Background: Lupus nephritis is characterized by intra-renal inflammation and lymphocyte activation. We examine the profile of cytokine gene expression in glomerulus and tubulointerstitium in patients with lupus nephritis.
Methods: We recruited 36 consecutive SLE patients with active renal disease and required kidney biopsy. Glomerular and tubulointestitial cytokine expression of interleukin (IL)-2, 4, 10, 12, 18, interferon-gamma (IFN- γ), T-bet (the Th-1 transcription factor), GATA-3 (the Th-2 transcription factor), transforming growth factor-beta (TGF-γ) and monocyte chemoattractant protein-1 (MCP-1) were studied by laser microdissection of the renal biopsy specimen, followed by real time quantitative polymerase chain reaction.
Results: There were 13 patients with WHO class III nephritis, 14 patients with class IV, and 9 patients with class V. There was significant correlation between serum C3, C4 and anti-double strand DNA antibody level with glomerular expression of T-bet, IFN-γ and IL- 2. There was a significant correlation between histological Activity Index and glomerular expression of IL-12, IL-18, IL-10 and MCP-1. In addition, the degree of glomerular leukocyte infiltration significantly correlated with glomerular expression of IFN-γ, IL-10, IL-12 and IL-18. In contrast, histological Chronicity Index correlated with the tubulointerstitial expression of IL-2, MCP-1 and GATA-3.
Conclusions: We conclude that intra-glomerular expression of certain target genes correlate with the severity of systemic as well as histological activity, while the tubulointerstitial expression of other target genes correlate with the degree of chronic kidney scarring. Our result may shed light on the immunopathogenesis of lupus nephritis.