Angiopoietin-2, endothelial dysfunction and renal involvement in patients with systemic lupus erythematosus.

BACKGROUND

Angiopoietin-2 (ang-2) that activates endothelial cells and increases vascular inflammation might have significant roles in the pathogenesis of glomerular diseases. This study aimed at assessing the level of ang-2 as a marker of renal involvement in SLE patients to elucidate its correlation with disease activity and endothelial dysfunction.

METHODS

This study included 81 subjects. The control group included 21 healthy subjects. The patients group included 60 SLE patients, 24 patients without lupus nephritis (LN) and 36 patients with LN. Clinical examination and laboratory investigations including 24 hours urinary protein, estimation of serum ang-2 and creatinine and calculation of estimated glomerular filtration rate (eGFR). Measurement of SLE disease activity index (SLEDAI), flow mediated dilatation (FMD) and carotid intima media thickness (CIMT) were done. Renal biopsy was done for patients with LN.

RESULTS

Ang2 level was significantly higher in subjects with FMD <=10%, than in subjects with FMD >10%. Ang2 level was significantly increased in SLE patients than controls, and it was significantly higher in patients with LN than in patients without nephritis. Ang2 was significantly positively correlated with SLEDAI, 24 hours urinary protein and histological activity index, and was negatively correlated with C3, eGFR and FMD. There were no significant differences between patients with proliferative and non proliferative LN regarding Ang2 level.

CONCLUSIONS

Ang2 can reflect the extent of endothelial activation and may be used as a biomarker of both disease activity and renal involvement in SLE patients. Ang2 level cannot distinguish between proliferative and non proliferative lesions in LN.