选择性尿蛋白指数临床应用的前景及挑战

Prospects and challenges of selectivity proteinuria index in clinical practices

肾小球滤过膜由于存在孔径屏障和电荷屏障,对血浆蛋白质有选择滤过作用。选择性尿蛋白指数(selectivity proteinuria index,SPI)可通过比较血浆中不同分子量大小的蛋白质的肾脏清除率来反映肾小球滤过膜的损伤程度及活跃肾单位整体通透性的改变,不但操作简便、适用于有肾活检禁忌证的患者和无肾活检条件的地区,还可以弥补肾活检只获取局部组织的不足。改善全球肾脏病预后组织膜性肾病指南提出SPI可作为危险分层、启动和确定治疗方案的临床指标之一。然而,SPI也具有公式不统一、特异性不高和干扰因素多等局限性。因此,联合其他指标共同指导临床工作具有重要意义。本文就SPI原理、计算方法、临床应用价值及面临挑战进行综述。

Plasma proteins are selectively filtrated by glomerular filtration membrane due to their sizes and charge barriers.By comparing renal clearance of a larger molecular weight to a smaller molecular weight protein in plasma,selectivity proteinuria index(SPI)reflects the severity of injury in glomerular filtration membrane as well as the change of overall glomerular permeability in active nephrons.SPI is not only a convenient marker for patients with contraindications to renal biopsy and may be applied in areas where renal biopsy technique is not available,but also makes up for defects of focal renal biopsy tissues.Kidney Disease:Improving Global Outcomes(KDIGO)Guideline for Membranous Nephropathy has proposed SPI as one of the clinical indicators for risk stratification,initiation and decision on therapeutic strategies.However,SPI also has such limitations as inconsistent formulae,suboptimal specificity and complicated interfering factors.It is of great significance to guide clinical practices along with other indicators.This review summarized the basic principles,calculation methods,clinical application values and challenges of SPI.