Human Pluripotent Stem Cell-Derived Alveolar Organoids: Cellular Heterogeneity and Maturity

Chronic respiratory diseases such as idiopathic pulmonary fibrosis, chronic obstructive pulmonary disease, and respiratory infections injure the alveoli; the damage evoked is mostly irreversible and occasionally leads to death. Achieving a detailed understanding of the pathogenesis of these fatal respiratory diseases has been hampered by limited access to human alveolar tissue and the differences between mice and humans. Thus, the development of human alveolar organoid (AO) models that mimic in vivo physiology and pathophysiology has gained tremendous attention over the last decade. In recent years, human pluripotent stem cells (hPSCs) have been successfully employed to generate several types of organoids representing different respiratory compartments, including alveolar regions. However, despite continued advances in three-dimensional culture techniques and single-cell genomics, there is still a profound need to improve the cellular heterogeneity and maturity of AOs to recapitulate the key histological and functional features of in vivo alveolar tissue. In particular, the incorporation of immune cells such as macrophages into hPSC-AO systems is crucial for disease modeling and subsequent drug screening. In this review, we summarize current methods for differentiating alveolar epithelial cells from hPSCs followed by AO generation and their applications in disease modeling, drug testing, and toxicity evaluation. In addition, we review how current hPSC-AOs closely resemble in vivo alveoli in terms of phenotype, cellular heterogeneity, and maturity

Impacts of coexisting bronchial asthma on severe exacerbations in mild-to-moderate COPD : results from a national database

Acknowledgments The authors would like to thank Kyungjoo Kim for the confident statistical analyses in this work. This study was supported by a grant (2014P3300300) from the Korea Centers for Disease Control and Prevention. The abstract of this paper was presented at the Asian Pacific Society of Respirology 20th Congress as an oral presentation with interim findings. The poster’s abstract was published in “Poster Abstracts” in Respirology.Peer reviewedPublisher PD

Synchrotron x-ray imaging of pulmonary alveoli in respiration in live intact mice

Despite nearly a half century of studies, it has not been fully understood how pulmonary alveoli, the elementary gas exchange units in mammalian lungs, inflate and deflate during respiration. Understanding alveolar dynamics is crucial for treating patients with pulmonary diseases. In-vivo, real-time visualization of the alveoli during respiration has been hampered by active lung movement. Previous studies have been therefore limited to alveoli at lung apices or subpleural alveoli under open thorax conditions. Here we report direct and real-time visualization of alveoli of live intact mice during respiration using tracking X-ray microscopy. Our studies, for the first time, determine the alveolar size of normal mice in respiration without positive end expiratory pressure as 58 ± 14 (mean ± s.d.) μm on average, accurately measured in the lung bases as well as the apices. Individual alveoli of normal lungs clearly show heterogeneous inflation from zero to ~25% (6.7 ± 4.7% (mean ± s.d.)) in size. The degree of inflation is higher in the lung bases (8.7 ± 4.3% (mean ± s.d.)) than in the apices (5.7 ± 3.2% (mean ± s.d.)). The fraction of the total tidal volume allocated for alveolar inflation is 34 ± 3.8% (mean ± s.e.m). This study contributes to the better understanding of alveolar dynamics and helps to develop potential treatment options for pulmonary diseases

Does Changing Inhaler Device Impact Real-Life Asthma Outcomes? : Clinical and Economic Evaluation

This study was funded by Mundipharma Korea Limited (Seoul, Korea).Peer reviewedPostprin

Comparison of clinical baseline characteristics between Asian and Western COPD patients in a prospective, international, multicenter study

The study was designed and coordinated by the Respiratory Effectiveness Group (REG; www.effectivenessevaluation.org; Cambridge, UK) and delivered by Optimum Patient Care (OPC; www.optimumpatientcare.org). The following investigators participated in the study: Spain: Marc Miravitlles, Cristina Esquinas, Miriam Barrecheguren, Alexa Nuñez, Hospital Universitari Vall d’Hebron, Barcelona. Bernardino Alcazar, Hospital de Alta Resolución de Loja. Juan Luis García-Rivero, Karina Hueso, Hospital Comarcal de Laredo, Cantabria. Miguel Roman-Rodríguez, Primary Health-care Center Son Pisà. IB-Salut. Palma de Mallorca. Poland: Pawel Sliwinsk Sliwinski, Katarzyna Iwan, Jacek Kolakowski, Institute of Tuberculosis and Lung Diseases, Warsaw. Korea: Chin Kook Rhee, Esther Ahn, St Mary’s Hospital. Seoul. Singapore: Jessica Tan, Therese Lapperre, Karen Tan Li Leng, Nicole Chia, Ong Thun How, Syifa Binte Shamsuddin, Sherine Lim Shu Gim, Yap Chwee Bee, Soh Rui Ya, Singapore General Hospital. Augustine Tee, Jun Jie Yan, Samuel Hong, William Tan, Jessica Tan, Changi General Hospital. UK: Victoria Carter, Latife Hardaker, Andrew McLaughlin, Optimum Patient Care, Cambridge. Malta: Caroline Gouder, Mater Dei Hospital. Ireland: Richard W Costello, Royal College of Surgeons. Dublin. The study was funded by an unrestricted grant from Novartis AG.Peer reviewedPublisher PD

Interleukin-10 Promoter Polymorphism is Associated with the Predisposition to the Development of IgA Nephropathy and Focal Segmental Glomerulosclerosis in Korea

The roles of interleukin-10 (IL-10) have been emphasized in several models of glomerulonephritis (GN). Three biallelic polymorphisms within the IL-10 promoter region, at positions -1,082, -819, and -592 from the transcription initiation site, were shown to affect the level of IL-10 production. To investigate the effect of IL-10 promoter polymorphisms on the predisposition to development of GN in Korea, IL-10 promoter polymorphisms were assayed by polymerase chain reaction followed by restriction fragment length polymorphism in 108 patients with IgA nephropathy (IgAN), 49 focal segmental glomerulosclerosis (FSGS), and 100 healthy controls. In comparison with the control, the frequency of -1,082*G alleles were lower in IgAN and the frequencies of -592*C and -819*C were lower in FSGS, respectively. As for the haplotype, GCC haplotype was less frequent among IgAN than the control and ATA haplotype was more frequent among FSGS than the control (p<0.05). The frequency of intermediate producer genotypes (GCC/ACC and GCC/ATA) were lower among IgAN or FSGS than the control. Our findings suggested that IL-10 promoter polymorphism predisposed to the development of IgAN and FSGS in Korean patients

Gestational Estimated Glomerular Filtration Rate and Adverse Maternofetal Outcomes

Background/Aims: The association between gestational estimated glomerular filtration rate (eGFR) and adverse pregnancy outcomes has not been fully investigated. Methods: This observational cohort study included pregnancy cases of singleton mothers whose serum creatinine levels were measured during pregnancy at two tertiary hospitals in Korea from 2000 to 2015. Those with identified substantial renal function impairment (eGFR &#x3c; 60 mL/min/1.73 m2 at baseline, during, or after pregnancy) were excluded. The Chronic Kidney Disease Epidemiology Collaboration equation was used for the eGFR calculation. We computed the time-averaged eGFR during gestation to determine representative values when there were multiple measurements. We studied the following three gestational complications: preterm birth (&#x3c; 37 weeks’ gestational age), low birth weight (&#x3c; 2.5 kg), and preeclampsia. Results: Among the 12,899 studied pregnancies, 4,360 cases experienced one or more gestational complications. The adjusted odds ratio (aOR) and 95% confidence interval of composite gestational complications for eGFR ranges other than the reference range of 120–150 mL/ min/1.73m2 were: ≥150 mL/min/1.73m2, aOR 1.64 (1.38–1.95), P&#x3c; 0.001; 90–120 mL/min/1.73m2, aOR 1.41 (1.28–1.56), P&#x3c; 0.001; and 60–90 mL/min/1.73m2, aOR 2.56 (1.70–3.84), P&#x3c; 0.001. Incidence of preterm birth or low birth weight showed similar U-shaped association with eGFR values; otherwise, preeclampsia or small for gestational age occurred more often in mothers with a lower gestational eGFR than in those with a higher value. Conclusion: Considering the unique association between gestational eGFR and pregnancy outcomes, carefully interpreting these results may help predict obstetric complications

The Mildly Elevated Serum Bilirubin Level is Negatively Associated with the Incidence of End Stage Renal Disease in Patients with IgA Nephropathy

Oxidative stress plays various roles in the development and progression of IgA nephropathy, while bilirubin is known as a potent antioxidant. We therefore hypothesized that serum bilirubin would be associated with renal prognosis in IgA nephropathy. The study subjects comprised 1,458 adult patients with primary IgA nephropathy in Korea. We grouped patients according to the following quartile levels of bilirubin: <0.4 mg/dL (Q1), 0.4-0.5 mg/dL (Q2), 0.6-0.7 mg/dL (Q3), and >0.8 mg/dL (Q4). The outcome data were obtained from the Korean Registry of end-stage renal disease (ESRD). Eighty patients (5.5%) contracted ESRD during a mean follow-up period of 44.9 months. The ESRD incidences were 10.7% in Q1, 8.2% in Q2, 2.8% in Q3, and 2.8% in Q4 (p<0.001). The relative risk of ESRD compared to that in Q1 was 0.307 (95% confidence interval [CI], 0.126-0.751) in Q3 and 0.315 (95% CI, 0.130-0.765) in Q4. The differences of ESRD incidence were greater in subgroups of males and of patients aged 35 yr or more, with serum albumin 4.0 g/dL or more, with normotension, with eGFR 60 mL/min/1.73 m2 or more, and with proteinuria less then 3+ by dipstick test. In conclusion, higher bilirubin level was negatively associated with ESRD incidence in IgA nephropathy

Clinical Significance of Crescent Formation in IgA Nephropathy – a Multicenter Validation Study

Background/Aims: Additional validation study was warranted to confirm the clinical significance of C score, which was recently added to the Oxford classification for immunoglobulin A nephropathy (IgAN). Methods: We performed a multicenter retrospective cohort study in four hospitals in Korea. Patients who had biopsied glomeruli less than eight or inadequate follow-up information were excluded. Clinicopathologic parameters, including the degree of cellular or fibrocellular crescents, were collected and included in multivariable models for Cox regression analysis. The main outcome was a composite renal outcome, defined as a merge of progression to end-stage renal disease (ESRD) and halving of estimated glomerular filtration rate (eGFR) from baseline. Results: Among included 3,380 biopsy-confirmed IgAN patients, there were 664 (19.6%) patients with C1 and 60 (1.8%) patients with C2 scores in the study population. Although C0 and C1 patients shared similar baseline characteristics, C2 patients frequently had more clinicopathologic risk factors for poor prognosis of IgAN. Both C1 [adjusted HR 1.33 (1.11-1.58), P=0.002] and C2 [adjusted HR 2.24 (1.46-3.43), P&#x3c; 0.001] scores were associated with an increased risk of the composite outcome. C2 was a strong predictive parameter associated with both progression to ESRD and halving of eGFR, whereas C1 was mainly associated with the increased risk of halving of eGFR. Notably, the proportion of crescent showed a linear association with the risk of adverse renal outcome. Conclusion: The C score in the Oxford classification is a valid predictive parameter for IgAN prognosis. Additional clinical attention is necessary for IgAN patients with identified cellular or fibrocellular crescents