SuO043IS COPEPTIN A SPECIFIC MARKER OF CKD IN ADPKD PATIENTS?

Abstract

Introduction and Aims: Autosomal dominant polycystic kidney disease(ADPKD) is the most common inherited renal cystic disease. The disease is characterized by enlargement of renal cysts and progressive loss of kidney function. Some previous studies showed how Arginine Vasopressin (AVP) V2 receptor antagonists inhibits cytogenesis in ADPKD patients. The copeptin (CT-proAVP) may be useful alternative to direct measurement of AVP concentration. Previous study showed an increase of Copeptin with the progression of chronic kidney disease (CKD) in ADPKD patients suggesting its role as prognostic marker. Currently no study evaluated the difference in copetin levels in ADPKD and no-ADPKD patients in the different stage of CKD; it remains to be determined if this effect is specific to ADPKD or rather associated with CKD. The aim of our study is to evaluate whether the copeptin is associated with the severity of ADPKD or if the presence of CKD determines its increase regardless of pathology. Methods: We performed a cross sectional study in a group of ADPKD patients by Ravine criteria (ADPKD) and CKD patients (without ADPKD) as control group (CONTROL) matched for age, sex and CKD stage and enrolled in our department. Exclusion criteria were: age< 18 ys, dialysis, transplant, pregnancy, severe heart failure, Infectious/acute process, and medication that can modify the levels of copeptin. We evaluated copeptin, creatinine, and cystatin C in plasma. Patients were stratified in 5 groups according the K-Doqi stage (G1-G5) of CKD. All p-values were two sided, and statistical significance was set at p <0.05. Statistical analysis was performed by SPSS version 20. Results: A total of 251 patients was enrolled: 131 ADPKD (51%M) and 120 CONTROL (53%M). The mean (mean±SD) age of ADPKD was 46.10±13.73 years and of CONTROL was 51.82±12.9; the median eGFR evaluating by creatinine level was 69 [IQR, 24-95] mL/min/1.73 m2, while the median eGFR in CONTROL 81 [IQR,26-97] mL/min/1.73 m2. About 31% of our population belonged to stage G1, 26% to stage G2, 15% to stage G3, 14% to stage G4, and 14% to stage G5, respectively. The median copeptin level was 12.18 (IQR 5.24-26.72) pmol/L in ADPKD and 12.32 (IQR 4.41-29.84) pmol/L in CONTROL. We found a statically significant inverse-correlation between copeptin level and eGFR evaluating by creatinine on both group, specifically rho di Spearman were r=-0.81(p<0.001) and r=-0.73 ( p<0.001,) in ADPKD and in CONTROL respectively. Moreover, we found significant different levels of copeptin all CKD stage group (CKD-epi) in ADPKD and CONTROL (p<0.001). Finally, no significantly differences were found between ADPKD and CONTROL in CKD stage , specifically in G1 ( p=0.39) , G2 ( p=0.095), G3 ( p=0.239), G4 (p=0.731) and G5 (p=0.249). Conclusions: In our analysis Copeptin levels seem to be strongly correlated with kidney function and poorly dependent from the presence of ADPKD. Further prospective studies need to evaluated its role as prognostic marker in the early stage of CKD for ADPKD progression.