The performance evaluation of soluble ST2 detection kit and the clinical application of sST2 in diagnosing heart failure

Abstract

Objective To evaluate the performance of sST2 ELISA kit and investigate the clinical application of sST2. Methods This verification study validated the precision, linearity of sST2 ELISA kit according to the CLSI EP-15A, EP-6A protocols. 300 healthy adults（aged from 20 to 85, 124 male and 176 female） from 5 different districts of Shanghai were used to establish serum sST2 reference interval. The correlations between sST2, NT-ProBNP, LVEF and NYHA class were analyzed in 117 patients diagnosed with heart failure who were grouped according to the New York heart association (NYHA). Receiver operating characteristic (ROC) curve was used to compare the ablity of sST2, NT-ProBNP, LVEF in distinguishing heart failure patients. Results The within-lot and between-lot variation of three level samples were below 4% and 10% respectively. There was a good linear correlation (Y=0.995X+0.005, R2=0.999) between theoretical value and actual detection result in the range of 0 to 200 μg/ml. The reference interval of sST2 was 10.2 to 41.0 μg/ml for males and 8.9 to 28.1 μg/ml for females. sST2 was positively correlated with NT-ProBNP and NYHA class but did not correlate with LVEF in heart failure patients. Patients with NYHA class＞II (Median: 28.3,IQR:19.5-39.2)had higher serum sST2 level than patients with NYHA class≤II (Median:45.1,IQR:34.1-85.6), P<0.05. The AUC of sST2 in distinguishing heart failure patients from normal people was 0.815(sensitivity :51.2%,specificity:92.7%).The AUC of sST2 ,sST2+NT-ProBNP and sST2+NT-ProBNP+LVEF in distinguishing patients between NYHA class≤II and＞II were 0.743, 0.810, 0.831 respectively and the sensitivity of sST2+NT-ProBNP+LVEF was 94.7%. Conclusions Experimental results show that this sST2 ELISA kit has a good performance in the precision, linearity.sST2 correlates with NT-ProBNP and NYHA class but do not correlates with LVEF. Serum sST2 level is not influenced by age, BMI, renal function. sST2 could be a good supplement of NT-ProBNP and LVEF in distinguishing patients between NYHA class≤II and＞II. （Chin J Lab Med,2014,37:394-398） Key words: Receptors, cell surface; Peptide fragments; Natriuretic peptide, brain; Enzyme-linked immunosorbent assay; Stroke volume; Heart failure