Worsening proteinuria and renal function after intravitreal vascular endothelial growth factor blockade for diabetic proliferative retinopathy.

Systemic vascular endothelial growth factor (VEGF) inhibitions can induce worsening hypertension, proteinuria and glomerular diseases of various types. These agents can also be used to treat ophthalmic diseases like proliferative diabetic retinopathy, diabetic macular edema, central retinal vein occlusion and age-related macular degeneration. Recently, pharmacokinetic studies confirmed that these agents are absorbed at levels that result in biologically significant suppression of intravascular VEGF levels. There have now been 23 other cases published that describe renal sequela of intravitreal VEGF blockade, and they unsurprisingly mirror known systemic toxicities of VEGF inhibitors. We present three cases where stable levels of proteinuria and chronic kidney disease worsened after initiation of these agents. Two of our three patients were biopsied. The first patient's biopsy showed diabetic nephropathy and focal and segmental glomerulosclerosis (FSGS) with collapsing features and acute interstitial nephritis (AIN). The second patient's biopsy showed AIN in a background of diabetic glomerulosclerosis. This is the second patient seen by our group, whose biopsy revealed segmental glomerulosclerosis with collapsing features in the setting of intravitreal VEGF blockade. Though FSGS with collapsing features and AIN are not the typical lesions seen with systemic VEGF blockade, they have been reported as rare case reports previously. In addition to reviewing known elements of intravitreal VEGF toxicity, the cases presented encompass renal pathology data supporting that intravitreal VEGF blockade can result in deleterious systemic and renal pathological disorders.