Significance of plasma von Willebrand factor level and von Willebrand factor-cleaving protease activity in patients with chronic renal diseases.
BACKGROUND
von Willebrand factor (vWF) mediates the initial capture of platelets to vascular subendothelium and is essential for platelet aggregation under high fluid shear stress as in arterial stenosis. On release from endothelial cells, vWF is rapidly cleaved by ADAMTS13/vWF-cleaving protease (vWF-CP). We investigated the clinical significance of changes in plasma vWF and vWF-CP activities in chronic renal disease.


METHODS
Plasma vWF and vWF-CP activities were measured using enzyme-linked immunosorbent assay (ELISA) and residual collagen binding assay respectively in patients with lupus nephritis (n = 31), primary nephritic syndrome (n = 25), diabetic nephropathy (n = 45), chronic glomerulonephritis (n = 38) and 40 normal controls. The relation of their levels with pathological and renal status was analyzed.


RESULTS
In all diseased patients the levels of vWF were significantly higher and vWF-CP activity significantly lower than the controls (both P < 0.01). vWF in the four subgroups did not correlate with the stage of disease but correlated negatively with vWF-CP activity. vWF-CP activity was not changed two weeks after renal transplantation. Renal biopsy demonstrated that the vWF level in stage IV was higher than in stages II and III while vWF-CP activity was lower in patients with lupus nephritis. After eight-week treatment, the vWF level significantly decreased and the vWF-CP activity significantly increased in systemic lupus erythema, disease activity index < 9, but not with index = 9. Even though the vWF-CP activity was significantly lower in membranous nephropathy than in minimal change disease, mesangial proliferative glomerulonephritis or IgA glomerulonephritis, the vWF level was not significantly different.


CONCLUSIONS
The alterations of plasma vWF and vWF-CP activities were associated with different renal pathologies. Injury to endothelial cells and autoantibodies against vWF-CP activity may result in higher vWF level and lower vWF-CP activity in chronic renal disease and thus a mechanism for worsening of chronic renal disease and thrombosis.
Lu
Guo-yuan
GY
Department of Nephrology Jiangsu Institute of Haematology, First Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215006, China.
Shen
Lei
L
Wang
Zhao-yue
ZY
Guo
Xiao-fang
XF
Bai
Xia
X
Su
Jian
J
Ruan
Chang-geng
CG
D051722:ADAM Proteins / Q000097:blood*; D000071120:ADAMTS13 Protein; D000293:Adolescent; D000328:Adult; D000368:Aged; D002908:Chronic Disease; D005260:Female; D006801:Humans; D007674:Kidney Diseases / Q000097:blood*; D016030:Kidney Transplantation; D008181:Lupus Nephritis / Q000097:blood; D008297:Male; D008875:Middle Aged; D014841:von Willebrand Factor / Q000032:analysis*
D014841:von Willebrand Factor; D051722:ADAM Proteins; D000071120:ADAMTS13 Protein; C099604:ADAMTS13 protein, human