BACKGROUND AND OBJECTIVE: Congenital pulmonary malformations (CPM) are mostly recognized on prenatal ultrasound scans. In a minority of cases, they may impair breathing at birth. The factors predictive of neonatal respiratory distress are not well defined, but an understanding of these factors is essential for decisions concerning the need for the delivery to take place in a tertiary care center. The aim of this study was to identify potential predictors of respiratory distress in neonates with CPM. METHODS: We selected cases of prenatal diagnosis of hyperechoic and/or cystic lung lesions from RespiRare, the French prospective multicenter registry for liveborn children with rare respiratory diseases (2008–2013). Prenatal parameters were correlated with neonatal respiratory outcome. RESULTS: Data were analyzed for 89 children, 22 (25%) of whom had abnormal breathing at birth. Severe respiratory distress, requiring oxygen supplementation or ventilatory support, was observed in 12 neonates (13%). Respiratory distress at birth was significantly associated with the following prenatal parameters: mediastinal shift (P = .0003), polyhydramnios (P = .05), ascites (P = .0005), maximum prenatal malformation area (P = .001), and maximum congenital pulmonary malformation volume ratio (CVR) (P = .001). Severe respiratory distress, requiring oxygen at birth, was best predicted by polyhydramnios, ascites, or a CVR >0.84. CONCLUSIONS: CVR >0.84, polyhydramnios, and ascites increased the risk of respiratory complications at birth in fetuses with CPM, and especially of severe respiratory distress, requiring oxygen supplementation or more intensive intervention. In such situations, the delivery should take place in a tertiary care center.

Tracheal bronchus is a rare morphological anomaly of the tracheobronchial tree. Most often TB is associated with other birth defects such as another tracheo-bronchial tree malformation, vascular abnormality, congenital heart malformation or in the context of a syndromic pattern. A relationship between respiratory symptoms and the presence of TB is very rare and selective treatment is infrequent.

BackgroundCongenital Pulmonary Airway Malformation (CPAM) has an estimated prevalence between 0.87 and 1.02/10,000 live births and little is know about their pathogenesis. To improve our knowledge on these rare malformations, we analyzed the cellular origin of the two most frequent CPAM, CPAM types 1 and 2, and compared these malformations with adjacent healthy lung and human fetal lungs.MethodsWe prospectively enrolled 21 infants undergoing surgical resection for CPAM. Human fetal lung samples were collected after termination of pregnancy. Immunohistochemistry and proteomic analysis were performed on laser microdissected samples.ResultsCPAM 1 and 2 express mostly bronchial markers, such as cytokeratin 17 (Krt17) or α-smooth muscle actin (ACTA 2). CPAM 1 also expresses alveolar type II epithelial cell markers (SPC). Proteomic analysis on microlaser dissected epithelium confirmed these results and showed distinct protein profiles, CPAM 1 being more heterogeneous and displaying some similarities with fetal bronchi.ConclusionThis study provides new insights in CPAM etiology, showing clear distinction between CPAM types 1 and 2, by immunohistochemistry and proteomics. This suggests that CPAM 1 and CPAM 2 might occur at different stages of lung branching. Finally, the comparison between fetal lung structures and CPAMs shows clearly different protein profiles, thereby arguing against a developmental arrest in a localized part of the lung.

Mouse lung developmental maturation and final alveolarization phase begin at birth. During this dynamic process, alveolar cells modify their morphology and anchorage to the extracellular matrix. In particular, alveolar epithelial cell (AEC) type I undergo cytoplasmic flattening and folding to ensure alveoli lining. We developed FACS conditions for simultaneous isolation of alveolar epithelial and endothelial cells in the absence of specific reporters during the early and middle alveolar phase. We evidenced for the first time a pool of extractable epithelial cell populations expressing high levels of podoplanin at postnatal day (pnd)2, and we confirmed by RT-qPCR that these cells are already differentiated but still immature AEC type I. Maturation causes a decrease in isolation yields, reflecting the morphological changes that these cell populations are undergoing. Moreover, we find that major histocompatibility complex II (MHCII), reported as a good marker of AEC type II, is poorly expressed at pnd2 but highly present at pnd8. Combined experiments using LysoTracker and MHCII demonstrate the de novo acquisition of MCHII in AEC type II during lung alveolarization. The lung endothelial populations exhibit FACS signatures from vascular and lymphatic compartments. They can be concomitantly followed throughout alveolar development and were obtained with a noticeable increased yield at the last studied time point (pnd16). Our results provide new insights into early lung alveolar cell isolation feasibility and represent a valuable tool for pure AEC type I preparation as well as further in vitro two- and three-dimensional studies.