不同病因的慢性肾病患者血清氨基酸谱存在显著差异

慢性肾病(chronic kidney disease, CKD)患者血清氨基酸谱发生了显著性变化，但目前并无不同病因的CKD患者血清氨基酸谱的比较研究。本研究主要探究不同病因CKD患者血清氨基酸谱的差异，以及差异氨基酸与肾疾病发生发展的相互关系。选取79例确诊慢性肾病的成年患者，根据其病因，分糖尿病肾病组、高血压肾病组及慢性肾小球肾炎组。另选取25例性别年龄匹配的健康成年人为正常对照组。收集及处理清晨空腹血清标本，采用反相高效液相色谱法（reverse-phase high-performance liquid chromatography, RP-HPLC）测定血清中22种游离氨基酸的水平。结果显示，与正常对照组相比，3组CKD患者血清赖氨酸、丝氨酸、甘氨酸、伽马氨基丁酸(GABA)、色氨酸、亮氨酸以及酪氨酸水平均显著下降（P<0.05），而血氨水平显著升高（P<0.05）。糖尿病肾病组患者血清苏氨酸水平明显高于其余3组（P<0.05），而血清天冬氨酸水平显著低于其余3组（P<0.05）。慢性肾小球肾炎患者血清异亮氨酸水平显著低于糖尿病肾病及高血压肾病患者（P<0.05）。上述结果证实，慢性肾病患者血清氨基酸谱较正常对照发生显著变化，且不同病因CKD患者部分血清氨基酸水平存在显著差异。其中，色氨酸水平的差异可能是不同病因CKD患者肾功能恶化速度不一致的原因之一。

Significant Differences in Serum Amino Acid Profiles among Patients with Chronic Kidney Disease of Different Etiology

The serum amino acid profiles in chronic kidney disease (CKD) patients changed significantly. However, there is no study regarding to the differences of the serum amino acid profiles in CKD patients of different etiology. This study mainly focuses on the differences of the serum amino acid profiles in CKD patients of different etiology and discusses the roles of different amino acids in the occurrence and development of diseases. A total of 79 adults with advanced CKD were segregated into three cohorts by etiology: diabetic nephropathy (DN, n=20), hypertensive nephropathy (HN, n=26), and chronic glomerulonephritis (CGN, n=33). Twenty-five gender matched healthy adults were selected as healthy controls (HC, n=25). Early-morning fasting serum samples were collected, processed, and subjected to RP-HPLC. The results showed that all CKD patients of the three cohorts were chaacterized by a serum profile showing a decrease of lysine, serine, glycine, GABA, tryptophan, leucine, and tyrosine, and an increase of ammonia when compared to healthy controls (P<0.05). The DN patients were characterized by a serum profile of increased threonine and decreased aspartic acid levels as compared to the patients of HN and CGN groups and the healthy controls (P<0.05). The CGN cohort alone was characterized by a serum profile of decreased isoleucine when compared to the patients of DN and HN groups and the healthy controls (P<0.05). The present study clearly demonstrated that CKD patients with different etiology display significant differences in serum amino acids profiles, specifically some amino acids. The difference of tryptophan levels among CKD patients with different etiology may be one of the reasons for the different rates of renal function deterioration.