骨髓增生异常综合征患者骨髓中ABAT mRNA表达和ABAT甲基化水平对预后预测价值研究

Prognostic Value of ABAT mRNA Expression and ABAT Methylation Level in Bone Marrow of Patients with Myelodysplastic Syndrome

目的检测4-氨基丁酸转氨酶(4-aminobutyrate aminotransferase,ABAT)在骨髓增生异常综合征(myelodysplastic syndrome,MDS)患者骨髓中表达水平,并分析其对患者临床病理特征和预后的影响。方法回顾性收集2016年1月~2020年3月在邢台医学高等专科学校第一附属医院MDS患者92例,急性髓细胞白血病(acute myeloid leukemia,AML)30例。另收集30例在为期三年的随访中并未发展为MDS或其他血液系统克隆性疾病的免疫血小板减少症患者为对照组。实时荧光定量PCR(real-time fluorescence quantitative PCR,qRT-PCR)检测纳入研究者骨髓中ABAT mRNA相对表达水平和ABAT甲基化水平,比较MDS患者不同临床特征间ABAT mRNA相对表达水平和甲基化水平,采用多因素Logistic回归分析影响MDS不良预后的危险因素,受试者工作特征(ROC)曲线检测ABAT甲基化水平预测MDS患者不良预后的临床价值,Kaplan-Meier曲线分析不同ABAT mRNA相对表达水平和甲基化水平间的三年生存率并采用Log-rank检验进行比较。结果MDS组ABAT mRNA表达水平(0.42±0.08)低于对照组(0.56±0.15)和AML组(0.52±0.10),ABAT甲基化水平(32.51±5.32)高于AML组(26.21±4.58)和对照组(10.25±4.31),差异具有统计学意义(t=4.251,4.562;10.415,8.326,均P<0.05)。MDS患者IPSS危险分级高危患者ABAT甲基化水平(42.65±5.32)高于低危(25.63±4.16),中危-1(30.59±2.51)和中危-2(33.25±3.69)患者,差异具有统计学意义(t=8.329,7.077,5.874,均P<0.001)。核型分析差[OR(95%CI):4.973(1.524~8.581),P=0.004],IPSS危险分级高危[OR(95%CI):8.542(2.365~14.521),P<0.001]和ABAT高甲基化水平[OR(95%CI):6.178(1.589~13.021),P<0.001]为影响MDS不良预后的危险因素。ABAT甲基化水平预测MDS不良预后的截断值为30.54,曲线下面积、敏感度、特异度分别为0.92,0.874,0.851。ABAT甲基化高水平组(>30.54)三年存活率为66.67%,低于ABAT甲基化低水平组(≤30.54)的三年存活率(93.18%),差异具有统计学意义(Log-rankχ^(2)=9.814,P=0.002)。结论MDS骨髓中ABAT甲基化水平增加,是影响患者不良预后的危险因素,ABAT甲基化水平>30.54有望成为预测患者不良预后的因子。

Objective To detect the expression level of 4-aminobutyrate aminotransferase(ABAT)in bone marrow of patients with myelodysplastic syndrome(MDS),and analyze its influence on clinicopathological features and prognosis of patients.Methods From January 2016 to March 2020,92 patients with MDS and 30 patients with acute myeloid leukemia(AML)from the First Affiliated Hospital of Xingtai Medical College were retrospectively collected.Meanwhile,30 patients with immunothrombocytopenia who did not develop MDS or other clonal diseases of the blood system during a 3-year follow-up were collected as control group.Real-time quantitativefluorescent PCR(qRT-PCR)was used to detect the relative expression level and methylation level of ABAT mRNA of all patients,and the relative expression level and methylation level of ABAT mRNA among different clinical characteristics of MDS patients were compared.Multivariate logistic regression analysis was used to analyze the risk factors affecting the adverse prognosis of MDS.The clinical value of detecting ABAT methylation level in predicting poor prognosis of MDS patients was analyzed by receiver operating characteristic(ROC)curve.Kaplan-Meier method was used to calculate the 3-year survival rate between groups with different ABAT mRNA relative expression levels and methylation levels,and log-rank test was used for their comparison.Results The expression level of ABAT mRNA in MDS group(0.42±0.08)was lower than that in control group(0.56±0.15)and AML group(0.52±0.10),while the methylation level of ABAT(32.51±5.32)was higher than that of AML group(26.21±4.58)and control group(10.25±4.31),and the differences were significant(t=4.251,4.562;10.415,8.326,all P<0.001).The methylation level of ABAT in high-risk patients(42.65±5.32)was higher than that in low-risk patients(25.63±4.16),intermediate-risk-1 patients(30.59±2.51)and intermediate-risk-2 patients(33.25±3.69)by IPSS risk grade,and the differences were significant(t=8.329,7.077,15.874,all P<0.001).Poor Karyotype analysis result[OR(95%CI):4.973(1.524~8.581),P=0.004],high IPSS risk grade[OR(95%CI):8.542(2.365~14.521),P<0.001]and ABAT hypermethylation level[OR(95%CI):6.178(1.589~13.021),P<0.001]were the risk factors affecting the poor prognosis of MDS.The cut-offvalue of ABAT methylation level to predict the poor prognosis of MDS were 30.54,and the area under the curve(AUC),the sensitivity and specificity were 0.92,0.874 and 0.851,respectively.The 3-year survival rate of the high ABAT methylation group(>30.54)was 66.67%,which was lower than that of the low ABAT methylation group(≤30.54)was 93.18%,with significant difference(Log-rankχ^(2)=9.814,P=0.002).Conclusion The ABAT methylation levels in MDS bone marrow increase,which is a risk factor affecting the poor prognosis of patients.ABAT basal level>30.54 is expected to become a factors predicting the poor prognosis of patients.