Abstract
Lupus nephritis (LN) is one of the serious complications to be forced to dialysis due to end stage renal disease in systemic lupus erythematosus. LN is classified in class I-VI and recommended the individual treatment in each class by 2003 International Society of Nephrology/Renal Pathology Society classifications because renal prognosis is different. It is desirable to be diagnosed of the assessment in histological findings by the kidney biopsy, but the procedure is invasive. Therefore we examined the usefulness of the LN disease activity assessment as noninvasive inspection about Kim-1 (Kidney injury molecule-1) reported as urinary biomarker in acute kidney injury. Urinary Kim-1 level in active LN is increased compared with that in inactive LN and tubular Kim-1 expression is correlated with the glomerular crescent formation and sclerosis, and interstitial inflammation in the kidney. In addition, we treated with anti-Tim-1 (T cell immunoglobulin mucin domains-1) antibody in MRL-Faslpr mouse as LN model mouse. Anti-Tim-1 antibody improved the survival rate, reduced proteinuria, and improved of the renal tissue injury. Anti-Tim-1 also suppressed the inflammatory cytokines and increased the population of regulatory T and B cells.
These results indicated that Kim-1 is not only the useful tool of urinary biomarker in LN, but also the target in the treatment in the future.
