Repeated measures of Heparin-binding protein (HBP) and procalcitonin during septic shock: biomarker kinetics and association with cardiovascular organ dysfunction

BACKGROUND: Heparin-binding protein (HBP) is a neutrophil-derived pro-inflammatory protein, an inducer of endothelial dysfunction and vascular permeability and a promising prognostic biomarker in sepsis. This exploratory study aims to describe the kinetics of plasma HBP during septic shock and investigate an association between repeated measures of HBP concentration and cardiovascular organ dysfunction severity. METHODS: We included patients at or above 18 years with suspected septic shock on admission to the intensive care unit (ICU) during 2014 and 2016 to 2018. Plasma samples were collected from ICU admission and every 4 h for 72 h or until death or ICU discharge and batch analysed for HBP. Mean arterial blood pressure (MAP) and noradrenaline dose (NA dose) were recorded at each sampling time point, and systemic vascular resistance index (SVRI) was recorded when available from non-invasive monitoring. The association between HBP, NA dose, MAP and SVRI was assessed respectively using mixed-effects linear regression models. Procalcitonin (PCT) was used as a comparator. RESULTS: A total of 24 patients were included. The kinetics of plasma HBP was highly variable over time, with occasional >2-fold increases and decreases in between 4-h measurements. Every 100 ng/mL increase in HBP corresponded to a 30% increase in NA dose in a crude model (95% CI 3 to 60%, p = 0.03, n(obs) = 340), a 1.4-mmHg decrease in MAP in an adjusted model (95% CI − 1 to − 2.3 mmHg, p = 0.04) or a 99 dyne s cm(−5) m(−2) decrease in SVRI in another adjusted model (95% CI − 36 to − 162, p = 0.002, n(pat) = 13). PCT had a stronger association to NA dose than HBP in a crude model but was not significantly associated to NA dose, MAP or SVRI in any time-adjusted model. CONCLUSIONS: Plasma HBP displayed a highly variable kinetic pattern during septic shock and was significantly associated to cardiovascular organ dysfunction severity over time.