Pulmonary Function Testing Detects Distinct Phenotypes in Bronchopulmonary Dysplasia

Patients with severe bronchopulmonary dysplasia (sBPD) displayed 3 distinct phenotypes on infant pulmonary function testing (iPFT), according to the results of a prospective cohort study published in Pediatrics.

The investigators sought to explore the hypothesis that the use of iPFT would identify distinct phenotypes in infants with established sBPD during their initial stay in the neonatal intensive care unit. Data from infants with sBPD at the Nationwide Children’s Hospital in Columbus, Ohio, were prospectively gathered between May 1, 2003, and June 30, 2016. The use of iPFT categorized patients as having obstructive, restrictive, or mixed sBPD phenotypes.

Patients’ median gestational age at birth was 25 weeks (interquartile range, 24-27 weeks); their median birth weight was 707 g (range, 581-925 g). In a total patient cohort of 110 participants, 51% (n=56) of the infants had the obstructive phenotype, 9% (n=10) of them had the restrictive phenotype, and 40% (n=44) of individuals had the mixed phenotype. During the infants’ initial neonatal intensive care unit stay, researchers used iPFT data at a mean postmenstrual age of 52 weeks (interquartile range, 45-63 weeks).

Moderate or severe obstruction was observed in 86% of patients in the obstructive group and 78% of those in the mixed group. In the restrictive group, 70% of infants had moderate obstruction and 30% of infants had mild obstruction. Response to bronchodilator therapy was reported in 74% of obstructive phenotype patients, 63% of mixed phenotype patients, and 25% of restrictive phenotype patients.

The investigators concluded that future research in the infant sBPD population should focus on the development of bedside tests that can define distinct phenotypes of disease because most neonatal intensive care units do not have access to an iPFT laboratory. The use of iPFT can help guide ongoing therapeutic decisions in infants with sBPD who are not improving.

Reference

Shepherd EG, Clouse BJ, Hasenstab KA, et al. Infant pulmonary function testing and phenotypes in severe bronchopulmonary dysplasia [published online April 5, 2018]. Pediatrics. doi: 10.1542/peds.2017-3350