Alveolar capillary dysplasia

Respiratory distress of the term newborn infant

Respiratory distress is recognised as any signs of breathing difficulties in neonates. In the early neonatal period respiratory distress is common, occurring in up to 7% of newborn infants, resulting in significant numbers of term-born infants being admitted to neonatal units. Many risk factors are involved; the increasing number of term infants delivered by elective caesarean section has also increased the incidence. Additionally the risk decreases with each advancing week of gestation. At 37 weeks, the chances are three times greater than at 39-40 weeks gestation. Multiple conditions can present with features of respiratory distress. Common causes in term newborn infants include transient tachypnoea of the newborn, respiratory distress syndrome, pneumonia, meconium aspiration syndrome, persistent pulmonary hypertension of the neonate and pneumothorax. Early recognition of respiratory distress and initiation of appropriate treatment is important to ensure optimal outcomes. This review will discuss these common causes of respiratory distress in term-born infants.

Alveolar Capillary Dysplasia with Misalignment of Pulmonary Veins (ACD/MPV): A Case Series

Alveolar capillary dysplasia with misalignment of pulmonary veins (ACD/MPV) is a rare, fatal, developmental lung disorder, which usually presents as persistent pulmonary hypertension of the newborn (PPHN) unresponsive to treatment. The authors present their own experience with three cases admitted during the last 15 years.

Interstitial lung disease in infants: new classification system, imaging technique, clinical presentation and imaging findings

Interstitial lung disease (ILD) is defined as a rare, heterogeneous group of parenchymal lung conditions that develop primarily because of underlying developmental or genetic disorders. Affected infants typically present with clinical syndromes characterized by dyspnea, tachypnea, crackles and hypoxemia. Until recently, the understanding of ILD in infants has been limited largely owing to a lack of evidence-based information of underlying pathogenesis, natural history, imaging findings and histopathological features. However, ILD in infants is now better understood and managed because of (1) advances in imaging methods that result in rapid and accurate detection, (2) improved thoracoscopic techniques for lung biopsy, (3) a consensus regarding the pathological criteria for these particular lung conditions and (4) a new classification system based on the underlying etiology of ILD. This article reviews the new classification system, imaging technique, clinical presentation and imaging findings of ILD in infants. Specialized knowledge of this new classification system in conjunction with recognition of characteristic imaging findings of ILD in infants has great potential for early and accurate diagnosis, which in turn can lead to optimal patient management.

A novel mutation in FOXF1 gene associated with alveolar capillary dysplasia with misalignment of pulmonary veins, intestinal malrotation and annular pancreas

Alveolar capillary dysplasia with misalignment of pulmonary veins (ACD/MPV) is a rare, fatal, neonatal developmental lung disorder, which usually presents as persistent pulmonary hypertension unresponsive to treatment. The authors report the case of a neonate with persistent pulmonary hypertension, associated with duodenal stenosis secondary to annular pancreas and intestinal malrotation. Support treatment, inhaled nitric oxide, oral sildenafil and nebulized iloprost were used with no clinical improvement. The neonate presented an overwhelming course, with hypoxemia refractory to treatment. At autopsy lung histology showed the characteristic features of ACD/MPV. DNA sequence analysis revealed a heterozygous nonsense mutation c.539C>A;p.S180X, in the first exon of FOXF1. FOXF1 has been identified as one of the genes responsible for ACD/MPV associated with multiple congenital malformations. This clinical case is the first report of a heterozygous nonsense mutation c.539C>A;p.S180X in the first exon of FOXF1, in a patient with ACD/MPV associated with annular pancreas and intestinal malrotation.

Small noncoding differentially methylated copy-number variants, including lncRNA genes, cause a lethal lung developmental disorder

An unanticipated and tremendous amount of the noncoding sequence of the human genome is transcribed. Long noncoding RNAs (lncRNAs) constitute a significant fraction of non-protein-coding transcripts; however, their functions remain enigmatic. We demonstrate that deletions of a small noncoding differentially methylated region at 16q24.1, including lncRNA genes, cause a lethal lung developmental disorder, alveolar capillary dysplasia with misalignment of pulmonary veins (ACD/MPV), with parent-of-origin effects. We identify overlapping deletions 250 kb upstream of FOXF1 in nine patients with ACD/MPV that arose de novo specifically on the maternally inherited chromosome and delete lung-specific lncRNA genes. These deletions define a distant cis-regulatory region that harbors, besides lncRNA genes, also a differentially methylated CpG island, binds GLI2 depending on the methylation status of this CpG island, and physically interacts with and up-regulates the FOXF1 promoter. We suggest that lung-transcribed 16q24.1 lncRNAs may contribute to long-range regulation of FOXF1 by GLI2 and other transcription factors. Perturbation of lncRNA-mediated chromatin interactions may, in general, be responsible for position effect phenomena and potentially cause many disorders of human development.

Type IV intestinal atresia, congenital bilateral perisylvian syndrome, and chronic pulmonary hypertension secondary to multiple vascular disruption syndrome in a monochorionic twin

We describe a rare case of multiple intestinal atresias, congenital bilateral perisylvian polymicrogyria, and chronic pulmonary hypertension in a surviving monochorionic twin with co-twin demise. This constellation of congenital anomalies represents a multiple vascular disruption syndrome due to intrauterine vascular compromise in the setting of possible twin-to-twin transfusion syndrome.

Pulmonary vasodilator therapy in the NICU: inhaled nitric oxide, sildenafil, and other pulmonary vasodilating agents

The perinatal transition from fetal to extrauterine life requires a dramatic change in the circulatory pattern as the organ of gas exchange switches from the placenta to the lungs. Pulmonary hypertension can occur during early newborn life, and present as early respiratory failure or as a complication of more chronic diseases, such as bronchopulmonary dysplasia. The most effective pharmacotherapeutic strategies for infants with persistent pulmonary hypertension of the newborn are directed at selective reduction of pulmonary vascular resistance. This article discusses currently available therapies for pulmonary hypertension, their biologic rationales, and evidence for their clinical effectiveness.