Monocyte chemoattractant protein-1 as a marker of systemic lupus erythematosus: an observational study.

There is a pivotal need for new markers to be tested in every day clinical practice for systemic lupus erythematosus (SLE) and lupus nephritis (LN). The levels of monocyte chemoattractant protein-1 (MCP-1) in the serum and urine of 72 SLE patients (27 with LN and 45 without LN involvement) and 30 healthy individuals were studied to establish their clinical significance. The SLE Disease Activity Index (SLEDAI) was used to establish the disease activity. Urine and serum MCP-1 was determined using the sandwich enzyme immunosorbent assay. Urinary, but not serum MCP-1, positively correlated with proteinuria (r = 0.839; p < 0.001) and negatively correlated with glomerular filtration, evaluated using the modification of diet in renal disease (MDRD) formula (r = - 0.293; p < 0.05), and with C3 complement component in active LN patients (r = - 0.519, p = 0.019). Both serum and urinary MCP-1 demonstrated a positive correlation with SLEDAI (r = 0.318; p < 0.01 and r = 0.431; p < 0.001). We also demonstrated that the levels of serum and urinary MCP-1 were significantly higher in patients with SLE compared to healthy controls, regardless of the disease activity and renal involvement. We recommend MCP-1 measurement in the routine laboratory follow-up of the SLE patients.