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Wołoszczak J, Wrześniewska M, Hrapkowicz A, Janowska K, Szydziak J, Gomułka K. A Comprehensive Outlook on Pulmonary Alveolar Proteinosis-A Review. Int J Mol Sci 2024; 25:7092. [PMID: 39000201 PMCID: PMC11241585 DOI: 10.3390/ijms25137092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2024] [Revised: 06/13/2024] [Accepted: 06/24/2024] [Indexed: 07/16/2024] Open
Abstract
Pulmonary alveolar proteinosis (PAP) is an ultra-rare disease caused by impaired pulmonary surfactant clearance due to the dysfunction of alveolar macrophages or their signaling pathways. PAP is categorized into autoimmune, congenital, and secondary PAP, with autoimmune PAP being the most prevalent. This article aims to present a comprehensive review of PAP classification, pathogenesis, clinical presentation, diagnostics, and treatment. The literature search was conducted using the PubMed database and a total of 67 articles were selected. The PAP diagnosis is usually based on clinical symptoms, radiological imaging, and bronchoalveolar lavage, with additional GM-CSF antibody tests. The gold standard for PAP treatment is whole-lung lavage. This review presents a summary of the most recent findings concerning pulmonary alveolar proteinosis, pointing out specific features that require further investigation.
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Affiliation(s)
- Julia Wołoszczak
- Student Scientific Group of Internal Medicine and Allergology, Faculty of Medicine, Wroclaw Medical University, 50-368 Wroclaw, Poland
| | - Martyna Wrześniewska
- Student Scientific Group of Internal Medicine and Allergology, Faculty of Medicine, Wroclaw Medical University, 50-368 Wroclaw, Poland
| | - Aleksandra Hrapkowicz
- Student Scientific Group of Internal Medicine and Allergology, Faculty of Medicine, Wroclaw Medical University, 50-368 Wroclaw, Poland
| | - Kinga Janowska
- Student Scientific Group of Internal Medicine and Allergology, Faculty of Medicine, Wroclaw Medical University, 50-368 Wroclaw, Poland
| | - Joanna Szydziak
- Student Scientific Group of Internal Medicine and Allergology, Faculty of Medicine, Wroclaw Medical University, 50-368 Wroclaw, Poland
| | - Krzysztof Gomułka
- Clinical Department of Internal Medicine, Pneumology and Allergology, Faculty of Medicine, Wroclaw Medical University, 50-368 Wroclaw, Poland
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Huang J, Lin Z, Lin J, Xie S, Xia S, Chen G, Zheng Z, Xu Z, Liu F, Wu H, Li S. Causal role of lipid metabolism in pulmonary alveolar proteinosis: an observational and mendelian randomisation study. Thorax 2024; 79:135-143. [PMID: 38124156 DOI: 10.1136/thorax-2023-220789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 11/24/2023] [Indexed: 12/23/2023]
Abstract
BACKGROUND Pulmonary alveolar proteinosis (PAP) is a rare interstitial lung disease characterised by the accumulation of lipoprotein material in the alveoli. Although dyslipidaemia is a prominet feature, the causal effect of lipid traits on PAP remains unclear. This study aimed to explore the role of lipid traits in PAP and evaluate the potential of lipid-lowering drug targets in PAP. METHODS Clinical outcomes, lipid profiles and lung function tests were analysed in a clinical cohort of diagnosed PAP patients and propensity score-matched healthy controls. Genome-wide association study data on PAP, lipid metabolism, blood cells and variants of genes encoding potential lipid-lowering drug targets were obtained for Mendelian randomisation (MR) and mediation analyses. FINDINGS Observational results showed that higher levels of total cholesterol (TC), triglycerides and low-density lipoprotein (LDL) were associated with increased risks of PAP. Higher levels of TC and LDL were also associated with worse PAP severity. In MR analysis, elevated LDL was associated with an increased risk of PAP (OR: 4.32, 95% CI: 1.63 to 11.61, p=0.018). Elevated monocytes were associated with a lower risk of PAP (OR 0.34, 95% CI: 0.18 to 0.66, p=0.002) and mediated the risk impact of LDL on PAP. Genetic mimicry of PCSK9 inhibition was associated with a reduced risk of PAP (OR 0.03, p=0.007). INTERPRETATION Our results support the crucial role of lipid and metabolism-related traits in PAP risk, emphasising the monocyte-mediated, causal effect of elevated LDL in PAP genetics. PCSK9 mediates the development of PAP by raising LDL. These finding provide evidence for lipid-related mechanisms and promising lipid-lowering drug target for PAP.
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Affiliation(s)
- Junfeng Huang
- Guangzhou Institute of Respiratory Health, State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, National Center for Respiratory Medicine, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
- Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Zikai Lin
- Guangzhou Institute of Respiratory Health, State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, National Center for Respiratory Medicine, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
- Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Jinsheng Lin
- Guangzhou Institute of Respiratory Health, State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, National Center for Respiratory Medicine, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
- Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Shuojia Xie
- Guangzhou Institute of Respiratory Health, State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, National Center for Respiratory Medicine, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
- Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Shixin Xia
- Guangzhou Institute of Respiratory Health, State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, National Center for Respiratory Medicine, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
- Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Gengjia Chen
- Guangzhou Institute of Respiratory Health, State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, National Center for Respiratory Medicine, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
- Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Ziwen Zheng
- Guangzhou Institute of Respiratory Health, State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, National Center for Respiratory Medicine, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
- Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Zhe Xu
- Guangzhou Institute of Respiratory Health, State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, National Center for Respiratory Medicine, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
- Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Fangcheng Liu
- Guangzhou Institute of Respiratory Health, State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, National Center for Respiratory Medicine, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
- Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Hongkai Wu
- Guangzhou Institute of Respiratory Health, State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, National Center for Respiratory Medicine, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Shiyue Li
- Guangzhou Institute of Respiratory Health, State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, National Center for Respiratory Medicine, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
- Guangzhou Medical University, Guangzhou, Guangdong, China
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Abstract
Pulmonary surfactant is a critical component of lung function in healthy individuals. It functions in part by lowering surface tension in the alveoli, thereby allowing for breathing with minimal effort. The prevailing thinking is that low surface tension is attained by a compression-driven squeeze-out of unsaturated phospholipids during exhalation, forming a film enriched in saturated phospholipids that achieves surface tensions close to zero. A thorough review of past and recent literature suggests that the compression-driven squeeze-out mechanism may be erroneous. Here, we posit that a surfactant film enriched in saturated lipids is formed shortly after birth by an adsorption-driven sorting process and that its composition does not change during normal breathing. We provide biophysical evidence for the rapid formation of an enriched film at high surfactant concentrations, facilitated by adsorption structures containing hydrophobic surfactant proteins. We examine biophysical evidence for and against the compression-driven squeeze-out mechanism and propose a new model for surfactant function. The proposed model is tested against existing physiological and pathophysiological evidence in neonatal and adult lungs, leading to ideas for biophysical research, that should be addressed to establish the physiological relevance of this new perspective on the function of the mighty thin film that surfactant provides.
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Affiliation(s)
- Fred Possmayer
- Department of Biochemistry, Western University, London, Ontario N6A 3K7, Canada
- Department of Obstetrics/Gynaecology, Western University, London, Ontario N6A 3K7, Canada
| | - Yi Y Zuo
- Department of Mechanical Engineering, University of Hawaii at Manon, Honolulu, Hawaii 96822, United States
- Department of Pediatrics, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii 96826, United States
| | - Ruud A W Veldhuizen
- Department of Physiology & Pharmacology, Western University, London, Ontario N6A 5C1, Canada
- Department of Medicine, Western University, London, Ontario N6A 3K7, Canada
- Lawson Health Research Institute, London, Ontario N6A 4V2, Canada
| | - Nils O Petersen
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
- Department of Chemistry, Western University, London, Ontario N6A 5B7, Canada
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韩 俊, 张 蓉, 周 建, 胡 黎, 钱 莉, 陆 爱, 杨 琳, 马 阳, 乔 中, 张 澜. [Congenital pulmonary alveolar proteinosis in a neonate]. ZHONGGUO DANG DAI ER KE ZA ZHI = CHINESE JOURNAL OF CONTEMPORARY PEDIATRICS 2023; 25:1089-1094. [PMID: 37905769 PMCID: PMC10621054 DOI: 10.7499/j.issn.1008-8830.2307035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 08/08/2023] [Indexed: 11/02/2023]
Abstract
The male patient was referred to the hospital at 44 days old due to dyspnea after birth and inability to wean off oxygen. His brother died three days after birth due to respiratory failure. The main symptoms observed were respiratory failure, dyspnea, and hypoxemia. A chest CT scan revealed characteristic reduced opacity in both lungs with a "crazy-paving" appearance. The bronchoalveolar lavage fluid (BALF) showed periodic acid-Schiff positive proteinaceous deposits. Genetic testing indicated a compound heterozygous mutation in the ABCA3 gene. The diagnosis for the infant was congenital pulmonary alveolar proteinosis (PAP). Congenital PAP is a significant cause of challenging-to-treat respiratory failure in full-term infants. Therefore, congenital PAP should be considered in infants experiencing persistently difficult-to-treat dyspnea shortly after birth. Early utilization of chest CT scans, BALF pathological examination, and genetic testing may aid in early diagnosis.
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Affiliation(s)
| | | | | | | | - 莉玲 钱
- 复旦大学附属儿科医院呼吸科/国家儿童医学中心上海201102
| | - 爱珍 陆
- 复旦大学附属儿科医院呼吸科/国家儿童医学中心上海201102
| | - 琳 杨
- 复旦大学附属儿科医院 内分泌遗传代谢科上海201102
| | - 阳阳 马
- 复旦大学附属儿科医院病理科/国家儿童医学中心上海201102
| | - 中伟 乔
- 复旦大学附属儿科医院影像科/国家儿童医学中心上海201102
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