Elevation of serum von Willebrand factor and anti-endothelial cell antibodies in patients with immunoglobulin A nephropathy are associated with intrarenal arterial lesions

Aim: Recent studies suggest that intrarenal arterial lesions are frequently observed in patients with immunoglobulin A nephropathy (IgAN). However, the mechanisms of the injury have not been elucidated. The level of serum von Willebrand factor (vWF) and the prevalence of anti-endothelial cell antibodies (AECA) were investigated in patients with IgAN with different intrarenal arterial lesions. Methods: Sera from 28 patients with mild intrarenal arterial lesions (group 1) and 36 patients with severe intrarenal arterial lesions (group 2) were collected. Sera from 20 patients with idiopathic membranous nephropathy (group 3) and 50 healthy volunteers were also obtained as disease and normal controls, respectively. Serum vWF and AECA of both IgG and IgA isotype were detected. Results: In comparison with normal controls, serum vWF was significantly higher in group 2 and group 3. Serum vWF was also significantly higher in group 2 than in group 1. Both IgG-AECA and IgA-AECA could be detected in three groups of patients. The prevalence of anti-87 kD IgG-AECA was greatest in patients in group 2. IgAN patients, especially those in group 2 with IgG-AECA or anti-87 kD IgG-AECA, had significantly higher serum creatinine and lower creatinine clearance than those without. No significant difference could be found for IgA-AECA. The level of serum vWF was higher in IgAN patients with IgG-AECA than that in patients without. Conclusion: Intrarenal arterial lesions are associated with endothelial cell damage in IgAN, and vWF is a useful serological biomarker of severe intrarenal arterial lesions. AECA, especially IgG-AECA, may play an important role in the pathogenesis of intrarenal arterial damage in IgAN.