Medical Utility

  1. Prediction, diagnosis and monitoring of acute kidney injury in ED & ICU patients, e.g. with sepsis and acute heart failure
  2. Supports clinical decision making on:
    – treatment with nephrotoxic drugs
    – renal replacement therapy
    – hospital discharge

sphingotest® penKid Immunoassay

  • Measures a stable mid-regional fragment of Proenkephalin (penKid) as surrogate for the unstable Enkephalin
  • The sphingotest® penKid Broschure can be downloaded here.


Ng LL, Squire IB, Jones DJ, Cao TH, Chan DC, Sandhu JK, Quinn PA, Davies JE, Struck J, Hartmann O, Bergmann A, Mebazaa A, Gayat E, Arrigo M, Akiyama E, Sabti Z, Lohrmann J, Twerenbold R, Herrmann T, Schumacher C, Kozhuharov N, Mueller C, GREAT Network. Proenkephalin, Renal Dysfunction, and Prognosis in Patients With Acute Heart Failure: A GREAT Network Study. J Am Coll Cardiol. 2017. 69(1):56-69.

Arbit B, Marston N, Shah K, Lee EL, Aramin H, Clopton P, Maisel AS. Prognostic Usefulness of Proenkephalin in Stable Ambulatory Patients With Heart Failure. Am J Cardiol. 2016. 117(8):1310-4. PubMed PMID: 26916537.

Schulz CA, Christensson A, Ericson U, Almgren P, Hindy G, Nilsson PM, Struck J, Bergmann A, Melander O, Orho-Melander M. High Level of Fasting Plasma Proenkephalin-A Predicts Deterioration of Kidney Function and Incidence of CKD. J Am Soc Nephrol. 2016. 28(1):291-303. PubMed PMID: 27401687.

Marino R, Struck J, Hartmann O, Maisel AS, Rehfeldt M, Magrini L, Melander O, Bergmann A, Di Somma S. Diagnostic and short-term prognostic utility of plasma pro-enkephalin (pro-ENK) for acute kidney injury in patients admitted with sepsis in the emergency department. J Nephrol. 2015. 28(6):717-24. PubMed PMID: 25486879.

Shah KS, Taub P, Patel M, Rehfeldt M, Struck J, Clopton P, Mehta RL, Maisel AS. Proenkephalin predicts acute kidney injury in cardiac surgery patients. Clin Nephrol. 2015. 83(1):29-35. PubMed PMID: 25512100.

Ng LL, Sandhu JK, Narayan H, Quinn PA, Squire IB, Davies JE, Bergmann A, Maisel A, Jones DJ. Proenkephalin and prognosis after acute myocardial infarction. J Am Coll Cardiol. 2014. 63(3):280-9. PubMed PMID: 24140658.


Ernst A, Köhrle J, Bergmann A. Proenkephalin A 119-159, a stable proenkephalin precursor fragment identified in human circulation. Peptides. 2006. 27(7):1835-40.