Lipocalin-2, TWEAK, and other cytokines as urinary biomarkers for lupus nephritis.

Lupus nephritis (LN) is a major cause of morbidity and mortality in systemic lupus erythematosus (SLE). As the course of LN is often unpredictable, it is important to identify reliable, noninvasive methods to repeatedly assess the condition of the kidneys in these patients. Urinary biomarkers are easily obtained and probably are best at reflecting the current renal status, as they specifically represent local inflammatory activity. In this article, we review a number of potential urinary biomarkers, including Lipocalin-2, MCP-1, IP-10, IL-6, and IL-8. Additionally, we provide evidence for the possible utility of the novel cytokine TWEAK as a urinary biomarker for LN.