Nikulshin S, Tolstikova I, Bartule A, Kviluna D, Gravele D, Gardovska D
Clinical Laboratory, Children's Clinical University Hospital, Riga, Latvia.
Int J Lab Hematol. 2015 Feb;37(1):120-4. doi: 10.1111/ijlh.12252. Epub 2014 May 12.
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.
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.
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.
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.
髓过氧化物酶（MPO）是一种由中性粒细胞产生的酶，在细胞激活时释放，可杀灭病原体并导致组织损伤。由于新生儿的中性粒细胞在功能上不成熟，儿童体内的细胞MPO含量可能与年龄有关，且与成人不同。血液分析仪ADVIA 2120i（西门子公司）在常规评估中性粒细胞计数时，通过髓过氧化物酶指数（MPXI）来测量其MPO含量。目前尚未公布MPXI的儿科参考范围。
我们对51303例非血液系统儿科患者的连续常规血液检查中的MPXI值进行了回顾性研究，以寻找与年龄和性别相关的变异性。采用非参数统计分析（Spearman秩相关系数和Mann-Whitney U检验）进行评估。
出生后第一个月中性粒细胞MPO含量显著降低（P << 0.001），到第28天时升至儿科平均水平。出乎意料的是，该研究显示出显著的性别差异（P << 0.001），从出生到成年，男孩的MPXI均较低。
我们发现在医院环境中，儿童中性粒细胞MPO存在此前未报道的与年龄和性别相关的高度显著差异。这可能具有临床意义，特别是对于新生儿的中性粒细胞免疫以及成人血管事件中的性别差异。这一发现可能有助于完善婴儿的自动细胞计数。
