Proenkephalin a 119-159 (penKid) - a novel biomarker for acute kidney injury in sepsis: an observational study

BMC Emerg Med. 2019 Nov 28;19(1):75. doi: 10.1186/s12873-019-0283-9.


Background: Sepsis is a leading cause of death worldwide and a major challenge for physicians to predict and manage. Proenkephalin A 119-159 (penKid) is a reliable surrogate marker for the more unstable endogenous opioid peptide enkephalin, which has previously been shown to predict both acute and chronic kidney disease. The aim of this prospective observational study was to assess penKid as a predictor of acute kidney injury (AKI), multi-organ failure and mortality in sepsis among unselected sepsis patients presenting to the emergency department (ED).

Method: We enrolled 644 patients consecutively during office-hours (6 AM-6 PM) between December 1, 2013 and February 1, 2015. Fifty-six patients were excluded due to incomplete data. We measured penKid in 588 adult patients (patients under 18 years of age were excluded) with sepsis (≥2SIRS criteria + suspected infection) upon admission to the ED at Skåne University Hospital, Malmö, Sweden. Logistic regression analysis was used to relate levels of penKid at presentation to AKI, multi-organ failure, 28-day mortality and progression of renal SOFA subscore. Odds ratios are presented as the number of standard deviations from the mean of log-transformed penKid.

Results: In age and sex adjusted models, penKid predicted AKI within 48 h and 7 days, but these associations were attenuated after additional adjustment for estimated creatinine-based glomerular filtration rate (eGFR). In models adjusted for age, sex and eGFR, penKid significantly predicted progression from rSOFA = 0 and ≤ 1 to higher rSOFA scores as well as multi-organ failure and mortality. In contrast, eGFR did not predict 28-day mortality.

Conclusion: PenKid is an effective predictor of renal injury, severe multi-organ failure and mortality in unselected sepsis patients presenting to the emergency department.

Keywords: AKI; Acute kidney injury; Emergency department; Pro-enkephalin; Sepsis; penKid.

Publication types

  • Observational Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Academic Medical Centers
  • Acute Kidney Injury / blood
  • Acute Kidney Injury / etiology*
  • Aged
  • Aged, 80 and over
  • Biomarkers
  • Comorbidity
  • Emergency Service, Hospital / statistics & numerical data*
  • Enkephalins / blood*
  • Female
  • Glomerular Filtration Rate
  • Humans
  • Logistic Models
  • Male
  • Middle Aged
  • Multiple Organ Failure / blood
  • Multiple Organ Failure / etiology
  • Prognosis
  • Prospective Studies
  • Protein Precursors / blood*
  • ROC Curve
  • Sepsis / blood
  • Sepsis / complications*
  • Sepsis / mortality
  • Sweden


  • Biomarkers
  • Enkephalins
  • Protein Precursors
  • proenkephalin