[The significance of antiendothelial cell antibodies in patients with lupus nephritis: a clinical and renal pathological study].

OBJECTIVE

To investigate the prevalence and possible role of antiendothelial cell antibodies (AECA) in the pathogenesis of lupus nephritis.

METHODS

Sera from 58 patients with lupus nephritis were studied. Cellular ELISA were used to detect AECA, and immunoblotting was performed to determine specific endothelial target.

RESULTS

36% of the patients with lupus nephritis had elevated IgG-AECA. IgG-AECA was correlated with the higher incidence of thrombocytopenia, higher serum immuoglobulin G levels, lower serum C3(13 +/- 7) g/L and higher titers of antibodies against nucli and dsDNA. AECA consisted of a group of heterogeneous antibodies and reacted with different endothelial cell antigens ranging from 12,000 to 90,000 in molecular size. A correlation was demonstrated between heavy proteinuria (> 3.5 g/24 hr) and the existence of antibodies simultaneously against the 27,000, 29,000 endothelial cell antigens (34% vs 4%), we also found an association between the presence of glomerular capillary thrombi and antibody against the 29,000 endothelial cell antigen (60% vs 14%).

CONCLUSION

These results suggested that lupus nephritis patients with AECA showed a complex autoimmune disorder and provided an indirect evidence that AECA might contribute to the pathogenesis of lupus nephritis.