Open AccessAssay of urinary protein-bound sialic acid can differentiate steroidsensitive nephrotic syndrome from steroid-resistant cases
Author(s) -
G Niranjan,
Bidhan Chandra Koner,
Atanu Bhattacharjee,
Vishnu Bhat
Publication year - 2016
Publication title -
saudi journal of kidney diseases and transplantation/našrat amraḍ wa zira'aẗ al-kulaẗ
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.268
H-Index - 30
eISSN - 2320-3838
pISSN - 1319-2442
DOI - 10.4103/1319-2442.174066
Subject(s) - sialic acid , medicine , nephrotic syndrome , excretion , albumin , receiver operating characteristic , urine , endocrinology , urinary system , steroid , idiopathic nephrotic syndrome , proteinuria , biochemistry , chemistry , kidney , hormone
The protein selectivity index as measured from the ratio of urinary immunoglobulin to albumin failed to differentiate between steroid-sensitive (SS) and steroid-resistant (SR) cases of nephrotic syndrome (NS). Sialic acid contributes negative charges to many plasma proteins. The negative charge is a determinant of protein excretion rate. The prognostic significance of assay of urinary excretion of protein-bound sialic acid in NS has not been evaluated. Hence, the present study was designed to evaluate whether measurement of urinary protein bound sialic acid (UPBSA) can be used as a marker to differentiate SS from SR cases of NS. The urine samples of 70 (47 SS and 23 SR) pediatric NS children were assayed for UPBSA by Aminoff's method. The levels were compared and the receiver-operator curve was drawn to determine the optimum cutoff point to differentiate among the groups before starting the therapy. The excretion of UPBSA in SR cases of NS was significantly higher than that of SS cases (P<0.05). The optimum cutoff limit for UPBSA was 2.71 μg/mg of proteins with 75% sensitivity and 75.5% specificity for differentiating SS cases from SR cases (area under the plasma- concentration time curve=0.814, P=0.009). We conclude that UPBSA can differentiate SR cases from SS cases of NS in pediatric patients and may help in predicting the response to steroid therapy.