尿κ轻链早期诊断糖尿病肾病的价值初探

Diagnostic value of urine kappa light chain in the early phage of diabetic nephropathy

目的 探讨尿κ轻链 (KLC)在早期糖尿病肾病 (DN)中的变化及其临床诊断价值。方法 分别以散射比浊法和放射免疫法测定 12 3例 2型糖尿病患者尿KLC和尿白蛋白排泄率 (UAER)。结果 2型糖尿病组尿KLC高于对照组 (P <0 .0 0 1)。糖尿病微量白蛋白尿组尿KLC高于糖尿病正常白蛋白尿组及对照组 (P <0 .0 1)。早期糖尿病肾病患者大部分同时存在尿KLC和UAER的升高。尿KLC和UAER两种方法诊断早期糖尿病肾病有非常显著关联性 ,且诊断结果无差别。在 9.91mg dl水平 ,尿KLC诊断早期DN有较高的特异性。结论 尿KLC为诊断早期糖尿病肾病肾小管病变指标 ,因与UAER存在分离现象 ,和UAER联检可更好地早期诊断和监测糖尿病肾病 ,建议尿KLC≥ 9.91mg dl为诊断早期糖尿病肾病的界限值。

ObjectiveTo study the change of urinary excretion of immunoglobulin kappa light chain (KLC) in type 2 diabetic patients and its diagnostic value in the early course of diabetic nephropathy (DN).MethodsThe urinary concentrations of KLC were measured by rate nephelometry, and the urinary concentrations of albumin was determined by radioimmunoassay.Results Type 2 diabetic patients had a higher urinary excretion of KLC than normal people. The urinary excretion of KLC in patients with microalbuminuria (20 μg/min≤UAER<200 μg/min) was higher than that in patients with normal albuminuria(UAER<20 μg/min). The urinary KLC and UAER increased simultaneously in the majority of patients with early DN. The diagnostic result of urinary KLC was similar to that of UAER. At the level of 9.91mg/dl, the diagnostic specificity of urinary KLC was higher ( 85.33%). Conclusions Urinary KLC is an index in the early diagnosis of diabetic tubular damage. The diagnostic dividing line of 9.91 mg/dl of urinary KLC is recommended.