PURPOSE OF REVIEW:To provide a comprehensive and updated overview of post-infectious bronchiolitis obliterans (PIBO) in children, focusing on pathogenesis, diagnostic approaches, and current management strategies, while highlighting emerging mechanistic insights and future therapeutic directions. RECENT FINDINGS:Recent studies emphasize neutrophilic inflammation, inflammasome activation (e.g., interleukin-18, caspase-1), and genetic susceptibility as key contributors to disease development and progression. SUMMARY:PIBO is a heterogeneous and often underrecognized chronic lung disease requiring a structured diagnostic approach based on clinical, functional, and radiologic criteria. Management remains largely empirical and supportive, with limited evidence for disease-modifying therapies. Improved understanding of disease mechanisms may enable the development of targeted, phenotype-directed interventions in the future.

Introduction The benefits of early cystic fibrosis (CF) detection using newborn screening (NBS) has led to widespread use in NBS programs. Since 2002, a two-stage immunoreactive trypsinogen (IRT/IRT) screening strategy has been used as a CFNBS method in all public maternity units in the City of Buenos Aires, Argentina. This approach has been changed to the IRT/PAP (pancreatitis-associated protein) strategy since 2018. Objective to evaluate the cystic fibrosis newborn screening (CFNBS) program in the city of Buenos Aires during the period 2018-2022. Material & Methods All newborns born between January 2018 and December 2022 were included. IRT/PAP were obtained after 36 hours of life in a single dry blood sample. IRT was measured by immunofluorometric method (PerkinElmer, cut-off value 60 ng/ml) and PAP by ELISA method (Dynabio, cut-off value 1.6 ng/ml for samples with IRT values between 60 and 99 ng/ml and 0.5 ng/ml for values ≥100 ng/ml). Sweat Chloride Tests (ST) were performed using the Gibson and Cook method to confirm the diagnosis. Genetic studies (50 mutations) were done for all the detected and died patients. Results A total of 89082 newborns were screened; 533 had high IRT values (0.60 %). A total of 319 patients with elevated IRT/PAP were recalled to perform ST (0.31%). CF was diagnosed in 15 patients, 33 patients died without being able to perform ST, all of them had normal genetic studies. 53% were homozygous, 20% heterozygous F508del, and 13.3% had other mutations. The prevalence of CF was 1/5939. The median IRT value (x ±SD) in those affected was 192 ±78.4 ng/ml. CF diagnosis was confirmed at a median age (X ±SD) of 78 ±115 days of life. Conclusions The CF prevalence in the city of Buenos Aires is 1: 5939 live births. The recall rate was acceptable, optimizing the CFNBS of our program in this five-year evaluation.

Introduction. Primary ciliary dyskinesia (PCD) is a clinically heterogeneous condition that is difficult to diagnose. This study aimed to describe the clinical and imaging characteristics and the results of diagnostic tests in patients with suspected PCD, by implementing an unvalidated diagnostic strategy that combines screening questionnaires, nasal nitric oxide (nNO), high-speed videomicroscopy (HSVM), and genetic analysis. Population and methods. A cross-sectional observational study that included all patients referred for clinically suspected PCD between 2022 and 2025. Diagnostic tests: nNOn, HSVM, and genetic testing. Two clinical questionnaires were used to screen for PCD. Results. A total of 110 patients referred for suspected PCD were evaluated and classified into three groups: highly likely PCD (52 cases), highly unlikely PCD (54 cases), and indeterminate (4 cases). The diagnosis of PCD was made at a median age of 8.8 years. Most patients showed pulmonary involvement on their CT scans. Using the proposed diagnostic algorithm, PCD was highly unlikely in 49% of the referred cases. Conclusion. The age at diagnosis for patients with a high suspicion of PCD in our country was later than in other countries. At the time of diagnosis, the patients presented with lung damage confirmed by chest CT scans.Diagnosing PCD is a challenge in resource-limited countries. The initial approach combines screening questionnaires, nNO, and HSVM, and avoids genetic testing when a diagnosis of PCD is highly unlikely.

INTRODUCTION:Elexacaftor/Tezacaftor/Ivacaftor (ETI) has revolutionized cystic fibrosis (CF) care. In Argentina, the absence of patent restrictions allowed the production of a generic ETI formulation (ETIgf), significantly reducing costs. OBJECTIVE:This study evaluates the real-world clinical impact of ETIgf in people with CF (pwCF). METHODS:This prospective, single-center observational study in Buenos Aires, Argentina, included 71 pwCF (≥ 6 years) with responsive variants. Participants were categorized as: Group 1 (modulator-naïve) or Group 2 (previously on lumacaftor/ivacaftor). Clinical outcomes, including ppFEV1, LCI2.5, BMI z-score, CFQ-R, sweat chloride concentration (SCC), fecal elastase levels, liver enzymes and pulmonary exacerbations (PEx), were assessed over 12 months following the initiation of ETIgf. RESULTS:Group 1 included 43 patients, and Group 2 included 28 patients (median age: 10.9 and 10.6 years, respectively). The mean percentage change from baseline after 12 months of treatment for Group 1 and Group 2 was: ppFEV1 +20.8 (p < 0.01) and +18.5 (p < 0.01); LCI2.5 -13.3 (p < 0.01) and -11.2 (p < 0.05); CFQ-R + 66.1 (p < 0.01) and +30.4 (p < 0.01); and SCC -53.1 (p < 0.01) and -58.2 (p < 0.01), respectively. BMI z-score increased by 0.5 in Group 1 (p < 0.001), while Group 2 showed a non-significant increase. Pulmonary exacerbations were reduced by 95% in both groups. No changes were observed in fecal elastase levels. Adverse events were mild: five patients experienced elevated transaminase levels and three presented with a rash. CONCLUSION:ETIgf demonstrates robust clinical efficacy and safety, mirroring results reported for the originator. These findings highlight the viability of affordable generic modulators in expanding global access to life-changing therapy.

Postinfectious bronchiolitis obliterans (PiBO) is a rare and severe form of chronic obstructive lung disease caused by an infectious injury to the lower respiratory tract. The most commonly recognized inciting stimuli leading to PiBO are airway pathogens, such as adenovirus and Mycoplasma. PiBO is characterized by persistent and nonreversible airway obstruction, with functional and radiological evidence of small airway involvement. The literature has limited information on the aetiology, clinical profile, treatment, and outcome of PiBO.

The genetic basis of severe COVID-19 has been thoroughly studied, and many genetic risk factors shared between populations have been identified. However, reduced sample sizes from non-European groups have limited the discovery of population-specific common risk loci. In this second study nested in the SCOURGE consortium, we conducted a genome-wide association study (GWAS) for COVID-19 hospitalization in admixed Americans, comprising a total of 4702 hospitalized cases recruited by SCOURGE and seven other participating studies in the COVID-19 Host Genetic Initiative. We identified four genome-wide significant associations, two of which constitute novel loci and were first discovered in Latin American populations ( BAZ2B and DDIAS ). A trans-ethnic meta-analysis revealed another novel cross-population risk locus in CREBBP . Finally, we assessed the performance of a cross-ancestry polygenic risk score in the SCOURGE admixed American cohort. This study constitutes the largest GWAS for COVID-19 hospitalization in admixed Latin Americans conducted to date. This allowed to reveal novel risk loci and emphasize the need of considering the diversity of populations in genomic research.

Background Patients with inherited pulmonary surfactant metabolism disorders have a wide range of clinical outcomes and imaging findings. Response to current anti-inflammatory therapies has been variable and efficacy is unclear. Objective To describe and compare genetic, clinical, histological, and computed tomography (CT) outcomes in a cohort of patients with variants in the genes encoding surfactant protein C (SP-C) or adenosine triphosphate-binding cassette transporter A3 (ABCA3) in Argentina. Methods Observational cohort retrospective study. Patients carrying variants in genes encoding SP-C and ABCA3 proteins were included. Results Fourteen patients met the inclusion criteria: SFTPC n = 6, ABCA3 n = 8 (seven were heterozygous and one compound heterozygous). Neonatal respiratory distress was more frequent and severe in neonates with variants in the ABCA3 gene. The onset of the disease occurred in infancy before the age of 20 months in all cases. Patients with ABCA3 pathogenic variants had a severe clinical course, while long-term outcomes were more favorable in individuals with SFTPC variants. Initial CT findings were ground glass opacities and intraparenchymal cysts in both groups. Over time, signs of lung fibrosis were present in 57% of patients with ABCA3 variants and in 33% of the SFTPC group. The efficacy of anti-inflammatory interventions appears to be poor, especially for patients with ABCA3 pathogenic variants. Conclusions Clinical, histological, and radiological features are similar in patients with SFTPC and ABCA3 variants; however, the latter have more severe clinical course. Current anti-inflammatory regimens do not appear to stop the progression of the disease.

Cystic fibrosis (CF) is the most frequent recessive autosomal disorder in the Caucasian population. It is caused by mutations that result in a deficient or dysfunctional cystic fibrosis transmembrane conductance regulator (CFTR) protein activity. Among CFTR modulators, potentiator compounds increase channel opening, whereas corrector compounds increase CFTR quantity in the cell surface.

Asthma affects a large number of people living in the Americas, a vast and diverse geographic region comprising 35 nations in the Caribbean and North, Central and South America. The marked variability in the prevalence, morbidity, and mortality from asthma across and within nations in the Americas offers a unique opportunity to improve our understanding of the risk factors and management of asthma phenotypes and endotypes in children and adults. Moreover, a better assessment of the causes and treatment of asthma in less economically developed regions in the Americas would help diagnose and treat individuals migrating from those areas to Canada and the United States. In this focused review, we first assess the epidemiology of asthma, review known and potential risk factors, and examine commonalities and differences in asthma management across the Americas. We then discuss future directions in research and health policies to improve the prevention, diagnosis, and management of pediatric and adult asthma in the Americas, including standardized and periodic assessment of asthma burden across the region; large-scale longitudinal studies including omics and comprehensive environmental data on racially and ethnically diverse populations; and dissemination and implementation of guidelines for asthma management across the spectrum of disease severity. New initiatives should recognize differences in socioeconomic development and health care systems across the region while paying particularly attention to novel or more impactful risk factors for asthma in the Americas, including indoor pollutants such as biomass fuel, tobacco use, infectious agents and the microbiome, and psychosocial stressor and chronic stress.

EDITORIAL article Front. Pediatr., 03 May 2022Sec. Pediatric Pulmonology https://doi.org/10.3389/fped.2022.917221

Asthma affects a large number of people living in the Americas, a vast and diverse geographic region comprising 35 nations in the Caribbean and North, Central, and South America. The marked variability in the prevalence, morbidity, and mortality from asthma across and within nations in the Americas offers a unique opportunity to improve our understanding of the risk factors and management of asthma phenotypes and endotypes in children and adults. Moreover, a better assessment of the causes and treatment of asthma in less economically developed regions in the Americas would help diagnose and treat individuals migrating from those areas to Canada and the United States. In this focused review, we first assess the epidemiology of asthma, review known and potential risk factors, and examine commonalities and differences in asthma management across the Americas. We then discuss future directions in research and health policies to improve the prevention, diagnosis, and management of pediatric and adult asthma in the Americas, including standardized and periodic assessment of asthma burden across the region; large-scale longitudinal studies including omics and comprehensive environmental data on racially and ethnically diverse populations; and dissemination and implementation of guidelines for asthma management across the spectrum of disease severity. New initiatives should recognize differences in socioeconomic development and health care systems across the region while paying particular attention to novel or more impactful risk factors for asthma in the Americas, including indoor pollutants such as biomass fuel, tobacco use, infectious agents and the microbiome, and psychosocial stressor and chronic stress.

La hiperplasia de células neuroendocrinas de la infancia (HCNEI) constituye una de las enfermedades intersticiales más frecuentes en pediatría. Tanto su etiología como los mecanismos fisiopatológicos involucrados son inciertos. Suele presentarse en pacientes por lo demás sanos, durante los primeros meses de vida con taquipnea, retracciones costales, rales e hipoxemia. En la tomografía axial computada de tórax de alta resolución (TACAR) presenta imágenes características en vidrio esmerilado de distribución central y zonas de atrapamiento aéreo. Para el diagnóstico, además de la clínica y la TACAR, podemos recurrir a la biopsia en casos atípicos. Los hallazgos histológicos reflejan una arquitectura pulmonar normal y un aumento en el número de células neuroendocrinas. El manejo global es con medidas de sostén, ya que no se cuenta con un tratamiento específico. La sintomatología suele mejorar con la edad y el pronóstico es favorable.