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 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.

Capillary blood parameters are gestational age, birthweight, delivery mode and gender dependent in healthy preterm and term infants.

OBJECTIVES: The measurement of blood pH and gas analytes (BPGA), soon after birth, constitutes the first-line standard of care procedure in high-risk newborns. However, no data is available in capillary blood on perinatal bias such as gestational age (GA), weight at birth (BW), delivery mode, and gender. The aims of the present study were to investigate whether in a cohort of healthy preterm (PT) and term (T) infants BPGA were GA, BW, delivery mode and gender dependent, thus affecting BPGA reliability as diagnostic test. METHODS: We performed a prospective case-control study in 560 healthy infants (PT: n=115, T: n=445). BPGA was measured within 24-h from birth. Perinatal characteristics, outcomes, and clinical examination were also recorded. RESULTS: PT infants showed higher (p<0.001) carbon dioxide partial pressure (pCO2), fraction of fetal hemoglobin (HbF), base excess (BE), bicarbonate (HCO3), and lower lactate (Lac) levels. When corrected for delivery mode, higher (p<0.001) HbF, BE, HCO3, and lower Lac levels were found. Similarly, higher (p<0.05, for all) pCO2, HbF, BE, HCO3 and lower Lac levels were found between female and male PT and T infants. Repeated multiple logistic regression analysis showed that BPGA was GA, BW, delivery mode and gender dependent. CONCLUSIONS: The present results showing that BPGA can be affected by a series of perinatal outcomes open the way to further investigations providing longitudinal BPGA reference curves in the transitional phase, thus empowering BPGA role as a reliable diagnostic and therapeutic strategies efficacy marker.