Assessing proenkephalin as a biomarker of acute kidney injury: A systematic review
Abstract – Acute kidney injury (AKI) is a medical condition described by the rapid loss of kidney function that occurs in one out of five hospitalizations. Creatinine is the most widely used biomarker to detect AKI in critically ill patients. However, prior research suggests that the serum creatinine may be limited in its detection of AKI, as it has been shown to delay diagnosis by up to 72 hours. Cystatin C and NGAL are additional functional biomarkers used for detecting and monitoring kidney damage that outperform serum creatinine in early prediction of renal dysfunction. However, cystatin C has several confounding variables. Thus, new biomarkers are needed in critical care units in order to accurately predict AKI and follow up with the correct corresponding treatment in a timely manner. Proenkephalin A 119-159 (penKid) has been proposed by SphingoTec as a novel marker for AKI. This biomarker is still in its early stages and is yet to be used in intensive care units. Therefore, the purpose of this study is to systematically review evidence regarding proenkephalin and determine if it is the better biomarker of AKI as compared to the conventional markers. Databases such as Google Scholar, PubMed, and ScienceDirect were screened for English-language literature regarding the assessment of penKid as a biomarker of kidney function. The results suggested that proenkephalin is a promising biomarker, as it predicts AKI two days early, is not influenced by comorbidities, can predict mortality, and is sensitive to changes in patient condition.