Renal expression of vascular endothelial growth factor in lupus nephritis in the pediatric age group

Abstract

Background : Vascular endothelial growth factor (VEGF) plays a crucial role in preservation of renal functions and may also serve as a useful biomarker in monitoring the progression of lupus nephritis (LN). Objective : We thought to correlate VEGF expression in the kidney with renal histopathology in lupus nephritis to unveil its possible relation to disease activity and severity. Methods : We consecutively enrolled 15 patients with lupus nephritis and ten renal biopsy specimens from patients with cystic renal diseases as controls. The study measurements included SLEDAI, SLICC/ ACR damage index and BILAG renal score. Paraffin sections from renal biopsies were subjected to routine haematoxylin and eosin staining and Immunohistochemical staining for VEGF. Results : Among SLE patients, 7 (46.7%) showed mild expression of VEGF, 5 (33.3%) showed moderate while 3 (20%) had strong expression of the marker. On the contrary, the control samples (100%) revealed strong marker expression. All subjects with class IV and V lupus nephritis had mild renal expression of VEGF. Renal expression of VEGF had a significant positive correlation with serum creatinine and complement C3 levels. The 24 hours’ excretion of urinary proteins had a significant negative correlation with the renal expression of the marker. On the other hand, the activity indices and therapeutic modalities did not correlate with VEGF expression. Conclusion : This pilot study among pediatric cases of SLE revealed mild to moderate VEGF expression in most cases of proliferative LN. Further longitudinal studies are needed to investigate the consequences of this finding on the prognosis of the disease. Keywords : VEGF, SLE, renal biopsy, lupus nephritis.