Piva E, De Toni S, Caenazzo A, Pradella M, Pietrogrande F, Plebani M
Department of Laboratory Medicine, Hospital-University of Padua, Italy.
Acta Haematol. 1995;94(1):16-22. doi: 10.1159/000203965.
Neutrophil NADPH oxidase is a membrane-bound enzyme complex responsible for the reduction of oxygen to superoxide anion in the respiratory burst. Impaired neutrophil function has often been reported in myeloproliferative diseases and myelodysplastic syndromes (MDSs), but its laboratory features have not been well characterized. Traditionally, NADPH oxidase activity has been evaluated with a microscopic method by nitroblue tetrazolium salt reduction to blue-black insoluble formazan granules identified in positive neutrophils by microscopy. We investigated neutrophil NADPH oxidase in 22 patients with chronic myeloproliferative disorders (cMPDs) and 15 patients with MDSs, using the microscopic method as well as a photometric microplate assay, which monitored the cytochemical reaction for 30 min. The relationship between cMPD and patient susceptibility to infections was also investigated. In the photometric assay, the mean enzyme activity in MDSs and cMPDs was lower than in normal subjects. NADPH oxidase activity was greater in cMPDs (except myelofibrosis) than in MDSs (except chronic myelomonocytic leukemia), and these differences were less evident with microscopy. Moreover, for cMPDs, patients with susceptibility to infections showed a lower NADPH oxidase activity than patients without infections.
中性粒细胞NADPH氧化酶是一种膜结合酶复合物，负责在呼吸爆发中将氧气还原为超氧阴离子。在骨髓增殖性疾病和骨髓增生异常综合征（MDS）中，常报道中性粒细胞功能受损，但其实验室特征尚未得到很好的描述。传统上，NADPH氧化酶活性通过显微镜方法进行评估，即通过将硝基蓝四氮唑盐还原为蓝色至黑色的不溶性甲臜颗粒，在显微镜下在阳性中性粒细胞中鉴定。我们使用显微镜方法以及光度微孔板测定法，对22例慢性骨髓增殖性疾病（cMPD）患者和15例MDS患者的中性粒细胞NADPH氧化酶进行了研究，该测定法监测细胞化学反应30分钟。还研究了cMPD与患者感染易感性之间的关系。在光度测定中，MDS和cMPD中的平均酶活性低于正常受试者。cMPD（除骨髓纤维化外）中的NADPH氧化酶活性高于MDS（除慢性粒单核细胞白血病外），并且这些差异在显微镜下不太明显。此外，对于cMPD，感染易感性患者的NADPH氧化酶活性低于无感染患者。
