Endothelin-1 In Patients With Lupus Nephritis

Endothelin is a 21-residue peptide vasoconstrictor produced by endothelium. The exact role of endothelin in the pathophysiology of renal disease has not yet been extensively demonstrated. Thus, to elucidate the pathophysiological significance of plasma and urinary endothelin-1 (ET-1) in patients with lupus nephritis. we studied 7 patients diagnosed as lupus nephritis by kidney biopsy and 7 healthy volunteers. Serum and urinary biochemical studies including creatinine and ET-1 were done, and urinary excretion of N-acetyl-β-D-glucosaminidase(NAG) was also measured.

The results were as follows ;

1) Patient poop and control group showed no significant differences in their clinical characteristics, basic biochemical studies, serum creatinine, plasma ET-1, urinary excretion of protein. NAG and creatinine and ET-1 clearance. Of 7 lupus nephritis patients, only 2 patients showed abnormal serum complement and anti-dsDNA.

2) In lupus nephritis patients, plasma ET-1 level showed no correlation with serum creatinine, complement and anti-dsDNA(p>0.05).

3) ET-1 clearance showed no significant correlaticn with creatinine clearance rate, complement anti-dsDNA ana urinlary NAG excretion.

Plasma ET-1 level and its clearance rate could not reflect the lupus nephritis activity. But our study included small number of patients and only 2 patients of pathologically proven lupus nephritis showed active disease, biochemically and clinically, ana the majority of patients has alreday been in remission state after treatment. Above factors probably acted as a bias against the results, leading to statistical limitations. In further studies, we should broaden our subject group in number and to other renal diseases than limiting to lupus nephritis and prospective long term follow up study is indicated to further investigate the role of urinary excretion of ET-1 and their mechanism of action on renal disease.