Inflammatory changes in the lungs of premature infants with symptomatic patent ductus arteriosus

BACKGROUND: The aim of the study was to observe the inflammatory changes during the therapy for symptomatic patent ductus arteriosus (sPDA). METHODS: We investigated biochemically the sample of the tracheobroncheal aspirates (TA) from 11 intubated premature infants. Three i.v. doses of indomethacin (0.2 mg/kg)were administered with 24-h intervals. The samples were divided into two groups, the effective occasions (n = 10)and non-effective occasions (n = 6). The amounts of myeloperoxidase (MPO), soluble L-selectin (sL-selectin)in TA, and the polymorphonuclear leukocytes (PMN) of peripheral blood stream and TA were analyzed before and after treatment ofsPDA with indomethacin. RESULTS: In effective occasions, there were significant decreases of peripheral PMN and MPO and PMN in TA. However, this group had a significant increase of sL-selectin. In non-effective occasions, five out of six samples had decreases of MPO and PMNin TA, but not significantly. In contrast, there was a significant decrease of sL-selectin. CONCLUSION: These data suggested that anti-inflammatory change after closure of sPDA may be caused by not only indomethacin itself, but also ductal closure itself. However, further study is necessary to clarify the relationship between the closure of the ductus itself and anti-inflammatory action in the lung.