Successful treatment of relapsed acute promyelocytic leukemia with arsenic trioxide in a hemodialysis-dependent patient: A case report

BACKGROUND Arsenic trioxide(ATO)is recommended for patients who do not achieve molecular remission or who have molecular or morphologic relapse.However,there are no guidelines for adjusting ATO dosage in patients with severe renal failure or on dialysis.Herein,we report the successful treatment of relapsed acute promyelocytic leukemia(APL)in a patient on hemodialysis with ATO single agent and review the cases in literature.CASE SUMMARY A 46-year-old woman who has been on hemodialysis to chronic glomerulonephritis for 15 years visited our hospital for pancytopenia.She had been seen for pancytopenia 3 years ago and had been diagnosed with APL.She also received chemotherapy for APL but unfortunately was lost to follow-up after her second consolidation chemotherapy.She was noted to have pancytopenia by her nephrologist during hemodialysis 1 mo ago.Bone marrow biopsy and reverse transcriptase-polymerase chain reaction(RT-PCR)tests revealed a diagnosis of relapsed APL.Treatment for relapsed APL with ATO single agent was started and she achieved molecular remission after administering 24 doses of ATO.Thus far,four consolidation therapies have been performed with the ATO single agent,and,to date,the molecular remission has been maintained as negative promyelocytic leukemia/retinoic acid receptor-αfusion gene as confirmed by RTPCR testing for two years.CONCLUSION This is a rare case of relapsed APL successfully treated with the single agent ATO in a patient on hemodialysis.

CD71-mediated liposomal arsenic-nickel complex combined with all-trans retinoic acid for the efficacy of acute promyelocytic leukemia

Clinically,arsenic trioxide(ATO)was applied to the treatment of acute promyelocytic leukemia(APL)as a reliable and effective frontline drug.However,the administration regimen of AsⅢwas limited due to its fast clearance,short therapeutic window and toxicity as well.Based on CD71 overexpressed on APL cells,in present study,a transferrin(Tf)-modified liposome(LP)was established firstly to encapsulate AsⅢin arsenic-nickel complex by nickel acetate gradient method.The AsⅢ-loaded liposomes(AsLP)exhibited the feature of acid-sensitive release in vitro.Tf-modified AsLP(Tf-AsLP)were specifically taken up by APL cells and the acidic intracellular environment triggered liposome to release AsⅢwhich stimulated reactive oxygen species level and caspase-3 activity.Tf-AsLP prolonged half-life of AsⅢin blood circulation,lowered systemic toxicity,and promoted apoptosis and induced cell differentiation at lesion site in vivo.Considering that ATO combined with RA is usually applied as the first choice in clinic for APL treatment to improve the therapeutic effect,accordingly,a Tf-modified RA liposome(Tf-RALP)was designed to reduce the severe side effects of free RA and assist Tf-AsLP for better efficacy.As expected,the tumor inhibition rate of Tf-AsLP was improved significantly with the combination of Tf-RALP on subcutaneous tumor model.Furthermore,APL orthotopic NOD/SCID mice model was established by 60CO irradiation and HL-60 cells intravenously injection.The effect of co-administration(Tf-AsLP+Tf-RALP)was also confirmed to conspicuous decrease the number of leukemia cells in the circulatory system and prolong the survival time of APL mice by promoting the APL cells’apoptosis and differentiation in peripheral blood and bone marrow.Collectively,Tf-modified acid-sensitive AsLP could greatly reduce the systemic toxicity of free drug.Moreover,Tf-AsLP combined with Tf-RALP could achieve better efficacy.Thus,transferrinmodified AsⅢliposome would be a novel clinical strategy to improve patient compliance,with promising translation prospects.

LEUKOCYTOSIS AND RETINOIC ACID SYNDROME IN PATIENTS WITH ACUTE PROMYELOCYTIC LEUKEMIA TREATED WITH ARSENIC TRIOXIDE

Objective To study the incidence of leukocytosis and retinoic acid （RA） syndrome in newly diagnosed and relapsed acute promyelocytic leukemia （APL） patients treated with arsenic trioxide （ATO）. Methods Thirty patients with newly diagnosed or relapsed APL received ATO for remission induction at the dose of 10 mg/d. RA syndrome was defined when patient was with one or more of the following signs or symptoms： fever, dyspnea, serous cavity effusion, muscular pain, pulmonary infiltration, weight gain, or pulmonary infiltration on chest X-ray. Results Twenty-three （77%） patients achieved complete remission, mean time to remission was 37. 1 days. Leukocytosis was observed in 14 （47%） patients, mean time to leukocytosis was 12. 7 days, median baseline leukocyte count for patients with leukocytosis was 3.1 x 109/L, which was higher than that for patients who did not de,.＇elop leukocytosis （2.6 × 10^9/L, z = - 2. 635, P = 0. 008）. No other cytotoxic therapy was administered, and the leukocytosis resolved in all cases. The RA syndrome was observed in 9 （30%） patients, mean time to diagnose of RA syndrome was 13.9 days, median baseline leukocyte count for patients with RA syndrome was 3.6 × 10^9/L, which was higher than that for patients who did not develop RA syndrome （2. 6 × 10^9/L, z = - 1. 909, P =0. 046）. No patient died of RA syndrome. Conclusion Leukocytosis and RA syndrome are associated with ATO and baseline leukocyte count respectively, and there is distinct link between leukocytosis and RA syndrome.

All-trans Retinoic Acid,Arsenic Trioxide,and Anthracycline-based Chemotherapy Improves Outcome in Newly Diagnosed Acute Promyelocytic Leukemia Regardless of FLT3-ITD Mutation Status

All-trans retinoic acid(ATRA)and pre-upfront arsenic trioxide(ATO)have revolutionized the therapy of acute promyelocytic leukemia(APL).However,internal tandem duplication of FMS-like tyrosine kinase 3(FLT3-ITD)mutations is associated with increased risk of relapse.The aim of this study was to analyze the prognostic impact of FLT3-ITD on APL patients who received remission induction with ATRA,idarubicin(IDA)and/or ATO,followed by ATRA plus ATO along with anthracycline,as consolidation therapy.A total of 72 patients newly diagnosed with APL were included in this study.83.3%of the patients achieved complete remission(CR)after induction therapy.FLT3-ITD mutations were detected in 16(22.2%)patients and closely related to bcr-3 PML-RARa transcript(P<0.001).The 5-year overall survival(OS)rate was 100%in both FLT3-ITDposltlve and FLT3-ITD^(negatlve)groups,and there was no significant difference in 5-year event-free survival(EFS)between the two groups(78.3%vs.83.3%,P=0.85).ATRA plus ATO and anthracycline-based chemotherapy achieved great outcome in newly diagnosed APL regardless of the FLT3-ITD mutation status.

Experimental study on the inhibitory effect of arsenic trioxide combined with phorbol ester on the proliferation of acute promyelocytic leukemia cell line Kasumi-1

Objective:To study the effect of arsenic trioxide (As2O3) combined with phorbol ester (PMA) on the proliferation of acute promyelocytic leukemia cell line Kasumi-1.Methods:Acute promyelocytic leukemia cell lines Kasumi-1 were cultured and randomly divided into control group (treated with the RPMI1640 medium without drugs or serum), As2O3 group (treated with serum-free RPMI1640 medium containing 20 μmol/L As2O3), PMA group (treated with serum-free RPMI1640 medium containing 160 nmol/L PMA) and As2O3+ PMA group (treated with serum-free RPMI1640 medium containing 20 μmol/L As2O3 and 160 nmol/L PMA). After treatment, the cell proliferation activity, cell cycle ratio and the protein expression of related genes were measured.Results: 12 h, 24 h and 48 h after treatment, the cell proliferation activity of As2O3 group, PMA group and As2O3+PMA group were significantly lower than that of control group, and the cell proliferation activity of As2O3+PMA group was significantly lower than that of As2O3 group and PMA group;48 h after treatment, the G1 phase and S phase ratio as well as CDK1 and CyclinB1 expression of As2O3 group, PMA group and As2O3+PMA group were significantly lower than those of control group while the G2 phase ratio as well as Bax, Caspase-3, Caspase-9, p-Chk1 and p-Cdc25C9 expression were significantly higher than those of control group;the G1 phase and S phase ratio as well as CDK1 and CyclinB1 expression of As2O3+PMA group were significantly lower than those of As2O3 group and PMA group while the G2 phase ratio as well as Bax, Caspase-3, Caspase-9, p-Chk1 and p-Cdc25C9 expression was significantly higher than those of As2O3 group and PMA group.Conclusion:As2O3 combined with PMA can inhibit the proliferation of acute promyelocytic leukemia cell line Kasumi-1 by inducing apoptosis and blocking cell cycle.

Realgar-indigo naturalis formula for the treatment of patients with relapsed and arsenic trioxide-resistant acute promyelocytic leukemia:A case series

Introduction There is currently no standard treatment for relapsed and arsenic trioxide(ATO)-resistant acute promyelocytic leukemia(APL).Here,we report a case series of realgar-indigo naturalis formula(RIF)for the successful treatment of patients with relapsed and ATO-resistant APL.Case presentation Two patients in the first relapse and one in the second relapse failed to achieve hematologic complete remission(HCR)when reinduced by ATO;the other five patients progressed to relapse during ATO-based regimens for post-remission therapy.These eight patients received RIF in three doses per day totaling 130 mg/kg(≤30 pills)as induction therapy and achieved HCR at a median time of 46.5 days.They received 5 years of post-remission therapy,which consisted of combined chemotherapy followed by RIF.During this period,the patients did not experience renal dysfunction or QT interval prolongation.At the last follow-up,three patients survived without relapse,two patients survived with a second or third relapse and third or fourth remission,and the other three patients relapsed for a third or fourth time and died.The 5-year overall survival and event-free survival rates were 75.0%(95%confidence interval[CI]:31.5–93.1)and 37.5%(95%CI:5.6–71.7),respectively.Conclusion RIF for induction therapy and RIF combined with chemotherapy for post-remission therapy may represent an effective and safe protocol for the treatment of patients with relapsed and ATO-resistant APL.

In vitro study on arsenic sulfide (realgar)-induced apoptosis of retinoic acid susceptible or resistant acute promyelocytic leukemia cell lines

Objective: To further understand the possible mechanisms of arsenic sulfide (realgar) in the treatment of acute promyelocytic leukemia (APL). Methods: All-trans retinoic acid (ATRA)-susceptible APL cell line (NB4 cells) and ATRA-resistant APL cell line (MR2 subclone) were used as models in vitro. At various times after incubated with various concentrations of realgar, NB4 and MR2 cells were observed by cell viability , cell proliferation and cell morphology; cell cycle and the expression of Annexin V were assayed by flow cytometry. Results: Cell viability and proliferation of NB4 and MR2 cells were inhibited after the treatment, to some extent, in a dose and time dependent manner. 177 - 711g/L of realgar treated NB4 and MR2 cell presented morphologically some features of apoptotic cells such as intact cell membrane, chromatin condensation and nuclear fragmentation, apoptosis body could be found by electron microscopy as well. Sub-Gl cells and cell cycle arrest were observed by flow cytometry. The proportion of Annexin V -FITC+/PI cells , which represent apoptotic cells, was up-regulated. Conclusion: Realgar could induce apoptosis of acute promyelocytic leukemia cell despite its susceptibility to retinoic acid in the way that may be different from retinoic acid.

Arsenic Trioxide Induces Apoptosis of Glucocorticoid-Resistant Acute Lymphoblastic Leukemia CEM-C1 Cells

Objective： To explore the effects of arsenic trioxide （ATO） on the apoptosis of glucocorticoid （GC）-resistant T-acute lymphoblastic leukemia （ALL） CEM-C1 cells and its possible mechanisms. Methods： Different concentrations of ATO （0.25 μmol/L-5 μmol/L） were used to induce the apoptosis of CEM-C1 cells. The inhibition rate of cell proliferation and apoptosis were detected by MTT test, Annexin V-FITC/PI flow cytometry and optical microscopy, respectively. RT-PCR was applied to semi-quantitatively analyze the mRNA expression of pro-apoptotic proteins （Bad and PDCD4） and anti-apoptotic proteins （XIAP and MCL-1） induced by different concentrations of ATO at different time points. Results： ATO could inhibit proliferation and induce apoptosis of CEM-C1 cells at a concentration and time dependent manner. Low-dose ATO mildly inhibited the proliferation of CEM-C1 cells while higher concentrations （1 μmol/L and 5 μmol/L） had strong anti-tumor effect with the inhibiting rates of 40.07±7.98% and 88.67±2.88%, respectively. Annexin V-FITC/PI flow cytometry showed that the apoptotic rates of CEM-C1 ceils were significantly increased after 48 hours treatment of different concentrations of ATO. RT-PCR demonstrated up-regulated mRNA expression of pro-apoptotic protein Bad and PDCD4 but down-regulated mRNA expression of anti-apoptotic protein XIAP when CEM-C1 cells were treated with different concentrations of ATO at different time points. The MCL-1 mRNA expression was down-regulated only after the treatment of 5 μmol/L ATO. Conclusion： ATO can inhibit cell proliferation and induce cell apoptosis in GC-resistant CEM-C1 cells. The molecular mechanisms might involve the increased mRNA expression of pro-apoptotic protein Bad and PDCD-4, and rapid down-regulation of XIAP mRNA expression.

Cross-sectional network analysis of plasma proteins/metabolites correlated with pathogenesis and therapeutic response in acute promyelocytic leukemia

The treatment of PML/RARA+acute promyelocytic leukemia(APL)with all-trans-retinoic acid and arsenic trioxide(ATRA/ATO)has been recognized as a model for translational medicine research.Though an altered microenvironment is a general cancer hallmark,how APL blasts shape their plasma composition is poorly understood.Here,we reported a cross-sectional correlation network to interpret multilayered datasets on clinical parameters,proteomes,and metabolomes of paired plasma samples from patients with APL before or after ATRA/ATO induction therapy.Our study revealed the two prominent features of the APL plasma,suggesting a possible involvement of APL blasts in modulating plasma composition.One was characterized by altered secretory protein and metabolite profiles correlating with heightened proliferation and energy consumption in APL blasts,and the other featured APL plasma-enriched proteins or enzymes catalyzing plasma-altered metabolites that were potential trans-regulatory targets of PML/RARA.Furthermore,results indicated heightened interferon-gamma signaling characterizing a tumor-suppressing function of the immune system at the first hematological complete remission stage,which likely resulted from therapy-induced cell death or senescence and ensuing supraphysiological levels of intracellular proteins.Overall,our work sheds new light on the pathophysiology and treatment of APL and provides an information-rich reference data cohort for the exploratory and translational study of leukemia microenvironment.

Hemostatic abnormalities associated with acute promyelocytic leukemia and corrective effects of all-trans-retinoic acid or arsenic trioxide treatment

Objective To study in vivo effect of all trans retinoic acid (ATRA) or arsenic trioxide (As 2O 3) on the expression of tissue factor (TF) and the hemostatic disorders, a series of parameters were measured in bone marrow blasts and plasma from acute promyelocytic leukemia (APL) patients Methods The plasma variables were measured by ELISA or chromogenic study The TF transcription was assessed using reverse transcription polymerase chain reaction technique (RT PCR) Results The blast cell procoagulant activity (PCA), TF antigen of APL cell lysates, as well as the transcription of APL TF mRNA elevated at diagnosis, were reduced after ATRA or As 2O 3 therapy The plasma level of platelet α granular membrane protein 140, soluble fibrinomonomer complex, thrombomo^dulin, tissue plasminogen activator and D dimer significantly increased, fibrinogen, antigen level of protein C, plasminogen, α2 plasminogen inhibitor and plasminogen activator inhibitor decreased at diagnosis, were restored to normal after complete remission but protein C activity and protein S remained elevated in ATRA group Conclusions There existed activation of platelets and consumption of anticoagulants as well as activation of coagulation and fibrinolytic system before treatment Both ATRA and As 2O 3 therapy down regulated the expression of TF mRNA, decreased the PCA and TF level in APL cells, inhibited coagulation activation, secondary hyperfibrinolysis and recorrected other hemostatic abnormalities, thus greatly improved the bleeding symptom in early stage of the treatment

亚砷酸诱导的老年急性早幼粒细胞白血病早期死亡分析

目的分析经单药亚砷酸(arsenic trioxide,ATO)诱导治疗的老年(年龄≥60岁)初发急性早幼粒细胞白血病(acute promyelocytic leukemia,APL)的早期死亡(early death,ED)发生情况及预测因素。方法收集连续收治的71例老年APL患者和456例年轻APL患者的临床资料。选取临床上可以快速获取的10个临床及实验室检测参数,采用χ^(2)检验及Logistic回归模型进行统计学分析。结果老年患者的ED率(22.5%,16/71)高于年轻患者(15.1%,69/456),但差异无统计学意义(P=0.115)。老年感染相关ED(8.5%)和血栓相关ED(2.3%)的发生率均显著高于年轻患者(分别为2.0%和0.3%),差异有统计学意义(P<0.01)。男性和白细胞计数>10×10^(9)/L是两组患者ED的共同独立风险因素,低白蛋白血症(P<0.001)和血清纤维蛋白原<1g/L(P=0.001)还是年轻患者ED的独立风险因素。结论单药ATO诱导治疗的老年APL患者的入院临床特征、ED发生情况及风险因素与年轻患者明显不同。因此,有必要对APL患者的ED情况进行年龄分层研究。

Inhibition factors of arsenic trioxide therapeutic effects in patients with acute promyelocytic leukemia

Objective To summarize limitations involved in arsenic trioxide therapeutic effects in acute promyelocytic leukemia, because current studies show that some individuals of acute promyelocytic leukemia have relatively poor outcomes during treatment with arsenic trioxide. Data sources Most relevant articles were included in the PubMed database between 2000 and 2013 with the keywords ＂acute promyelocytic leukemia＂, ＂arsenic trioxide＂, ＂thiol＂ or ＂methylation＂. In addition, a few older articles were also reviewed. Study selection Data and articles related to arsenic trioxide effect in acute promyelocytic leukemia treatment were selected and reviewed. We developed an overview of limitations associated with arsenic trioxide therapeutic effect. Results This review focuses on the researches about the arsenic trioxide therapeutic effect in acute promyelocytic leukemia and summarizes three mainly limitations which can influence the arsenic trioxide therapeutic effect to different degrees. First, with the combination of arsenic and glutathione the therapeutic effect and cytotoxicity decrease when glutathione concentration increases; second, arsenic methylation, stable arsenic methylation products weaken the apoptosis effect of arsenic trioxide in leukemia cells; third, gene mutations affect the sensitivity of tumor cells to arsenic trioxide and increase the resistance of leukemia cells to arsenic trioxide. Conclusions The chief limitations are listed in the review. If we can exclude all of them, we can obtain a better therapeutic effect of arsenic trioxide in patients with acute promyelocytic leukemia.

A drug from poison:how the therapeutic effect of arsenic trioxide on acute promyelocytic leukemia was discovered

It is surprising that,while arsenic trioxide(ATO) is now considered as "the single most active agent in patients with acute promyelocytic leukemia(APL)",the most important discoverer remains obscure and his original papers have not been cited by a single English paper.The discovery was made during the Cultural Revolution when most Chinese scientists and doctors struggled to survive.Beginning with recipes from a countryside practitioner that were vague in applicable diseases,Zhang TingDong and colleagues proposed in the 1970s that a single chemical in the recipe is most effective and that its target is APL.More than 20 years of work by Zhang and colleagues eliminated the confusions about whether and how ATO can be used effectively.Other researchers,first in China and then in the West,followed his lead.Retrospective analysis of data from his own group proved that APL was indeed the most sensitive target.Removal of a trace amount of mercury chloride from the recipe by another group in his hospital proved that only ATO was required.Publication of Western replication in 1998 made the therapy widely accepted,though neither Western,nor Chinese authors of English papers on ATO cited Zhang's papers in the 1970s.This article focuses on the early papers of Zhang,but also suggests it worth further work to validate Chinese reports of ATO treatment of other cancers,and infers that some findings published in Chinese journals are of considerable value to patients and that doctors from other countries can benefit from the clinical experience of Chinese doctors with the largest population of patients.

Effect of all-trans retinoic acid and arsenic trioxide on tissue factor expression in acute promyelocytic leukemia cells

OBJECTIVE: To study the effect of all-trans retinoic acid (ATRA) and arsenic troxide (As2O3) on tissue factor (TF) expression and procoagulant activity (PCA) of acute promyelocytic leukemia (APL) cells in vivo and in vitro. METHODS: PCA from freshly isolated APL blasts from APL patients treated with ATRA or As2O3 was detected using a one-stage clotting assay. TF antigen was detected by ELISA and TF mRNA by RT-PCR. The maturation sensitive (NB4) or resistant subclones (NB4-R1) of the promyelocytic NB4 cell line, as well as U937 cells infected with pMSCV-PML-RARa treated with or without ATRA or As2O3, were also examined. RESULTS: Both ATRA and As2O3 can down-regulate the TF antigen, its mRNA transcription and membrane PCA of APL cells in vivo and in vitro, in a time-dependent manner. The TF antigen level in PML-RARa + U937 cells was significantly higher than that in U937 cells infected with retrovirus vector. Both ATRA and As2O3 can also down-regulate the TF antigen in U937 cells transfected with or without PML-RARa. CONCLUSION: Tissue factor expression and PCA in APL cells may be down-regulated by ATRA and As2O3. By down-regulating TF expression, As2O3 might also be used to improve the DIC-related hemorrhage in APL. Our data indicate that elevated TF antigen in PML-RARa + U937 may be related to the fusion protein PML-RARa. The down-regulating effect of ATRA and As2O3 on TF expression in U937 cells might not involve this fusion protein.

Arsenic trioxide in treatment of de novo acute basophilic leukemia

Acute basophilic leukemia （ABL） is a rare subtype of .acute myeloid leukemia （AML）, accounting for 4%-5% of AML and less than 2% of all hematopoietic malignancies. It is usually characterized by a very rapid clinical course, symptoms of hyperhistaminemia, peptic ulceration, gastrointestinal cerebrovascular bleeding and resistance to therapy.^1 However, the clinical outcome of ABL remains disapp2ointing. Most patients died within 1 year after diagnosis.

二甲双胍与三氧化二砷对KG1a细胞增殖的抑制作用

目的:探讨二甲双胍协同三氧化二砷对急性髓系白血病KG1a细胞增殖的影响及其可能的机制。方法:采用CCK-8法检测二甲双胍、三氧化二砷以及联合应用对KG1a细胞的杀伤作用;Annexin V-FITC/PI双染法流式细胞术检测应用二甲双胍协同三氧化二砷对KG1a细胞凋亡的影响;Western blot检测胞内凋亡、自噬相关蛋白的表达。结果:二甲双胍与三氧化二砷联合及单独应用均可抑制KG1a细胞增殖,诱导KG1a细胞凋亡,联合用药组增殖抑制率及凋亡率高于单独用药组(P<0.05)。联合用药诱导KG1a细胞中Caspase 8和P62蛋白表达上调且高于单药组(P<0.05)。结论:二甲双胍能协同三氧化二砷杀伤KG1a细胞,其作用机制可能与诱导凋亡和增强自噬有关。

Advances in Management of Acute Promyelocytic Leukemia with Arsenic Trioxide

Acute promyelocytic leukemia （APL）, with specific features in cell morphology, is classified as M3 by French-American-British （FAB）. Among M3, 95% of patients show specific chromosome translocation t（15;17）q（22;21） with PML-RAR fusion gene, and 5% of patients show other subtypes. According to the statistical analysis of 2 540 adult acute myeloid leukemia （AML） cases in Harbin institute of Hematology ＆ Oncology, APL accounted for 23%.

Effect of arsenic trioxide on cytokine expression by acute promyelocytic leukemia cells

Objective To detect the expression of cytokines by acute promyelocytic leukemia (APL) cells before and after exposure to arsenic trioxide.Methods Diagnoses were performed according to the FAB cytological classification criteria and cytogenetic criteria. Bone marrow or blood samples from APL patients were collected in heparinized tubes,then primary APL cells were separated by traditional Ficoll-Hypaque density centrifugation and purified after adherence to plastic surfaces. IL-1β, IL-6, IL-8, TNFα and G-CSF levels in the leukemia cell culture supernatants were detected by ELISA. At the same time, nitro blue tetrazolium (NBT) reduction test was used to detect the differentiation of APL cells.Results After 96 hours exposure to arsenic trioxide, 10-6 mol/L in vitro or 10 mg/d in vivo, APL cells showed a significant increase of IL-1β ( P < 0. 05) and G-CSF ( P < 0. 05) production, and a significant decrease of IL-6 (P<0. 05) and IL-8 (P<0. 05). However, there was no obvious variation of TNFα when compared with APL cells without exposure to arsenic trioxide. On the other hand, the proliferation ratio of APL cells in vitro was statistically correlated to the IL-1β secretion ratio or G-CSF secretion ratio. The cell number ratio in patients with detectable IL-1βor G-CSF was higher than that without detectable IL-1β or G-CSF.Conclusion IL-1β and G-CSF secretion may play an important role in the proliferation of APL cells after exposure to arsenic trioxide.