Evidence-based management guidelines for noncystic fibrosis bronchiectasis in children and adolescents

Noncystic fibrosis bronchiectasis is a chronic respiratory disease that carries high socioeconomic and medical burdens and is caused by diverse respiratory illnesses. To improve clinical outcomes, early recognition, active treatment of exacerbations, and prevention of further exacerbations are essential. However, evidence for the treatment and prevention of acute exacerbation of noncystic fibrosis bronchiectasis, especially in children, is lacking. Therefore, the evidence- and consensus-based guidelines for medical and nonmedical treatment strategies for noncystic fibrosis bronchiectasis in children and adolescents were developed by the Korean Academy of Pediatric Allergy and Respiratory Disease using the methods recommended by the Grading of Recommendations Assessment, Development, and Evaluation working group with evidence published through July 2, 2020. This guideline encompasses evidence-based treatment recommendations as well as expert opinions, addressing crucial aspects of the treatment and management of noncystic fibrosis bronchiectasis in children. This includes considerations for antibiotics and airway clearance strategies, particularly in areas where evidence may be limited. Large, well-designed, and controlled studies are required to accumulate further evidence of management strategies for noncystic fibrosis bronchiectasis in children and adolescents.

Exosome Precipitation by Ionic Strength Modulation: ExoPRISM

Extracellular vesicles (EVs) are emerging as crucial materials for precision theragnostic applications. However, current separation methods are time-consuming, costly, and not scalable and deliver limited yields or purity. Here, we present EV precipitation by ionic strength modulation (ExoPRISM), a simple, low-cost, user-friendly, and readily adaptable approach for separating EVs in high yields without compromising their biological functions. Adding an electrolyte solution to blood plasma in small increments generates the sequential precipitation of proteins and EVs, allowing for fractional separation of EVs using low-speed centrifugation. The coprecipitated electrolytes are easily washed away, and the entire EV separation and washing process takes less than an hour. This approach successfully separates EVs from a broad range of volumes and types of biological fluids, including culture medium, urine, plasma, and serum, showing promise as a robust tool for next-generation liquid biopsies and regenerative medicine.

Particulate matter exposure during pregnancy increases risk of childhood asthma: modified by gender and NRF2 genotype

BACKGROUND

Exposure to particulate matter (PM) has been known to develop asthma in children and the oxidative stress-related mechanisms are suggested. For the development of asthma, not only the exposure dose but also the critical window and the risk modifying factors should be evaluated.

OBJECTIVE

We investigated whether prenatal exposure to PM10 increases the risk of childhood asthma and evaluated the modifying factors, such as gender and reactive oxidative stress-related gene.

METHODS

A general population-based birth cohort, the Panel Study of Korean Children (PSKC), including 1572 mother-baby dyads was analyzed. Children were defined to have asthma at age 7 when a parent reported physician-diagnosed asthma. Exposure to PM10 during pregnancy was estimated by land-use regression models based on national monitoring system. TaqMan method was used for genotyping nuclear factor, erythroid 2-related factor, NRF2 (rs6726395). A logistic Bayesian distributed lag interaction model (BDLIM) was used to evaluate the associations between prenatal PM10 exposure and childhood asthma by gender and NRF2.

RESULTS

Exposure to PM10 during pregnancy was associated with the development of asthma (aOR 1.03, 95% CI 1.001.06). Stratifying by gender and NRF2 genotype, exposure to PM10 during 26-28 weeks gestation increased the risk of childhood asthma, especially in boys with NRF2 GG genotype.

CONCLUSIONS

A critical window for PM10 exposure on the development of childhood asthma was during 26-28 weeks of gestation, and this was modified by gender and NRF2 genotype.

POU6F2 mutation in humans with pubertal failure alters GnRH transcript expression

Idiopathic hypogonadotropic hypogonadism (IHH) is characterized by the absence of pubertal development and subsequent impaired fertility often due to gonadotropin-releasing hormone (GnRH) deficits. Exome sequencing of two independent cohorts of IHH patients identified 12 rare missense variants in POU6F2 in 15 patients. POU6F2 encodes two distinct isoforms. In the adult mouse, expression of both isoform1 and isoform2 was detected in the brain, pituitary, and gonads. However, only isoform1 was detected in mouse primary GnRH cells and three immortalized GnRH cell lines, two mouse and one human. To date, the function of isoform2 has been verified as a transcription factor, while the function of isoform1 has been unknown. In the present report, bioinformatics and cell assays on a human-derived GnRH cell line reveal a novel function for isoform1, demonstrating it can act as a transcriptional regulator, decreasing GNRH1 expression. In addition, the impact of the two most prevalent POU6F2 variants, identified in five IHH patients, that were located at/or close to the DNA-binding domain was examined. Notably, one of these mutations prevented the repression of GnRH transcripts by isoform1. Normally, GnRH transcription increases as GnRH cells mature as they near migrate into the brain. Augmentation earlier during development can disrupt normal GnRH cell migration, consistent with some POU6F2 variants contributing to the IHH pathogenesis.

CD5 Expression Dynamically Changes During the Differentiation of Human CD8+ T Cells Predicting Clinical Response to Immunotherapy

Defining the molecular dynamics associated with T cell differentiation enhances our understanding of T cell biology and opens up new possibilities for clinical implications. In this study, we investigated the dynamics of CD5 expression in CD8+ T cell differentiation and explored its potential clinical uses. Using PBMCs from 29 healthy donors, we observed a stepwise decrease in CD5 expression as CD8+ T cells progressed through the differentiation stages. Interestingly, we found that CD5 expression was initially upregulated in response to T cell receptor stimulation, but diminished as the cells underwent proliferation, potentially explaining the differentiation-associated CD5 downregulation. Based on the proliferation-dependent downregulation of CD5, we hypothesized that relative CD5 expression could serve as a marker to distinguish the heterogeneous CD8+ T cell population based on their proliferation history. In support of this, we demonstrated that effector memory CD8+ T cells with higher CD5 expression exhibited phenotypic and functional characteristics resembling less differentiated cells compared to those with lower CD5 expression. Furthermore, in the retrospective analysis of PBMCs from 30 non-small cell lung cancer patients, we found that patients with higher CD5 expression in effector memory T cells displayed CD8+ T cells with a phenotype closer to the less differentiated cells, leading to favorable clinical outcomes in response to immune checkpoint inhibitor (ICI) therapy. These findings highlight the dynamics of CD5 expression as an indicator of CD8+ T cell differentiation status, and have implications for the development of predictive biomarker for ICI therapy.

UBAP2 plays a role in bone homeostasis through the regulation of osteoblastogenesis and osteoclastogenesis

Osteoporosis is a condition characterized by decreased bone mineral density (BMD) and reduced bone strength, leading to an increased risk of fractures. Here, to identify novel risk variants for susceptibility to osteoporosis-related traits, an exome-wide association study is performed with 6,485 exonic single nucleotide polymorphisms (SNPs) in 2,666 women of two Korean study cohorts. The rs2781 SNP in UBAP2 gene is suggestively associated with osteoporosis and BMD with p-values of 6.1 × 10-7 (odds ratio = 1.72) and 1.1 × 10-7 in the case-control and quantitative analyzes, respectively. Knockdown of Ubap2 in mouse cells decreases osteoblastogenesis and increases osteoclastogenesis, and knockdown of ubap2 in zebrafish reveals abnormal bone formation. Ubap2 expression is associated with E-cadherin (Cdh1) and Fra1 (Fosl1) expression in the osteclastogenesis-induced monocytes. UBAP2 mRNA levels are significantly reduced in bone marrow, but increased in peripheral blood, from women with osteoporosis compared to controls. UBAP2 protein level is correlated with the blood plasma level of the representative osteoporosis biomarker osteocalcin. These results suggest that UBAP2 has a critical role in bone homeostasis through the regulation of bone remodeling.

Evaluation of Blood Tumor Mutation Burden for the Efficacy of Second-Line Atezolizumab Treatment in Non-Small Cell Lung Cancer: BUDDY Trial

This study aimed to investigate the feasibility of blood-based biomarkers, including blood tumor mutation burden (bTMB), to predict atezolizumab efficacy in relapsed and advanced non-small cell lung cancer (NSCLC). Stage IV NSCLC patients who had previously received platinum-doublet chemotherapy were recruited and received 1200 mg of atezolizumab every three weeks. Blood was collected to obtain plasma cell-free DNA (cfDNA) before the first cycle (C0) and at the fourth cycle (C4). bTMB was measured by CT-ULTRA in patients with cfDNA over 10 ng. The objective response rate (ORR) of the enrolled 100 patients was 10%, and there was no difference in ORR according to bTMB (cutoff: 11.5 muts/Mb) at C0 (high bTMB: 8.1% vs. low bTMB: 11.1%). However, the C4/C0 bTMB ratio was significantly lower in the durable clinical benefit (DCB) patients. The cfDNA concentration at C0, the C4/C0 ratio of the cfDNA concentration, the highest variant allele frequency (hVAF), and the VAF standard deviation (VAFSD) were significantly lower in the DCB patients. In the multivariate analysis, a high cfDNA concentration at C0 (cutoff: 8.6 ng/mL) and a C4/C0 bTMB ratio greater than 1 were significantly associated with progression-free survival. These results suggest that baseline levels and dynamic changes of blood-based biomarkers (bTMB, cfDNA concentration, and VAFSD) could predict atezolizumab efficacy in previously treated NSCLC patients.

Combined effects of microplastics and benz[a]anthracene on cardiotoxicity in zebrafish (Danio rerio) larvae: Size matters

The size of microplastics (MPs) plays an important role in combined toxic effects including synergistic or antagonistic effects. However, the influence of the size of MPs on the combined toxicity of contaminants remains unclear. In this study, we employed a zebrafish model to investigate the effects of MP size on the combined toxicity of benz[a]anthracene (BaA), a representative polyaromatic hydrocarbon, using three different sizes of polystyrene MPs (PSMPs) (0.2, 1.0, and 10 μm). Treatment of all groups did not result in any mortality of the zebrafish larvae. However, small-sized PSMPs (0.2 μm) enhanced the toxic effect of BaA in larvae such as cardiac defect and disruption of vessel formation. Medium-sized PSMPs (1.0 μm) were boundary in terms of the combined toxic effect; however, large-sized PSMPs (10 μm) alleviated the cardiotoxicity of BaA, including cardiac defect, ROS levels, and cell death. The combined effects showed a correlation with the body burden of MPs and BaA in larvae according to particle size (in the order of 0.2 μm > 1.0 μm > 10 μm). The synergistic effects occurred likely because the small PSMPs facilitated the body burden of BaA, induced excessive ROS by Ahr-mediated activity, and caused cell death in the heart, resulting in increased heart defects in the larvae. In contrast, large PSMPs abated the combined toxic effect through decreased body burden, whereas medium PSMPs form a boundary in combined effects. Therefore, the combined toxic effects of MPs are dependent on their size, which plays an important role in the transport and accumulation of environmental pollutants.

The association between MTHFR polymorphism, dietary methyl donors, and childhood asthma and atopy

BACKGROUND

Studies investigating the genetic association of the C677T methylenetetrahydrofolate reductase (MTHFR) genotype and dietary methyl donors with asthma and atopy are limited, and have variable results.

OBJECTIVE

To investigate the effect of dietary methyl donor intake on the risk of childhood asthma and atopy, based on the C677T polymorphism in the MTHFR gene.

METHODS

This cross-sectional study included 2,333 elementary school children aged 6-8 years across Korea during 2005 and 2006, as part of the first Children's Health and Environmental Research survey. Genotyping for the MTHFR (rs1801133) polymorphism was performed using the TaqMan assay. Multivariable-adjusted logistic regression analysis was performed to determine a descriptive association between the dietary methyl donor intake, MTHFR polymorphism, and childhood asthma and atopy.

RESULTS

Intake of dietary methyl donors like folates was significantly associated with a decreased risk of the wheezing symptom, in the past 12 months, and "ever asthma" diagnosis, respectively. Vitamin B6 intake was also associated with a decreased atopy risk. The T allele of the MTHFR (rs1801133) gene was significantly associated with a decreased risk of atopy. Increased intakes of folate, vitamin B2, and vitamin B6 were protective factors against atopy, especially in children with the T allele on the MTHFR gene, compared to those with lower intakes and the CC genotype.

CONCLUSIONS

High intakes of dietary methyl donors were associated with reduced risk of atopy and asthma symptoms. These may have additive effects related to the susceptibility alleles of the MTHFR gene. The clinical implications require evaluation.

Transplantation of PSA-NCAM-Positive Neural Precursors from Human Embryonic Stem Cells Promotes Functional Recovery in an Animal Model of Spinal Cord Injury

BACKGROUND

Spinal cord injury (SCI) results in permanent impairment of motor and sensory functions at and below the lesion site. There is no therapeutic option to the functional recovery of SCI involving diverse injury responses of different cell types in the lesion that limit endogenous nerve regeneration. In this regard, cell replacement therapy utilizing stem cells or their derivatives has become a highly promising approach to promote locomotor recovery. For this reason, the demand for a safe and efficient multipotent cell source that can differentiate into various neural cells is increasing. In this study, we evaluated the efficacy and safety of human polysialylated-neural cell adhesion molecule (PSA-NCAM)-positive neural precursor cells (hNPCsPSA-NCAM+) as a treatment for SCI.

METHODS

One hundred thousand hNPCsPSA-NCAM+ isolated from human embryonic stem cell-derived NPCs were transplanted into the lesion site by microinjection 7 days after contusive SCI at the thoracic level. We examined the histological characteristics of the graft and behavioral improvement in the SCI rats 10 weeks after transplantation.

RESULTS

Locomotor activity improvement was estimated by the Basso-Beattie-Bresnahan locomotor rating scale. Behavioral tests revealed that the transplantation of the hNPCsPSA-NCAM+ into the injured spinal cords of rats significantly improved locomotor function. Histological examination showed that hNPCsPSA-NCAM+ had differentiated into neural cells and successfully integrated into the host tissue with no evidence of tumor formation. We investigated cytokine expressions, which led to the early therapeutic effect of hNPCsPSA-NCAM+, and found that some undifferentiated NPCs still expressed midkine, a well-known neurotrophic factor involved in neural development and inflammatory responses, 10 weeks after transplantation.

CONCLUSION

Our results demonstrate that hNPCsPSA-NCAM+ serve as a safe and efficient cell source which has the potential to improve impaired motor function following SCI.

A review on the impacts of nanomaterials on neuromodulation and neurological dysfunction using a zebrafish animal model

Nanomaterials have been widely employed from industrial to medical fields due to their small sizes and versatile characteristics. However, nanomaterials can also induce unexpected adverse effects on health. In particular, exposure of the nervous system to nanomaterials can cause serious neurological dysfunctions and neurodegenerative diseases. A number of studies have adopted various animal models to evaluate the neurotoxic effects of nanomaterials. Among them, zebrafish has become an attractive animal model for neurotoxicological studies due to several advantages, including the well-characterized nervous system, efficient genome editing, convenient generation of transgenic lines, high-resolution in vivo imaging, and an array of behavioral assays. In this review, we summarize recent studies on the neurotoxicological effects of nanomaterials, particularly engineered nanomaterials and nanoplastics, using zebrafish and discuss key findings with advantages and limitations of the zebrafish model in neurotoxicological studies.

Simply structured polarization-independent high efficiency multilayer dielectric gratings

A polarization-independent multilayer dielectric diffraction grating with a low aspect ratio and high diffraction efficiency was designed and fabricated. The diffraction grating designed with a grating density of 1200 lines/mm had an aspect ratio of 0.59, mean polarization-independent diffraction efficiency in the Littrow angle of ±2.5^∘, and 1030-1080 nm wavelength range of 97.2%. The designed grating was fabricated using ion assisted deposition and reactive ion etching techniques. The mean polarization-independent diffraction efficiency of the fabricated grating was 96.1%, and its standard deviation was 0.68%. The fabricated diffraction grating was irradiated with a 1064 nm cw laser, with a power density of 30kW/cm², for 1 min to measure the temperature change before and after the laser application. It was verified that the temperature variation of the diffraction grating without heat treatment was 8.8°C, and the temperature variation after heat treatment at 400°C decreased to 2.3°C.

Atopic Dermatitis With Coexisting Food Allergy in Early Life Is Associated With Childhood Asthma

PURPOSE

Atopic dermatitis (AD) and food allergy (FA) are associated with respiratory comorbidities, in the concept of 'atopic march.' However, children with AD and a coexisting FA have various disease courses, and the mechanism of atopic march remains unclear. In this study, we investigated whether the phenotype of AD with coexisting FA in early life affected asthma or allergic rhinitis (AR) in school children.

METHODS

A total of 1,579 children from the Panel Study on Korean Children (PSKC) cohort were followed-up in 2013. The participants diagnosed with AD in this cohort were classified by the age of AD onset and persistence as well as FA history. We compared the presence of comorbidities-asthma and rhinitis-among different AD phenotypes.

RESULTS

Asthma and AR with current symptoms within 12 months at age 6-8 years were associated with early-onset persistent AD phenotype, regardless of coexisting FA. AD with FA conferred a higher risk of recent wheezing at 8 years of age than AD without FA (adjusted odds ratio, 8.09; 95% confidence interval, 2.54-25.76). Children with early-onset persistent AD with FA manifested a distinctive trajectory with a higher prevalence of wheezing and AR at age 5-8 years than those without AD.

CONCLUSIONS

AD with FA in early life is strongly associated with asthma and AR in school children, and the early-onset persistent AD with FA had a strong additive effect on the risk of asthma at school age. Classifying AD phenotypes regarding FA in early life will help predict and prevent asthma and AR in school children.

Abstract 5166: Blood-based biomarker analysis for predicting efficacy of definitive concurrent chemoradiotherapy and durvalumab consolidation in patients with unresectable locally advanced non-small cell lung cancer

Background: This study aimed to investigate the feasibility of using circulating tumor cells (CTCs) and peripheral blood cells (PBCs) as biomarkers for predicting the efficacy of concurrent chemoradiotherapy (CCRT) and durvalumab consolidation (DC) in patients with locally advanced non-small cell lung cancer (NSCLC).

Methods: We recruited patients diagnosed with unresectable stage III NSCLC who received definitive CCRT between March 2020 and March 2021. DC was permitted in patients who did not progress after CCRT and tumor PD-L1 ≥1%. Blood samples were collected before (C0) and after CCRT (C1) to calculate PBC counts and analyze CTCs. CTCs, isolated using CD-PRIME࣪ system, exhibited EpCAM/CK+/CD45− phenotype in BioViewCCBS࣪.

Results: A total of 50 patients were enrolled and 23 patients received DC. The median duration of follow-up was 16.3 months, and the median progression-free survival (PFS) was not significantly different between patients with and without DC (13.1 vs. 13.5 months; p=0.355). In overall, patients with higher platelets (PLThi, >252x103/uL) at C1 had worse median PFS than those with lower platelets (PLTlo, ≤252x103/uL) (5.9 vs. 15.1 months; p<0.001). In DC group, patients with residual CTC clusters after CCRT (C1) had worse median PFS than those without detectable CTC cluster (9.5 vs. not reached; p=0.034). In multivariate analysis, PLThi at C1 was an independent factor for PFS (hazard ratio [HR] 4.12, 95% confidence interval [CI] 1.77-9.61; p=0.001), and patients with DC who had PLThi and residual CTC clusters at C1 showed the worst PFS (2.6 months, HR 44.40; p=0.001), even worse than those without DC who had PLThi (5.9 months, HR 15.65; p=0.002).

Conclusions: Comprehensive analysis of CTC and PBC counts before and after CCRT, especially CTC clusters and platelets at C1, demonstrated they might be biomarkers for predicting survival. This finding could aid in risk stratification of patients with unresectable stage III NSCLC who are eligible for DC after definitive CCRT.

Citation Format: Cheol-Kyu Park, Hwa-Kyung Park, Hyung-Joo Oh, Hyun-Ju Cho, In-Jae Oh, Young-Chul Kim. Blood-based biomarker analysis for predicting efficacy of definitive concurrent chemoradiotherapy and durvalumab consolidation in patients with unresectable locally advanced non-small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5166.

NOS2 and S-nitrosothiol signaling induces DNA hypomethylation and LINE-1 retrotransposon expression

Inducible nitric oxide synthase (NOS2) produces high local concentrations of nitric oxide (NO), and its expression is associated with inflammation, cellular stress signals, and cellular transformation. Additionally, NOS2 expression results in aggressive cancer cell phenotypes and is correlated with poor outcomes in patients with breast cancer. DNA hypomethylation, especially of noncoding repeat elements, is an early event in carcinogenesis and is a common feature of cancer cells. In addition to altered gene expression, DNA hypomethylation results in genomic instability via retrotransposon activation. Here, we show that NOS2 expression and associated NO signaling results in substantial DNA hypomethylation in human cell lines by inducing the degradation of DNA (cytosine-5)–methyltransferase 1 (DNMT1) protein. Similarly, NOS2 expression levels were correlated with decreased DNA methylation in human breast tumors. NOS2 expression and NO signaling also resulted in long interspersed noncoding element 1 (LINE-1) retrotransposon hypomethylation, expression, and DNA damage. DNMT1 degradation was mediated by an NO/p38-MAPK/lysine acetyltransferase 5–dependent mechanism. Furthermore, we show that this mechanism is required for NO-mediated epithelial transformation. Therefore, we conclude that NOS2 and NO signaling results in DNA damage and malignant cellular transformation via an epigenetic mechanism.

Food allergy in early childhood increases the risk of oral allergy syndrome in schoolchildren: A birth cohort study

BACKGROUND

The level of pollen in Korea has increased over recent decades. Research suggests that oral allergy syndrome (OAS) may be more frequent in childhood than previously recognized. We aimed to investigate the prevalence and characteristics of OAS in children aged 6-10 years from a general-population-based birth cohort.

METHODS

We analyzed 930 children from the cohort for childhood origin of asthma and allergic diseases (COCOA). Allergic diseases were diagnosed annually by pediatric allergists. The skin prick tests were performed with 14 common inhalant allergens and four food allergens for the general population of children aged 3 and 7 years.

RESULTS

Of the 930 eligible children, 44 (4.7%) aged 6-10 years were diagnosed with OAS. The mean age at onset was 6.74 years. OAS prevalence was 7.2% among children with allergic rhinitis (AR) and 19.1% among those with pollinosis, depending on comorbidity. OAS was more prevalent in schoolchildren with atopic dermatitis, food allergy, and sensitization to food allergens and grass pollen in early childhood. In schoolchildren with AR, only a history of food allergy until the age of 3 years increased the risk of OAS (aOR 2.971, 95% CI: 1.159-7.615).

CONCLUSION

Food allergy and food sensitization in early childhood were associated with OAS in schoolchildren with AR. Further study is required to elucidate the mechanism by which food allergy in early childhood affects the development of OAS.

PLXNB1 mutations in the etiology of idiopathic hypogonadotropic hypogonadism

Idiopathic hypogonadotropic hypogonadism (IHH) comprises a group of rare genetic disorders characterized by pubertal failure caused by gonadotropin-releasing hormone (GnRH) deficiency. Genetic factors involved in semaphorin/plexin signaling have been identified in patients with IHH. PlexinB1, a member of the plexin family receptors, serves as the receptor for semaphorin 4D (Sema4D). In mice, perturbations in Sema4D/PlexinB1 signaling leads to improper GnRH development, highlighting the importance of investigating PlexinB1 mutations in IHH families. In total, 336 IHH patients (normosmic IHH, n = 293 and Kallmann syndrome, n = 43) from 290 independent families were included in the present study. Six PLXNB1 rare sequence variants (p.N361S, p.V608A, p.R636C, p.V672A, p.R1031H, and p.C1318R) are described in eight normosmic IHH patients from seven independent families. These variants were examined using bioinformatic modeling and compared to mutants reported in PLXNA1. Based on these analyses, the variant p.R1031H was assayed for alterations in cell morphology, PlexinB1 expression, and migration using a GnRH cell line and Boyden chambers. Experiments showed reduced membrane expression and impaired migration in cells expressing this variant compared to the wild-type. Our results provide clinical, genetic, molecular/cellular, and modeling evidence to implicate variants in PLXNB1 in the etiology of IHH.

Increased risk of cardiovascular diseases in patients with chronic rhinosinusitis: a longitudinal follow-up study using a national health screening cohort

BACKGROUND

Chronic rhinosinusitis (CRS) is one of the most common chronic inflammatory diseases and is characterized by sinonasal inflammation that lasts longer than 12 weeks. Whether the effect of chronic inflammation caused by CRS on cardiovascular diseases (CVDs) is similar to its effect on other inflammatory disorders has not been thoroughly evaluated. We aimed to demonstrate whether CRS patients have a higher prevalence of CVDs, including stroke and ischemic heart disease (IHD).

METHODOLOGY

We compared the prevalence of various comorbidities between CRS and control participants through a case-control cohort study from 2002 to 2015 that included 514,866 participants. CRS (n=6,552) and control (n=26,208) participants who were over 40 years old were selected by matching age, sex, income, and area of residence at a 1:4 ratio.

RESULTS

A stratified Cox proportional hazards model was utilized to assess the hazard ratio (HR) of CRS for stroke and IHD. The HRs for stroke and IHD were significantly increased in CRS patients compared to controls after adjusting for obesity, alcohol consumption, smoking, systolic and diastolic blood pressure, fasting blood glucose, total cholesterol, hemoglobin, and Charlson Comorbidity Index (CCI) scores. The HR of stroke was significantly higher in the absence of nasal polyps than in the presence of nasal polyps. The HR of IHD was significantly increased in the CRS group regardless of the presence of nasal polyps.

CONCLUSIONS

This study showed that CRS participants had a significantly higher prevalence of stroke and IHD.

Host tp53 mutation induces gut dysbiosis eliciting inflammation through disturbed sialic acid metabolism

BACKGROUND

Host tp53 mutations are frequently found during the early stages of colitis-associated colorectal cancer (CAC), but whether such mutations induce gut microbiota dysbiosis and chronic intestinal inflammation that contributes to the development of CAC, remains unknown.

RESULTS

We found that zebrafish tp53 mutant larvae exhibited elevated intestinal inflammation, by monitoring the NFκB activity in the mid-distal intestines of zebrafish larvae using an NFκB:EGFP transgenic reporter line in vivo as well as neutrophil infiltration into the intestine. This inflammation was due to dysbiotic gut microbiota with reduced diversity, revealed using both 16S rRNA amplicon sequencing and a germfree larva model. In this dysbiosis, Aeromonas spp. were aberrantly enriched as major pathobionts and exhibited the capacity for aggressive colonization in tp53 mutants. Importantly, the ex-germfree experiments supported the causality of the host tp53 mutation for inducing the inflammation. Transcriptome and high-performance liquid chromatography analyses of the host gastrointestinal tracts identified dysregulated sialic acid (SA) metabolism concomitant with increased host Neu5Gc levels as the key determinant of aberrant inflammation, which was reversed by the sialidase inhibitors oseltamivir and Philippin A.

CONCLUSIONS

These results demonstrate a crucial role for host tp53 in maintaining symbiosis and immune homeostasis via SA metabolism. Disturbed SA metabolism via a tp53 mutation may be exploited by specific elements of the gut microbiome, eliciting both dysbiosis and inflammation. Manipulating sialometabolism may therefore provide an efficacious therapeutic strategy for tp53 mutation-induced dysbiosis, inflammation, and ultimately, related cancers. Video Abstract.

Zero lock-in implementation by phase wrapping/unwrapping in a ring laser gyroscope

The main factors that limit the performance of ring laser gyroscopes include random walk, quantization noise, and bias stability. The first two factors determine the alignment time for navigation systems, and the bias stability error can result in long-term accuracy. We show that a phase wrapping/unwrapping algorithm, which has been widely used in interferometry fields, can be utilized to remove lock-in and quantization errors by implementing a zero-lock-in ring laser gyroscope. Furthermore, the performance of the ring laser gyroscope with no mechanical dither is described, and mirror dithering, instead of mechanical dithering, is proposed.

CD8+ TILs in NSCLC differentiate into TEMRA via a bifurcated trajectory: deciphering immunogenicity of tumor antigens

Background

CD8⁺ tumor-infiltrating lymphocytes (TILs) comprise phenotypically and functionally heterogeneous subpopulations. Of these, effector memory CD45RA re-expressing CD8⁺ T cells (Temra) have been discovered and characterized as the most terminally differentiated subset. However, their exact ontogeny and physiological importance in association with tumor progression remain poorly understood.

Methods

We analyzed primary tumors and peripheral blood samples from 26 patients with non-small cell lung cancer and analyzed their phenotypes and functional characteristics using flow cytometry, RNA-sequencing, and bioinformatics.

Results

We found that tumor-infiltrating Temra (tilTemra) cells largely differ from peripheral blood Temra (pTemra), with distinct transcriptomes and functional properties. Notably, although majority of the pTemra was CD27⁻CD28⁻ double-negative (DN), a large fraction of tilTemra population was CD27⁺CD28⁺ double-positive (DP), a characteristic of early-stage, less differentiated effector cells. Trajectory analysis revealed that CD8⁺ TILs undergo a divergent sequence of events for differentiation into either DP or DN tilTemra. Such a differentiation toward DP tilTemra relied on persistent expression of CD27 and CD28 and was associated with weak T cell receptor engagement. Thus, a higher proportion of DP Temra was correlated with lower immunogenicity of tumor antigens and consequently lower accumulation of CD8⁺ TILs.

Conclusions

These data suggest a complex interplay between CD8⁺ T cells and tumors and define DP Temra as a unique subset of tumor-specific CD8⁺ TILs that are produced in patients with relatively low immunogenic cancer types, predicting immunogenicity of tumor antigens and CD8⁺ TIL counts, a reliable biomarker for successful cancer immunotherapy.

Pulmonary function of healthy Korean children from three independent birth cohorts: Validation of the Global Lung Function Initiative 2012 equation

BACKGROUND AND OBJECTIVE

Global Lung Function Initiative (GLI) 2012 equations were developed to resolve the age-related disparity in interpreting spirometry results. Local validation of the equation is needed, especially in Northeast Asian children. This study evaluated the GLI equation in Korean children.

METHODS

Spirometry indices (FEV1, FVC, FEV1/FVC, and FEF25%-75%) and clinical information were gathered from three population-based birth cohorts. Predicted GLI reference values and z scores of spirometry results were calculated for 1239 healthy children. The mean, standard deviation of z scores were compared with the expected 0 and 1. Probabilities of falling below the lower limit of normal (LLN) (z score: -1.64) were compared with the expected value 5%. GLI z scores were assessed according to low (<-2), normal (≥-2 and ≤2), and high (>2) BMI z score groups.

RESULTS

Mean z scores significantly differed from 0 for FEV1/FVC in males (mean [95% confidence interval]: 0.18 [0.08, 0.27]) and forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) in females (-0.23 [-0.31, -0.15] and -0.26 [-0.36, -0.16], respectively). The standard deviation was larger than 1 for all variables in males and FVC and FEV1/FVC in females. The probability of falling below the LLN was significantly larger than 5% for FEV1 (12.13% [9.64, 14.77]), FVC (15.86% [13.06, 18.81]), and forced expiratory flow at 25%-75% of forced vital capacity (FEF25%-75%) (7.31% [5.29, 9.49]) in males and FVC (11.91% [9.40, 14.60]) in females. FEV1 and FVC z scores increased across low to high body mass index (BMI) groups, and FEV1/FVC decreased from low to high BMI groups.

CONCLUSION

GLI equations marginally differ from real-world values, which should be considered by pulmonologists in practice or research.

Mid-pregnancy PM2.5 exposure affects sex-specific growth trajectories via ARRDC3 methylation

Prenatal particulate matter <2.5 μm (PM_2.5) is associated with adverse birth growth. However, the longitudinal growth impacts have been little studied, and no mechanistic relationships have been described. We investigated the association between prenatal PM_2.5 exposure and growth trajectories, and the possible role of epigenetics. We enrolled 1313 neonates with PM_2.5 data measured by ordinary kriging from the COhort for Childhood Origin of Asthma and allergic diseases, followed up at 1, 3, and 5 years to evaluate growth. Differential DNA methylation and pyrosequencing of cord blood leukocytes was evaluated according to the prenatal PM_2.5 levels and birth weight (BW). PM_2.5 exposure during the second trimester (T2) caused the lowest BW in both sexes, further adjusted for indoor PM_2.5 levels [female, aOR 1.39 (95% CI 1.05-1.83); male, aOR 1.36 (95% CI 1.04-1.79)]. Bayesian distributed lag models with indoor PM_2.5 adjustments revealed a sensitive window for BW effects at 10-26 weeks gestation, but only in females. Latent class mixture models indicated that a persistently low weight-for-height percentile trajectory was more prevalent in the highest PM_2.5 exposure quartile at T2 in females, compared to a persistently high trajectory (36.5% vs. 20.3%, P = 0.022). Also, in the females only, the high PM_2.5 and low BW neonates showed significantly greater ARRDC3 methylation changes. ARRDC3 methylation was also higher only in females with low weight at 5 years of age. Higher fetal PM_2.5 exposure during T2 may cause a decreased growth trajectory, especially in females, mediated by ARRDC3 hyper-methylation-associated energy metabolism.

Abstract 597: Comprehensive analysis of blood-based biomarkers to immunotherapy using circulating tumor cells, peripheral blood cells and circulating tumor DNA in advanced non-small cell lung cancer

Background: This study aimed to investigate the feasibility of liquid biopsy using circulating tumor cells (CTCs), peripheral blood cells (PBCs) and circulating tumor DNA (ctDNA) as predictive blood-based biomarkers to immunotherapy in advanced non-small cell lung cancer (NSCLC).

Methods: This study included patients with advanced NSCLC receiving pembrolizumab or atezolizumab from July 2019 to June 2020. Blood was collected in K2-EDTA tube before each administration from cycle 1 to 4 (C1-4), and PBC counts (absolute neutrophil count[ANC], neutrophil-to-lymphocyte ratio[NLR], derived NLR[dNLR], platelet-to-lymphocyte ratio[PLR]) were calculated at each cycle. CTCs were enriched by using CD-PRIMETM system, the antibody-independent size-based isolation method, and identified by single positive cells (EpCAM/CK+CD45-) in BioViewCCBSTM system. Cell-free DNA was purified and extracted from plasma at baseline and C4 or end-of-treatment.

Results: Among 83 response-evaluable patients, objective response rate was 19% and durable clinical benefit (DCB) were 34%. Baseline (C1) CTC, PBC count and ctDNA amount did not show a significant difference according to best response and DCB. However, patients with lower NLR, dNLR, PLR and ctDNA level at C1 showed significant benefit in progression-free survival (PFS) and overall survival (OS) (p&lt;0.05 for all). Patients with decreased CTC at C2 compared to C1 showed benefit in median PFS (6.2 vs 2.3, p=0.078) and OS (not reached [NR] vs 6.8, p=0.021) than those with increased CTC count. Low dNLR (≤2.0) at C1 and decreased CTC at C2 compared to C1 were the independently significant factors for survival.

Conclusion: Comprehensive analysis of CTC, PBC count and ctDNA amount at baseline and their changes during treatment could be potential biomarkers to predict the survival benefit and may help risk-group stratification in patients with advanced NSCLC who received anti-PD-1/PD-L1 immunotherapy.

Citation Format: Cheol-Kyu Park, Hyun-Ju Cho, In-Jae Oh, Young-Chul Kim. Comprehensive analysis of blood-based biomarkers to immunotherapy using circulating tumor cells, peripheral blood cells and circulating tumor DNA in advanced non-small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 597.

Comprehensive analysis of blood-based biomarkers for predicting immunotherapy benefits in patients with advanced non-small cell lung cancer

Background

This study aimed to investigate the feasibility of using circulating tumor cells (CTCs), peripheral blood cells (PBCs), and circulating cell-free DNA (cfDNA) as biomarkers of immune checkpoint inhibitor treatment response in patients with advanced non-small cell lung cancer (NSCLC).

Methods

We recruited patients diagnosed with advanced NSCLC who received pembrolizumab or atezolizumab between July 2019 and June 2020. Blood was collected before each treatment cycle (C1–C4) to calculate absolute neutrophil count (ANC), neutrophil-to-lymphocyte ratio (NLR), derived NLR (dNLR), and platelet-to-lymphocyte ratio (PLR). CTCs, isolated using the CD-PRIME^TM system, exhibited EpCAM/CK+/CD45− phenotype in BioViewCCBS^TM. The cfDNA was extracted from plasma at the beginning of C1 and C4.

Results

The durable clinical benefit (DCB) rate among 83 response-evaluable patients was 34%. CTC, PBC, and cfDNA levels at baseline (C1) were not significantly correlated with treatment response, although patients with DCB had lower CTC counts from C2 to C4. However, patients with low NLR, dNLR, PLR, and cfDNA levels at C1 had improved progression-free survival (PFS) and overall survival (OS). Patients with decreased CTC counts from C1 to C2 had higher median PFS (6.2 vs. 2.3 months; P=0.078) and OS (not reached vs. 6.8 months, P=0.021) than those with increased CTC counts. Low dNLR (≤2.0) at C1 and decreased CTC counts were independent factors for predicting survival.

Conclusions

Comprehensive analysis of CTC, PBC, and cfDNA levels at baseline and during treatment demonstrated they might be biomarkers for predicting survival benefit. This finding could aid in risk stratification of patients with advanced NSCLC who are undergoing immune checkpoint inhibitor treatment.

Genetic Approaches Using Zebrafish to Study the Microbiota-Gut-Brain Axis in Neurological Disorders

The microbiota-gut-brain axis (MGBA) is a bidirectional signaling pathway mediating the interaction of the microbiota, the intestine, and the central nervous system. While the MGBA plays a pivotal role in normal development and physiology of the nervous and gastrointestinal system of the host, its dysfunction has been strongly implicated in neurological disorders, where intestinal dysbiosis and derived metabolites cause barrier permeability defects and elicit local inflammation of the gastrointestinal tract, concomitant with increased pro-inflammatory cytokines, mobilization and infiltration of immune cells into the brain, and the dysregulated activation of the vagus nerve, culminating in neuroinflammation and neuronal dysfunction of the brain and behavioral abnormalities. In this topical review, we summarize recent findings in human and animal models regarding the roles of the MGBA in physiological and neuropathological conditions, and discuss the molecular, genetic, and neurobehavioral characteristics of zebrafish as an animal model to study the MGBA. The exploitation of zebrafish as an amenable genetic model combined with in vivo imaging capabilities and gnotobiotic approaches at the whole organism level may reveal novel mechanistic insights into microbiota-gut-brain interactions, especially in the context of neurological disorders such as autism spectrum disorder and Alzheimer's disease.

Severe Periodontal Disease Increases Acute Myocardial Infarction and Stroke: A 10-Year Retrospective Follow-up Study

This study aimed to evaluate the causal association of periodontal disease with acute myocardial infarction (AMI) and stroke, after controlling for various confounders among the Korean population. A retrospective cohort study using the National Health Insurance Service-National Health Screening Cohort (NHIS-HEALS) was performed during 2002 to 2015 (baseline: 2002 to 2005; follow-up: 2006 to 2015) in the Republic of Korea. A total of 298,128 participants with no history of AMI or stroke were followed up for 10 y. AMI and stroke were defined by a diagnosis using the International Classification of Diseases, 10th Revision (ICD-10) guideline. Periodontal condition was classified into 3 groups (healthy, moderate periodontal disease, severe periodontal disease [SPD]) using the combination of ICD codes, treatment codes in the NHIS, and recommendation of periodontal treatment by the dentists in HEALS. Various confounders, such as sociodemographic, behavioral, systemic, and oral health factors, including hypercholesterolemia, were considered. Multivariable Cox regression analysis was applied to estimate adjusted incidence rate ratio (adjusted hazard ratio [aHR]) based on person-year of periodontal condition for AMI, stroke, and nonfatal major adverse cardiovascular events (MACEs) encompassing AMI or stroke controlling for various confounders. Stratified analyses according to age group, sex, and toothbrushing frequency were also performed. After controlling for various confounders, participants with SPD compared with non-SPD participants had a higher incidence by 11% for AMI (aHR, 1.11; 95% confidence interval [CI], 1.02-1.20), by 3.5% for stroke (aHR, 1.035; 95% CI, 1.01-1.07), and by 4.1% for MACEs (aHR, 1.04; 95% CI, 1.01-1.07). The association of SPD with AMI and MACE was highly modified in females and adults aged 40 to 59 y. In the total Korean population, SPD increased total AMI events by 4.3%, total stroke events by 1.4%, and the total MACEs by 1.6%. Our data confirmed that SPD was causally associated with the new events of AMI and stroke.

Molecular profiling of Asian patients with advanced melanoma receiving check-point inhibitor treatment

Objective

Melanoma is major medical challenge and being able to monitor treatment response is critical. This study aimed to use molecular profiling of Asian patients with advanced melanoma who were receiving treatment with check-point inhibitors (CPIs) to identify novel biomarkers of tumor response.

Methods

Next-generation sequencing (NGS) was performed using tumor specimens collected from 178 Asian patients with metastatic melanoma receiving CPIs. The NGS data and clinical-pathological factors were analyzed for potential genetic biomarkers of tumor response to CPI treatment.

Results

The most common melanoma subtype was acral melanoma (40%), followed by cutaneous melanoma (32%), mucosal melanoma (26%), and others (2%). For calculation of treatment efficacy, 164 of the patients could be evaluated. The overall response rate was 45.7%, of which 41 cases exhibited complete responses (25.0%) and 34 showed partial responses (20.7%). There were no significant differences in tumor responses based on melanoma subtype (P = 0.295). Genetically, NRAS mutations, TP53 mutations, and NF2 deletions were significantly associated with resistance to CPIs (P < 0.05). In contrast, MYC and RPS6KB1 amplifications were associated with responsiveness to CPIs (P < 0.05). Median progression-free survival (PFS) for patients treated with CPIs was 5.9 months (95% CI, 3.8-8.05 months). Univariate analysis identified TP53 and BRAF mutations, NF2 deletions, and BIRC2 amplifications as poor prognostic factors for PFS (P < 0.05).

Conclusions

This study determined the integrated genomic profiles of Asian patients with metastatic melanoma receiving CPIs and identified candidate biomarkers that reflected treatment outcomes.

•

The molecular characterization of Asian melanoma patients receiving check-point inhibitors (CPIs) using NGS has not been reported.

•

NRAS and TP53 mutations and NF2 deletions were significantly associated with resistance to CPIs.

•

MYC and RPS6KB1 amplifications were associated with responsiveness to CPIs.

•

TP53 and BRAF mutations, NF2 deletions, and BIRC2 amplifications were poor prognostic factors for progression-free survival.

•

This is the largest integrated genomic study to date that identifying novel biomarkers of CPIs in Asian melanoma patients.

Vegetable dietary pattern may protect mild and persistent allergic rhinitis phenotype depending on genetic risk in school children

BACKGROUND

The effect of diet on allergic rhinitis (AR), its severity in children, and whether it modifies AR depending on genetic susceptibility are unknown. We investigated the association between dietary patterns and AR in school children and the influence of diet on AR according to a genetic risk score (GRS).

METHODS

Totally, 435 7-year-old school children were recruited from the Panel Study on Korean Children. We used dietary patterns (vegetable, sugar, and meat) and dietary inflammatory index (DII) as dietary parameters. AR and its severity were defined by questionnaires about treatment in the previous 12 months and the Allergic Rhinitis and its Impact on Asthma (ARIA) guideline, respectively. A GRS was calculated using 6 single nucleotide polymorphisms for allergic diseases.

RESULTS

A vegetable diet containing a lot of anti-inflammatory nutrients and higher vitamin D level in blood were negatively correlated, while DII was positively correlated with triglyceride level and triglyceride/HDL cholesterol. Vegetable diet (aOR, 95% CI = 0.73, 0.58-0.94) and DII (1.13, 1.01-1.28) were associated with AR risk. In particular, a high-vegetable diet resulted in a lower risk of mild and persistent AR (aOR, 95% CI = 0.24, 0.10-0.56) while a high DII represented a higher risk (2.33, 1.06-5.10). The protective effect of vegetable diet on AR appeared only among children with a lower GRS (adjusted P = .018).

CONCLUSIONS

A vegetable dietary pattern characterized by high intake of anti-inflammatory nutrients and higher vitamin D level in blood might be associated with a lower risk of mild and persistent AR. This beneficial effect is modified by a genetic factor.

Prenatal PM2.5 exposure and vitamin D-associated early persistent atopic dermatitis via placental methylation

BACKGROUND

The effects of prenatal particulate matter with an aerodynamic diameter ranging from 0.1 μm to 2.5 μm (PM_2.5) and vitamin D on atopic dermatitis (AD) phenotypes have not been evaluated. DNA methylation and cord blood (CB) vitamin D could represent a plausible link between prenatal PM_2.5 exposure and AD in an offspring.

OBJECTIVE

To determine the critical windows of prenatal PM_2.5 exposure on the AD phenotypes, if vitamin D modulated these effects, and if placental DNA methylation mediated these effects on AD in offspring.

METHODS

Mother-child pairs were enrolled from the birth cohort of the Cohort for Childhood Origin of Asthma and allergic diseases (COCOA) study. PM_2.5 was estimated by land-use regression models, and CB vitamin D was measured by chemiluminescence immunoassay. AD was identified by the parental report of a physician's diagnosis. We defined the following 4 AD phenotypes according to onset age (by the age of 2 years) and persistence (by the age of 3 years): early-onset transient and persistent, late onset, and never. Logistic regression analysis and Bayesian distributed lag interaction model were used. DNA methylation microarray was analyzed using an Infinium Human Methylation EPIC BeadChip (Illumina, San Diego, California) in placenta.

RESULTS

PM_2.5 exposure during the first trimester of pregnancy, especially during 6 to 7 weeks of gestation, was associated with early-onset persistent AD. This effect increased in children with low CB vitamin D, especially in those with PM_2.5 exposure during 3 to 7 weeks of gestation. AHRR (cg16371648), DPP10 (cg19211931), and HLADRB1 (cg10632894) were hypomethylated in children with AD with high PM_2.5 and low CB vitamin D.

CONCLUSION

Higher PM_2.5 during the first trimester of pregnancy and low CB vitamin D affected early-onset persistent AD, and the most sensitive window was 6 to 7 weeks of gestation. Placental DNA methylation mediated this effect.

A Phase II Trial of Osimertinib as the First-Line Treatment of Non-Small Cell Lung Cancer Harboring Activating EGFR Mutations in Circulating Tumor DNA: LiquidLung-O-Cohort 1

Purpose

Osimertinib is a potent, irreversible third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor for both EGFR-activating and T790M resistant mutation. The treatment efficacy of osimertinib was assessed in previously untreated patients with metastatic non–small cell lung carcinoma (NSCLC) harboring activating EGFR mutations in circulating tumor DNA (ctDNA) as well as tumor DNA.

Materials and Methods

Patients with activating EGFR mutations in their tumor DNA underwent screening with ctDNA analysis using Mutyper and Cobas v2 assays. Enrolled subjects received osimertinib 80 mg, once daily. Primary endpoint was objective response rate (ORR) and secondary endpoints were ctDNA test sensitivity, progression-free survival (PFS), duration of response (DoR), and safety.

Results

Among 39 screened patients, 29 were ctDNA positive for activating EGFR mutations and 19 were enrolled (ex19del, n=11; L858R/L861Q, n=7; G719A, n=1). Median age was 70 and most patients had brain metastases (15/19, 79%). ctDNA test sensitivity for activating EGFR mutations was 74% using both methods and 62% (Mutyper) or 64% (Cobas v2) for individual methods. ORR was 68% (13/19), median PFS was 11.1 months (95% confidence interval [CI], 0.0 to 26.7), and median DoR was 17.6 months (95% CI, 3.5 to 31.7). ORR and median PFS were significantly superior with ex19del (91%; 21.9 months; 95% CI, 5.5 to 38.3) than with L858R/L861Q (43%; 5.1 months; 95% CI, 2.3 to 7.9). One patient discontinued the drug because of drug-related interstitial pneumonitis.

Conclusion

Osimertinib had favorable efficacy in the first-line treatment of metastatic NSCLC harboring activating EGFR mutations in ctDNA as well as tumor DNA.

Abstract 5373: Circulating tumor cell as a predictive marker for immunotherapy in advnaced non-small cell lung cancer

Background: Circulating tumor cells (CTCs) have potential to provide minimally invasive way for the response monitoring of various cancer. This study aimed to investigate the feasibility of CTCs as a predictive marker for anti-PD-L1 immunotherapy in patients with advanced non-small cell lung cancer (NSCLC).

Methods: This study included 37 patients with advanced NSCLC receiving atezolizumab monotherapy as second-line or more from July to November 2019. Blood was collected in a K2-EDTA tube and CTCs were isolated and enriched by using CD-PRIMETM system which is antibody-independent size-based isolation method. By Bioview CCBS system, total CTCs (tCTCs) were identified by a sum of single EpCAM/CK-positive (sCTCs) and double EpCAM/CK-CD45-positive cells (dCTCs).

Results: Among 26 response-evaluable patients, objective response rate (ORR) and disease control rate (DCR) were 11.5% (3/26) and 57.7% (15/26), respectively. At cycle 1 (C1), patients with progression (PD) showed higher sCTC count (median, 8.6 vs. 4.3, p=0.065) and sCTC-to-tCTC ratio (median %, 35.9 vs. 9.8, p=0.024) than those without PD. During treatment, tCTC and sCTC count showed significant increase from C1 to C2 (p=0.019 and p=0.022). The subgroup with high sCTC increase from C1 to C2 (more than 2-folds) showed higher DCR than subgroup with low sCTC increase (less than 2-folds) (88.9% vs. 44.4%, p=0.066). Patients with high sCTC-to-tCTC ratio at C1 showed worse progression-free survival (median, 2.1 months) than those with low sCTC-to-tCTC ratio (not reached, hazard ratio 2.87, 95% confidence interval: 1.06-7.75, p=0.082).

Conclusion: The baseline sCTC count and sCTC increase (more than 2-folds) at the first 3-week after atezolizumab could be potential biomarkers to predict the disease progression and poor survival in advanced NSCLC.

Citation Format: Cheol-Kyu Park, Joon-Young Yoon, Min-Suk Kim, Bo-Gun Koh, Hyun-Ju Cho, In-Jae Oh, Young-Chul Kim. Circulating tumor cell as a predictive marker for immunotherapy in advnaced non-small cell lung cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5373.

Effects of chloromethylisothiazolinone/methylisothiazolinone (CMIT/MIT) on Th2/Th17-related immune modulation in an atopic dermatitis mouse model

Exposure to chloromethylisothiazolinone/methylisothiazolinone (CMIT/MIT) has been associated with allergic contact dermatitis and occupational asthma. Despite this association however, no study has investigated the effects of CMIT/MIT exposure on the development of atopic dermatitis (AD). This study was conducted to investigate the influence of epicutaneous exposure to CMIT/MIT on AD in a mouse model and the underlying biological mechanisms. BALB/C mice were exposed to CMIT/MIT for 3 weeks and AD was developed using ovalbumin (OVA) epidermal sensitization. CMIT/MIT epicutaneous exposure in normal mice significantly enhanced AD-like phenotypes (e.g., transepidermal water loss, clinical score, total serum immunoglobulin E level and infiltration of inflammatory cells). In addition, CMIT/MIT exposure significantly augmented the mRNA expression level of T helper (Th) 2-related cytokines (thymic stromal lymphopoietin, interleukin (IL)-6 and IL-13), Th2 chemokine (chemokine (C-C motif) ligand 17) and the population of CD4⁺IL-4⁺ cells in the skin. Moreover, mice exposed to CMIT/MIT in the OVA challenge had greater AD-like phenotypes, higher IL-4 and IL-17A skin mRNA expression levels, and a larger population of CD4⁺IL-4⁺- and IL-17A⁺-producing cells in the skin-draining lymph nodes. Our current findings in a mouse model thus suggest that CMIT/MIT exposure may cause AD symptoms through the dysregulation of Th2/Th17-related immune responses.

Particulate matter at third trimester and respiratory infection in infants, modified by GSTM1

OBJECTIVES

To investigate the association between particulate matter with an aerodynamic diameter of less than 2.5 μm (PM_2.5 ) exposure during each trimester of pregnancy and development of lower respiratory tract infections (LRTIs) during the first 3 years of life and whether GSTM1 gene polymorphisms modify these effects.

METHODS

This study included 1,180 mother-child pairs from the Cohort for Childhood Origin of Asthma and allergic diseases. The PM_2.5 levels during pregnancy were estimated by residential address using land-use regression models based on a national monitoring system. A diagnosis of LRTIs was based on a parental report of a physician's diagnosis. Real-time polymerase chain reaction was used for GSTM1 genotyping.

RESULTS

Higher PM_2.5 exposure during the third trimester was associated with LRTIs at 1 year of age (aRR, 1.06; 95% CI, 1.00-1.13). This result did not change after adjusting for PM_2.5 exposures during the first and second trimesters (aRR, 1.06; 95% CI, 0.99-1.13). This association was significant after adjusting for PM_2.5 exposures during first year of age (aRR, 1.08; 95% CI, 1.02-1.15) and exposures to NO₂ and ozone at the third trimester (aRR, 1.07; 95% CI, 1.00-1.16). In addition, PM_2.5 exposure during the third trimester increased the risk of LRTIs at 1 year of age in cases with the GSTM1 null genotype (aRR, 1.26; 95% CI, 1.01-1.57; P for interaction .20).

CONCLUSION

Higher PM_2.5 exposure during the third trimester of pregnancy may increase the susceptibility to LRTIs at 1 year of age. This effect is modified by GSTM1 gene polymorphisms.

Prenatal mold exposure is associated with development of atopic dermatitis in infants through allergic inflammation

OBJECTIVE

Mold exposure in early life may be associated with development of atopic dermatitis; however, studies of this link are inconclusive and evidence for the underlying mechanism(s) is lacking. This study identified the association between the time of mold exposure and development of atopic dermatitis and investigated the underlying mechanisms.

METHOD

The association between atopic dermatitis and mold exposure was examined in the Cohort for Childhood Origin of Asthma and Allergic Diseases birth cohort study (n=1446). Atopic dermatitis was diagnosed at 1 year of age by pediatric allergists. Exposure to mold was assessed by questionnaire. The Illumina MiSeq platform was used to examine the environmental mycobiome in 20 randomly selected healthy infants and 20 infants with atopic dermatitis at 36 weeks of gestation.

RESULTS

Prenatal, but not postnatal, mold exposure was significantly associated with atopic dermatitis (adjusted odds ratio, 1.36; 95% confidence interval, 1.01-1.83). Levels of total serum IgE at 1 year of age were higher in infants with atopic dermatitis exposed to mold during pregnancy than in healthy infants not exposed to mold during pregnancy (p=0.021). The relative abundance of uncultured Ascomycota was higher in infants with atopic dermatitis than in healthy infants. The relative abundance of uncultured Ascomycota correlated with total serum IgE levels at 1 year of age (r=0.613, p<0.001).

CONCLUSION

Indoor mold exposure during the fetal period is associated with development of atopic dermatitis via IgE-mediated allergic inflammation. Avoidance of mold exposure during this critical period might prevent the development of atopic dermatitis.

Early-life exposure to humidifier disinfectant determines the prognosis of lung function in children

BACKGROUND

Use of humidifier disinfectants (HD) at home leads to chemical airborne exposure, causing HD associated lung injury (HDLI) with high mortality. However, the lung function in children diagnosed with HDLI is not well studied. We investigated the effect of HD exposure on lung function, prognosis, and exposure characteristics associated with the lung function phenotype in children.

METHODS

Eighty-one children diagnosed with HDLI in a nationwide cohort were tested for spirometry and diffusing capacity of the lung for carbon monoxide (DLco) from July 2013 and followed up with at five time points over 2 years. The results were compared with 122 children without HD exposure as controls. Home investigation and questionnaire analysis were conducted to assess HD inhalation exposure.

RESULTS

HDLI survivor's mean percent of predicted forced expiratory volume in 1 s (FEV₁), forced vital capacity (FVC), and corrected DLco were significantly lower compared with the control group. On longitudinal assessment, FVC was within the normal range, but flattened, and spirometry showed a predominantly restrictive pattern. Corrected DLco did not normalize above 80% despite increasing age. The persistently low phenotype of lung function was associated with initial exposure age, especially less than 12 months of age. Higher density HD exposure during sleep and close distance between the bed and the humidifier were significantly associated with persistently low corrected DLco.

CONCLUSIONS

HD exposure affects prolonged decrement in lung function, especially DLco, particularly among children who are exposed within the first year of life. These results suggested that early-life HD exposure determines long-term prognosis of lung function in children.

Postpartum women’s experience of abuse in childhood, postnatal depression, and thoughts of self-harm

Background

Postnatal depression threatens the health of both mothers and babies. To improve maternal and child health in Seoul, South Korea, a nurse home visitation program for pregnant women and new mothers and babies has been implemented since 2013.

Methods

Cross-sectional data collected from 9,124 mothers while they were visiting a public health center for prenatal services or a nurse was visiting their home within 6 weeks after birth between 2014 and 2018 were analyzed. Mothers were asked whether they had experienced physical, emotional, or sexual abuse in their childhood. Postnatal depression and thoughts of self-harm were measured using the Edinburgh Postnatal Depression Scale (EPDS). Postnatal depression was defined as a total EPDS score of 13 or higher; thoughts of self-harm were defined as a response of “yes, quite often,” “sometimes,” or “hardly ever” to the corresponding item, excluding the response of “never".

Results

Overall, 3.2% of mothers had experienced child abuse; 8.1% experienced postnatal depression and 5.4% reported thoughts of self-harm. Postnatal depression was more common in mothers who had experienced child abuse than among those who had not (24.2% vs. 7.6%). A similar pattern was found for thoughts of self-harm (21.1% vs. 4.9%, respectively). When controlling for mothers’ age, economic status, history of receiving treatment for mental health problems, and other factors, having experienced child abuse was associated with a 2.73-fold increase in the odds of postnatal depression (odds ratio, 2.02-3.70) and a 3.58-fold increase in the odds of thoughts of self-harm (odds ratio, 2.58-4.96).

Conclusions

Mothers should be screened for having experienced child abuse when providing public health perinatal care to improve mothers’ mental health and parenting practices and to promote their children’s growth and development.

Key messages

Child abuse may have a lifelong negative effect on victims, and the effect extends to the next generation’s health and development. Public health policy and interventions to prevent child abuse are needed to tackle health inequality beginning in early childhood.

P313ADGRL2 is an essential surface molecule for cardiac lineage specification and heart development

Background

Specific surface markers that enable monitoring of cell subsets would be valuable for establishing the conditions under which pluripotent stem cells (PSCs) differentiate into cardiac progenitor cells (CPCs) and cardiomyocytes (CMCs).

Methods and results

To verify whether a specific marker is expressed during heart development, we assessed its expression using the CLARITY technique. After immersion in a solution with a refractive index matching that of the CLARITY hybrid, the mouse embryo became transparent. After immunostaining the cleared embryo sample, Adgrl2 was exclusively observed in cardiac cells expressing α-SA at embryonic day E9.5 and E10.5. Our clarified 3D images and movies show that four chambers of the heart are fully developed at E10.5 but not at E9.5. At E9.5, Adgrl2 is observed at the ventricle and atrium, while Adgrl2 is present in all chambers of the heart at E10.5. Next, we performed LacZ (β-Gal) staining in heterozygous Adgrl2 KO embryos to evaluate Adgrl2 expression. As a result, LacZ staining showed that Adgrl2 was predominantly expressed in the heart during the embryonic developmental stage. Adgrl2 knockout in mice was embryonically lethal because of severe heart, but not vascular, defects. To examine the use of Adgrl2 as a bona fide CPC marker during heart development, we tracked Adgrl2 expression during early embryonic development. The heart of Adgrl2−/− embryos at E10.5 exhibited occlusion of the RV, and the expression levels of Gata4 and Nkx2.5 were not as high as those in wild-type and Adgrl2+/− embryos. Interestingly, the heart of Adgrl2−/− embryos, unlike those of wild-type and Adgrl2+/− embryos between E13.5 and E15.5 had a single ventricle revealing a ventricular septal defect. The specific expression pattern of Adgrl2 in PSC-derived cardiac lineage cells as well as in embryonic heart, adult mice, and human heart tissues.

Conclusion

We demonstrate that Adgrl2 plays a pivotal and functional role across all strata of the cardiomyogenic lineage, as early as the precursor stage of heart development. These findings shed light on heart development and regeneration.

Acknowledgement/Funding

Grants from “Strategic Center of Cell and Bio Therapy” (grant number: HI17C2085) and “Korea Research-Driven Hospital” (HI14C1277)

P3479Sequential stimulation and inhibition of lysophosphatidic acid receptor 4 are critical for cardiac differentiation and repair

Background

The clinical application of cell therapy to repair the damaged heart needs to understand the precise differentiation process of stem cells and the characteristics of cardiac progenitor cells.

Purpose

We examined the cardiac-specific markers that expressed on the cell surface and determined their functional significance during cardiac differentiation.

Methods and results

We screened cell-surface expressing proteins on cardiac progenitor cells at differentiation day 3 compared to undifferentiated pluripotent stem cells (PSCs). Among candidates, we identified lysophosphatidic acid receptor 4 (LPAR4) that is a G protein-coupled receptor. During in vitro differentiation of mouse PSCs toward cardiac cells, LPAR4 expression peaked for 3–5 days and then and declined immediately. Also in vivo, LPAR4 was specifically expressed in the early stage of heart development in embryos and disappeared completely in adults, suggesting that stimulatory signal of LPAR4 at an early stage should be shut off for further progression of differentiation. We next have identified the LPAR4 downstream signaling molecule, p38MAPK, by comparing PSCs and LPAR4 knockdown PSCs. In both mouse and human PSCs, ODP (LPAR4 specific agonist) followed by p38MAPK blocker (SB203580) treatment significantly increased cardiac differentiation efficiency. Furthermore, we investigated whether LPAR4 is the maker for adult cardiac progenitor cells. We found that LPAR4-positive cells were rarely present in normal adult mouse hearts, but LPAR4-positive cells were increased when the heart was damaged. LPAR4-positive cells from adult hearts differentiated into cardiomyocytes. After myocardial infarction (MI), the sequential stimulation and inhibition of LPAR4 with ODP and p38MAPK blocker resulted in the reduction of infarct size and improvement of left ventricular dysfunction.

Conclusion

We demonstrated that LPAR4 is a cardiac progenitor-specific marker and its functional significance during cardiac differentiation and regeneration. Our findings provide a new insight in cell-free cardiac repair by the modulation of progenitor-specific downstream signaling.

Acknowledgement/Funding

Grants from “Strategic Center of Cell and Bio Therapy” (grant number: HI17C2085) and “Korea Research-Driven Hospital” (HI14C1277)

Association between sensitization and allergic diseases in 7-years-old Korean children

BACKGROUND

Sensitization is associated with the exacerbation, severity, and prognosis of allergic diseases in children OBJECTIVE: We characterized the association between sensitization patterns and allergic diseases.

METHODS

A cohort of 548 children was enrolled from Panel Study of Korean Children (PSKC) study. Skin prick tests (SPTs) for 18 common allergens, blood tests, and methacholine bronchial challenge tests were performed at age 7. The Korean version of International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire was used.

RESULTS

The sensitization rate on SPTs was 46.4%. Sensitization to indoor allergens showed an association with symptoms of asthma (adjusted odds ratio [aOR], 2.39; 95% confidence intervals [95% CIs], 1.10-5.23), allergic rhinitis (AR, aOR 2.08, 95% CIs 1.42-3.06), and atopic dermatitis (AD, aOR 2.36, 95% CIs 1.24-4.50) in the preceding 12 months. In contrast, sensitization to outdoor allergens was associated with AR diagnosis only (aOR 2.40, 95% CIs 1.30-4.41). The number of sensitized allergens was associated with a lifetime diagnosis and symptoms in the preceding 12 months of AR and asthma, but not with AD or BHR. A higher degree of sensitization to indoor allergens was associated with symptoms in the preceding 12 months of asthma, AR, AD, and that for outdoor allergens was associated with symptoms in the prior 12 months of asthma and AR.

CONCLUSION

The sensitization patterns including allergen type, number, and degree of sensitization are helpful for interpreting the association between sensitization and allergic diseases and identifying the pathophysiologies and diverse phenotypes of allergic diseases.

Nasal Placode Development, GnRH Neuronal Migration and Kallmann Syndrome

The development of Gonadotropin releasing hormone-1 (GnRH) neurons is important for a functional reproduction system in vertebrates. Disruption of GnRH results in hypogonadism and if accompanied by anosmia is termed Kallmann Syndrome (KS). From their origin in the nasal placode, GnRH neurons migrate along the olfactory-derived vomeronasal axons to the nasal forebrain junction and then turn caudally into the developing forebrain. Although research on the origin of GnRH neurons, their migration and genes associated with KS has identified multiple factors that influence development of this system, several aspects still remain unclear. This review discusses development of the olfactory system, factors that regulate GnRH neuron formation and development of the olfactory system, migration of the GnRH neurons from the nose into the brain, and mutations in humans with KS that result from disruption of normal GnRH/olfactory systems development.

Vascular defects of DYRK1A knockouts are ameliorated by modulating calcium signaling in zebrafish

DYRK1A is a major causative gene in Down syndrome (DS). Reduced incidence of solid tumors such as neuroblastoma in DS patients and increased vascular anomalies in DS fetuses suggest a potential role of DYRK1A in angiogenic processes, but in vivo evidence is still scarce. Here, we used zebrafish dyrk1aa mutant embryos to understand DYRK1A function in cerebral vasculature formation. Zebrafish dyrk1aa mutants exhibited cerebral hemorrhage and defects in angiogenesis of central arteries in the developing hindbrain. Such phenotypes were rescued by wild-type dyrk1aa mRNA, but not by a kinase-dead form, indicating the importance of DYRK1A kinase activity. Chemical screening using a bioactive small molecule library identified a calcium chelator, EGTA, as one of the hits that most robustly rescued the hemorrhage. Vascular defects of mutants were also rescued by independent modulation of calcium signaling by FK506. Furthermore, the transcriptomic analyses supported the alterations of calcium signaling networks in dyrk1aa mutants. Together, our results suggest that DYRK1A plays an essential role in angiogenesis and in maintenance of the developing cerebral vasculature via regulation of calcium signaling, which may have therapeutic potential for DYRK1A-related vascular diseases.

Summary: The roles of DYRK1A in angiogenesis and maintenance of the developing cerebral vasculature mediated by calcium signaling were revealed using zebrafish dyrk1aa knockout mutants.

Bioaccumulation of polystyrene nanoplastics and their effect on the toxicity of Au ions in zebrafish embryos

As nano- and micro-sized plastics accumulate in the environment and the food chain of animals, including humans, it is imperative to assess the effects of nanoplastics in living organisms in a systematic manner, especially because of their ability to adsorb potential toxicants such as pollutants, heavy metals, and organic macromolecules that coexist in the environment. Using the zebrafish embryo as an animal model, we investigated the bioaccumulation and in vivo toxicity of polystyrene (PS) nanoplastics individually or in combination with the Au ion. We showed that smaller PS nanoplastics readily penetrated the chorion and developing embryos and accumulated throughout the whole body, mostly in lipid-rich regions such as in yolk lipids. We also showed that PS nanoplastics induced only marginal effects on the survival, hatching rate, developmental abnormalities, and cell death of zebrafish embryos but that these effects were synergistically exacerbated by the Au ion in a dose- and size-dependent manner. Such exacerbation of toxicity was well correlated with the production of reactive oxygen species and the pro-inflammatory responses synergized by the presence of PS, supporting the combined toxicity of PS and Au ions. The synergistic effect of PS on toxicity appeared to relate to mitochondrial damage as determined by ultrastructural analysis. Taken together, the effects of PS nanoplastics were marginal but could be a trigger for exacerbating the toxicity induced by other toxicants such as metal ions.

Bioaccumulation of polystyrene nanoplastics and their effect on the toxicity of Au ions in zebrafish embryos

As nano- and micro-sized plastics accumulate in the environment and the food chain of animals, including humans, it is imperative to assess the effects of nanoplastics in living organisms in a systematic manner, especially because of their ability to adsorb potential toxicants such as pollutants, heavy metals, and organic macromolecules that coexist in the environment. Using the zebrafish embryo as an animal model, we investigated the bioaccumulation and in vivo toxicity of polystyrene (PS) nanoplastics individually or in combination with the Au ion. We showed that smaller PS nanoplastics readily penetrated the chorion and developing embryos and accumulated throughout the whole body, mostly in lipid-rich regions such as in yolk lipids. We also showed that PS nanoplastics induced only marginal effects on the survival, hatching rate, developmental abnormalities, and cell death of zebrafish embryos but that these effects were synergistically exacerbated by the Au ion in a dose- and size-dependent manner. Such exacerbation of toxicity was well correlated with the production of reactive oxygen species and the pro-inflammatory responses synergized by the presence of PS, supporting the combined toxicity of PS and Au ions. The synergistic effect of PS on toxicity appeared to relate to mitochondrial damage as determined by ultrastructural analysis. Taken together, the effects of PS nanoplastics were marginal but could be a trigger for exacerbating the toxicity induced by other toxicants such as metal ions.