Yoshinori Morita

Intrauterine sensitization of allergen-specific IgE analyzed by a highly sensitive new allergen microarray

BACKGROUND To design a rational allergy prevention program, it is important to determine whether allergic sensitization starts in utero under the maternal immune system. OBJECTIVE To investigate the origin of allergen-specific IgE antibodies in cord blood (CB) and maternofetal transfer of immunoglobulins. METHODS The levels of food and inhalant allergen-specific IgE, IgA, IgG, and IgG(4) antibodies in CB and maternal blood (MB) from 92 paired neonates and mothers were measured by using a novel allergen microarray of diamond-like-carbon-coated chip, with high-sensitivity detection of allergen-specific antibodies and allergen profiles. RESULTS The levels of allergen-specific IgE antibodies against food and inhalant allergens and allergen profiles were identical in CB and newborn blood, but the levels and profiles, specifically against inhalant allergens, were different from those in MB. The level of allergen-specific IgA antibodies was below the detection levels in CB despite clear detection in MB. Therefore, contamination with MB in CB was excluded on the basis of extremely low levels of IgA antibodies in CB and the obvious mismatch of the allergen-specific IgE and IgA profiles between CB and MB. However, the levels of allergen-specific IgG and IgG(4) antibodies and their allergen profiles were almost identical in both MB and CB. CONCLUSION Allergen-specific levels of IgE and IgA antibodies and their allergen profiles analyzed by the diamond-like-carbon allergen chip indicate that IgE antibodies in CB are of fetal origin. Food-allergen specific IgE antibodies were detected more often than inhalant-allergen specific IgE antibodies in CB, the reason of which remains unclarified.

Prebiotic consumption in pregnant and lactating women increases IL-27 expression in human milk.

The consumption of probiotics by pregnant and lactating women may prevent the onset of allergic disorders in their children by increasing the concentrations of immunoactive agents such as cytokines in breast milk. Prebiotics such as fructo-oligosaccharides (FOS) increase the number of beneficial organisms such as bifidobacteria. Thus, prebiotics may have an effect similar to that of probiotics. The objective of the present study was to carry out a comprehensive analysis of mRNA expression in human milk cells to identify changes in the concentrations of cytokines in breast milk after the consumption of FOS (4 g × 2 times/d) by pregnant and lactating women. The microarray analysis of human milk cells demonstrated that the expression levels of five genes in colostrum samples and fourteen genes in 1-month breast milk samples differed more than 3-fold between the FOS and control groups (sucrose group). The mRNA expression level of IL-27, a cytokine associated with immunoregulatory function, was significantly higher in 1-month breast milk samples obtained from the FOS group than in those obtained from the control group. In addition, the protein concentrations of IL-27 in colostrum and 1-month breast milk samples were significantly higher in the FOS group than in the control group. In conclusion, the consumption of FOS by pregnant and lactating women increases the production of IL-27 in breast milk. Future studies will address the association of this phenomenon with the onset of allergic disorders in children.

Cytokine biomarker candidates in breast milk associated with the development of atopic dermatitis in 6-month-old infants.

Background: A few studies have reported that the quantity of selected cytokines/chemokines in breast milk might be associated with atopic dermatitis (AD). Using the multiplex cytokine assay system, we examined cytokines/chemokines in human milk in order to identify new biomarkers related to AD. Methods: We recruited 49 infants with or without AD who participated in a birth cohort and measured the concentrations of cytokines/chemokines in the colostrum (collected within 4–5 days after birth) and mature milk (collected at 1 month postpartum) received by the infants. Results: There were significant differences in the concentrations of interleukin (IL)-1β and IL-12p40 in the colostrum, and in those of IL-4, eotaxin, granulocyte colony-stimulating factor (G-CSF), granulocyte macrophage colony-stimulating factor (GM-CSF), interferon (IFN)-α2 and MIP-1α in the mature milk between the milk received by infants who developed AD at the age of 6 months and that received by the control infants. There was weak to moderate correlation between those 6 cytokines/chemokines in mature milk. Atopic history and IgE levels of mothers were not related to cytokine/chemokine concentrations in breast milk. Logistic regression analyses showed that high levels of eotaxin in the mature milk were a risk for the development of AD at 6 months of age. Conclusion: These results suggest that several cytokines/chemokines, especially eotaxin, are potential biomarkers for development of AD in early infancy.

Functional variants in the thromboxane A2 receptor gene are associated with lung function in childhood‐onset asthma

The thromboxane A2 receptor (TBXA2R) gene is associated with asthma, but no functional genetic variations are known to associate with the disease or its related phenotypes.

Induction of the Matrix Metalloproteinase 13 Gene in Bronchial Epithelial Cells by Interferon and Identification of its Novel Functional Polymorphism.

Matrix metalloproteinases (MMPs) are a class of extra-cellular and membrane-bound proteases involved in a wide array of physiological and pathological processes including tissue remodeling, inflammation, and cytokine secretion and activation. MMP-13 has been shown to be involved in lung diseases such as acute lung injury, viral infections, and chronic obstructive pulmonary disease; however, the molecular pathogenesis of MMP-13 in these conditions is not well understood. In this study, we investigated the mechanisms and roles of MMP-13 secretion in human small airway epithelial cells (SAECs) and functional polymorphisms of the MMP13 gene. Polyinosinic–polycytidylic acid (poly(I:C)) and interferon β (IFN-β) stimulated the secretion of MMP-13 from SAECs by more than several hundred-fold. Stimulation of the secretion by poly(I:C) was abolished by SB304680 (p38 inhibitor), LY294002 (PI3K inhibitor), Janus kinase (JAK) inhibitor I, RNA-activated protein kinase (PKR) inhibitor, and Bay 11-7082 (NF-κB inhibitor), while stimulation by IFN-β was inhibited by all except Bay 11-7082. These data suggested that the secretion of MMP-13 was mediated through IFN receptor pathways independently of nuclear factor kappa B (NF-κB) and that poly(I:C) stimulated IFN secretion in an NF-κB-dependent manner from SAECs, leading to IFN-stimulated MMP-13 secretion. Chemical MMP-13 inhibitors and MMP-13 small interfering RNA (siRNA) inhibited IFN-stimulated secretion of interferon gamma-inducible protein 10 (IP-10) and regulated on activation, normal T-cell expressed and secreted (RANTES), suggesting that MMP-13 is involved in the secretion of these virus-induced proinflammatory chemokines. We identified a novel functional polymorphism in the promoter region of the MMP13 gene. The MMP13 gene may play important roles in defense mechanisms of airway epithelial cells.

A case of infantile Takayasu arteritis with a p.D382E NOD2 mutation: an unusual phenotype of Blau syndrome/early-onset sarcoidosis?

Blau syndrome/early-onset sarcoidosis (Blau/EOS) is an autoinflammatory disease characterized by granulomatous arthritis, uveitis, and skin rash. It has been shown that gain-of-function NOD2 mutations cause Blau/EOS. In this paper, we describe a patient with a gain-of-function NOD2 mutation who developed infantile Takayasu arteritis, which is rare in Blau/EOS, but who has not yet had significant granulomatous changes in joints, eyes, or skin. We suspect that this case is an unusual phenotype of Blau/EOS.

Maternal Prebiotic Ingestion Increased the Number of Fecal Bifidobacteria in Pregnant Women but Not in Their Neonates Aged One Month

Fructooligosaccharides (FOS) can selectively stimulate the growth of bifidobacteria. Here, we investigated the effect of maternal FOS ingestion on maternal and neonatal gut bifidobacteria. In a randomized, double-blind, placebo-controlled study, we administered 8 g/day of FOS or sucrose to 84 women from the 26th week of gestation to one month after delivery. The bifidobacteria count was detected using quantitative PCR in maternal (26 and 36 weeks of gestation) and neonatal (one month after delivery) stools. Maternal stool frequency was recorded from 24 to 36 weeks of gestation. The number of fecal Bifidobacterium spp. and Bifidobacterium longum in the FOS group was significantly higher than that in the placebo group at 36 weeks of gestation (2.7 × 1010/g vs. 1.1 × 1010/g and 2.3 × 1010/g vs. 9.7 × 109/g). In their neonates, these numbers did not differ between the groups. Also, stool frequency in the FOS group was slightly higher than that in the placebo group two weeks after the intervention (1.0 vs. 0.8 times/day), suggesting a potential constipation alleviation effect. In conclusion, the maternal FOS ingestion showed a bifidogenic effect in pregnant women but not in their neonates.

An immunocompetent child with chromosomally integrated human herpesvirus 6B accidentally identified during the care of Mycoplasma pneumoniae infection

Human herpesvirus 6 (HHV-6) is the only virus known to integrate into human chromosomes and be transmitted from parents to offspring. Less than 1% of the population carries integrated HHV-6 in their genomes. Here, we report the case of a 9-year-old Japanese girl with an extraordinarily high copy number of HHV-6B in her genome. The integrated virus genome was detected by real-time polymerase chain reaction (PCR) in cerebrospinal fluid and serum during the treatment of meningoencephalitis and pneumonia caused by Mycoplasma pneumoniae infection. Furthermore, the HHV-6B genome was detected in hair follicle, plasma, and whole blood in the patient and her mother, but not in the patients father. Fluorescence in situ hybridization revealed that the viral genome was integrated into chromosome 22. Therefore, these results emphasize the importance of screening for chromosomally integrated HHV-6 prior to starting unnecessary antiviral therapies, particularly for patients harboring HHV-6 with a high copy number.

Association Study of Matrix Metalloproteinase-12 Gene Polymorphisms and Asthma in a Japanese Population

Background: Matrix metalloproteinase 12 gene (MMP12) has been shown to be associated with asthma in a Caucasian population. In this study, we investigate whether single-nucleotide polymorphisms (SNPs) of MMP12 are associated with a risk for asthma in a Japanese population. Methods: We tested for an association between SNPs in MMP12 and asthma, including its severity, in a Japanese population (630 pediatric and 417 adult patients with atopic asthma and 336 children and 632 adults as controls). The rs652438 A and G variants (N357S) were generated by site-directed mutagenesis and an assay with artificial peptide substrates was used to compare two types of MMP12 activity. The effect of MMP12 inhibition with MMP12-specific small interfering RNA (siRNA) on chemokine secretion from airway epithelial cells was also tested in vitro. Results: N357S showed a p value <0.05 for childhood and combined (adult plus childhood) asthma in the dominant model [odds ratio (OR) 1.60, 95% confidence interval (CI) 1.00–2.56, p = 0.047; OR 1.40, 95% CI 1.04–1.89, p = 0.028, respectively]. This risk variant is associated with asthma severity in adult patients. In the functional assay, the minor-allele enzyme showed significantly lower activity than the major-allele enzyme. MMP12-specific siRNA suppressed IP-10 secretion from airway epithelial cells upon stimulation with IFN-β. Conclusions: Our results suggest that MMP12 confers susceptibility to asthma and is associated with asthma severity in a Japanese population. MMP12 may be associated with asthma through inappropriate attraction of leukocytes to the inflamed tissue.

Milk allergy in the neonatal intensive care unit: comparison between premature and full-term neonates

Background There have been several reports on neonates with milk allergy in a neonatal ward. This type of allergy is mostly categorized as a non-IgE-mediated food allergy. Although most cases of milk allergy occur in the first few months of life, the differences in clinical characteristics between premature and full-term neonates are still unclear. Objective This study aimed to clarify the differences in clinical characteristics of milk allergy between premature and full-term neonates. Methods We retrospectively evaluated 2,116 neonates admitted to the Department of Neonatology, Chiba Kaihin Municipal Hospital, between 2001 and 2007. Results We identified 24 neonates strongly suspected of having milk allergy because of symptoms, such as bloody stools, repeated vomiting, diminished sucking and abdominal distension, as well as objective laboratory findings of eosinophilia in stool cytology and/or positive results for a rectal milk challenge test. Twelve of these 24 neonates were premature (median gestational age, 31 ± 3 weeks; median birth weight, 1,656 ± 592 g) and the other 12 were full-term (median gestational age, 38 ± 1 weeks; median birth weight, 2,760 ± 560 g). There were no differences in symptoms and time to start of feeding between premature and full-term neonates, but there was a significant difference in the median postnatal age at onset (premature neonates: 23 days; vs. full-term neonates: 3.5 days; p < 0.01). Conclusion All premature neonates developed a milk allergy after 32 weeks of corrected gestational age, suggesting that the development of milk allergy requires a certain degree of immunological maturation.