• Clinical and Experimental Pediatrics
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• 제53권12호
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• pp.979-984
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• 2010

Recent progress in neonatal medicine has enabled survival of many extremely low-birth-weight infants. Prenatal steroids, surfactants, and non-invasive ventilation have helped reduce the incidence of the classical form of bronchopulmonary dysplasia characterized by marked fibrosis and emphysema. However, a new form of bronchopulmonary dysplasia marked by arrest of alveolarization remains a complication in the postnatal course of extremely low-birth-weight infants. To better understand this challenging complication, detailed alveolarization mechanisms should be delineated. Proper alveolarization involves the temporal and spatial coordination of a number of cells, mediators, and genes. Cross-talk between the mesenchyme and the epithelium through soluble and diffusible factors are key processes of alveolarization. Lung interstitial cells derived from the mesenchyme play a crucial role in alveolarization. Peak alveolar formation coincides with intense lung interstitial cell proliferation. Myofibroblasts are essential for secondary septation, a critical process of alveolarization, and localize to the front lines of alveologenesis. The differentiation and migration of myofibroblasts are strictly controlled by various mediators and genes. Disruption of this finely controlled mechanism leads to abnormal alveolarization. Since arrest in alveolarization is a hallmark of a new form of bronchopulmonary dysplasia, knowledge regarding the role of lung interstitial cells during alveolarization and their control mechanism will enable us to find more specific therapeutic strategies for bronchopulmonary dysplasia. In this review, the role of lung interstitial cells during alveolarization and control mechanisms of their differentiation and migration will be discussed.

• Clinical and Experimental Pediatrics
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• 제62권10호
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• pp.367-373
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• 2019

Bronchopulmonary dysplasia (BPD) is a chronic lung disease of preterm infants with multiple factors affected from prenatal to postnatal periods. Despite significant advances in neonatal care over almost 50 years, BPD rates have not decreased; in fact, they may have even increased. Since more preterm infants, even at periviable gestational age, survive today, different stages of lung development affect the pathogenesis of BPD. Hence, the definition of BPD has changed from "old" to "new." In this review, we discuss the various definitions of BPD, risk factors from the prenatal to postnatal periods, management strategies by phase, and future directions for research.

• Clinical and Experimental Pediatrics
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• 제52권1호
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• pp.6-13
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• 2009

Recent advances in perinatal care have resulted in improved survival of extremely low birth weight infants (ELBWI). However, bronchopulmonary dysplasia (BPD) remains one of the major complications in ELBWI. BPD was originally described over 40 years ago; the clinical characteristics, epidemiology, and pathogenesis of BPD have changed markedly through this period. In this article, I have reviewed recent progress in research concerning the clinical presentation and characteristics, epidemiology, and pathogenesis of BPD.

• Clinical and Experimental Pediatrics
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• 제57권4호
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• pp.171-177
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• 2014

Purpose: Eosinophilia is common in premature infants, and its incidence increases with a shorter gestation period. We investigated the clinical significance of eosinophilia in premature infants born at <34 weeks gestation. Methods: We analyzed the medical records of premature infants born at <34 weeks gestation who were admitted to the neonatal intensive care unit at Ewha Womans University Mokdong Hospital between January 2003 and September 2010. Eosinophilia was defined as an eosinophil percentage of >3% of the total leukocytes. Perinatal parameters and clinical parameters were also analyzed. Results: Of the 261 infants born at <34 weeks gestation, 22.4% demonstrated eosinophilia at birth. The eosinophil percentage peaked in the fourth postnatal week at 7.5%. The incidence of severe eosinophilia increased after birth up to the fourth postnatal week when 8.8% of all patients had severe eosinophilia. Severity of eosinophilia was positively correlated with a lower gestational age, birth weight, and Apgar score. Respiratory distress syndrome, bronchopulmonary dysplasia, nephrocalcinosis, intraventricular hemorrhage, and sepsis were associated with a higher eosinophil percentage. The eosinophil percentage was significantly higher in infants with bronchopulmonary dysplasia from the first postnatal week and the percentage was the highest in the fourth postnatal week, with the maximal difference being 4.1% (P<0.001). Conclusion: Eosinophilia is common in premature infants and reaches peak incidence and severity in the fourth postnatal week. The eosinophil percentage was significantly higher in bronchopulmonary dysplasia patients from the first postnatal week. Severe eosinophilia was significantly associated with the incidence of bronchopulmonary dysplasia even after adjusting for other variables.

• Neonatal Medicine
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• 제18권2호
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• pp.177-181
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• 2011

Bronchopulmonary dysplasia (BPD) is characterized by arrest of vascular and alveolar development in premature infants. Recent advances in neonatology have increased the survival of immature babies. Consequently, the prevalence of BPD is increasing. Animal studies and autopsy findings of BPD have demonstrated interruption in vascular development and reversal of lung injury through promotion of vasculogenesis. Normal lung development is driven by temporal and spatial specific growth factors and cellto-cell signaling in vascular development. Lung injury through various pathways causes disruption in this complex interactive process and results in aberrant vascular development and subsequent BPD. By understanding the regulation of vascular growth of the lung, it would be possible to find new targets in the treatment and prevention of BPD in premature infants.

• Neonatal Medicine
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• 제18권2호
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• pp.165-176
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• 2011

The pathologic hallmark of new bronchopulmonary dysplasia (BPD) is an arrest in alveolarization and vascular development. Alveoli are the fully mature gas-exchange units and alveolarization denotes the process through which the developing lung attains its fully mature structure. In human, alveolarization is mainly a postnatal event and begins in utero around 35 postmenstrual weeks and continues to 2 postnatal years. Beginning of respiration with very immature lungs as a result of preterm delivery renders the immature lung to be exposed to various injuries such as mechanical stretch, hyperoxia, infection/inflammation and leads to a disruption of normal alveolarization process, which is a main pathologic finding of BPD. Better understanding of the control mechanisms of normal alveolarization process should help us to figure out the pathophysiology of BPD and discover effective preventive or therapeutic measures for BPD. In this review, the pathologic evolution of BPD from 'old' to 'new' BPD, the detailed mechanisms of normal alveolarization, and the factors that disrupt normal alveolarization will be discussed.

• Neonatal Medicine
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• 제25권3호
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• pp.91-95
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• 2018

Bronchopulmonary dysplasia-associated pulmonary hypertension (BPD-PH) is increasingly being recognized as a cause of morbidity and mortality in preterm infants. Recently, BPD-PH has also been shown to have additional long-term negative effects on neurodevelopmental outcomes and right ventricular function. Several significant risk factors associated with the development of BPD-PH have been identified. A screening strategy for BPD-PH is needed for infants presenting more than one risk factor. In addition, an early echocardiogram within 14 days of age may be a useful tool to identify infants at high-risk for BPD-PH. We have reviewed recent progress in research concerning clinical characteristics, presentation, and outcomes of BPD-PH and have suggested direction for future studies.

• Clinical and Experimental Pediatrics
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• 제53권6호
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• pp.688-693
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• 2010

An increase in the number of preterm infants and a decrease in the gestational age at birth have resulted in an increase in the number of patients with significant bronchopulmonary dysplasia (BPD) and secondary pulmonary hypertension (PH). PH contributes significantly to the high morbidity and mortality in the BPD patients. Therefore, regular monitoring for PH by using echocardiography and B-type natriuretic peptide (BNP) or N-terminal-proBNP must be conducted in the BPD patients with greater than moderate degree to prevent PH and to ensure early treatment if PH is present. In the BPD patients with significant PH, multi-modality treatment, including treatment for correcting an underlying disease, oxygen supply, use of diverse selective pulmonary vasodilators (inhaled nitric oxide, inhaled prostacyclins, sildenafil, and endothelin-receptor antagonist) and other methods, is mandatory.

• Clinical and Experimental Pediatrics
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• 제60권7호
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• pp.203-207
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• 2017

Chorioamnionitis is an inflammation in the fetal membranes or placenta. When chorioamnionitis develops, fetal lungs are exposed to inflammatory cytokines and mediators via amniotic fluid. Because inflammation plays a pivotal role in the development of bronchopulmonary dysplasia (BPD), a chronic lung disease of prematurity, fetal lung inflammation induced by chorioamnionitis has been considered to be one of the major pathogenetic factors for BPD. Although there have been a number of studies that demonstrated the relationship between chorioamnionitis and BPD, there are still controversies on this issue. The controversies on the relationship between chorioamnionitis and BPD arise from not-unified definitions of chorioamnionitis and BPD, different study populations, and the proportion of contribution between inflammation and infectious microorganisms. The publication bias also contributes to the controversies. Clinical trials targeting chorioamnionitis or microorganisms that cause chorioamnionitis will answer on the actual relationship between chorioamnionitis and BPD and provide a novel prophylactic strategy against BPD based on that relationship.

• Clinical and Experimental Pediatrics
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• 제52권1호
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• pp.44-49
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• 2009

목 적 : 폐표면 활성제의 조기 투여와 연성 환기 요법에 의한 인공호흡기 치료 단축에도 불구하고 장기간 산소 보충이 필요한 만성 폐질환은 여전히 해결해야 할 난제이다. 저산소의 사용, 연성 환기에 의한 호흡기 치료 기간의 단축이 폐 손상을 줄이는데 기여하나 예방에는 한계가 있다고 한다. 이에 저자들은 폐표면 활성제의 조기 사용 및 연성 환기, 공격적인 기도 발관을 통한 인공호흡기 치료 기간의 단축이 만성 폐질환의 발생에 미치는 영향에 관해서 알아보고자 하였다. 방 법 : 2001년 1월부터 2006년 12월까지 본원 신생아실에 입원한 재태 연령 36주 이하 출생체중 1,500 g 이하의 환아 139예를 대상으로 병력지를 기초로 후향적으로 조사하였다. 2단계 이하인 경한 호흡곤란 증후군이 있는 환아를 대상으로 폐표면 활성제는 2시간 이내에 조기 투여하였으며 인공호흡기 치료 기간은 대부분 3일 미만으로 상태가 안정되는 즉시 공격적인 기도 발관을 시행하여 만성 폐질환의 발생률을 조사하였다. 결 과 : 총 139예의 환아 중 2단계 이하인 경한 호흡 곤란 증후군에서 조기 폐표면 활성제 치료를 시행한 대상 환아는 총 82예(59%)였으며 인공호흡기 치료 기간이 길수록 RDS의 정도가 심할수록 출생당시의 상태가 좋지 않을수록 만성 폐질환 발생이 증가하였다(P<0.001). 경증의 호흡 곤란 증후군에서 조기 폐표면 활성제를 사용하고 2일 이하로 조기 발관을 시행한 그룹에서도 상당한 수에서 경증 만성 폐질환은 발생하는 것을 알 수 있다. 출생당시 상태가 좋지 않아 기도 삽관을 시행한 그룹에서 출생 당시 상태가 비교적 양호한 군에 비해서 인공호흡기 치료 기간이 길었음을 알 수 있었다(P=0.020). 결 론 : 조기 폐표면 활성제의 투여와 연성 환기에 의한 인공호흡기 치료 기간의 단축만으로는 여전히 저 농도의 산소가 필요한 경증의 만성 폐질환 예방에는 한계가 있으며 출생 당시의 초기 처치가 만성 폐질환의 발생에 영향을 미치는 것으로 보아 향후 분만실에서 조건 및 nasal canula를 통한 초기 치료의 질적 향상과 nasal CPAP의 적극적 활용이 필요할 것으로 사료되며 nasal canula를 통한 저 농도 산소 공급역시 사용기간을 줄이는데 많은 노력을 해야 할 것으로 생각된다. 하지만 본 연구에서는 만성 폐질환에 영향을 줄 수 있는 여러 요인들을 복합적이 데이터 분석이 이루어지지 못하였으며 대조군을 통한 비교 연구가 되지 않은 점은 문제점이라 생각되며 앞으로 이에 대한 더 많은 연구가 필요할 것으로 사료된다.