Monocyte chemoattractant protein-1 expression in renal tissue is associated with monocyte recruitment and tubulo-interstitial lesions in patients with lupus nephritis.
OBJECTIVE
To investigate the pattern of monocyte chemoattractant prolein-1 (MCP-1) distribution in the renal interstitium and evaluate its pathogenic role in tubulo-interstitial lesions in patients with lupus nephritis, the distribution of MCP-1 in renal tissue was observed.


METHODS
Eighteen female patients with biopsy-proven lupus nephritis were enrolled in this study. No intensive immunosuppresive therapy was used in these patients during the 3 months prior to renal biopsy. The distribution of MCP-1, infiltration of CD68+ (macrophage/monocyte), CD4+ and CD8+ cells in the tubulo-interstitium of patients with lupus nephritis was detected using immunohistochemical staining with specific antibodies. Renal specimens from patients with minimal change glomerulonephritis were used as controls.


RESULTS
MCP-1 protein was widely distributed in the renal tissue of patients with lupus nephritis, mainly located at the baso-lateral surface of tubular epithelial cells (16/18 biopsies), and on the wall of interstitial blood vessels (9/18 biopsies). In contrast, tubular MCP-1 staining was weak and rare in renal tissue from controls (7.4 +/- 6.2% vs 26.7 +/- 22.8%, P < 0.01). Tubulo-interstitial infiltration of CD68+, CD4+ and CD8+ cells was markedly increased in patients with lupus nephritis as compared to controls. The tubular expression of MCP-1 was strongly associated with the amount of CD68+ cell infiltration in the interstitium (r = 0.5420, P < 0.05) and the extent of interstitial fibrosis. There was no correlation between MCP-1 production in tubules and the degree of urinary protein excretion in patients with lupus nephritis (r = 0.0547, P > 0.05).


CONCLUSIONS
The expression of MCP-1 in the renal tubules and vascular wall was markedly increased in patients with lupus nephritis. The overproduction of MCP-1 in renal tissue may contribute to monocyte recruitment in the interstitium and thus result in tubulo-interstitial damage in lupus nephritis.
Dai
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C
Research Institute of Nephrology, Jinling Hospital, 305 East Zhongshan Road, Nanjing 210002, China.
Liu
Z
Z
Zhou
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H
Li
L
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D000328:Adult; D018932:Chemokine CCL2 / Q000096:biosynthesis* / Q000378:metabolism; D005260:Female; D006801:Humans; D007668:Kidney / Q000378:metabolism*; D008181:Lupus Nephritis / Q000378:metabolism* / Q000473:pathology; D009000:Monocytes / Q000502:physiology; D009395:Nephritis, Interstitial / Q000378:metabolism* / Q000473:pathology
D018932:Chemokine CCL2