502例急性髓系白血病患者髓过氧化物酶的表达及其在分型诊断中的意义

OBJECTIVE: To investigate the myeloperoxidase (cMPO) expression pattern by flow cytometry (FCM) in patients with acute myeloid leukemia (AML) and its role in classifying AML. METHODS: Eight-color multiparametric FCM with CD45/SSC gating was used to determine the cMPO expression in 502 AML patients. RESULTS: The positive rate of cMPO in all patients was 58.0%, in which the proportion of normal positivity, dim positivity and partial positivity was 21.5%, 34.1% and 2.4%, respectively. The remaining cases (42.0%) were all negative. In AML with t(15;17) (q22;q12)/PML-RARα, the positive rate was the highest (100%) and the intensity was similar to that of the normal granular leukocytes, followed by AML with t(8;21) (q22;q22)/RUNX1-RUNX1T1, the positive rate was 91.4% and the intensity was mostly dim. AML with minimal differentiation and acute megakaryoblastic leukemia were all cMPO negative. The positive rates of cMPO in the remaining subtypes were between 22.7% and 76.2%. CONCLUSION: The positive rate and intensity of cMPO were significantly different among different subtypes of AML.