液相色谱质谱法对47例非透析慢性肾脏病患者色氨酸-犬尿氨酸通路的分析

目的利用液相色谱-质谱(LC-MS)代谢组学方法探讨慢性肾脏病(chronic kidney disease，CKD)1-4期非透析患者色氨酸(tryptophan, Trp)-犬尿氨酸(kynurenine, Kyn)通路的改变及意义。 方法2018年3月至2018年6月苏州大学附属第一医院肾内科CKD1～4期非透析患者47例，同期30例健康志愿者作为对照组。应用LC-MS法对受试者血浆进行代谢物分析。应用Human Metabolome Database (HMDB)，MassBank，LipidMaps等数据库匹配不同CKD分期Kyn通路差异代谢物，绘制受试者曲线(receiver operating characteristic, ROC)评估差异代谢物敏感性与特异性。采用Metaboanalyst软件进行代谢通路拓扑分析。以Kyn/Trp比值(KT值)表示Kyn通路限速酶吲哚胺-2，3-双加氧酶(indoleamine-2，3-dioxygenase, IDO)活性。 结果Kyn在CKD2期即有明显升高(P<0.05)，犬尿喹啉酸(kynurenine acid, KA)在CKD3期明显升高(P<0.01)，二者随CKD分期增加呈上升趋势(P<0.01)。KT值在CKD2期即有升高(P<0.05)，且随CKD分期增加呈上升趋势(P<0.01)。Trp代谢在CKD早期即出现紊乱。 结论Trp-Kyn通路在CKD早期即增强，Kyn、KA、IDO可能作为CKD早期诊断及进展的生物标志物。

Analysis of tryptophan-kynurenine pathway in 47 non-dialysis patients with chronic kidney disease by liquid chromatography-mass spectrometry

ObjectiveTo explore the changes and significance of the tryptophan (Trp)- kynurenine (Kyn) pathway in non-dialysis patients with chronic kidney disease (CKD) stage 1-4 by liquid chromatography-mass spectrometry (LC-MS) metabolomics method. MethodsFrom March 2018 to June 2018, 47 non-dialysis patients with CKD stage 1-4 from the Department of Nephrology, First Hospital Affiliated to Suzhou University were recruited, together with 30 healthy volunteers as the control group. LC-MS was used to analyze the blood samples of the subjects. Databases as Human Metabolome Database (HMDB), MassBank, and LipidMaps, etc, were used to match different metabolites of the kynurenine pathway of different CKD stages, and draw the receiver operating characteristic (ROC) curve to evaluate the sensitivity and specificity of the different metabolites. The Metaboanalyst software was used for metabolic pathway topology analysis. The ratio of Kyn to Trp (KT value) was used to express the activity of the indoleamine-2, 3-dioxygenase (IDO), a rate-limiting enzyme in the kynurenine pathway. ResultsIn comparison with those of the control, Kyn increased in CKD stage 2 (P<0.05) while kynurenic acid (KA) increased in CKD stage 3 (P<0.01). Both Kyn and KA increased with the progressive loss of renal function (P<0.01). KT value increased in CKD stage 2 (P<0.05), and also increased with the progressive loss of renal function (P<0.01). Disorder of Trp metabolism was observed in the early stage of CKD. ConclusionThe Trp-Kyn pathway was enhanced in the early stage of CKD. Kyn, KA, and IDO might be used as biomarkers of both CKD early diagnosis and CKD progression.