Juxtaglomerular apparatus hyperplasia under dual angiotensin blockade. A footprint of adequate RAS inhibition or a concern for renal fibrosis?

BACKGROUND: Dual renin-angiotensin system blockade with angiotensin-converting enzyme inhibitors and angiotensin receptor blockers has been advocated to minimize proteinuria. However, recent trials have questioned the renal safety of this approach. Our understanding on the molecular effects of dual blockade in humans is incomplete. CASE PRESENTATION: We present a patient with corticoid resistant nephrotic syndrome who developed marked juxtaglomerular apparatus hyperplasia and renin expression in the context of dual angiotensin system blockade. CONCLUSIONS: Although renin may have profibrotic effects mediated by (pro)renin receptor activation, this report raises questions on the potential consequences of local renin activation on chronic kidney disease in patients with dual angiotensin blockade.