Biological variation of galectin-3 and soluble ST2 for chronic heart failure: Implication on interpretation of test results

Background Galectin-3 and soluble ST2 (sST2) are novel serum biomarkers of chronic heart failure. Methods and Results The biological variability of galectin-3 and sST2 was measured from a cohort of 17 healthy subjects where blood was taken once every 2 weeks for 8 weeks (n = 4 samples) and from 12 subjects where blood was taken hourly (for galectin-3 only). The analytical, intraindividual, and interindividual variation were measured for galectin-3 (BG Medicine, Waltham, MA) and sST2 (Critical Diagnostics, San Diego, CA). From these measurements, the reference change (RCV) and index of individuality was 39% (hourly) and 61% (weekly) and 1.0 (hourly and weekly) for galectin-3. Corresponding RCV and index of individuality values for sST2 were 30% and 0.25. Conclusion The RCV result for sST2 was lower than the corresponding results for galectin-3, B-type natriuretic peptide, and N-terminal pro–B-type natriuretic peptide. These data suggest that sST2 may be more useful for monitoring long-term heart failure, and galectin-3 may be more useful for the diagnosis of heart failure remodeling.