Association of Urinary Monocyte Chemoattractant Protein-1 Levels with Histologic Class of Lupus Nephritis

Abstract

Abstract Context: When renal tissue is damaged or stimulated, MCP-1 expression increases, promotes inflammation, and hence, MCP 1 has a direct correlation with the stage and severity of renal injury. In lupus nephritis, there is increased MCP-1 expression in glomeruli and tubular epithelial cells, which correlates with glomerular hypercellularity, glomerulosclerosis, crescent formation, and vasculitis. Aims: The purpose of this study is to evaluate the diagnostic utility of Urinary MCP-1 in predicting the histological class of LN, and if it can act as a surrogate marker for biopsy. Settings and Design: This is a prospective cross-sectional study conducted in a tertiary care hospital which included biopsy proven lupus nephritis. Class -VI lupus nephritis was excluded. Methods and Material: UMCP-1 was measured and correlated with histopathology parameters, activity index, class of lupus nephritis (LN), ds-DNA titre and complement level. Statistical Analysis: Chi-square test was used as a test of significance for categorical data, and t-test for continuous data. The ANOVA test was used for comparison between more than two categories of data. Pearson’s correlation was used to check the association between two parameters. Results: A total of 38 patients were enrolled in the study, of whom 89.47% were female. The mean age at presentation was 29 ± 9.09 years. The mean eGFR and UPCR were 60.03 ± 47.04 mL/min/1.73 m 2 and 2.4 ± 2.08, respectively. The most common clinical presentation was nephrotic syndrome (36.8%), followed by reduced eGFR (28.9%) and RPGN (18.42%). On histopathology, the majority had proliferative lesions, with 52.6% and 23.6% having class IV and class III LN, respectively. There was a significant association between histological class and UMCP-1 levels (p=0.004). The mean UMCP-1 value was high in RPGN presentation (633.01 ± 225.7 ng/L) and in the proliferative class of LN (558.46 ± 169.35 ng/L). Significant association was also noted with activity indices karyorrhexis (0.021) and endocapillary hypercellularity (0.001). Higher MCP-1 values were reported in the low-complement group (p=0.03) and in patients with high dsDNA levels. Conclusions: High UMCP-1 level in our study was associated with proliferative lupus nephritis, high NIH activity index, high titre ds-DNA titre and low complement level. This indicated UMCP-1 corelates with severity of lupus nephritis.