ABSTRACT
BACKGROUND: Arsenic trioxide [ATO, inorganic arsenite (iAsIII) in solution] plays an important role in the treatment of acute promyelocytic leukemia (APL). However, the long-term adverse effects (AEs) and the retention of arsenic among APL patients are rarely reported. In this study, we focused on arsenic methylation metabolism and its relationship with chronic hepatic toxicity, as we previously reported, among APL patients who had finished the treatment of ATO. METHODS: A total of 112 de novo APL patients who had completed the ATO-containing treatment were enrolled in the study. Arsenic species [iAsIII, inorganic arsenate (iAsV), and their organic metabolites, monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA)] in patients' plasma, urine, hair and nails were detected by high-performance liquid chromatography combined with inductively coupled plasma mass spectrometry (HPLC-ICP-MS). Eighteen single nucleotide polymorphisms (SNPs) of the arsenic (+ 3 oxidative state) methylation transferase (AS3MT) gene, which was known as the main catalyzer for arsenic methylation, were tested with the polymerase chain reaction method. RESULTS: The study showed the metabolic pattern of arsenic in APL patients undergoing and after the treatment of ATO, in terms of total arsenic (TAs) and four species of arsenic. TAs decreased to normal after 6 months since cessation of ATO. But the arsenic speciation demonstrated significantly higher portion of iAsIII in patient's urine (40.08% vs. 1.94%, P < 0.001), hair (29.25% vs. 13.29%, P = 0.002) and nails (30.21% vs. 13.64%, P = 0.003) than the healthy controls', indicating a decreased capacity of arsenic methylation metabolism after the treatment of ATO. Urine primary methylation index (PMI) was significantly lower in patients with both chronic liver dysfunction (0.14 vs. 0.28, P = 0.047) and hepatic steatosis (0.19 vs. 0.3, P = 0.027), suggesting that insufficient methylation of arsenic might be related to chronic liver disorders. Two SNPs (A9749G and A27215G) of the AS3MT gene were associated with impaired urine secondary methylation index (SMI). CONCLUSIONS: The long-term follow-up of arsenic speciation indicated a decreased arsenic methylation metabolism and a probable relationship with chronic hepatic disorders among APL patients after the cessation of ATO. Urine PMI could be a monitoring index for chronic AEs of ATO, and the SNPs of AS3MT gene should be considered when determining the dosage of ATO.
ABSTRACT
To illustrate the clinical and genetic features of elderly and secondary acute myeloid leukemia (AML) patients, we compared 145 elderly AML (e-AML) and 55 secondary AML (s-AML) patients with 451 young de novo AML patients. Both e-AML and s-AML patients showed lower white blood cell (WBC) and bone marrow (BM) blasts at diagnosis. NPM1, DNMT3A, and IDH2 mutations were more common while biallelic CEBPA and IDH1 mutations were less seen in e-AML patients. s-AML patients carried a higher frequency of KMT2A-AF9. In treatment response and survival, e/s-AML conferred a lower complete remission (CR) rate and shorter duration of event-free survival (EFS) and overall survival (OS) compared with young patients. In multivariate analysis, s-AML was an independent risk factor for OS but not EFS in the whole cohort. Importantly, intensive therapy tended to improve the survival of e/s-AML patients without increasing the risk of early death, and hematopoietic stem cell transplantation (HSCT) could rescue the prognosis of s-AML, which should be recommended for the treatment of fit patients.