PS-C26-10: THE PROPKD SCORE IS ASSOCIATED WITH THE PROGRESSION OF RENAL INVOLVEMENT IN PATIENTS WITH POLYCYSTIC KIDNEY DISEASE TREATED WITH TOLVAPTAN

Abstract

Background: The PROPKD score has been proposed to evaluate the risk of the progression to end stage renal failure in patients with autosomal dominant polycystic kidney disease (ADPKD), based on gender (male: 1point), hypertension under 35 years old (2 points), urological event under 35 years old (2 points), and gene mutation (PKD1 truncating mutation: 4 points, PKD1 non-truncating mutation: 2 points, PKD2: 0 point). Although tolvaptan has benefits for renal involvement, whether PROPKD score could predict future renal involvement in patients with ADPKD treated with tolvaptan is unknown. Thus, we explored the effects of tolvaptan on the annual changes in total kidney volume (%TKV) and estimated glomerular filtration rate (%eGFR) according to the PROPKD score in these patients. Methods: 32 ADPKD patients treated tolvaptan for at least a year were retrospectively analyzed (the mean observation period: 3.6 years). We examined the decline in renal function, %TKV by computed tomography, and gene mutation. The association between %eGFR and %TKV change before and after tolvaptan treatment, annual TKV change (%TKV) and PROPKD score was analyzed. Results: We identified gene mutations in ADPKD patients: PKD1 truncating mutation (n = 15), PKD1 non-truncating mutation (n = 5), PKD2 mutation (n = 6), and mutation not found (n = 6). Mean %TKV and eGFR were 1843 ± 986 ml and 54.7 ± 21.0 ml/min/1.73 m2, respectively. The mean PROPKD score was 3.3 ± 2.4 points and showed a significant negative correlation with %eGFR before and after tolvaptan treatment (p = 0.044/0.016), and no significant correlation with %TKV before and after tolvaptan treatment. Conclusion: The higher PROPKD score, the faster the decrease in %eGFR during tolvaptan therapy, suggesting that the PROPKD score may be useful as a predictor of the risk of progression to renal failure after tolvaptan introduction.