Biomarkers in systemic lupus erythematosus: Do they make the mark?

Biomarkers are indicators of biological processes. In lupus we especially require activity biomarkers to look at predicting flares, differentiating damage from activity, and assessing response to treatment. There are numerous molecules that have been evaluated for these purposes, but studies suffer from limitations of design, statistical rigor, and outcome measure. The best biomarker remains the oldest one, double-standard deoxyribonucleic acid (dsDNA) and has many longitudinal studies to back it, and shows the ability to predict renal flares. Apart from this anti-C1q, cell-bound complement activation products and urinary molecules-chemokines and neutrophil gelatinase-associated lipocalin (NGAL)-are promising. The interferon signature has not lived up to its promise; however, microRNA (miRNA) signature is newly coming up as a marker of activity. Even if we do come up with better biomarkers, there is lack of clarity on issues of socio-economic impact as well as psychological impact of frequent testing for biomarkers.