ABNORMAL EXPRESSION OF PULMONARY BOMBESIN-LIKE PEPTIDE IMMUNOSTAININGCELLS IN INFANTS WITH CONGENITAL DIAPHRAGMATIC-HERNIA

Infants with congenital diaphragmatic hernia (CDH) have a high neonata l mortality and morbidity owing to lung hypoplasia and persistent pulm onary hypertension. Pulmonary neuroendocrine cells produce bombesin-li ke peptide (BLP), a peptide with growth factor-like properties involve d in lung development. We examined the expression of BLP immunostainin g in pulmonary neuroendocrine cells (PNEC), and in clusters of these c ells called neuroepithelial bodies (NEB), in the lungs of three groups of infants: patients with CDH, newborns with lung hypoplasia due to o ther causes, and control subjects without lung abnormalities. Morphome tric analysis included: 1) percent immunostained airways; 2) percent i mmunostained epithelium (i.e. frequency of PNEC and NEB); and 3) NEB s ize. Controls and infants with lung hypoplasia did not differ with res pect to BLP immunostaining. The ipsilateral and the contralateral lung s in CDH had a similar BLP immunostaining pattern of PNEC and NEB. The BLP immunostaining varied between CDH cases, possibly due to the diff erences in clinical presentation. The mean NEB size was significantly increased in infants with CDH compared with the other two groups (p = 0.02). Some CDH cases with large NEBs also showed a high percentage of immunostained epithelium. Lung-body weight ratio correlated positivel y with percent immunostained airways, and negatively with the NEB size . We conclude that in lungs of CDH patients BLP immunostaining in PNEC and NEB differs from that of infants with lung hypoplasia due to othe r causes and controls. The increased BLP immunostaining observed in so me cases of CDH might reflect a compensatory mechanism related to impa ired lung development and/or failure of neuropeptide secretion during neonatal adaptation.