Association of peripheral eosinophilia with chronic neonatal lung disease in preterm babies

Abstract

Introduction: Chronic lung disease of prematurity (BPD) is a common complication of premature birth. Although the cause of BPD is multifactorial an inflammatory process is playing a role in the pathogenesis of BPD. Eosinophils might be part of this inflammatory process. We hypothesized that elevated eosinophil levels in a Full Blood Count (FBC) soon after birth are associated with the development of BPD. Method: Two separate analyses were performed, which each included 50 premature infants. 25 preterm infants with BPD (mean gestational age 25.9 and 26.1 weeks, mean birth weight 875 and 846 g) were compared to 25 control infants without BPD (mean gestational age 26.3 and 26.1 weeks, mean birth weight 935 and 869 g) in each analysis. In the first analysis, we identified a possible threshold in eosinophil levels that may be used as a predictor for the development of BPD. The second analysis would be used to assess the validity of the predictor. Eligible infants were assessed for the absolute eosinophil counts and the eosinophil percentage in the first three weeks of life. Three day binned average values were used for calculations. Results: We analysed 611 FBCs in the first and 619 FBCs in the second analysis. Eosinophil levels increased during the observation period (mean 0.14x10^9/L at birth and 0.43x10^9/L at three weeks of age). There was no significant correlation demonstrated in both analysis between elevated eosinophil levels and future development of BPD. Discussion: No significant correlation was found between peripheral eosinophil levels in the first 3 weeks of life and the development of BPD. This study improves the characterization of eosinophil levels in preterm infants.