Relative gene expression levels of the gene coding for monocyte chemoattractant protein-1 (MCP-1) as a urinary biomarker in lupus nephropathy

Abstract

Introduction

Lupus nephropathy (LN) is a chronic inflammatory process, characterized by the activation of T cells and high levels of various cytokines, such as MCP-1 at the level of the renal glomerulus and the interstitial tubule. MCP-1 is a chemoattractant of monocytes and lymphocytes, it is responsible for the infiltration of leukocytes in the kidney, which is why MCP-1 levels in urine of patients with LN correlate with the active form of the disease.

Objective

The present study aims to evaluate the expression levels of MCP-1 in patients with LN and to correlate their urinary levels with serum autoimmunity markers.

Material and methods

Our study is of the case-control type, where the groups were made up of 112 patients diagnosed with SLE or LN, and 28 apparently healthy people with no clinical or family history of autoimmune diseases, respectively. MCP-1 expression levels were estimated using qRT-PCR. In addition, clinical parameters and serum levels were evaluated (anti-ds-DNA, anti-nucleosome, anti-C1q antibodies, β2-microglobulin levels, and C3 and C4 complement fraction). Finally, clinical, and molecular data were correlated.

Results

Our study included 39 patients with active SLE (median 36 years), 32 with active LN (median 32.5 years), 28 with inactive SLE (median 41.5 years), 13 with inactive LN (median 38 years), and 28 control patients (median 28.5 years). The comparison of MCP-1 expression levels between patients with active LN and active SLE did not show statistically significant values (p > 0.05). Likewise, a statistically significant correlation was observed between the expression levels of MCP-1 with the levels of anti-C1q (r = 0.255 p < 0.025); however, no correlation was found with the other markers.

Conclusion

The use of MCP-1 expression levels in the Bolivian population would not be a useful biomarker to evaluate Lupus Nephropathy. However, the anti-C1q biomarker is suggested as a serological marker for monitoring the disease.