased the number of NO-producing, CD300b+ inflammatory dendritic cells (DCs) in wild-type mice, thus decreasing NO production and neutrophil recruitment. Similarly, CD300b deficiency decreased the NO-dependent recruitment of neutrophils to zymosan-treated joint cavities, thus ameliorating subsequent arthritis. We identified phytosphingosine, a lipid component of zymosan, as a potential ligand of CD300b. Phytosphingosine stimulated NO production in inflammatory DCs and promoted neutrophil recruitment in a CD300b-dependent manner. Together, these results suggest that the phytosphingosine-CD300b interaction promotes zymosan-dependent neutrophil accumulation by inducing NO production by inflammatory DCs and that CD300b may contribute to antifungal immunity.

Leukocyte mono-immunoglobulin-like receptor 8 (LMIR8)/CLM-6 is an FcRγ-coupled receptor selectively expressed in mouse tissue plasmacytoid dendritic cells.

Plasmacytoid dendritic cells (pDCs) produce large amounts of type-I interferon (IFN) in response to viral infection or self nucleic acids. Leukocyte mono-immunoglobulin-like receptor 8 (LMIR8), also called CMRF-35-like molecule-6 (CLM-6), is a putative activating receptor among mouse LMIR/CLM/CD300 members; however, the expression and function of LMIR8 remain unclear. Here, we characterize mouse LMIR8 as a pDC receptor. Analysis of Flag-tagged LMIR8-transduced bone marrow (BM)-derived mast cells demonstrated that LMIR8 can transmit an activating signal by interacting with immunoreceptor tyrosine-based activating motif (ITAM)-containing FcRγ. Flow cytometric analysis using a specific antibody for LMIR8 showed that LMIR8 expression was restricted to mouse pDCs residing in BM, spleen, or lymph node. FcRγ deficiency dampened surface expression of LMIR8 in mouse pDCs. Notably, LMIR8 was detected only in pDCs, irrespective of TLR9 stimulation, suggesting that LMIR8 is a suitable marker for pDCs in mouse tissues; LMIR8 is weakly expressed in Flt3 ligand-induced BM-derived pDCs (BMpDCs). Crosslinking of transduced LMIR8 in BMpDCs with anti-LMIR8 antibody did not induce IFN-α production, but rather suppressed TLR9-mediated production of IFN-α. Taken together, these observations indicate that LMIR8 is an FcRγ-coupled receptor selectively expressed in mouse tissue pDCs, which might suppress pDC activation through the recognition of its ligands.

Screening and analysis of adsorbents for pemphigus autoantibodies.

Pemphigus represents a potentially life-threatening, blistering, chronic autoimmune disease involved with autoantibodies against desmosomal adhesion proteins, desmoglein 1 (Dsg1) and desmoglein 3 (Dsg3). These autoantibodies belong to biased immunoglobulin subclasses, predominantly IgG1 and IgG4. Although plasmapheresis is established for the treatment of pemphigus, specific immunoadsorption of the autoantibodies has not been clinically applied. In order to search for a novel adsorbent for the pemphigus autoantibodies, we screened a library of 26 chemical ligand adsorbents using the effluent of double filtration plasmapheresis obtained from pemphigus patients. As a result of the screening, we found that each adsorbent whose ligand is 2-thiophene ethylamine, tryptophan, para-guanidinophenylalanine, phenylalanine, or thienylglycine adsorb both antibodies to Dsg3 and Dsg1 efficiently, in that order. Furthermore, the thiophene adsorbent exhibited a high affinity for the IgG4 subclass. These results suggest that the thiophene adsorbent may be suitable for pemphigus immunoadsorption. Further in vivo animal studies and clinical trials are needed.

Redox potentials and HPLC behavior of cobalt and iron complexes with pyridylazo compounds.

The redox potentials of cobalt and iron complexes with ten pyridylazo compounds, E(0)(ML2) (ML(2)(+/0); M: Co(III/II), Fe(III/II); L(-): pyridylazo compounds), have been determined in order to explore the difference in their reversed-phase HPLC behavior. The redox potentials of Co complexes were in the range of -0.62 - 0.03 V, while those of Fe complexes were -0.06 - 0.59 V relative to 0.20 V for ferricinium/ferrocene. The redox potentials of both the Co and Fe complexes were linearly correlated to the basicities of the ligands. The correlation was quantitatively explained by a difference in dependence of the stabilities of M(III) and M(II) complexes on the ligand basicities. The complex of [Co(III)L(2)](+) or [Fe(II)L(2)] with any compound injected in the reversed-phase HPLC system was detected without any change in the composition. When [Co(II)L(2)] was injected, only those complexes having the highest potentials of E(0)(CoL2) congruent with 0.0 V were detected as [Co(II)L(2)], while other complexes having lower potentials gave a peak of [Co(III)L(2)](+). When [Fe(III)L(2)](+) was injected, only complexes having the lowest potentials of E(0)(FeL2) congruent with 0.0 V were detected as [Fe(III)L(2)](+), while others having higher potentials gave a peak of [Fe(II)L(2)].

Status of plasmapheresis for the treatment of toxic epidermal necrolysis in Japan.

This study describes the efficacy of plasmapheresis for the treatment of toxic epidermal necrolysis (TEN), as reported in Japan. TEN patients treated with plasmapheresis were collected from Japanese literature. The type of plasmapheresis, number of sessions, efficacy of plasmapheresis, and present outcome were examined. Forty-seven TEN patients treated with plasmapheresis have been reported in the literature: 19 men and 28 women with ages ranging from 1 to 96 years (mean 50.3 years). Twenty-five of these treatments included simple plasma exchange (PE), 13 included double filtration plasmapheresis (DFPP), and one included PE and DFPP. The number of plasmapheresis sessions ranged from 1 to 6 and the mean number of sessions was 3.1. The efficacy of plasmapheresis for the treatment of TEN was as follows: excellent, 30 cases; good, 8 cases; fair, 3 cases; no effect, 5 cases; and unknown, 1 case. The rate of effectiveness was 80.9%; eleven patients died; and the mortality rate was 23.4%. In summary, plasmapheresis, including both PE and DFPP, were found to be effective treatments for Japanese patients with TEN, who had been unresponsive to corticosteroids, and for those who show severe clinical manifestations.

Liquid-liquid extraction and liquid chromatographic studies on interactions of inorganic anions with coordinatively unsaturated copper(II) complexes of heterocyclic azo compounds.

The interactions between Cu(II) complexes with heterocyclic azo compounds and several anions were studied by equilibrium analysis of ion-pair extraction, RP-HPLC of metal complexes, and ion chromatography of anions on an ODS column coated with Cu(II) complexes of the long alkyl derivatives. Both ion-pair extraction and HPLC studies demonstrated that a dicationic complex with 8-(3,5-dibromo-2-pyridylazo)-5-aminoquinoline interacted with anions stronger than a monocationic complex with 2-(2-pyridylazo)methylphenol. Anions were more retained on the column coated with dicationic Cu(II) complex. Such differences were quantitatively ascribed to the first ion-pair formation of the dicationic complex giving a monocationic species.