AST-120 (Kremezin®) for the Renal Protection and Attenuation of Decline in Acute Kidney Disease

Study Procedures： 1. Total Number of Subjects The total number of subjects planned for enrollment is 100. The study will include two groups: 1. Experimental Group: 50 patients receiving AST-120 (6g/day) in combination with standard post-AKD care. 2. Control Group: 50 patients receiving only standard post-AKD care. The sample size is determined based on the statistical power needed to detect a significant difference in the primary endpoint (percentage changes in IS levels), with consideration for potential dropout rates. The evaluable number is estimated to be close to 90, allowing for a 10% dropout rate, making the enrolled number 100. 2\. Interventions, Procedures, and Tests for Each Group Subjects will undergo the following interventions, procedures, and tests according to the schedule: 1. Baseline (Day 0): \- Demographic data collection. * Blood tests for serum creatinine, eGFR, IS, p-CS, and urinary albumin-to-creatinine ratio (UACR). * Randomization into experimental or control groups. 2. Treatment Period (Day 1-14): * Experimental Group: Receive AST-120 (6g/day, divided into three doses per day). * Control Group: Standard post-AKD care only. * Both groups will undergo regular clinical assessments and adverse event monitoring. 3. Day 14: * Blood tests for IS, p-CS, serum creatinine, eGFR, and UACR. * Follow-up (Day 90 and Day 180): * Assess eGFR, serum creatinine, UACR. * Monitor for major adverse kidney events (MAKE) and major adverse cardiovascular events (MACE). 3\. Trial Procedure Timeline The trial procedure follows this timeline: 1. Day 0: Baseline measurements and randomization. 2. Day 1-14: Treatment phase (AST-120 administration or standard care). 3. Day 14: Blood tests and assessment of treatment efficacy. 4. Day 90 and Day 180: Follow-up visits for MAKE and MACE assessments, and blood tests for kidney function. 4\. Specimen Collection and Processing 1. Specimen: Blood samples will be collected on Day 0 (baseline), Day 14 (end of treatment), Day 90, and Day 180 (follow-up). 2. Transport and Storage: Specimens will be transported to the laboratory within the hospital for immediate processing. They will be stored in a temperature-controlled facility if needed. 3. Processing: Blood samples will undergo centrifugation for serum separation. Serum will be used for measuring IS, p-CS, serum creatinine, and other biomarkers. 4. Analysis: The following tests will be performed: * IS and p-CS levels. * Serum creatinine and eGFR. * UACR. 5\. Clinical Data Collection and Questionnaires Clinical data collected will include: 1. Demographic data (age, sex, medical history). 2. Lab results for IS, p-CS, creatinine, eGFR, UACR. No specific questionnaires will be used for this study.