Transcription factor Zbtb1 interacts with bridging factor Lmo2 and maintains the T-lineage differentiation capacity of lymphoid progenitor cells.

Hematopoietic stem and progenitor cells can differentiate into all types of blood cells. Regulatory mechanisms underlying pluripotency in progenitors, such as the ability of lymphoid progenitor cells to differentiate into T-lineage, remain unclear. We have previously reported that LIM domain only 2 (Lmo2), a bridging factor in large transcriptional complexes, is essential to retain the ability of lymphoid progenitors to differentiate into T-lineage. However, biochemical characterization of Lmo2 protein complexes in physiological hematopoietic progenitors remains obscure. Here, we identified approximately 600 Lmo2-interacting molecules in a lymphoid progenitor cell line by two-step affinity purification with LC-MS/MS analysis. Zinc finger and BTB domain containing 1 (Zbtb1) and CBFA2/RUNX1 partner transcriptional corepressor 3 (Cbfa2t3) were found to be the functionally important binding partners of Lmo2. We determined CRISPR/Cas9-mediated acute disruption of Zbtb1 or Cbfa2t3 in the lymphoid progenitor or bone marrow-derived primary hematopoietic progenitor cells causes significant defects in the initiation of T-cell development when Notch signaling is activated. Our transcriptome analysis of Zbtb1- or Cbfa2t3-deficient lymphoid progenitors revealed that Tcf7 was a common target for both factors. Additionally, ChIP-seq analysis showed that Lmo2, Zbtb1, and Cbfa2t3 cobind to the Tcf7 upstream enhancer region, which is occupied by the Notch intracellular domain/RBPJ transcriptional complex after Notch stimulation, in lymphoid progenitors. Moreover, transduction with Tcf7 restored the defect in the T-lineage potential of Zbtb1-deficient lymphoid progenitors. Thus, in lymphoid progenitors, the Lmo2/Zbtb1/Cbfa2t3 complex directly binds to the Tcf7 locus and maintains responsiveness to the Notch-mediated inductive signaling to facilitate T-lineage differentiation.

Allergic Sensitization Is Crucial for the Suppressive Role of Streptococcus pneumoniae in the Acute Exacerbation of Asthma.

INTRODUCTION: Allergic sensitization is an important factor in the development, severity, and exacerbation of asthma, which is attributed to type 2 (T2) inflammation. Evidence suggests that respiratory bacterial pathogens (e.g., Streptococcus pneumoniae) exert suppressive effects on airway T2 inflammation. To clarify the role of allergic inflammation in bacterial colonization in asthma based on allergic sensitization, we investigated pharyngeal bacterial colonization, biomarkers (e.g., serum eosinophil cationic protein (ECP) and cytokines/chemokines), and symptoms in the acute exacerbation of childhood asthma. METHODS: Pharyngeal samples were collected from 53 children (mean/median age 2.7/2.5 years). Serum levels of total and allergen-specific IgE against aeroallergens, ECP, and 17 cytokines/chemokines were measured. RESULTS: Allergic sensitization was recognized in 62.2% patients. S. pneumoniae, Moraxella catarrhalis, Haemophilus influenzae, and other bacteria were detected in 47.1%, 11.3%, 11.3%, and 30.1% of all patients, respectively. Patients with S. pneumoniae had a significantly shorter duration of wheezing than those without (4.7 ± 3.6 vs. 7.1 ± 3.5 days, p = 0.024). In patients with allergic sensitization, patients with S. pneumoniae had a significantly shorter duration of wheezing than those without (4.0 ± 3.6 vs. 7.7 ± 4.0 days, p = 0.003). Serum total IgE was significantly lower in patients with S. pneumoniae than in those without (81.9 [7.8-894] vs. 287 [4.4-1,840] IU/mL, p = 0.014). Serum ECP was significantly higher (33.1 [2-109] vs. 7.8 [3-35] ng/mL, p = 0.042), and IFN-γ was significantly lower (5.6 [4-10] vs. 16.4 [7-28] pg/mL, p = 0.032) in patients with allergic sensitization than those without. DISCUSSION/CONCLUSION: Our results suggested that the suppressive effects of S. pneumoniae colonization were observed only in patients with allergic sensitization, wherein serum total IgE, ECP, and IFN-γ may have an important role on acute exacerbation of asthma.

Antibiotic Treatments Prolong the Wheezing Period in Acute Exacerbation of Childhood Bronchial Asthma.

INTRODUCTION: Although current guidelines recommend against routine antibiotic prescription for acute exacerbation of bronchial asthma, children with acute exacerbation of asthma receive antibiotic treatment more frequently. In addition, those antibiotics are often prescribed only for exacerbation of asthma without concurrent bacterial infection. OBJECTIVE: To clarify the association between antibiotic treatment and bacterial colonization in acute exacerbation of asthma, we investigated whether or not antibiotics affect the clinical condition, laboratory findings, and pharyngeal bacterial colonization in those patients. METHODS: Potential bacterial pathogens were investigated in pharyngeal samples of 111 children with acute exacerbation of asthma (mean/median age: 2.8/2.6 years old, respectively). We collected clinical data, such as the duration of wheezing and antibiotic use, and measured the peripheral white blood cell counts, C-reactive protein, and serum levels of total and allergen-specific IgE. RESULTS: Antibiotics were used in 50.5% patients with acute asthma exacerbation and included cephalosporin, penicillin, macrolide, and others. Episodes of wheezing were significantly longer in patients with antibiotic treatment than in those without it (6.7 ± 3.6 days vs. 6.0 ± 3.1, p = 0.044). Similarly, episodes of wheezing were significantly longer in moderate exacerbation patients with antibiotics than in those without them. Furthermore, in patients with Streptococcus pneumoniae, antibiotic treatment was associated with an extended duration of wheezing in cases of acute moderate exacerbation (7.0 ± 2.4 days vs. 4.8 ± 4.1, p = 0.043). CONCLUSIONS: These results suggest that antibiotic treatment in acute exacerbation of asthma might lead to longer asthmatic symptoms, specifically in patients with pharyngeal S. pneumoniae colonization.

The Suppressive Role of Streptococcus pneumoniae Colonization in Acute Exacerbations of Childhood Bronchial Asthma.

INTRODUCTION: Little is known about the association between bacterial infections and exacerbations of bronchial asthma. OBJECTIVE: To elucidate the effect of bacterial infections on bronchial asthma, we examined pharyngeal bacterial colonization, duration of wheezing, and serum levels of cytokines and chemokines during acute exacerbations of asthma in children. METHODS: Potential bacterial pathogens were investigated in pharyngeal samples and viruses obtained from nasal secretions of 111 children who were outpatients and/or in patients with acute exacerbations of asthma (mean/median age: 2.8/2.6, respectively). We also measured serum levels of 27 different cytokines/chemokines. RESULTS: Pharyngeal bacterial cultures were positive in 110 of 111 children. The 3 major bacterial pathogens were Streptococcus pneumoniae (29.7%), Moraxella catarrhalis (11.7%), and Haemophilus influenzae (10.8%). M. catarrhalis was detected more frequently in patients with pneumonia. Furthermore, patients with S. pneumoniae colonization had significantly shorter wheezing episodes than those without it. In contrast, the duration of wheezing did not differ significantly among cases with other bacteria such as M. catarrhalis and H. influenzae. Furthermore, the length of wheezing episode in patients with S. pneumoniae colonization showed significant inverse correlation with peripheral white blood cell count, neutrophil count, and C-reactive protein, while there was no significant correlation between duration of wheezing and these 3 parameters among patients with M. catarrhalis or H. influenza. Among the 27 cytokines/chemokines, only serum tumor necrosis factor (TNF)-α was significantly lower in patients with S. pneumoniae colonization than in those without it. CONCLUSIONS: These results suggested that pharyngeal S. pneumoniae colonization plays a suppressive role on the pathophysiology during acute exacerbations of asthma.

Palivizumab prophylaxis in preterm infants and subsequent wheezing/asthma: 10-year follow-up study.

BACKGROUND: Respiratory syncytial virus (RSV) causes not only infantile recurrent wheezing but also the development of asthma. To investigate whether palivizumab, an anti-RSV monoclonal antibody, prophylaxis given to preterm infants during the first RSV season reduces the incidence of subsequent recurrent wheezing and/or development of asthma, at 10 years of age. METHODS: We conducted an observational prospective multicenter (52 registered hospitals in Japan) case-control study in preterm infants with a gestational age between 33 and 35 weeks followed for 6 years. During the 2007-2008 RSV season, the decision to administer palivizumab was made based on standard medical practice (SCELIA study). Here, we followed these subjects until 10 years of age. Parents of study subjects reported the patients' physician's assessment of recurrent wheezing/asthma, using a report card and a novel mobile phone-based reporting system using the internet. The relationship between RSV infection and asthma development, as well as the relationship between other factors and asthma development, were investigated. RESULTS: Of 154 preterm infants enrolled, 113 received palivizumab during the first year of life. At 10 years, although both recurrent wheezing and development of asthma were not significantly different between the treated and untreated groups, maternal smoking with aeroallergen sensitization of the patients was significantly correlated with physician-diagnosed asthma. CONCLUSIONS: In contrast to the prior study results at 6 years, by 10 years palivizumab prophylaxis had no impact on recurrent wheezing or asthma, but there was a significant correlation between maternal passive smoking with aeroallergen sensitization and development of asthma by 10 years of age.

Effect of Post-nasal Drip on Overnight-cough Frequency and Cough Pattern in Children with Asthma.

OBJECTIVE: In children, post-nasal drip (PND)-induced cough is speculated. However, the relationship between PND and cough is still unclear. METHODS: During acute exacerbation of asthma, the number of overnight coughs and the cough pattern were compared in the children with atopic asthma with PND (n = 8) and the children with atopic asthma without PND (n = 27). All subjects had allergic rhinitis according to our original cough monitor. RESULTS: The total number of overnight coughs was significantly higher in the subjects with PND than in the subjects without PND (P < 0.05). In contrast, the overnight cough pattern of the subjects with PDN was found to be the same as in the subjects without PND, showing an increase in the number of coughs at the sleep onset and in the early morning. CONCLUSION: Our results suggest that PND may increase the number of nighttime coughs in children with atopic asthma and allergic rhinitis. In contrast, the overnight cough pattern was the same in the two groups, suggesting that this specific cough pattern is due to allergic inflammation of the upper and lower airways.

Anti-cyclic Citrullinated Peptide Antibody-positive Girl with Chronic Polyarthritis Later Diagnosed with Juvenile Systemic Lupus Erythematosus: A Case Report.

BACKGROUND: Arthritis is one of the earliest symptoms of juvenile systemic lupus erythematosus (SLE) but is unusual in cases presenting with chronic arthritis or deforming/erosive arthritis. Overlap of juvenile idiopathic arthritis (JIA) and juvenile SLE is a rare clinical condition known as "rhupus" syndrome. The clinical and serological characteristics of rhupus syndrome in children remain to be established. In addition, no studies regarding anti-cyclic citrullinated peptide (CCP) antibody in juvenile SLE or juvenile rhupus syndrome have been reported. CASE REPORT: A 12-year-old girl suffered from polyarthralgia lasting for one week. She was tentatively diagnosed with polyarticular JIA because of her symptom of chronic arthritis and a positive result for anti-CCP antibody. After six months of follow-up for JIA, she presented with a fever, malar rash, and worsening of arthralgia. Laboratory examinations revealed hypocomplementemia and a positive result for anti-double-stranded DNA antibody. She was diagnosed with juvenile SLE. CONCLUSIONS: It is important to note that patients with chronic arthritis, as well as those with anti-CCP antibody-positive polyarthritis, should be carefully followed for their clinical and serological condition, considering the possibility of them developing juvenile SLE.

A Boy Presenting with a Fever and Pancytopenia Diagnosed with Systemic Lupus Erythematosus without a Positive Anti-ds-DNA Antibody Result or Hypocomplementemia: A Case Report.

BACKGROUND: Hematological involvement, including anemia, leukopenia, lymphopenia, and thrombocytopenia, is one of the most common manifestations of childhood-onset systemic lupus erythematosus (cSLE). Specifically, relatively severe forms of hematological involvement, such as macrophage activation syndrome (MAS) and thrombotic microangiopathy, occur in the course of the disease. Positivity for anti-double stranded-DNA (ds-DNA) antibody and hypocomplementemia are important as not only criteria of diagnosing cSLE but also in the determination of the disease activity. CASE REPORT: A 13-year-old boy without pre-existing disease was referred to our hospital chiefly complaining of a fever for > 7 days, long-lasting malaise, nausea, and non-malar face rash. His blood examination showed pancytopenia and hyperferritinemia, but positive results for anti-ds-DNA antibody and hypocomplementemia were not recognized. Bone marrow aspiration revealed no evidence of malignant diseases, hemophagocytic lymphohistiocytosis, or MAS. A renal biopsy for the differential diagnosis of proteinuria and hematuria revealed class IIIa +V lupus nephritis, leading to the diagnosis of cSLE. CONCLUSIONS: It is important for cSLE to be considered in patients with pancytopenia, even those without positive anti-ds-DNA antibody findings or hypocomplementemia, and for aggressive approaches to be adopted for the differential diagnosis, including a renal biopsy.

A Family Case of COVID-19 Pneumonia with Different Chest CT Features and Duration of SARS-CoV-2 Shedding: a Case Report from Japan.

Coronavirus disease 2019 (COVID-19) pneumonia in children characteristically has a milder clinical presentation, with milder inflammatory biomarkers and radiological findings. Accumulating evidence indicates a difference in chest computed tomography (CT) features and the duration of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) shedding between children and adults. Here, we report a family case of COVID-19 pneumonia in which 2 brothers (aged 14 years and 2 years) had different findings. On admission, the 2-year-old brother had few symptoms with no signs of pneumonia, whereas the older brother had presented with pneumonia on admission. Both were positive for SARS-CoV-2 infection on polymerase chain reaction and showed obvious characteristic signs of COVID-19 pneumonia on chest CT. However, CT findings in the younger brother were nonspecific and similar to those of other pneumonias. The older brother required longer treatment because of the longer shedding period of SARS-CoV-2 detected in nasopharyngeal samples. Both boys were discharged without complications. This family case suggests that the clinical features of COVID-19 pneumonia might differ between younger and older children.

Differences in Virus Detection and Cytokine Profiles between First Wheeze and Childhood Asthma.

OBJECTIVE: To distinguish between first wheeze and asthma in early childhood, we investigated respiratory viruses and cytokine/chemokine profiles among patients with first wheeze and established asthma. METHODS: We enrolled children with acute exacerbations of wheezing (17 first wheeze and 32 asthma) and 11 controls (no wheezing) aged between 10 months and 6 years. Nasal aspirates were obtained, and virus detection was performed with antigenic assay kits and/or RT-PCR. Serum 27 cytokines/chemokines were assayed by a multi-cytokine detection system. RESULTS: Rhinovirus and respiratory syncytial (RS) virus were dominant in acute exacerbations of asthma. However, many types of viruses were isolated in first wheeze. Serum IL-8 and IL-12 values were significantly higher in first wheeze than in acute asthma or the controls. IL-5 and IP-10 levels in acute asthma and first wheeze cases were higher than in the controls. Both of them were significantly higher in cases of acute asthma than in convalescence stage of asthma cases. Only IP-10 was significantly higher in first wheeze than in convalescence stage of first wheeze cases. CONCLUSIONS: Different profiles in virus detection and production of IL-8 and IL-12 might distinguish between first wheeze and childhood asthma.

Sweet Potato Was Not So Sweet: Undetected Foreign-body Aspiration in a Healthy Child Leading to Acute Bronchial Asthma.

INTRODUCTION: Sweet potato may contain furanoterpenoids, including ipomeamarone, which cause lung edema. CASE PRESENTATION: A 10-year-old schoolgirl was hospitalized with asthma exacerbation and acute pneumonia. Chest radiographs showed a diffuse opacity of the left lung and hyperpermeability of the right lung. Computed tomography indicated foreign-body aspiration. Flexible bronchoscopy revealed an inhaled piece of sweet potato obstructing the left main bronchus. Although the patient's dyspnea worsened after removal of the sweet potato, she recovered with the treatment based on the 2014 Japanese Childhood Asthma Guidelines. CONCLUSION: Cases of sweet potato aspiration need careful treatment after removal of the foreign body.