Alterations of Epidermal Lipid Profiles and Skin Microbiome in Children With Atopic Dermatitis

Kim Jihyun,Kim Byung Eui,Goleva Elena,Berdyshev Evgeny,배재웅,Kim Seokjin,Kim Hye-young,Lee Un Ha,Kim Myoung Shin,Jung Minyoung,Kim Hyunmi,Lee Jinyoung,Donald Y.M. Leung,Ahn Kangmo 대한천식알레르기학회 2023 Allergy, Asthma & Immunology Research Vol.15 No.2

Purpose: We aimed to investigate epidermal lipid profiles and their association with skin microbiome compositions in children with atopic dermatitis (AD). Methods: Specimens were obtained by skin tape stripping from 27 children with AD and 18 healthy subjects matched for age and sex. Proteins and lipids of stratum corneum samples from nonlesional and lesional skin of AD patients and normal subjects were quantified by liquid chromatography tandem mass spectrometry. Skin microbiome profiles were analyzed using bacterial 16S rRNA sequencing. Results: Ceramides with nonhydroxy fatty acids (FAs) and C18 sphingosine as their sphingoid base (C18-NS-CERs) N-acylated with C16, C18 and C22 FAs, sphingomyelin (SM) N-acylated with C18 FAs, and lysophosphatidylcholine (LPC) with C16 FAs were increased in AD lesional skin compared to those in AD nonlesional skin and that of control subjects (all P < 0.01). SMs N-acylated with C16 FAs were increased in AD lesional skin compared to control subjects (P < 0.05). The ratio of NS-CERs with long-chain fatty acids (LCFAs) to short-chain fatty acids (SCFAs) (C24-32:C14-22), the ratio of LPC with LCFAs to SCFAs (C24-30:C16-22) as well as the ratio of total esterified omega-hydroxy ceramides to total NS-CERs were negatively correlated with transepidermal water loss (rho coefficients = −0.738, −0.528, and −0.489, respectively; all P < 0.001). The proportions of Firmicutes and Staphylococcus were positively correlated to SCFAs including NS ceramides (C14-22), SMs (C17-18), and LPCs (C16), while the proportions of Actinobacteria, Proteobacteria, Bacteroidetes, Corynebacterium, Enhydrobacteria, and Micrococcus were negatively correlated to these SCFAs. Conclusions: Our results suggest that pediatric AD skin shows aberrant lipid profiles, and these alterations are associated with skin microbial dysbiosis and cutaneous barrier dysfunction.

Bifidobacterium longum and Galactooligosaccharide Improve Skin Barrier Dysfunction and Atopic Dermatitis-like Skin

Kim Sukyung,Han Song-Yi,Lee Jinyoung,Kim Na-Rae,Lee Bora,Kim Hyunmi,Kwon Mijeoung,Ahn Kangmo,Noh Youngbae,Kim Sang Jong,Lee Phyrim,Kim Dongki,Kim Byung Eui,김지현 대한천식알레르기학회 2022 Allergy, Asthma & Immunology Research Vol.14 No.5

Purpose: The beneficial effects of a combination therapy using Bifidobacterium longum and galactooligosaccharide (GOS) for the treatment of atopic dermatitis (AD) have not been elucidated. Methods: Gene expressions of interleukin (IL)-4 and IL-13 from peripheral blood mononuclear cells and fecal abundance of B. longum from 12-month-old infants were evaluated. Human primary epidermal keratinocytes (HEKs) and hairless mice were treated with B. longum, GOS, B. longum-derived extracellular vesicles (BLEVs), dinitrochlorobenzene (DNCB), or a synbiotic mixture of B. longum and GOS. Expression of epidermal barrier proteins and cytokines as well as serum immunoglobulin E (IgE) levels were analyzed in HEKs and mice. Dermatitis scores, transepidermal water loss (TEWL), epidermal thickness, and fecal B. longum abundance were evaluated in mice. Results: Fecal abundance of B. longum was negatively correlated with blood IL-13 expression in infants. B. longum or BLEVs increased expression of filaggrin (FLG) and loricrin (LOR) in HEKs. B. longum increased the efficacy of GOS to upregulate FLG and LOR expressions in HEKs. Oral administration of GOS increased fecal abundance of B. longum in mice. Oral administration of B. longum attenuated DNCB-induced skin inflammation, abnormal TEWL, AD-like skin, and deficiency of epidermal barrier proteins. Moreover, the combination of B. longum and GOS showed greater effects to improve DNCB-induced skin inflammation, abnormal TEWL, AD-like skin, serum IgE levels, IL-4 over-expression, and the deficiency of epidermal barrier proteins than the administration of B. longum alone. Conclusions: B. longum and GOS improve DNCB-induced skin barrier dysfunction and AD-like skin.

Quality of Life in Food Allergy: Validation of the Korean Version of the Food Allergy Quality of Life Questionnaire Parent Form (K-FAQLQ-PF) and Risk Factor Analysis

Kim Sukyung,Kim Minji,Kim Jiwon,Park Boram,Min Nuri,Jung Minyoung,Yu Seoyoung,Lee Ji Young,Yoo Hye Won,Kim Hye-Young,Ahn Kangmo,Kim Jihyun 대한천식알레르기학회 2023 Allergy, Asthma & Immunology Research Vol.15 No.1

Purpose: This study aimed to evaluate the reliability and validity of the Korean version of the Food Allergy Quality of Life Questionnaire-Parent Form (K-FAQLQ-PF) and to identify clinical characteristics related to low quality of life (QoL) in Korean children with food allergy (FA). Methods: Parents of 0–12-year-old patients with FA were enrolled. The English version of FAQLQ-PF was translated into Korean. Construct validation was confirmed by the Food Allergy Independent Measure-Parent Form (FAIM-PF) and the Child Health Questionnaire Parent Form 28 (CHQ-PF28). Logistic regression analyses were used to evaluate associations between potential risk factors and QoL outcomes. Results: A total of 182 patients with a median age of 5.0 years were enrolled in the study. Cronbach’s α coefficient values indicating internal consistency were higher than 0.8. Intraclass correlation coefficient values for test-retest reliability were good for all age groups (r > 0.6). Total K-FAQLQ-PF scores were positively correlated with the FAIM-PF (r = 0.56, P < 0.05) and were negatively correlated with the parental impact-emotional domain in the CHQ-PF28 (r = −0.44, P < 0.05). In multivariable logistic regression analysis, low QoL was significantly associated with female sex (adjusted odds ratio [aOR], 2.07; 95% confidence interval [CI], 1.03–4.18), age ≥ 5 years (aOR, 2.84; 95% CI, 1.31–6.16), FA diagnosis before the age of 3 years (aOR, 3.96; 95% CI, 1.13–13.93), the presence of atopic dermatitis (aOR, 2.21; 95% CI, 1.07–4.57), and residence in non-metropolitan areas (aOR, 3.44; 95% CI, 1.73–6.85). Conclusions: According to parental perceptions, the K-FAQLQ-PF is a valid and reliable tool to assess psychosocial QoL in Korean children with FAs. Age, sex, residential area, and comorbid AD can affect the QoL of pediatric patients with FA.

Malignancy in Patients With Inborn Errors of Immunity Beyond Infectious Complication: Single Center Experience for 30 Years

( Doo Ri Kim ),( Kyung-ran Kim ),( Hwanhee Park ),( Joon-sik Choi ),( Yoonsun Yoon ),( Sohee Son ),( Hee Young Ju ),( Jihyun Kim ),( Keon Hee Yoo ),( Kangmo Ahn ),( Hee-jin Kim ),( Eun-suk Kang ),( Ju 대한소아감염학회 2023 Pediatric Infection and Vaccine Vol.30 No.3

목적: 선천면역장애 환자들은 감염에 취약할 뿐만 아니라, 면역이 정상인 사람들에 비해 암 발생률도 높은 것으로 알려져 있다. 본 연구는 단일 기관에서 추적 중인 선천면역장애 환자들에서의 암 발생을 조사하여 보고자 하였다. 방법: 1994년 11월부터 2023년 9월까지 삼성서울병원에서 선천면역장애 진단 하에 추적하는 환자를 대상으로 후향적으로 의무기록을 리뷰하였다. 선천면역장애 환자 중에서 암으로 진단된 환자를 확인하였다. 결과: 총 194명의 선천면역장애 환자 중, 7명(3.6%)의 환자에서 암이 진단되었다. 5명의 환자가 림프종으로 진단받았으며 그 중 4명의 환자는 Epstein-Barr 바이러스 연관 림프종이었다. 나머지 암은 위암과 다발 골수종이었다. 암 진단 당시 나이는 중앙값 18세 (범위, 1세-75세)였다. 암이 발생한 환자들의 면역결핍 질환은 X-linked lymphoproliferative disorder-1 (XLP-1) 3명, activated phosphoinositide 3-kinase delta disease (APDS) 2명, cytotoxic T-lymphocyte antigen 4 (CTLA-4) haplo-insufficiency 2명이었다. 개별 질환별로 분석하였을 때, XLP-1 환자의 75.0%, APDS 환자의 40.0%, CTLA-4 환자의 50.0%에서 암이 발생하였다. XLP-1 환자는 APDS 및 CTLA-4 haplo-insufficiency 환자에 비해 더 이른 나이에 암이 발생하였다 (중앙연령 5세, P<0.001). 한 명은 조혈모세포 이식 치료 중 사망하였다. 결론: 국내 단일 기관에서 진료받는 선천면역장애 환자들의 3.6%에서 암이 발생하였다. 선천면역장애 환자들을 진료하는 의료진들은 이들 환자에서 감염이나 염증 등의 문제외에도 암 발생의 가능성, 특히 Epstein-Barr 바이러스 감염과 연관된 암의 비중이 높은 것에 대한 인식을 갖는 것이 중요하다 Purpose: Cancer incidence is known to be higher in patients with inborn errors of immunity (IEI) compared to the general population in addition to traditionally well-known infection susceptibility. We aimed to investigate cancer occurrence in patients with IEI in a single center. Methods: Medical records of IEI patients treated at Samsung Medical Center, Seoul, Korea were retrospectively reviewed from November 1994 to September 2023. Patients with IEI and cancer were identified. Results: Among 194 patients with IEI, seven patients (3.6%) were diagnosed with cancer. Five cases were lymphomas, 4 of which were Epstein-Barr virus (EBV)-associated lymphomas. The remaining cases included gastric cancer and multiple myeloma. The median age at cancer diagnosis was 18 years (range, 1-75 years). Among patients with cancer, underlying IEIs included X-linked lymphoproliferative disease-1 (XLP-1, n=3), activated phosphoinositide 3-kinase delta syndrome (APDS, n=2), and cytotoxic T-lymphocyte antigen 4 (CTLA-4) haplo-insufficiency (n=2). Seventy-five percent (3/4) of XLP-1 patients, 40.0% (2/5) of APDS patients, and 50.0% (2/4) of CTLA-4 haplo-insufficiency patients developed cancer. Patients with XLP-1 developed cancer at earlier age (median age 5 years) compared to those with APDS and CTLA-4 (P<0.001). One patient with APDS died during hematopoietic cell transplantation. Conclusions: Cancer occurred in 3.6% of IEI patients at a single center in Korea. In addition to infectious complications and inflammation, physicians caring for IEI patients should be aware of the potential risk of cancer, especially in association with EBV infection

Severe Human Rhinovirus Lower Respiratory Tract Infections in Young Children

( Doo Ri Kim ),( Kyung-ran Kim ),( Hwanhee Park ),( Esther Park ),( Joongbum Cho ),( Jihyun Kim ),( Hee Jae Huh ),( Kangmo Ahn ),( Nam Yong Lee ),( Yae-jean Kim ) 대한소아감염학회 2023 Pediatric Infection and Vaccine Vol.30 No.3

목적: 리노바이러스의 감염은 하기도 감염을 일으키기도 한다. 본 연구에서는 리노바이러스에 의한 중증 하기도 감염을 보이는 소아환자의 특성을 알아보고자 하였다. 방법: 2016년부터 2020년까지 삼성서울병원 소아청소년과에 리노바이러스 하기도감염으로 입원한 환자의 의무기록을 후향적으로 분석하였다. 입원 시 연령이 생후90일 이상, 5세 미만인 소아 환자를 대상으로 하였다. 다른 호흡기 병원체와의 동시 감염이 확인된 환자는 제외하였다. 리노바이러스에 의한 중증 하기도감염은 고유량 산소요법 치료가 필요한 경우, 기계 호흡이 필요한 경우 또는 중환자실 입원하는 경우로 정의하였다. 결과: 해당 기간 동안 총 115건의 리노바이러스 하기도 감염 입원이 확인되었다. 연령 중앙값은 17개월 (범위, 3-56개월) 이었으며, 입원 일수 중앙값은 4일 (범위, 2-31일) 이었다. 115 건 중 18건의 입원 (15.7%)은 중증 리노바이러스 하기도 감염 그룹으로 분류되었다. 중증 경과 그룹 환자의 연령 중앙값은 그렇지 않은 그룹에 비해 연령 중앙값이 낮았다 (9.5개월 vs. 19.0 개월, P=0.001). 18명의 중증 리노바이러스 하기도 감염 그룹 환자 중 11명 (61.1%)는 기저질환을 가지고 있었으며, 만성 폐질환이 가장 많은 비율을 차지하였다 (63.6%). 여섯 명의 환자는 (33.3%) 기계 호흡을 필요로 하였다. 일곱 명의 기저질환이 없는 환자도 중증 리노바이러스 하기도 감염 그룹에 포함되어 있었다. 이들 일곱 명의 환자 중 네 명은 추후에 천식으로 진단되었다. 115건의 입원을 기저질환이 없는 환자군 (n=60)과 기저질환이 있는 환자군 (n=55)으로 나누어 분석하였을 때, 리노바이러스에 의한 중증 하기도 감염을 보이는 비율은 각각 11.7% 와 20.0%였다 (P=0.219). 결론: 리노바이러스 감염은 중증 하기도감염의 원인이 될 수 있으며, 기저질환자 뿐 아니라 건강한 소아에서도 중증 하기도감염을 일으킬 수 있다 Purpose: Human rhinovirus (HRV) infections can result in lower respiratory tract infections (LRTIs). We aimed to investigate the characteristics of severe HRV LRTI in young children. Methods: Medical records were reviewed retrospectively in patients who were hospitalized for HRV LRTIs from 2016 to 2020 at the Samsung Medical Center in Seoul, Korea. Patients aged 90 days or older and younger than 5 years were included. Patients with co-infections with other respiratory pathogens were excluded. Severe HRV LRTI was defined as the following: the need for high-flow oxygenation, mechanical ventilation, or intensive care unit admission. Results: A total of 115 cases were identified. The median age was 17 months (range, 3-56 months) and the median hospital days were 4 days (range, 2-31 days). Of the 115 cases, 18 patients (15.7%) developed severe HRV LRTI. The median age was younger in the severe group compared to the non-severe group (9.5 months vs. 19.0 months, P=0.001). Of 18 patients with severe HRV LRTI, 11 (61.1%) had underlying diseases - chronic lung diseases accounted for the largest proportion (63.6%). Six patients (33.3%) required mechanical ventilation. Of note, 7 previously healthy children were diagnosed with severe HRV LRTI. Of those 7 children, 4 of them were diagnosed with asthma later. When the 115 cases were divided into previously healthy (n=60) and underlying disease (n=55) groups, severe courses of HRV LRTI were observed in 11.7% and 20.0% of children, respectively (P=0.219). Conclusions: HRV can cause severe LRTI even in previously healthy children as well as in children with comorbidities

Allergenicity Assessment of Cry Proteins in Insect-resistant Genetically Modified Maize Bt11, MON810, and MON863

Jae-Hwan Kim,Young-Ju Seo,Ji-Young Kim,Young-Shin Han,Kwang-Shin Lee,Sun-Ah Kim,Han-Na Kim,Kangmo Ahn,Sang-Il Lee,Hae-Yeong Kim 한국식품과학회 2009 Food Science and Biotechnology Vol.18 No.5

This study aimed to evaluate the potential allergenicity of Cry proteins in insect-resistant genetically modified (GM) maizes (Bt11, MON810, and MON863) using serum screening tests. Serum samples were obtained from Korean children (0-15 years old) with allergic symptoms who had positive maize-specific IgE. The levels of serum specific IgE was measured by the Phadia ImmunoCAP system and considered as positive when they are 0.35 kU/ℓ or higher. Cry proteins (Cry1Ab in Bt11, mCry1Ab in MON810, and Cry3Bb1 in MON863) were expressed in Escherichia coli and purified for serum screening. The reactivity of purified Cry proteins was confirmed by IgE immunoblots in 50 patients (maize-sensitized patients). There was no reaction between Cry proteins and sera from maize-sensitized patients. Our results suggest that these Cry proteins are not likely to cause allergic reactions. Further studies using more sera from patients with true clinical allergies are needed to evaluate the potential allergenicity of novel proteins in GM maize.

Psychological Distress and Perceived Burden in Parents of Korean Children With IgE-Mediated Food Allergy

Jung Minyoung,Kang Urim,Kim Sukyung,Yoo Hye Won,Kim Hye-Young,Kim Minji,Lee Ji Young,Kim KyooSang,Lee Eunsun,Kang Byoung-Chul,Park Boram,Ahn Kangmo,Kim Jihyun 대한의학회 2023 Journal of Korean medical science Vol.38 No.27

Background: Food allergy (FA) can have a profound effect on quality of life (QoL), stress, and anxiety in the family. We aimed to validate the Korean version of the Food Allergy Quality of Life-Parental Burden (FAQL-PB) and identify factors related to the parental psychosocial burden of caring for children with FAs. Methods: Parents of children aged between 6 months and 17 years with immunoglobulin E (IgE)-mediated FAs from the Pediatric Allergy Department of five university hospitals in Korea were enrolled in the study. Parents were asked to complete the FAQL-PB, Food Allergy Independent Measure-Parent Form (FAIM-PF), Child Health Questionnaire-Parents Form 28 (CHQ-PF28), Beck’s Anxiety Inventory, Connor-Davidson Resilience Scale, and Patient Health Questionnaire-9 for depression. Statistical analyses included internal consistency, test-retest reliability, concurrent validity, discriminative validity, and logistic regression analyses. Results: A total of 190 parents were enrolled. Social activity limitation was the item with the highest FAQL-PB scores. The Cronbach’s α for each item was higher than 0.8. The test-retest reliability was good (intra-class correlation coefficient, 0.716; 95% confidence interval [CI], 0.100–0.935). An increase in the FAQL-PB was significantly associated with an increase in the FAIM-PF (β = 0.765, P < 0.001) (concurrent validity). There was a positive correlation between parental burden, anxiety, and depression, while resilience was inversely correlated with parental burden (all P < 0.001). The total FAQL-PB score in parents of children who had experienced anaphylaxis was significantly higher than that in parents of children who did not experience it (P = 0.008). When adjusting for age, sex, and underlying diseases, anaphylaxis (β = 9.32; 95% CI, 2.97 to 15.68), cow’s milk (CM) allergy (β = 8.24; 95% CI, 2.04 to 14.44), soybean allergy (β = 13.91; 95% CI, 1.62 to 26.20), higher anxiety (β = 1.05; 95% CI, 0.07 to 1.41), higher depression (β = 2.15; 95% CI, 1.61 to 2.69), and lower resilience (β = −0.42; 95% CI, −0.61 to −0.2) were significantly associated with greater parental burden in children with IgE-mediated FAs. Conclusion: FAQL-PB is a reliable and valid tool for use in Korea. Anaphylaxis, CM or soybean allergies, more anxiety and depression symptoms, and lower resilience are associated with poorer QoL in parents of children with FAs.

소아에서 성공한 isoniazid와 rifampin에 대한 신속 탈감작요법 1예

이혜림 ( Heirim Lee ),김민선 ( Min-sun Kim ),양혜경 ( Hea-kyoung Yang ),김민지 ( Minji Kim ),이지영 ( Ji Young Lee ),김종민 ( Jong-min Kim ),강지만 ( Ji-man Kang ),김예진 ( Yae-jean Kim ),안강모 ( Kangmo Ahn ),김지현 ( Jihyun Kim 대한천식알레르기학회 2016 Allergy Asthma & Respiratory Disease Vol.4 No.3

Hypersensitivity reactions to antituberculosis medicine are obstacles to the treatment of tuberculosis. However, rapid drug desensitization can secure successful treatment with essential antituberculosis medicines in pediatric patients. A 17-year-old boy with active pulmonary tuberculosis complained of generalized erythematous rashes, pruritus on the 11th day of tuberculosis treatment. He was diagnosed with hypersensitivity reactions to isoniazid and rifampin by the oral provocation test. After desensitization, the patient continued to take antituberculosis treatment with isoniazid, rifampin, pyrazinamide, and ethambutol. We report here a case of successful desensitization in an adolescent with hypersensitivity to isoniazid and rifampin. (Allergy Asthma Respir Dis 2016;4:212-216)

Association between cord blood 25-hydroxyvitamin D concentrations and respiratory tract infections in the first 6 months of age in a Korean population: a birth cohort study (COCOA)

Shin, Youn Ho,Yu, Jinho,Kim, Kyung Won,Ahn, Kangmo,Hong, Seo-Ah,Lee, Eun,Yang, Song-I,Jung, Young-Ho,Kim, Hyung Young,Seo, Ju-Hee,Kwon, Ji-Won,Kim, Byoung-Ju,Kim, Hyo-Bin,Shim, Jung Yeon,Kim, Woo Kyun The Korean Pediatric Society 2013 Clinical and Experimental Pediatrics (CEP) Vol.56 No.10

Purpose: Previous studies suggest that the concentration of 25-hydroxyvitamin D [25(OH)D] in cord blood may show an inverse association with respiratory tract infections (RTI) during childhood. The aim of the present study was to examine the influence of 25(OH)D concentrations in cord blood on infant RTI in a Korean birth cohort. Methods: The levels of 25(OH)D in cord blood obtained from 525 Korean newborns in the prospective COhort for Childhood Origin of Asthma and allergic diseases were examined. The primary outcome variable of interest was the prevalence of RTI at 6-month follow-up, as diagnosed by pediatricians and pediatric allergy and pulmonology specialists. RTI included acute nasopharyngitis, rhinosinusitis, otitis media, croup, tracheobronchitis, bronchiolitis, and pneumonia. Results: The median concentration of 25(OH)D in cord blood was 32.0 nmol/L (interquartile range, 21.4 to 53.2). One hundred and eighty neonates (34.3%) showed 25(OH)D concentrations less than 25.0 nmol/L, 292 (55.6%) showed 25(OH)D concentrations of 25.0-74.9 nmol/L, and 53 (10.1%) showed concentrations of ${\geq}75.0$ nmol/L. Adjusting for the season of birth, multivitamin intake during pregnancy, and exposure to passive smoking during pregnancy, 25(OH)D concentrations showed an inverse association with the risk of acquiring acute nasopharyngitis by 6 months of age (P for trend=0.0004). Conclusion: The results show that 89.9% of healthy newborns in Korea are born with vitamin D insufficiency or deficiency (55.6% and 34.3%, respectively). Cord blood vitamin D insufficiency or deficiency in healthy neonates is associated with an increased risk of acute nasopharyngitis by 6 months of age. More time spent outdoors and more intensified vitamin D supplementation for pregnant women may be needed to prevent the onset of acute nasopharyngitis in infants.

Multicenter Surveillance of Cystic Fibrosis in Korean Children

Kim Hyung Young,Hong Soo-Jong,Ahn Kangmo,Suh Dong In,Noh Shin Hye,Kim Soo Yeon,유진호,Ko Jung Min,이민구,김경원 대한천식알레르기학회 2022 Allergy, Asthma & Immunology Research Vol.14 No.5

Purpose: Cystic fibrosis (CF), caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, is rare among non-Caucasians. We aimed to identify the clinical features and CFTR mutations in Korean children. Methods: We included 18 pediatric patients with CF diagnosed using sweat chloride test or genetic analysis for 30 years. HEK293 cells were transfected with wild-type CFTR, ΔF508-CFTR, and L441P-CFTR mutant plasmids for 24 hours and treated with CFTR correctors (VX809 and VX661). Results: The median age at diagnosis was 9.2 years. Eleven patients had growth retardation, and 6 had a respiratory failure at diagnosis. Genetic analysis was used for all patients, while sweat testing was for 8 patients. At diagnosis, the median z scores of forced expiratory volume in one second (FEV1), FEV1/forced vital capacity, and forced expiratory flow at 25%–75% of forced vital capacity were −3.61 (−5.78, 1.78), −3.38 (−4.40, −0.60), and −4.45 (−5.78, 0.54), respectively. Two patients were treated with dornase alfa and only one with CFTR modulator. Patients were followed up for 3.7 years as a median. Four patients died at 10.6 years, with 4.2 years of post-diagnosis survival. The most common mutation was exon 16-17b deletion (19.4%). Among 11 single nucleotide variants, c.1322T>C (p.Leu441Pro, L441P) was detected in 4 patients. In the functional assay, L441P-CFTR correction was well restored by CFTR correctors compared with ΔF508. Conclusions: CF is extremely rare in Korean children and is caused by different mutations from those commonly observed in Caucasians. Early diagnosis and treatment availability may improve outcomes. CFTR modulators may be effective for Asian patients with rare CFTR mutations, c.1322T>C (p.Leu441Pro).