Spasovski Dejan, Masin-Spasovska Jelka, Nada Marina, Calovski Jordan, Sandevska Emilija, Osmani Baskim, Sotirova Tatjana, Balkanov Svetlana, Dukovski Dusko, Ljatifi Arif, Spasovski Goce
Department of Rheumatology, University Clinical Center, Skopje, R. Macedonia.
Clin Lab. 2011;57(5-6):305-14.
Proximal tubules of the kidney have a dominant function in the excretion of different enzymes in the urine. These enzymes can be used as markers for secondary renal damage under the action of different diseases, medicines, and toxins. The aim of this study was to evaluate the values of alanine aminopeptidase (AAP), gamma-glutamyl transferase (gamma-GT), and beta2 microglobulin (beta2m) in urine of patients with untreated rheumatoid arthritis (RA) and to define the possible association between untreated rheumatoid arthritis and tubular function at the brush border region.
We used a kinetic assay for AAP, standard methods by the International Federation for Clinical Chemistry (IFCC) for gamma-GT and Microparticle Enzyme Immunoassay (MEIA), (Abbott A(x)SYM System) for the determination of beta2m in urine of 70 participants (35 untreated RA patients and 35 healthy volunteers (HC)).
From the total of 35 RA patients, AAP enzymuria was found in 24 patients with test sensitivity (68.57%), gamma-GT in 16 patients with test sensitivity (45.71%), while the presence of urinary beta2m was found in a very low percentage of cases. Out of 18 rheumatoid factor (RF) negative patients, 14 patients were AAP and 10 patients were gamma-GT positive, while the presence of beta2m in urine was not detected. Among 17 RF positive RA patients, the presence of AAP and gamma-GT was noticed in 10 and 6 patients, respectively, while the presence of beta2m in urine was not detected.
In conclusion, AAP had a higher sensitivity than gamma-GT and beta2m in detection of asymptomatic renal lesions in untreated RA.
肾脏近端小管在尿液中不同酶的排泄中起主要作用。这些酶可作为不同疾病、药物和毒素作用下继发性肾损伤的标志物。本研究的目的是评估未治疗的类风湿关节炎（RA）患者尿液中丙氨酸氨基肽酶（AAP）、γ-谷氨酰转移酶（γ-GT）和β2微球蛋白（β2m）的值，并确定未治疗的类风湿关节炎与刷状缘区域肾小管功能之间的可能关联。
我们采用动力学分析法检测AAP，采用国际临床化学联合会（IFCC）的标准方法检测γ-GT，采用微粒酶免疫分析法（MEIA）（雅培A(x)SYM系统）检测70名参与者（35名未治疗的RA患者和35名健康志愿者（HC））尿液中的β2m。
在35例RA患者中，24例患者检测到AAP酶尿，检测敏感性为68.57%；16例患者检测到γ-GT，检测敏感性为45.71%；而尿β2m的检出率非常低。在18例类风湿因子（RF）阴性患者中，14例AAP阳性，10例γ-GT阳性，未检测到尿β2m。在17例RF阳性的RA患者中，分别有10例和6例检测到AAP和γ-GT，未检测到尿β2m。
总之，在检测未治疗的RA患者无症状性肾损害方面，AAP的敏感性高于γ-GT和β2m。
