Prenatal period to adolescence: the variable presentations of congenital cystic adenomatoid malformation

The Role of Hypoxia in Improving the Therapeutic Potential of Mesenchymal Stromal Cells. A Comparative Study From Healthy Lung and Congenital Pulmonary Airway Malformations in Infants

Mesenchymal stromal cells (MSCs) play an important role in the field of regenerative medicine thanks to their immunomodulatory properties and their ability to secrete paracrine factors. The use of MSCs has also been tested in children with congenital lung diseases inducing fibrosis and a decrease in lung function. Congenital malformations of the pulmonary airways (CPAM) are the most frequently encountered lung lesion that results from defects in early development of airways. Despite the beneficial properties of MSCs, interventions aimed at improving the outcome of cell therapy are needed. Hypoxia may be an approach aimed to ameliorate the therapeutic potential of MSCs. In this regard, we evaluated the transcriptomic profile of MSCs collected from pediatric patients with CPAM, analyzing similarities and differences between healthy tissue (MSCs-lung) and cystic tissue (MSCs-CPAM) both in normoxia and in cells preconditioned with hypoxia (0.2%) for 24 h. Study results showed that hypoxia induces cell cycle activation, increasing in such a way the cell proliferation ability, and enhancing cell anaerobic metabolism in both MSCs-lung and MSCs-CPAM-lung. Additionally, hypoxia downregulated several pro-apoptotic genes preserving MSCs from apoptosis and, at the same time, improving their viability in both comparisons. Finally, data obtained indicates that hypoxia leads to a greater expression of genes involved in the regulation of the cytoskeleton in MSCs-lung than MSCs-CPAM.

SARS-CoV-2 Exposed Mesenchymal Stromal Cell from Congenital Pulmonary Airway Malformations: Transcriptomic Analysis and the Expression of Immunomodulatory Genes

The inflammatory response plays a central role in the complications of congenital pulmonary airway malformations (CPAM) and severe coronavirus disease 2019 (COVID-19). The aim of this study was to evaluate the transcriptional changes induced by SARS-CoV-2 exposure in pediatric MSCs derived from pediatric lung (MSCs-lung) and CPAM tissues (MSCs-CPAM) in order to elucidate potential pathways involved in SARS-CoV-2 infection in a condition of exacerbated inflammatory response. MSCs-lung and MSCs-CPAM do not express angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TRMPSS2). SARS-CoV-2 appears to be unable to replicate in MSCs-CPAM and MSCs-lung. MSCs-lung and MSCs-CPAM maintained the expression of stemness markers MSCs-lung show an inflammatory response (IL6, IL1B, CXCL8, and CXCL10), and the activation of Notch3 non-canonical pathway; this route appears silent in MSCs-CPAM, and cytokine genes expression is reduced. Decreased value of p21 in MSCs-lung suggested no cell cycle block, and cells did not undergo apoptosis. MSCs-lung appears to increase genes associated with immunomodulatory function but could contribute to inflammation, while MSCs-CPAM keeps stable or reduce the immunomodulatory receptors expression, but they also reduce their cytokines expression. These data indicated that, independently from their perilesional or cystic origin, the MSCs populations already present in a patient affected with CPAM are not permissive for SARS-CoV-2 entry, and they will not spread the disease in case of infection. Moreover, these MSCs will not undergo apoptosis when they come in contact with SARS-CoV-2; on the contrary, they maintain their staminality profile.

Symptom development in originally asymptomatic CPAM diagnosed prenatally: a systematic review

PURPOSE

For the approximately three quarters of patients with a prenatal diagnosis of congenital pulmonary airway malformation (CPAM) who are asymptomatic at birth, the chance of eventually developing symptoms is unknown. We sought to explore the natural history of asymptomatic CPAM.

METHODS

We searched EMBASE, MEDLINE, and the first 50 results from Google Scholar. Studies describing the natural history of prenatally diagnosed, initially asymptomatic CPAM were included. For asymptomatic patients initially managed non-surgically, we tabulated the proportion who went on to develop symptoms as well as the median age at symptom development.

RESULTS

We included data from 19 retrospective studies on 353 patients. Of the 128 patients managed expectantly, 31 (24.2%) developed symptoms requiring surgical intervention. The median age at symptom development was 7.5 months (range 15 days-5 years).

CONCLUSION

The risk for developing respiratory symptoms exists with originally asymptomatic CPAM patients, but the exact risk is difficult to predict. Parents may be given the value of approximately 1 in 4 as an estimate of the proportion of asymptomatic CPAM patients who go on to develop symptoms, which will help them make an informed decision regarding the option of elective surgery.

CPAM type 2-derived mesenchymal stem cells: Malignancy risk study in a 14-month-old boy

INTRODUCTION

The association between congenital pulmonary airway malformations (CPAM) and malignancy is reported in the literature. Interactions between the tumor, immune, and mesenchymal stromal/stem cells (MSCs) have been recognized as crucial for understanding tumorigenesis. We characterized MSCs isolated from CPAM lesions in order to define potential malignancy risks.

METHODS

CPAM II pulmonary tissue was used for MSC expansion; a "healthy" lung section from the same child was used as a comparator. Morphology, immunophenotype, differentiation and immunological capacity, proliferative growth, gene signature telomerase activity, and in vivo tumorigenicity in nude mice were evaluated.

RESULTS

MSCs were successfully isolated and propagated from CPAM tissue. CPAM-MSCs presented the typical MSC morphology and phenotype, while exhibiting high proliferative capacity, reaching confluence at a median time of 5 days as well as differentiation capabilities. CPAM-MSCs at early passages were not neoplastic and chromosomally normal, even though unbalanced chromosomal rearrangements were noted by molecular karyotype.

CONCLUSIONS

CPAM-MSCs exhibited specific features similar to tumor derived MSCs. Whilst there was no evidence of malignant transformation in the cystic tissue, our results provide evidence that this abnormal tissue has malignant potential. MSCs are considered important players in the tumor microenvironment and they have been closely linked to regulation of tumor survival, growth, and progression. Thus, early lesion resection also in asymptomatic patients might be indicated to exclude that the microenvironment may be potentially permissive to cancer development.

Congenital Cystic Adenomatoid Malformation with Bronchial Atresia in Elderly Patients

Congenital cystic adenomatoid malformation (CCAM) is an uncommon, nonhereditary anomaly caused by arrest of lung. Patients with CCAM may present with respiratory distress as newborns, or may remain asymptomatic until later in life. CCAM type I is rarely found in association with bronchial atresia (BA) in adults; we present such a case. Case: A 54-year-old female presented with chronic cough and blood-tinged sputum. Physical examination and laboratory tests were unremarkable. Chest radiographs and a CT scan of the chest showed multiple large air-filled cysts consistent with a CCAM in the right lower lobe, and an oval-shaped opacity in the distal right middle lobal bronchus. Based on the radiologic findings, right middle lobectomy and a medial basal segmentectomy of the right lower lobe were performed via a thoracotomy. These lesions were consistent with Stocker's Type I CCAM and BA in the different lobes.

Systematic review and meta-analysis of the postnatal management of congenital cystic lung lesions

BACKGROUND

Antenatally detected asymptomatic congenital cystic lung lesions may be managed conservatively or by surgical resection. We undertook a systematic review and meta-analysis to quantify the risks of elective surgery, emergency surgery, and observation.

METHODS

All series published between 1996 and 2008, where the postnatal management of congenital cystic lung lesions was described, were reviewed. A meta-analysis was performed to determine whether elective or emergency surgery was associated with a higher risk of adverse outcomes.

RESULTS

There were 41 reports describing 1070 patients (of whom 79% were antenatally detected). Five hundred five neonates survived without surgery into infancy, of whom only 16 (3.2%) became symptomatic. For all ages, elective surgery was associated with significantly less complications than emergency surgery. The risk ratio was 2.8 (95% confidence interval, 1.4-5.5; P < .005) when comparing complications after elective surgery with emergency surgery.

CONCLUSIONS

The risk of asymptomatic cases developing symptoms is small. However, elective surgery is associated with a better outcome than emergency surgery. If elective surgery is undertaken, it should be performed before 10 months. Although no prognostic indicators have so far been identified in the literature, a conservative approach may be appropriate for small lesions.