Time-course changes of eosinophil counts in premature infants: No effects of medical manipulation, except erythropoietin treatment, on eosinophilia

In order to determine the factors responsible for eosinophilia during the n eonatal period, we counted the eosinophils of premature infants every week and compared the medical profiles of infants with eosinophil counts above t he 95th percentile and those below that percentile during the course of stu dy. Medical treatments such a mechanical ventilation, antibiotics administr ation and intravenous catheterization had no significant effects: on the in crease of eosinophils. Furthermore, the incidence of eosinophil counts abov e the 95th percentile was not different between breast-fed and formula-fed infants. The infants treated with erythropoietin had greater eosinophil cou nts than those with no treatment. It is probable that medical manipulation using foreign bodies such as intratracheal tube, intravenous catheter, anti biotics and artificial formula had no significant effects on the increase o f eosinophil counts, except for exogenous erythropoietin.