Identifying Rapid Progression in Patients with ADPKD

New Orleans—The most frequently inherited kidney disease is autosomal dominant polycystic kidney disease (ADPKD). The progressive cyst growth associated with ADPKD, combined with interstitial damage, causes progressive kidney failure; there is wide variation of the severity of ADPKD among this patient population. The European Medicines Agency has approved tolvaptan for adults with CKD stage 1 to 3 at baseline who experience rapid progression.

The mean age for onset of ESRD in European patients with ADPKD is 58 years; the European Renal Association-European Dialysis and Transplant Association Working Group on Inherited Kidney Disorders European Best Practices Guidelines (ERA-EDTA WGKID/EBPG) recommendations call for consideration of rapid progression in patients predicted to reach ESRD prior to age 58 years.

Monica Furlano and colleagues in Spain conducted an analysis of 297 patients with ADPKD who were assessed for rapid progression according to ERA-EDTA WGKID/EBPG guidelines. Patients 18 to 50 years of age were eligible for inclusion. Results were presented during a poster session at Kidney Week 2017 in a poster titled Assessing Rapid ADPKD Progression in Clinical Practive in the Era of Tolvaptan.

Assessment was indicated when estimated glomerular filtration rate (eGFR) was >45 mL/min/1.73 m2 and when eGFR was <90 mL/min/1.73 m2 for patients 30 to 40 years of age and <60 mL/min/1.73 m2 for those 40 to 50 years of age. Retrospective eGFR decline was assessed according to age; patients were considered to be rapid progressing if the decline in eGFR was >5 mL per year or >2.5 mL per year for three consecutive years.  Ultrasound diameters was assessed in patients who did not meet the retrospective eGFR criteria. For patients <45 years of age, renal diameter >16.5 cm indicated rapid progression.

Patients who did not meet any of those criteria had total kidney volume measured by magnetic resonance imaging, and the Mayo ADPKD calculator was applied. Patients in class 1C, D, E were considered rapid progressive. Patients <35 years of age with hypertension or urinary symptoms that did not meet any of the criteria had genetic testing performed and the PROPKD score was applied.

The step-by-step process to assess rapid progression using the ERA-EDTA WGKID/EBPG guidelines was cost-effective and sensitive to identify rapid progression. Of patients with CKD stage 1, rapid progression was identified in 16.5%; of those with CKD stage 2, 29%; and in patients with CKD stage 3a, 34.3%. Among patients 18 to 30 years of age, 53.8% had rapid progression; the number decreased to 30.9% among patients 31 to 40 years of age and 15.3% among those 41 to 50 years of age.

In conclusion, the researchers said, “The multi-step algorithm provided by the ERA-EDTA WGKID/EBPG is useful to identify rapid progression that would benefit from tolvaptan treatment. The use of the algorithm is cost-effective and fairly easy to incorporate into clinical practice.”

Source: Furlano M, Marti T, giménes IL, et al. Assessing rapid ADPKD progression in clinical practice in the era of tolvaptan. Abstract of a poster presented at the American Society of Nephrology 2017 Kidney Week, November 3, 2017, New Orleans, Louisiana.