Table 3. Studies on presepsin measurement interpretation in renal failure.

AKI: Acute kidney injury, pg/ml: picograms per millilitre, PCT: procalcitonin, RIFLE: Risk, Injury, Failure, Loss of kidney function, and End-stage kidney disease.

1st Author and year of publication	Study design	Type of patients/database	Major findings
Miyoshi [54], 2019	Cross-sectional	Study on the effect kidney function on presepsin levels in healthy volunteers (47) and individuals with chronic renal failure (85)	A range of presepsin levels in the absence of acute pathology was established for individuals with normal renal function compared with patients with chronic renal failure. Individuals with grade 3, 4 and 5 renal failure had baseline presepsin values significantly above the other group, with values of 208.1 ± 70.2 pg/mL, 320.2 ± 170.1 pg/mL, 712.8 ± 336.3 pg/mL, respectively.
Nakamura [55], 2019	Prospective cohort study	806 patients with/without acute kidney injury (AKI)	The study assessed the validity of presepsin and procalcitonin plasma levels for diagnosing sepsis in patients with and without acute kidney injury. Each group of patients was subdivided according to sepsis status for each stage of the kidney injury. The results showed that for patients with severe acute kidney injury, the accuracy of the diagnosis of sepsis with procalcitonin was significantly higher compared to that with presepsin.
Takahashi [56], 2015	Retrospective case-control study	91 patients with/without acute kidney injury (AKI)	In a retrospective study with 91 patients, the diagnostic accuracy of PCT and presepsin was assessed when patients were divided into two groups with/without acute kidney injury (AKI). PCT and presepsin levels were increased significantly in the non-AKI and AKI patients with infection. It was concluded that PCT and presepsin are useful markers of bacterial infections in AKI but different thresholds should be applied.
Nakamura [57], 2014	Single center retrospective case-control study	247 ICU patients with/without acute kidney injury (AKI)	A single center retrospective study referred to 247 patients admitted to the ICU aimed to determine levels of blood presepsin in patients with or without sepsis and among non-AKI patients or patients with different degrees of acute kidney injury (AKI) disease. Patients were classified into non-AKI and AKI according to the RIFLE criteria. It was finally showed that presepsin level can be a reliable indicator of sepsis, also in sepsis patients with less severe forms of AKI.