Proenkephalin (penKid) sheds light on the diagnostic blind spots in assessing acute kidney injury in children
• For children burdened with life-threatening acute kidney injury (AKI) there are no reliable diagnostics to assist the management of pediatric AKI.
• The biomarker proenkephalin (penKid) sets a firm foundation in pediatric kidney assessment as it can identify fast and accurate pediatric AKI and its severity, overcoming current limitations.
Hennigsdorf, Germany, March 15, 2022
- The diagnostic company SphingoTec GmbH (SphingoTec) SphingoTec GmbH (SphingoTec) announces that its kidney function biomarker penKid is reliably identifying AKI in infants, offering a solution to the shortcomings in pediatric critical care. AKI is mostly diagnosed too late for successful intervention which leads to steep mortality rates and chronic kidney disease (1,2).
AKI is a life-threatening complication to every 1 in 3 children in intensive care - a shockingly high prevalence (1). The current routine measurements are not only biased by non-AKI related factors (3), but also identify with an unacceptable delay of 72 hours the impairment, when 50% of the kidney function is already lost (4).
PenKid is a blood-based biomarker that supports clinicians overcoming these limitations. High or increasing penKid concentrations accurately predict AKI and its severity in infants (5), offering an unprecedented alternative to managing pediatric AKI. PenKid is not influenced by non-renal factors making it easy to adopt in critical care (6,7). As a non-invasive biomarker, penKid provides unparalleled real-time and accurate information for the early recognition, severity, and recovery from AKI (8,9). Since AKI is a sudden and severe disease, this information can help vital interventions and improve recovery.
Dr. Andreas Bergmann, CEO of SphingoTec, commented: “AKI is a challenging setting in pediatric critical care with persisting unmet diagnostic needs. With clinical symptoms showing only shortly before kidney failure, it remains a blind spot and a silent threat on the pediatric wards. PenKid offers a solution for the early recognition of AKI in children which is a main condition for improving their prognosis.”
During the recent scientific sessions at AKI & CRRT 2022 in San Diego, CA, Prof. Peter Pickkers (Radboud University, Nijmegen) presented the data on penKid in pediatric AKI, alongside a new formula that translates penKid into a familiar scale for the clinical routine use initially in adults. Data from the researchers of Radboud University, The Netherlands, and Mayo Clinic, US confirms that the new formula is overcoming the limitations of the current clinical practice.
References:
1. Sutherland et al (2015) AKI in Hospitalized Children: Comparing the pRIFLE, AKIN, and KDIGO Definitions, Clin J Am Soc Nephrol, doi: 10.2215/CJN.01900214.
2. Kaddourah A, Basu RK, Bagshaw SM, Goldstein SL. Epidemiology of Acute Kidney Injury in Critically Ill Children and Young Adults. N Engl J Med 2017;376:11-20.
3. Jetton JG, Askenazi DJ. Update on acute kidney injury in the neonate. Curr Opin Pediatr 2012;24:191-6.
4. Bennett MR, Nehus E, Haffner C, Ma Q, Devarajan P. Pediatric reference ranges for acute kidney injury biomarkers. Pediatr Nephrol 2015;30:677-85.
5. 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.
6. Caironi et al. Circulating Proenkephalin, Acute Kidney Injury, and Its Improvement in Patients with Severe Sepsis or Shock. Clin Chem. 2018;64(9):1361-9.
7. Kim et al. Proenkephalin Predicts Organ Failure, Renal Replacement Therapy, and Mortality in Patients with Sepsis. Ann Lab Med. 2020;40(6):466-73
8. 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
9. 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
About SphingoTec
SphingoTec GmbH ("SphingoTec"; Hennigsdorf near Berlin, Germany) develops and markets innovative in vitro diagnostic (IVD) tests for novel and proprietary biomarkers for the diagnosis, prediction and monitoring of acute medical conditions. SphingoTec's proprietary biomarker portfolio includes bioactive Adrenomedullin (bio-ADM), a biomarker for real-time assessment of endothelial function in conditions like sepsis, and Proenkephalin (penKid), a biomarker for real-time assessment of kidney function. Dipeptidyl Peptidase 3 (DPP3), a biomarker for cardiac depression. IVD tests for SphingoTec’s biomarkers are made available as sphingotest® microtiter plate tests as well as point-of-care tests on the Nexus IB10 immunoassay platform by SphingoTec’s subsidiary Nexus Dx Inc. (San Diego, CA, USA). The Nexus IB10 portfolio is complemented by established and commonly used biomarker tests for acute and critical care such as PCT, Troponin, NT-proBNP, D-Dimer, TSH and others.
Media contact SphingoTec:
Ruxandra Lenz
Sr. Manager Marketing and Communications
SphingoTec GmbH
Neuendorfstr. 15 A
16761 Hennigsdorf
Tel. +49-3302-20565-0
• New ELISA sphingotest® penKid® enables widespread measurement of the kidney function biomarker Proenkephalin 119-159 (penKid) using standard laboratory equipment. • Only available test to match SphingoTec’s reference chemiluminescence assay, developed with patented high-sensitivity technology to provide consistent results across platforms. Hennigsdorf/Berlin, Germany, April 28 2026 - SphingoTec GmbH announces the launch of the ELISA sphingotest® penKid®, a new assay designed to make testing of its proprietary biomarker broadly accessible to research laboratories and pharmaceutical partners. Providing ease-of-use and precision, the test facilitates large-scale investigations of human kidney function in both acute and broader clinical research contexts. Responding to growing research interest The launch follows increasing demand from the scientific community to study penKid - a biomarker reflecting the current state of kidney function in critical care environments. While SphingoTec’s high-sensitivity sphingotest® penKid® assay serves as the reference method for clinical research and third-party IVD assays, the assay technology requiring dedicated equipment was not easily adoptable in research laboratories. The new ELISA sphingotest® penKid® now allows researchers worldwide to benefit from SphingoTec’s patented detection technology using standard photometers, extending penKid testing capability to a wider range of laboratories. Proven performance and data continuity The ELISA sphingotest® penKid® has been developed to achieve excellent correlation with SphingoTec’s reference chemiluminescence assay, ensuring consistent, high-quality results across different assay platforms. Both methods share the same underlying technology capable of detecting penKid concentrations in the picomolar range. Thanks to this technology transfer, researchers can rely on the same analytical precision and reliability that supported the clinical studies establishing penKid as a valuable kidney function biomarker. The assay’s robust design and German manufacturing ensure durable consistency and reproducibility. With this research-use ELISA, SphingoTec responds to the increasing availability of non-validated assays and encourages researchers to not compromise assay quality and performance to ensure trustworthy results - since data from non-validated tests may reflect assay limitations rather than the true performance of the penKid biomarker. Complementary approaches for clinical use and scientific exploration SphingoTec pursues its commercial strategy for the biomarker penKid through strategic out-licensing partnerships such as Boditech Med, which has developed an IVDR-certified assay for routine clinical use and rapid diagnostics. The newly launched ELISA sphingotest® penKid® represents a complementary initiative, specifically designed to support high-throughput clinical and translational research. Through this dual approach, SphingoTec reaffirms its commitment to fostering scientific collaboration and promoting the broader exploration of penKid across diverse research settings. “Developing the ELISA sphingotest® penKid® reflects our long-term commitment to improving critical care diagnostics,” said Deborah Bergmann, Managing Director and CEO of SphingoTec GmbH. “Beyond its currently validated clinical applications, we see strong potential for penKid to support research and improve diagnostics in other fields where kidney function is relevant. By encouraging scientists worldwide to incorporate penKid into their studies and clinical programs, we aim to accelerate innovation and advance best-fit diagnostic solutions that ultimately improve patient care.” About SphingoTec SphingoTec GmbH ("SphingoTec"; Hennigsdorf near Berlin, Germany) is a biomarker company focusing on the out-licensing of innovative critical care solutions for diagnosing, predicting, and monitoring acute medical conditions. SphingoTec develops its biomarkers to the commercial stage and partners with IVD companies to make them available on different IVD platforms. SphingoTec's proprietary biomarker portfolio includes Proenkephalin A 119-159 (penKid), a biomarker for the assessment of kidney function in critical diseases, and bioactive Adrenomedullin 1-52 (bio-ADM), a biomarker for the assessment of endothelial function in conditions like sepsis. Discover more on www.sphingotec.com Media Contact: Email: press@sphingotec.com Phone +49-3302-20565-0 SphingoTec GmbH Neuendorfstr. 15A 16761 Hennigsdorf, Germany
• PenKid surpasses serum creatinine on Day 1 post-transplant in detecting delayed graft function (DGF), with an AUROC of 0.87 versus 0.56 for creatinine. • PenKid differentiates slow graft function (SGF) from DGF up to 8 days earlier than current methods, supporting more timely clinical decisions. • PenKid levels remain unaffected by kidney replacement therapy (KRT), allowing for more accurate assessment of kidney function. • Independent validation in transplant cohort from Australia confirms performance and broad applicability. Hennigsdorf/Berlin, Germany, July 1, 2025 - Diagnostic company SphingoTec GmbH (“SphingoTec”) announces a landmark study (1) published in Transplant International, led by Heidelberg University Hospital in Germany in collaboration with researchers from Sydney, Australia, which identifies Proenkephalin A 119-159 (penKid) as a reliable biomarker for early and precise assessment of graft function trajectories following kidney transplantation. The research demonstrates that PenKid not only identifies patients at risk for DGF significantly earlier than traditional markers but also distinguishes between slow and delayed graft function with remarkable accuracy, offering clinicians a valuable new tool for patient management. The study prospectively evaluated 159 consecutive kidney transplant recipients at Heidelberg University Hospital and validated findings in an independent cohort from Sydney. PenKid consistently outperformed serum creatinine (SCr) in predicting graft function trajectories, particularly in the critical early post-transplant period. Notably, PenKid’s ability to remain unaffected by KRT—a treatment for severe kidney dysfunction—further sets it apart from SCr, which can be influenced by non-renal factors and KRT itself, thereby enhancing the reliability of graft function assessment. Multivariate analysis confirmed PenKid as the strongest independent predictor of both short-term graft function and 30-day outcomes, underscoring its clinical utility for early risk stratification. The biomarker’s superior granularity allows for nuanced classification of DGF severity, supporting more informed decisions regarding the initiation of dialysis or biopsy and offering potential for individualized patient care. With these findings, penKid steps forward as a practical addition to the transplant clinician’s toolkit, promising to sharpen decision-making for optimal outcomes. Its adoption could help transplant teams act with greater confidence and precision, ultimately strengthening the standard of care in kidney transplantation. ## References 1. Benning L et al. (2025) Proenkephalin A 119-159 in Kidney Transplantation: A Novel Biomarker for Superior Tracking of Graft Function Trajectories. Transpl. Int. 38:14366. doi: 10.3389/ti.2025.14366 About SphingoTec SphingoTec GmbH ("SphingoTec"; Hennigsdorf near Berlin, Germany) is a biomarker company focusing on the out-licensing of innovative critical care solutions for diagnosing, predicting, and monitoring acute medical conditions. SphingoTec develops its biomarkers to the commercial stage and partners with IVD companies to make them available on different IVD platforms. SphingoTec's proprietary biomarker portfolio includes Proenkephalin A 119-159 (penKid), a biomarker for the assessment of kidney function in critical diseases, commercially available on diagnostic platforms AFIAS and Nexus IB10 and bioactive Adrenomedullin 1-52 (bio-ADM), a biomarker for the assessment of endothelial function in conditions like sepsis. Discover more on www.sphingotec.com Contact : Ruxandra Lenz Marketing and Communication SphingoTec GmbH Phone +49-3302-20565-0 Email: press@sphingotec.com