MAYO AND PRO-PKD SCORE CONCORDANCE FOR PROGRESSION OF RENAL FALIURE EVALUATION IN ADPKD PATIENTS

Abstract Background and Aims Autosomal dominant polycystic kidney disease (ADPKD) is a multisystemic disease characterized by the progressive development of bilateral renal cysts, resulting in enlargement of the kidney volume due to cystic formations, hypertension, haematuria, and loss of renal function. Recent advances in genomics have contributed to have a better understanding of the pathogenesis of the disease suggesting new treatment strategies to inhibit or delay cysts formation and expansion.Since 2015, the European Medicines Agency approved Vaptans as therapy to slow the growth of kidney volume and the decline in kidney function in patients defined rapid progressors. In 2016 European Renal Association-European Dialysis and Transplant Association (ERA-EDTA) Working Groups on Inherited Kidney Disorders and European Renal Best Practice (WGIKD/ ERBP) published a position statement for definition of rapid progression. These recommendations included two algorithms to assess indications for initiation of ADPKD treatment. They selected three criteria based on: 1) the relationship between TKV(total kidney volume) and the decline in renal function according CRISP study, using Mayo Clinic Score 2) eGFR slope with an average ≥2.5 mL/min/1.73 m2/ yearly loss of renal function over a period of 5 yearsor 3) the link between genetic mutation and clinical information study using Propkd score.A 5 –years follow-up is not always available to achieve the criteria for rapid progressor, therefore the use of scores in clinical practice is widespread.In this scenario both scores (MAYO and PRO-PKD) are able to define rapid progressor patients and it is possible to use them alternatively as reported in literature. The aim of this study is to evaluate the prognostic scores in a real life experience. Method All ADPKD patients in follow-up in our Nephrology Unit from January 2017 to July 2019 were included in the study. Descriptive statistics were used to summarize demographic and clinical characteristics. Therefore we classified them for TKV, genetic mutation, renal function, Mayo score and Propkd score. Rapid progression was defined as 1C-D-E Mayo and high risk PRO PKD while non rapid progressors was 1A-1B mayo and low and intermediate PRO-PKD. Kappa statistic was used to determinate the concordance between Mayo and PROPKD score. Change in renal function within patients with the same class of score where analysed using Paired Wilcoxon signed rank sum test. Results We examined75 patients, 78% between 18-50 years, equally distributed for sex. The results shown thatdisease was more frequent familiar (88 %) witha percentage of mutations of PKD1 versus PKD2 mutation (90,7%/9,3%). 31patients (41%) had a GFR between 45-89 ml/min, 52patients (69%) achieved the criteria for nephromegaly according guideline (TKV > 750CC). Respectively 76% (57pt) and 21%(16pt) were defined as rapid progressors for Mayo score ad Propkd score. The slope of GFR was worse in patients defined rapid progressor in spite of non rapidprogressor according MAYO score (-2,8 ml/min vs 0,3 ml/min) as for propkd classification (-3 vs - 1,75ml/min). Only for 15 patients the results were concordant for this two scores,43 patients identified as rapid progressor for Mayo score were non rapid progressor for Propkd score, in the same way 2 patients classified for Propkd were not rapid progressor for Mayo score. K of Coen of 0,07. Conclusion High risk patients present a significant decline in renal function in the first year with both score systems, confirming results of previous studies. Currently the scores used to define rapid progressors select patients differently. Concordance between scores il low (K of Cohen 0,076). The Propkd score is more selective compared to Mayo score. NeverthelessProPKD allows to identify some rapid progressor patients excluded from the use of the Mayo score only. The combined use of scoring may however increases the ability to identify progressive patients.