Kidney Diseases, Chronic

The goal of this clinical trial is to compare a new intravenous drug, Anruikefen, with a traditional oral medication, nalfurafine orally disintegrating tablets, in improving sleep quality in patients with chronic kidney disease-associated pruritus. Sleep quality will be primarily assessed using the Pittsburgh Sleep Quality Index (PSQI). The study will also evaluate the safety of Anruikefen. The main questions it aims to answer are: * Does Anruikefen injection improve sleep quality better than oral nalfurafine? * Does Anruikefen injection improve patients' quality of life more than oral nalfurafine? Researchers will compare Anruikefen with nalfurafine (an active control drug) to evaluate differences in their effects on sleep quality in patients with chronic kidney disease-associated pruritus. Participants will: * Receive either Anruikefen injection (0.3 μg/kg, three times per week) or nalfurafine hydrochloride orally disintegrating tablets (2.5 μg once daily). * Continue treatment for 4 weeks, followed by a 1-week safety follow-up. * Complete the Pittsburgh Sleep Quality Index and other quality-of-life questionnaires after one month.

The purpose of this study is to determine if zigakibart is safe and effective for long-term use in patients with immunoglobulin A nephropathy (IgAN). This is an extension study for patients who have already completed an another zigakibart study.

The goal of this observational study is to learn more about how genes impact the risk of kidney disease. Anyone 18 or older living in the US is eligible, and a diagnosis of kidney disease is NOT required. Study participation is online, and it takes about 20 minutes to complete health surveys and request a saliva collection kit sent through US mail. In return, study participants may opt to receive information about their genetic ancestry at no cost.