Background
Renal involvement affects about 50% of SLE patients accounting for significant morbidity and mortality in these patients[1]. The adipokine “Visfatin” acting as a growth factor for B-lymphocyte-precursors, exerts several proinflammatory functions[2]. It was demonstrated as a marker of endothelial dysfunction (ED) in chronic kidney disease (CKD) thus could be a factor linking inflammation in SLE and kidney disease[3].
Objectives
To assess serum visfatin level in patients with lupus nephritis (LN)and its correlation to disease activity in these patients.
Methods
The present study included 40 patients with SLE and forty age and sex matched healthy subjects served as control group.Oral consent was obtained from all patients and controls after a full explanation of the study.Clinical assessment od disease activity by SLE Disease activity index (SLEDAI)[4].Lupus nephritis was assessed clinically with the renal SLE disease activity index (renal SLEDAI).Renal biopsies were taken from the patients with LN and were classified according to the modified WHO classification [5].Serum level of visfatin were measured for the patients and controls using enzyme-linked immunosorbent assay (ELISA).
Results
A significantly higher serum visfatin level was found on comparing SLE patients (mean 109±180 ng/ml, median18) with controls (mean 9.4±11 ng/ml, median2.5) with statistically highly significant difference (z 5.2, P<0.001).Also there was a statistically significant difference as regards serum visfatin level between active SLE patients (mean 173±111 ng/ml, median 14) and inactive patients (mean 139±88 ng/ml, median 5) (z 2.1, p<0.05) as well as between patients with LN (mean 226±180 ng/ml, median18) and patients with no LN (mean 101±140 ng/ml, median 8 (2-229)) (z=2.1, p<0.05). Visfatin had a highly significant positive correlation with disease duration (r=0.48, p<0.001), SLEDAI (r=0.62, p<0.001) as well as ESR, CRP and, renal score (r=0.45, 0.35, and 0.65 respectively) while inverse correlation with estimated GFR (r=-0.614) and C3 & C4 titre (r=-0.26, r=-0.35 respectively) was recorded. Visfatin showed high sensitivity in detecting active SLE & LN 83% and 85% respectively.
Conclusions
Serum visfatin is strongly associated with LN in SLE patients and is a promising biomarker for prediction of renal involvement in these patients. It reflects SLE activity specially LN activity namely renal score & GFR decline.
References
Molino C, Fabbian F, Longhini C. Clinical approach to lupus nephritis: recent advances.European Journal of Internal Medicine2009; 20(5):447-53.
Fukuhara A, Matsuda M, Nishizawa M, Segawa K, Tanaka M, Kishimoto K et al. Visfatin: a protein secreted by visceral fat that mimics the effects of insulin. Science 2005;307: 426–30.
Yilmaz MI, Saglam M, Carrero JJ, Qureshi AR, Caglar K, Eyileten T et al. Serum visfatin concentration and endothelial dysfunction in chronic kidney disease. Nephrol Dial Transplant 2008;23(3): 959-65.
Bombardier C, Gladman DD, Urowitz MB, Caron D, Chang CH, Derivation of the SLEDAI. ...