Background/Purpose: Cystatin C has been developed as a novel biomarker of renal function in last decade and thought as more sensitive than serum creatinine (sCr). However, the clinical significance of serum cystatinC (sCysC) in lupus nephritis (LN) has been rarely reported. We aim to compare serum CysC with traditional indices of renal function and SLEDI in LN patients.

Methods: 75 patients with renal biopsy approved LN based on the ISN/ACR 2003 classification criteria were from The First Hospital of China Medical University since 2009 to 2014. sCysC (mg/L), sCr (umol/L), blood urea nitrogen (BUN, mmol/L), glomerular filtration rate (GFR, ml/min) measured by MDRD and EPI equation, serum albumin (sAlb, mg/L) and urinalysis including 24hr total protein (uTP, g/day), albumin (uAlb, g/L), and Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) were measured before and 6 months after glucosteroid and cyclophosphamide(CTX) treatment. The correlation between sCysC and each traditional indicator were analyzed by Person and the difference of these indices before and after-treatment was analyzed by student ttest.     

Results: sCysC showed closer correlation with traditional indices of renal impairment and SLE activity (Table1). sCysC also displayed a better statistical p value in the response to the treatment of glucosteroid and CTX than sCr and BUN (Table2).

Conclusion: The significance of sCysC should be more emphasized in clinical practice in LN patients. Prospective study needs to be contacted on the effect of early treatment giving based on the increase of sCysC but before sCr rise in large cohort of patients with lupus nephritis.

Table1. Comparison of sCysC with SCr and BUN in correlation efficiency with disease activity of lupus nephritis

Table2. The changes of sCysC and traditional biomarkers before and after the treatment