Selective proteinuria index

Selective proteinuria index is an auxiliary test method to check whether kidney function is normal. Clinically, the renal clearance of two plasma proteins with large differences in molecular weight is often measured, and the ratio is calculated to give the selectivity index (SPI). Generally, transferrin (molecular weight 79,000) and IgG (molecular weight 170,000) are used to measure blood and urine concentrations by immunoturbidimetric method or one-way immunodiffusion method, respectively. This test can objectively reflect the severity of glomerular lesions and can be used as a predictor of the therapeutic effects of immunosuppressive agents such as hormones in nephrotic syndrome. It is worth mentioning that nephrotic syndrome caused by renal vein embolism, proteinuria in patients with renal amyloidosis and hereditary nephropathy are also highly selective, but are ineffective against hormones and immunosuppressants.