Related Experiment Videos
Eosinophilia in premature infants: correlation with chronic lung disease
C Yamamoto1, T Kojima, K Hattori
1Department of Paediatrics, Kansai Medical University, Osaka, Japan.
Insights
Eosinophils, a type of white blood cell, may play a role in bronchopulmonary dysplasia (BPD) in premature infants. Higher eosinophil counts and activation markers were found in infants with BPD, suggesting a link to disease severity.
Area of Science:
- Neonatology
- Pulmonology
- Immunology
Background:
- Bronchopulmonary dysplasia (BPD) is a chronic lung disease affecting premature infants.
- The role of eosinophils in the pathophysiology of BPD remains unclear.
- Eosinophils are implicated in inflammatory processes in various lung conditions.
Purpose of the Study:
- To investigate the pathophysiological significance of eosinophilia in premature infants with BPD.
- To correlate peripheral eosinophil markers with BPD severity and inflammatory markers.
Main Methods:
- Studied 17 premature infants: 7 with BPD (stages III-IV) and 10 without BPD.
- Weekly measurements of peripheral eosinophil counts, nuclear segmentation, serum eosinophilic cationic protein (ECP).
- Analysis of intratracheal aspirates (TA) for ECP and polymorphonuclear leukocyte (PMN) elastase.
- Immunohistochemical staining for eosinophil major basic protein (MBP) in lung tissue.
Main Results:
- Infants with BPD showed higher peripheral eosinophil counts and more hypersegmented eosinophils.
- Peripheral eosinophil counts correlated with serum ECP levels.
- Significantly elevated ECP levels in TA of BPD infants, correlating with PMN elastase.
- Eosinophils positive for MBP were observed in lung tissue of BPD infants.
Conclusions:
- Peripheral eosinophils in sick premature infants may be activated.
- Eosinophil activation appears correlated with the severity of bronchopulmonary dysplasia.
- Further research is needed to elucidate the precise physiological role of eosinophils in BPD.
Abstract:
We attempted to clarify the possible pathophysiological significance of eosinophilia in bronchopulmonary dysplasia (BPD). The subjects studied were 17 premature infants, i.e. seven with respiratory distress syndrome (RDS) followed by bronchopulmonary dysplasia (the BPD group: four with stage IV and three with stage III BPD) and 10 infants without BPD (the non-BPD group), who comprised seven with RDS, two with meconium aspiration syndrome and one with transient tachypnea of the newborn. Peripheral eosinophil counts, the number of nuclei of eosinophils and serum eosinophilic cationic protein (ECP) levels, and ECP and polymorphonuclear leukocyte (PMN) elastase levels of intratracheal aspirates (TA) were determined once a week during the first 4 weeks of life. Peripheral eosinophil counts were higher in infants with BPD than those in the non-BPD group. Hypersegmented nuclei of peripheral eosinophils with more than four nuclei were more frequently present in the infants with BPD. A good correlation was observed between peripheral eosinophil counts and serum ECP levels. ECP levels of the TA in the infants with BPD were significantly elevated. There was a good correlation between ECP and PMN elastase levels of the TA. Lung tissue specimens of two infants of the BPD group, both of whom had patent ductus arteriosus (PDA), were obtained from the lower portion of the left lung when they underwent an operative procedure for PDA at 24 and 25 days of life, respectively. Immunohistochemical staining of eosinophil-derived granular major basic protein (MBP) was performed on the lung tissue specimens. Infiltration of a few MBP-staining eosinophils was observed on the specimens from both infants. Our results suggest that peripheral eosinophils in sick premature infants may be activated and appear to be correlated with the severity of BPD. Further studies will be needed to more clarify the physiological role of eosinophils in premature infants.