Analysis of early diagnostic markers for acute kidney injury after cardiac surgery

This study aimed to find diagnostic biomarkers for predicting cardiac surgery-associated acute kidney injury in children. We found that the change of exomiRs level in circulatory system occurred in the early stage after cardiac operation, and the changes of hsa-miR-184 and hsa-miR-6766-3p content in circulatory system could predict CSA-AKI well. Overall design: At 4 hours after cardiac surgery, blood samples were collected for about 4ml. After standing at room temperature for 30 minutes,blood samples were centrifuged at 3,000 g at room temperature for 10 min. The upper liquid (serum) was frozen at -80°C until further analysis. After exosome extraction, we sequenced the miRNAs using in each individual sample one by one. Sequencing libraries were constructed by QIAseq miRNA Library Kit for Illumina (Cat #331505, Qiagen) according to manufacturer's instructions. The sequencing was performed on an Illumina NovaSeq platform(Illumina, San Diego, CA, USA) and analyzed at Shanghai Biochip Co., Ltd., Shanghai, China.