Recombinant surfactant protein D improves lung mechanics in preterm lamb study

The commentary reviews a study in which 22 preterm lambs, delivered at 127 days’ gestation, received mechanical ventilation for 300 minutes. Groups received poractant alfa alone, rfhSP-D after poractant, or rfhSP-D mixed with the initial poractant dose. Investigators assessed respiratory mechanics, inflammatory markers and lung structure.

At 30 minutes, lung compliance was 0.26 mL/cmH₂O/kg in controls, compared with 0.35 in the mixed-treatment group and 0.34 in the delayed-treatment group. Peak inspiratory pressures were also lower in the treated groups. Bronchoalveolar lavage showed fewer inflammatory cells in the mixed group, with a significant reduction in neutrophils; pooled treated groups had lower pro-inflammatory cytokine gene expression. Histology and airspace measures generally favored treatment, although results varied by outcome and group.

The findings suggest possible effects on lung mechanics, but do not establish that rfhSP-D prevents bronchopulmonary dysplasia. The study involved a small number of animals, brief ventilation and fixed ventilation parameters. The commentary notes that mixing rfhSP-D with surfactant may alter surfactant behavior, and calls for replication before clinical translation.