Urinary Excretion of Rantes is Elevated in Lupus Nephritis

Yoon, Chong Hyeon; Park, Kyung Soo; Choi, Jin Jung; Cho, Mi La; Min, So Youn; Kim, Wan Uk; Min, Do June; Min, Jun Ki; Hong, Yeon Sik; Park, Sung Hwan; Cho, Chul Soo; Kim, Ho Youn

Abstract

OBJECTIVE
Infiltrating T cells and monocytes have been implicated in the pathogenesis of lupus nephritis (LN). Chemokines may play a key role in the recruitment of these cells. We investigated whether RANTES (regulated on activation normal T cell expressed and secreted), one of the CC chemokine family, may be involved in the pathogenesis of LN.
METHODS
We measured the levels of RANTES in sera and urine from 87 systemic lupus erythematosus (SLE) patients and 78 healthy controls using ELISA. Clinical and laboratory assessment including SLE disease activity index (SLEDAI) were performed at the time of sampling.
RESULTS
Serum RANTES levels were significantly higher in the patients with SLE than in healthy controls (115.0+/-5.6 vs. 91.5+/-4.0 pg/ml, p=0.001, mean+/-SEM). Serum RANTES levels correlated well with anti-dsDNA antibody titer (r=0.29, p<0.05) and inversely with serum complement C4 level (r=-0.28, p<0.05). Urinary RANTES/creatinine ratios were significantly higher in patients with nephritis than those without (3.4+/-0.4 vs. 2.2+/-0.3, p=0.004), while serum RANTES level was not different between patients with nephritis and those without. Moreover, urinary RANTES/creatinine ratio positively correlated with urine protein/creatinine ratio (r=0.41, p<0.001).
CONCLUSIONS
Our results demonstrate that serum RANTES was elevated in patients with SLE and urinary excretion of RANTES was strongly associated with presence of nephritis. These data suggest that RANTES may be expressed in renal inflammatory sites and may participate in the pathogenesis of LN possibly by augmenting the recruitment of T cells and monocytes.