Effect of temperature on presepsin pre-analytical stability in biological fluids of preterm and term newborns

Objectives: Thermostability is one of the pre-requisites for the reliability of analytes in clinical practice and biomedical research. Although presepsin represents a promising new biomarker for the early diagnosis of sepsis in newborns, data on its stability under different storage conditions are lacking. We aimed to investigate presepsin thermostability in blood, urine and saliva samples after thawing at 4 predetermined monitoring time-points in a cohort of preterm and term infants.Methods: We conducted an observational study, where each case served as its own control, in 24 preterm and term infants. Blood, urine and saliva samples were stored at -80 C-degrees for 18 months, and presepsin measured in different biological fluids at thawing (T0), 24 (T1), 48 (T2) and at 72 (T3) hours after thawing.Results: No significant differences (p>0.05, for all) in presepsin levels were observed at T0-T3 in the different biological fluids. Furthermore, no differences at T0-T3 were observed in presepsin levels between blood and saliva fluids, whilst urine levels were significantly higher (p<0.05, for all) than blood and saliva at T0-T3.Conclusions: Results on presepsin pre-analytical thermo-stability in different biological fluids after long-term refrigeration support the reliability of this biomarker in the diagnosis and monitoring of perinatal sepsis.