#3521 ASSOCIATION BETWEEN NEPROLITHIASIS AND KIDNEY DISEASE PROGRESSION IN AUTOSOMAL DOMINANT POLYCYSTIC KIDNEY DISEASE PATIENTS: A PROSPECTIVE COHORT STUDY

Abstract

Abstract Background and Aims Nephrolithiasis is a common complication in Autosomal dominant polycystic kidney disease (ADPKD) patients and is known to occur in up to 8% to 36% of the patients. A few in vitro and in vivo studies showed that kidney and ureter stone formation could accelerate renal disease progression in ADPKD. However, its association between nephrolithiasis and renal function deterioration remains unknown in ADPKD patients. Methods This is a study from single center prospective cohort called HOPE-PKD. A total of 410 study subjects with abdominal computed tomography (CT) scan within 1 year before the enrollment were analyzed. Study subjects were divided into two groups according to the CT results as follows: Patients with papillary calcification, calyceal stone, ureter stone, or renal stone were classified as a stone group (n = 80, 19.5%), and patients only with renal cyst calcification or without any stones in the kidney and ureter were classified as a no-stone group (n = 330, 80.5%). The primary outcome was defined as the initiation of renal replacement therapy due to end-stage renal disease. The secondary outcome was a composite outcome of a 50% decline in estimated glomerular filtration rate (eGFR), doubling serum creatinine from baseline, or the initiation of renal replacement therapy. The hazard ratios (HRs) and 95% confidence interval (95% CI) for the outcome were analyzed using multivariate Cox regression analysis. Results There was no difference in the baseline characteristics between the stone group and the no-stone group. During a median 5.18 [interquartile range 3.41 - 8.03] year of follow-up, the primary and secondary outcomes occurred in 51 (12.4%) and 96 (23.4%) patients, respectively. In the unadjusted Cox regression analysis, there was no significant difference in the survival analysis between the two groups. However, after adjusting possible confounding factors (age, sex, body mass index, eGFR, comorbidity of hypertension and diabetes, serum uric acid, phosphorous and calcium level, results of PKD1 and PKD2 gene analysis, and Mayo classification), the stone group showed an increased risk of the primary and secondary outcome of HR 2.84 (95% CI 1.26 - 6.38; p-value 0.012) and HR 1.83 (95% CI 1.03 - 3.27; p-value 0.041), respectively compared to the no-stone group (Figure 1). Conclusion This is the first prospective cohort study showing that nephrolithiasis is associated with poor renal outcomes in patients with APDKD. Further clinical studies of nephrolithiasis in ADPKD patients are warranted to improve renal outcomes.