부산대학교 도서관

Introduction Myeloperoxidase ( MPO) is an enzyme produced by neutrophil leukocytes and released upon activation, killing pathogens and causing tissue damage. As neutrophils in neonates are functionally immature, cellular MPO content in children may be age-related and different from adults. Hematological analyzer ADVIA 2120i (Siemens AG), while routinely assessing neutrophil count, measures their MPO content by means of myeloperoxidase index ( MPXI). No pediatric reference range for MPXI has been published. Methods We performed a retrospective study of MPXI values in 51 303 consecutive routine blood tests of nonhematologic pediatric patients, looking for age- and gender-related variability. Nonparametric statistical analysis (Spearman rho and Mann-Whitney U-test) was used for evaluation. Results Neutrophil MPO content was highly significantly lower during the first month of life ( P << 0.001) and rose to average pediatric values by day 28. Unexpectedly, the study revealed a highly significant gender difference ( P << 0.001), MPXI being lower in boys from birth to adulthood. Conclusions We found previously unreported highly significant age- and gender-related variations of neutrophil MPO in children in hospital setting. There are possible clinical implications, particularly concerning neutrophil immunity of neonates and gender-related difference in vascular events in adults. The finding may be considered for refining automatic cell counting in infants. [ABSTRACT FROM AUTHOR]