Surfactant protein D concentration in a pediatric population with suspected sleep disorder

Area of Science:

• Pediatric Pulmonology
• Sleep Medicine
• Immunology

Background:

• Obstructive sleep apnea (OSA) affects 2-4% of children, necessitating novel diagnostic and prognostic biomarkers.
• Surfactant protein D (SP-D), an innate immune system component, possesses anti-inflammatory and antimicrobial properties.
• Investigating SP-D's role in pediatric OSA may reveal new insights into disease mechanisms.

Purpose of the Study:

• To evaluate plasma concentrations of SP-D in children suspected of having OSA.
• To explore potential correlations between SP-D levels and OSA severity, including the apnea-hypopnea index (AHI).

Main Methods:

• Prospective study involving 178 children with suspected OSA.
• Collection of blood samples, sleep parameters, feeding habits, anthropometric, sociodemographic, and family data.
• Measurement of plasma SP-D concentrations using enzyme-linked immunosorbent assay (ELISA).

Main Results:

• No statistically significant correlation was found between SP-D concentration and the AHI.
• SP-D levels showed a significant correlation with arousals (r = -0.258, p = 0.014 adjusted), suggesting a link to sleep fragmentation.
• Intermittent hypoxia was strongly correlated with C-reactive protein levels (r = 0.542, p < 0.001 adjusted).

Conclusions:

• While SP-D did not directly correlate with AHI in pediatric OSA, its association with arousals suggests a potential role in sleep fragmentation.
• Further research is warranted to elucidate the mechanisms underlying SP-D level changes in OSA and its potential as a biomarker.
• The strong link between intermittent hypoxia and CRP highlights inflammatory pathways in pediatric OSA.