Add-on therapy with angiotensin II receptor 1 blocker in children with chronic kidney disease already treated with angiotensin-converting enzyme inhibitors

The standard renoprotection is based on the inhibition of the renin-angiotensin system (RAS) by angiotensin convertase inhibitors (ACEi) or angiotensin II receptor 1 blockers (AT1B). The aim of our study was to analyze the effects of the addition of AT1B to ACEi-based renoprotection in children with chronic kidney disease. We examined 11 children with a mean age of 10.5 years (range, 0.5–18 years) with a mean glomerular filtration rate (GFR) of 61±61 ml/min/1.73 m². In four patients, the primary renal disease was hemolytic uremic syndrome, in three congenital nephrotic syndrome (CNS), in two reflux nephropathy, prune-belly syndrome in one and acute cortical necrosis in one. All patients were treated with complex hypotensive ACEi-based therapy. AT1B losartan was added in a mean dose of 0.9 mg/kg/day. The change in GFR, proteinuria and blood pressure at two 12-month intervals before and after adding AT1B was compared. The results showed that during the 12 months preceding AT1B therapy, there was no change in blood pressure and proteinuria, but the GFR declined in 7 of 11 patients. After the 12th month of add-on therapy with AT1B, there was a significant decrease in both absolute and indexed blood pressure values. Proteinuria decreased in eight patients, did not change in one and increased in two, including one with CNS. The GFR stabilized or increased in eight patients and decreased in three patients with CNS. In 7 of 11 patients, there was a significant, but not threatening increase in serum potassium. In conclusion, add-on renoprotection with AT1B added to ACEi is safe and significantly improves the renoprotective effects of ACEi treatment in children with progressive nephropathies, including patients with advanced CKD.