Copeptin

Primary monosymptomatic nocturnal enuresis (PMNE) is one of the most common urinary system problems in childhood. The exact pathological mechanism has not been fully elucidated yet, but excessive nocturnal urination is considered one of the core pathogenic mechanisms. Studies have found that a considerable number of PMNE patients have abnormal secretion of arginine vasopressin (AVP) at night. Currently, the "gold standard" for diagnosing nocturnal polyuria is through a voiding diary, which is cumbersome and the records may contain errors, and there are many inconveniences in clinical implementation. Therefore, finding objective and simple biomarkers to assist in diagnosis and classification is a current clinical research hotspot. Copeptin is the C-terminal fragment of the precursor protein of AVP and is released into the blood simultaneously at the same molar ratio as AVP, making it an ideal alternative biomarker for AVP. This study aims to systematically and deeply explore the diagnostic value of serum copeptin in PMNE, especially in its different subtypes (NP-PMNE vs. NNP-PMNE), analyze its correlation with clinical severity, and explore more precise detection strategies, in order to provide new and objective biological tools for the clinical management of PMNE.

Central diabetes insipidus (CDI),a disease caused by the decrease of AVP (a hormone involved in the control of water-electrolyte balance ) secretion and characerized by polyuria, is a common complication after neurosurgerical intervention and there is a lack of diagnostic criteria.Since the surgry casuses damage to patients' AVP-secreting neuronal cells, transient CDI (t-CDI) usually occurs 24-48h postoperatively and gradually resolves in about 10 days.However,permanent CDI (p-CDI) occurs in a small percentage of patients.Copeptin is a fragment of AVP, which has been shown to response the secretion of AVP.Multiple international studies have identified clinical applications for the use of copeptin to differentially diagnose adults with CDI , to assess electrolyte disturbances associated with AVP regulation, and to predict postoperative CDI after pituitary surgery.This study aims to investigate the trend of serum copeptin levels and its clinical value for postoperative CDI in pediatric patients after neurosurgerical intervention in ICU.

This work aims to investigate and compare the levels of serum endocan and serum copeptin on the first day of life and correlate their levels to the severity of respiratory distress in preterm neonates suffering from respiratory distress syndrome.