{"title":"Test-Retest Reliability, Learning Effect and Measurement Error of the Modified Shuttle Test (MST) in Children With Asthma: A Multicenter Study.","authors":"Lara Bezerra Radis, Vitória Cavalheiro Puzzi, Thaila Corsi Dias, Natielly Soares Correia, Jéssica Lane Felippe Montes, Mariana Mazzuca Reimberg, Fernanda Cordoba Lanza, Evelim Leal de Freitas Dantas Gomes, Cláudio Luiz Castro Gomes de Amorim, Karina Couto Furlanetto","doi":"10.1002/ppul.71852","DOIUrl":"https://doi.org/10.1002/ppul.71852","url":null,"abstract":"<p><strong>Objective: </strong>To investigate test-retest reliability, measurement error (standard error of measurement [SEM] and minimum detectable difference [MDD]), and the learning effect of the Modified Shuttle Test (MST) in children with asthma.</p><p><strong>Methods: </strong>Multicenter cross-sectional study including clinically stable children aged 6-12 years with asthma. Lung function and exercise capacity were assessed using MST. Intraclass Correlation Coefficient (ICC) was calculated to assess test-retest reliability. The first and second tests were compared using the paired Student's t-test to assess differences between tests. SEM and MDD were calculated to quantify measurement error.</p><p><strong>Results: </strong>One hundred and twenty three children were included (71 boys [57%]; median age 9 [7-10] years). The mean distance covered in the best MST was 611 ± 214 meters (confidence interval [95% CI] = 573-649meters). The MST showed an excellent test-retest reliability (ICC = 0.96; 95% CI: 0.95-0.97). Distance was significantly lower in the second test than in the first (574 ± 218 vs. 601 ± 216 m; p = 0.0001). Learning effect was -27 ± 79 (4% ± 14%), the SEM was 56 meters (9.5%), and the MDD was 156 m (26.6%).</p><p><strong>Conclusion: </strong>The MST demonstrated excellent test-retest reliability and acceptable measurement error for assessing exercise capacity in children with asthma. Although a systematic difference was observed between tests, there was no evidence of a consistent learning effect, with individual variability in repeated performance.</p>","PeriodicalId":19932,"journal":{"name":"Pediatric Pulmonology","volume":"61 10","pages":"e71852"},"PeriodicalIF":2.4,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13628282/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149113043","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Anna Wiesner, Katarzyna Jończyk-Potoczna, Marcin Mikoś, Katarzyna Krenke, Maciej Pronicki, Renata Langfort, Monika Duś-Żuchowska, Anna Bręborowicz, Irena Wojsyk-Banaszak
{"title":"Case Report: Epstein-Barr Virus (EBV) and Acid Sphingomyelinase Deficiency (ASMD) Type A/B: Possible Interaction.","authors":"Anna Wiesner, Katarzyna Jończyk-Potoczna, Marcin Mikoś, Katarzyna Krenke, Maciej Pronicki, Renata Langfort, Monika Duś-Żuchowska, Anna Bręborowicz, Irena Wojsyk-Banaszak","doi":"10.1002/ppul.71878","DOIUrl":"https://doi.org/10.1002/ppul.71878","url":null,"abstract":"","PeriodicalId":19932,"journal":{"name":"Pediatric Pulmonology","volume":"61 10","pages":"e71878"},"PeriodicalIF":2.4,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149195714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Modernizing Pediatric Pulmonology Training: The Necessity of Pivoting to a 2-Year Fellowship Model.","authors":"Don Hayes","doi":"10.1002/ppul.71886","DOIUrl":"https://doi.org/10.1002/ppul.71886","url":null,"abstract":"","PeriodicalId":19932,"journal":{"name":"Pediatric Pulmonology","volume":"61 10","pages":"e71886"},"PeriodicalIF":2.4,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149216632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cara Morgan, Alistair Calder, Matina Prapa, Thivya Sekar, Andrew Constantine, Tomas Woodgate, Annabelle Barnes, Eimear McGovern, Paul Aurora, Rossa Brugha, Sadia Quyam, Andrew Bush, Shahin Moledina
{"title":"Variant Class-Specific Phenotypes and Outcomes in Pediatric TBX4-Associated Pulmonary Hypertension.","authors":"Cara Morgan, Alistair Calder, Matina Prapa, Thivya Sekar, Andrew Constantine, Tomas Woodgate, Annabelle Barnes, Eimear McGovern, Paul Aurora, Rossa Brugha, Sadia Quyam, Andrew Bush, Shahin Moledina","doi":"10.1002/ppul.71857","DOIUrl":"10.1002/ppul.71857","url":null,"abstract":"<p><strong>Aim: </strong>To describe the variant class associations with phenotype, natural history, treatment response, and outcomes in children with TBX4-associated pulmonary hypertension (TBX4-PH).</p><p><strong>Methods: </strong>Retrospective cohort analysis of children < 18 years referred to the National Paediatric Pulmonary Hypertension Service between 2001 and 2025.</p><p><strong>Results: </strong>Twenty-one children were identified carrying either a copy number variant (CNV group = 10) encompassing TBX4 or a single nucleotide variant (SNV group = 11). Distinct phenotypic differences were observed between variant classes. Children in the CNV group were referred at a younger age (p = 0.03), more frequently had prolonged oxygen dependence from birth (p < 0.01), more severe lung disease (p < 0.01) and cyanosis (p = 0.04), congenital heart disease (p = 0.03), neurodevelopmental disorders (p < 0.01), and deafness (p = 0.01). Children in the SNV group were less likely to have any lung disease (p = 0.03). Histopathology from five children (CNV = 3, SNV = 2) demonstrated predominantly lung growth abnormalities with variable pulmonary vascular remodeling. Twenty of 21 (95%) children received long-term pulmonary vasodilator therapy, and 9 (43%) received concurrent calcium-channel blockers. Treatment-naïve children (n = 12) demonstrated stable/improved functional class with therapy initiation. Median follow-up was 7.1 years (range 0.7-17.2). Transplant- or Potts shunt-free survival at 1 and 5 years was 100% and 94.4% respectively and was worse in the CNV group (Log-rank p < 0.05).</p><p><strong>Conclusions: </strong>In this large pediatric TBX4-PH cohort, children carrying CNVs had greater multisystem involvement and poorer outcomes than those carrying SNVs, highlighting the importance of the underlying genetic finding for risk stratification and tailored management strategies.</p>","PeriodicalId":19932,"journal":{"name":"Pediatric Pulmonology","volume":"61 10","pages":"e71857"},"PeriodicalIF":2.4,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13640964/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149113091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Marta Agüera, Aleix Soler-Garcia, Sara Castellà, Sara Moussalam-Merino, Carme Alejandre, Daniel Penela-Sánchez, Cristina Esteva, Clàudia Fortuny, Mariona Fernández de Sevilla, Juan-José García-García, Iolanda Jordan, Carmen Muñoz-Almagro, Cristian Launes
{"title":"Assessing the Effects of Nirsevimab on Respiratory Syncytial Virus Bronchiolitis Outcomes: Insights From A Two-Season Analysis.","authors":"Marta Agüera, Aleix Soler-Garcia, Sara Castellà, Sara Moussalam-Merino, Carme Alejandre, Daniel Penela-Sánchez, Cristina Esteva, Clàudia Fortuny, Mariona Fernández de Sevilla, Juan-José García-García, Iolanda Jordan, Carmen Muñoz-Almagro, Cristian Launes","doi":"10.1002/ppul.71873","DOIUrl":"10.1002/ppul.71873","url":null,"abstract":"<p><strong>Objectives: </strong>Nirsevimab was approved in Europe in 2022 for respiratory syncytial virus (RSV) prevention. In October 2023, Catalonia (Spain) launched a universal immunization program for infants under 6 months during their first RSV season. This study aims to assess the characteristics of patients admitted with bronchiolitis following nirsevimab implementation and to compare the features of the immunized patients across two consecutive seasons.</p><p><strong>Methods: </strong>This prospective, observational, single-center study included infants aged up to 12 months admitted for bronchiolitis between October 2023 and May 2025, comparing clinical and epidemiological data across two seasons (S1: October 2023-May 2024; S2: October 2024-May 2025).</p><p><strong>Results: </strong>574 patients were included (S1: 352; S2: 222), with a median age of 3.2 months (interquartile range [IQR]: 1.5-6.5). Most were previously healthy (437/574, 76.1%) and immunized with nirsevimab (406/574, 70.7%). RSV was detected in 215/574 (37.5%) of cases. 159/574 (27.7%) required Pediatric Intensive Care Unit (PICU) admission, and the median length of hospital stay was 5 days (IQR:3-8). In S2, immunization rates increased (S1:61.6% vs S2:85.1%, p = < 0.001) whereas RSV infections decreased (S1:41.2% vs S2: 31.5%, p = 0.020). Among immunized patients, S2 exhibited a higher proportion of healthy children (S1:65.0% vs S2:77.8%, p = 0.005), fewer PICU admissions (S1:33.2% vs S2:21.2%, p = 0.007) and shorter hospital stays (S1: 6 [IQR:4-9.5] days vs S2: 5 [IQR:3-7.5] days, p = 0.033). Furthermore, in multivariable logistic regression analysis, admission during the second season remained independently associated with a lower risk of PICU admission (adjusted OR 0.587, 95% CI 0.368-0.936; p = 0.025).</p><p><strong>Conclusion: </strong>Among hospitalized infants with bronchiolitis after nirsevimab implementation, immunized patients admitted during the second season showed more favorable clinical outcomes, including lower PICU utilization and shorter hospitalizations.</p>","PeriodicalId":19932,"journal":{"name":"Pediatric Pulmonology","volume":"61 10","pages":"e71873"},"PeriodicalIF":2.4,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13662497/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149183876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Effects of Neurally Adjusted Ventilatory Assist on Lung Ultrasound Aeration and Diaphragmatic Function in Extremely Preterm Infants With Evolving or Established Bronchopulmonary Dysplasia.","authors":"Anay Kulkarni, Justin Richards, Touqueer Fatima, Shavindra Chellen, Donovan Duffy, Sandeep Shetty","doi":"10.1002/ppul.71885","DOIUrl":"10.1002/ppul.71885","url":null,"abstract":"<p><strong>Background: </strong>Neurally adjusted ventilatory assist (NAVA) delivers ventilatory support proportional to diaphragmatic electrical activity, improving patient-ventilator synchrony. Its effects on lung aeration and diaphragmatic workload in extremely preterm infants have not been well characterized.</p><p><strong>Objectives: </strong>We hypothesized that initiation of NAVA in preterm infants born at < 32 weeks' gestation would result in improved lung recruitment while allowing effective ventilation at lower airway pressures without increasing diaphragmatic workload.</p><p><strong>Methods: </strong>This prospective observational pilot study was conducted in a tertiary neonatal intensive care unit. Nineteen preterm infants (median gestational age 24 + 5 weeks; median birth weight 700 g, range 380-1352 g) were transitioned to NAVA at a median postnatal age of 30 + 5 days according to a pre-specified unit protocol. Lung ultrasound aeration scores (LUS), diaphragmatic excursion and thickness, peak electrical diaphragmatic activity (EAdi peak), mean airway pressure (MAP), and FiO<sub>2</sub> were measured immediately before and 1 h after NAVA initiation. Paired statistical analyses were performed.</p><p><strong>Results: </strong>LUS decreased markedly following NAVA initiation (mean 15.21 ± 3.26 vs. 7.11 ± 2.47; p < 0.001; Cohen's d = 3.02), with the effect observed in both invasive and non-invasive NAVA groups. MAP decreased significantly (11.82 ± 1.63 vs. 9.56 ± 1.64 cmH<sub>2</sub>O; p < 0.001) and FiO<sub>2</sub> showed a non-significant trend towards improvement (0.35 vs. 0.32; p = 0.020). Diaphragmatic excursion (7.05 ± 2.1 vs. 6.7 ± 2.2 mm; p = 0.650) and EAdi peak (8.4 vs. 8.3 mV; p = 0.839) were unchanged.</p><p><strong>Conclusions: </strong>In this pilot cohort, initiation of NAVA in extremely preterm infants was associated with rapid improvement in lung ultrasound aeration scores and reduced ventilatory pressures, without evidence of increased diaphragmatic loading. These findings are hypothesis-generating and larger controlled studies are needed to confirm them.</p>","PeriodicalId":19932,"journal":{"name":"Pediatric Pulmonology","volume":"61 10","pages":"e71885"},"PeriodicalIF":2.4,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149220507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Effectiveness of Surfactant Administration in Two Different Methods (MIST, INSURE) on the Short-Term Outcome of Preterm Infants With Respiratory Distress Syndrome: A Randomized Clinical Trial.","authors":"Fatemeh Heidarzadeh, Samira Pournajaf, Zahra Akbarian-Rad, Nesae Bozorgnezhad, Hemmat Gholinia Ahangar, Mohsen Haghshenas","doi":"10.1002/ppul.71874","DOIUrl":"10.1002/ppul.71874","url":null,"abstract":"<p><strong>Introduction: </strong>Preterm birth (< 37 weeks) causes high neonatal mortality, with respiratory distress syndrome (RDS) as a major complication due to surfactant deficiency. Surfactant administered via several methods. This study compares effectiveness and complications of two different methods of surfactant therapy.</p><p><strong>Methods: </strong>This randomized clinical trial was conducted involving two groups of a total of 80 neonates aged 28-34 weeks who, based on clinical conditions, required surfactant administration. In the INSURE method, the infant is first intubated with an appropriate size endotracheal tube, subsequently, surfactant is administered in a controlled manner using a feeding catheter and 20 cmH<sub>2</sub>O positive pressure ventilation (PPV) and 5 cmH<sub>2</sub>O positive end expiratory pressure (PEEP) with a T-piece device, and in the MIST method, while the infant is on nasal CPAP with a PEEP of 5 cmH<sub>2</sub>O, a thin feeding catheter is inserted into the trachea and Surfactant is then slowly administered at the same dose, the catheter is immediately removed and nasal CPAP is continued. And the outcomes included the duration of respiratory support, need for surfactant re-administration, mechanical ventilation and complications such as pulmonary hemorrhage, pneumothorax evaluated.</p><p><strong>Results: </strong>indicated that none of the infants in the MIST group developed pneumothorax, required a second dose of surfactant, or underwent mechanical ventilation, compared with 12.8% (p = 0.055), 10.3% (p = 0.123), and 10.3% (p = 0.123), respectively, in the INSURE group. similarly, the duration of CPAP support and oxygen therapy did not differ significantly between the groups.</p><p><strong>Conclusions: </strong>Although many of the findings did not reach statistical significance, MIST appears to be associated with potentially important clinical benefits that should not be overlooked. Further studies with larger sample sizes are warranted to confirm these findings.</p>","PeriodicalId":19932,"journal":{"name":"Pediatric Pulmonology","volume":"61 10","pages":"e71874"},"PeriodicalIF":2.4,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149183909","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abigail Bergman-Sieger, Marc-André Turcot, Lawrence E Ostrowski, Patrick R Sears, Maimoona A Zariwala, Fateh Bechkir, Lisa R Young, Adam J Shapiro, Maureen B Parenti
{"title":"Variants in CEP135 Cause Congenital Microcephaly and Primary Ciliary Dyskinesia.","authors":"Abigail Bergman-Sieger, Marc-André Turcot, Lawrence E Ostrowski, Patrick R Sears, Maimoona A Zariwala, Fateh Bechkir, Lisa R Young, Adam J Shapiro, Maureen B Parenti","doi":"10.1002/ppul.71866","DOIUrl":"https://doi.org/10.1002/ppul.71866","url":null,"abstract":"<p><strong>Introduction: </strong>Primary ciliary dyskinesia (PCD), a disorder of motile ciliary dysfunction causing chronic respiratory infections, may also rarely present with aspects of non-motile ciliary dysfunction, including retinitis, central nervous system malformations, skeletal dysplasia, and sensorineural hearing loss. However, congenital microcephaly has not been previously associated with PCD.</p><p><strong>Methods: </strong>We identified three children with congenital microcephaly and chronic respiratory disease consistent with PCD. Comprehensive PCD diagnostic testing and whole exome sequencing were performed. Characterization of nasal epithelial cells after expansion and regrowth included reverse transcription polymerase chain reaction, high speed videomicroscopy, and transcript analysis of novel genetic variants.</p><p><strong>Results: </strong>Three pediatric cases from two families had primary microcephaly from autosomal recessive variants in CEP135. All cases displayed chronic suppurative respiratory symptoms, recurrent otitis media, and bronchiectasis with low nasal nitric oxide. One case had pathogenic, compound heterozygous, loss of function variants, while the other two cases had homozygous variants of uncertain significance. Transcript analyses of CEP135 variants of uncertain significance supported a splicing defect as disease-causing. Regrown nasal epithelial cells demonstrated overall normal ciliary ultrastructure with decreased numbers of full-length axonemes. Ciliary beat pattern was grossly abnormal, and distal axoneme swelling with bulbous-tip structures were identified pre- and post-cellular regrowth.</p><p><strong>Conclusion: </strong>These cases establish variants in CEP135 as a novel cause of PCD with microcephaly. The TEM findings of bulbous ciliary tips may be a reliable marker of overlapping ciliopathies in patients with aspects of motile and non-motile ciliary dysfunction.</p>","PeriodicalId":19932,"journal":{"name":"Pediatric Pulmonology","volume":"61 10","pages":"e71866"},"PeriodicalIF":2.4,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13634309/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149113080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chelsea C Flora, Rebecca S Pettit, Hilary Vogt, Molly Bozic
{"title":"Use of Vanzacaftor/Tezacaftor/Deutivacaftor in Pediatric People With Cystic Fibrosis Liver Disease.","authors":"Chelsea C Flora, Rebecca S Pettit, Hilary Vogt, Molly Bozic","doi":"10.1002/ppul.71858","DOIUrl":"https://doi.org/10.1002/ppul.71858","url":null,"abstract":"","PeriodicalId":19932,"journal":{"name":"Pediatric Pulmonology","volume":"61 10","pages":"e71858"},"PeriodicalIF":2.4,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149113085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Residual-Function and Splicing CFTR Variants Characterize False-Negative IRT Newborn Screening: A Ten-Year Single-Center Cohort From Türkiye.","authors":"Çiğdem Korkmaz, Osman Talha Akpınar, Aysel Kılıç, Serap Dinçer Kartkaya, Abdurrahman Zarif Güney, Furkan Yılmaz, Berrak Öztosun, Abdülhamit Çollak, Ayşe Ayzıt Kılınç Sakallı","doi":"10.1002/ppul.71864","DOIUrl":"https://doi.org/10.1002/ppul.71864","url":null,"abstract":"<p><strong>Background: </strong>Cystic fibrosis (CF) newborn screening in Türkiye uses a two-step immunoreactive trypsinogen (IRT/IRT) algorithm with fixed cutoffs. The infants missed by fixed-cutoff screening remain poorly characterized.</p><p><strong>Methods: </strong>In this retrospective single-center cohort (2015-2025), 90 children with confirmed CF were classified as IRT-positive (n = 78; IRT-1 ≥ 90 ng/mL) or IRT-negative (n = 12; IRT-1 < 90 ng/mL). CFTR variants were re-evaluated (ACMG/AMP) and stratified by Welsh-Smith class and residual-function status. Clinical, perinatal, pre-analytical, microbiological and genotype data were compared with standardized effect sizes.</p><p><strong>Results: </strong>IRT-negative patients were diagnosed later (median 12 vs. 2 months; p < 0.001) and had higher early Pseudomonas aeruginosa colonization (33.3% vs. 9.0%; unadjusted p = 0.037). Height standard deviation score was higher in IRT-negative patients (p = 0.004; Cohen's d = -0.77; not retained after false-discovery-rate adjustment). Mean IRT-1 was four-fold lower (44.5 vs. 189.1 ng/mL; p < 0.001). Class IV-V variants accounted for 33.3% of classified IRT-negative versus 11.1% of IRT-positive alleles; IRT-negative patients were enriched for residual-function and splicing variants, including 2789 + 5 G > A (9.5% vs. 2.0%), R334W and Y1032C. Pre-analytical and perinatal factors did not differ.</p><p><strong>Conclusion: </strong>In every missed case, the first-tier IRT value fell below the fixed national cutoff, without evidence of pre-analytical or perinatal contributions. Missed cases clustered among carriers of residual-function and splicing CFTR variants, whose attenuated pancreatic injury may keep neonatal IRT below the cutoff. Because the Turkish protocol forgoes second-tier testing in IRT-1-negative infants, this subgroup is invisible to the current algorithm; the fixed cutoff warrants optimization.</p>","PeriodicalId":19932,"journal":{"name":"Pediatric Pulmonology","volume":"61 10","pages":"e71864"},"PeriodicalIF":2.4,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149113425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}