neonatal surfactant deficiency

Definition: Congenital surfactant deficiency (CSD) is a newly identified neonatal lung disorder associated with a variety of molecular defects affecting surfactant synthesis and secretion in alveolar type II cells.

Synopsis

 pulmonary alveolar proteinosis (PAP)
 acinar dysplasia
 desquamative interstitial pneumonitis (DIP)

Ultrastructure (16316951)

Ultrastructurally, alveolar type II cells lacked mature lamellar bodies, and their cytoplasm contained numerous pleomorphic inclusions with membranous and vesicular structures not seen in normal type II cells.

 absence of mature lamellar bodies in type II cells
 mixture of cytoplasmic electron-dense inclusions with concentric membranes and distinctive electron dense aggregates
 abnormal lamellar bodies

In SP-B deficiency, the absence of mature lamellar bodies is consistent with the postulated role for this protein in the formation of lamellar bodies. (16316951)

The lack of mature lamellar bodies in the ABCA3 gene mutations is due to the dysfunction of this endogenous lipid transporter that targets surfactant lipid moieties to the lamellar bodies. (16316951)

Etiology

 SP-B deficiency
 mutations in ABCA3 transporter gene

See also

 neonatal respiratory distress syndrome (MIM.267450)
 alveolar proteinosis

• neonatal alveolar proteinosis

References

 Edwards V, Cutz E, Viero S, Moore AM, Nogee L. Ultrastructure of lamellar bodies in congenital surfactant deficiency. Ultrastruct Pathol. 2005 Nov-Dec;29(6):503-9. PMID: 16316951