Proenkephalin useful biomarker for AKI management- ADQI consensus statement
Acute Kidney Injury is affecting 1 in 3 Intensive Care Unit (ICU) patients and the current standard of care diagnostics has considerable sensitivity and specificity limitations, there is an urgent need to implement new biomarkers to assist a better management of AKI.
Acute Disease Quality Initiative (ADQI) has recommended the use of novel biomarkers for AKI, including functional biomarkers as Proenkephalin (penKid®).
The latest consensus meeting of international experts in critical care and nephrology supports the use of novel biomarkers in the prevention and management of Acute Kidney Injury (AKI).
The consensus recommends using a combination of damage and functional biomarkers together with clinical information for routine practice.
Proenkephalin (penKid®), the kidney function biomarker, proposed as a marker for the assessment of AKI progression and kidney recovery.
The CE-IVD marked assay for penKid® is available for point of care usage on the fully automated Nexus IB10 platform.
IB10 sphingotest® penKid® measures Proenkephalin (penKid®), a stable fragment of the kidney stimulating hormone Enkephalin. penKid® has been demonstrated to be a real-time surrogate biomarker for glomerular filtration rate, the gold standard to assess renal function. Measuring penKid® blood concentrations allows for timely information on kidney function in critically ill patients. Early assessment of worsening and improving of renal function on intensive care units and in emergency departments allows adjustment of nephrotoxic drug administration and the initiation of kidney-protective strategies to prevent acute kidney injury and thereby improve outcomes.
The current consensus recommendations  support clinicians in making more informed decisions and improve outcomes with biomarker guided management of AKI patients, including triage, diagnosis, and guidance of therapy. Among the main recommendation of the ADQI meeting is the use of novel biomarkers to assess AKI progression and kidney recovery. The consensus statements highlight the performance and added value of penKid® for the prediction of duration and recovery of AKI. Based on the results of a multicenter trial (3), the presented evidence shows that penKid® concentration is significantly lower in AKI patients with improving kidney function when compared to patients without kidney recovery. Additional data (4) is used by the experts in ADQI to convey that significantly higher penKid® levels are indicating those patients with major adverse kidney events, patients with persistent AKI, and those who had worsening of kidney function. Furthermore, the consensus statement also underlines that penKid® is an earlier biomarker than today's standard of care diagnostics in identifying the patients with worsening kidney function.
Prof. Peter Pickkers (Radboud University, Nijmegen), member of the ADQI explained "Since the last evaluation of novel AKI biomarkers 9 years ago, we have collected enough evidence now to consider the usage of functional and damage biomarkers in the prediction and management of AKI. Although many novel biomarkers can measure the damage that already occurred in the kidneys, there are few choices available for measuring the kidney function. Besides Cystatin C, penKid is the only novel functional biomarker available for clinical routine practice."
The kidney function biomarker penKid® was previously validated in over 40.000 patients and published data  demonstrate that penKid® can detect the presence and severity of AKI and enables the identification of patients at high risk of unfavorable outcomes. Moreover, previous findings from the AdrenOSS 1, a 24-centers study, show that penKid® not only diagnoses AKI earlier than today's standard of care, but it also indicates the renal recovery.  The utility of penKid® has been proved both in adult and children population.
Dr. Andreas Bergmann, CEO and founder of SphingoTec stated "We are excited that penKid® has been recognized by ADQI as a suitable functional kidney biomarker. Not only that penKid® reflects kidney function and true GFR independent of inflammation and comorbidities, but unpublished clinical data could complement the consensus recommendation to further evaluate the functional biomarker's role in defining the optimal timing for initiating and stopping kidney replacement therapy."
To support timely treatment decisions that are likely to improve patient management in critical care patients, SphingoTec makes available the CE-IVD marked assay for penKid® on its proprietary Nexus IB10 platform. The fully automated point-of-care analyzer uses whole blood, delivers results in only 20 minutes, and can be flexibly deployed in near-patient as well as laboratory settings.
(1) Ponce et al (2016), Acute kidney injury: risk factors and management challenges in developing countries, Int J Nephrol Renovasc Dis., DOI: 10.2147/IJNRD.S104209
(2) Ostermann et al (2020), Recommendation on Acute Kidney Injury Biomarkers From the Acute Disease Quality Initiative Consensus Conference | Consensus Statement, Critical Care Medicine, DOI: 10.1001/jamanetworkopen.2020.19209
(3) Caironi et al (2018), Circulating proenkephalin, acute kidney injury, and its improvement in patients with severe sepsis or shock. Clin Chem; DOI:10.1373/clinchem.2018.288068
(4) Hollinger et at (2018), Proenkephalin A 119-159 (Penkid) Is an Early Biomarker of Septic Acute Kidney Injury: The Kidney in Sepsis and Septic Shock (Kid-SSS) Study, Kidney Int Rep, DOI: 10.1016/j.ekir.2018.08.006
(5) Marino et al (2015), Diagnostic and short-term prognostic utility of plasma proenkephalin (pro-ENK) for acute kidney injury in patients admitted with sepsis in the emergency department, J Nephrol, DOI 10.1007/s40620-014-0163-z
 Hartman et al (2020), Proenkephalin as a New Biomarker for Pediatric Acute Kidney Injury - Reference Values and Performance in Children Under One Year of Age, Clin Chem Lab Med, doi: 10.1515/cclm-2020-0381.