Circadian Variation of Plasminogen-Activator-Inhibitor-1 Levels in Children with Meningococcal Sepsis

OBJECTIVE: To study whether the circadian variation of plasminogen-activator-inhibitor-1 (PAI-1) levels, with high morning levels, is associated with poor outcome of children with meningococcal sepsis presenting in the morning hours. DESIGN: Retrospective analysis of prospectively collected clinical and laboratory data. SETTING: Single center study at Erasmus MC-Sophia Children’s Hospital, Rotterdam, the Netherlands. SUBJECTS: 184 patients aged 3 weeks to 18 years with meningococcal sepsis. In 36 of these children, PAI-1 levels at admission to the PICU were measured in plasma by ELISA. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Circadian variation was studied by dividing one day in blocks of 6 hours. Patients admitted between 6:00 am and 12:00 am had increased illness severity scores and higher PAI-1 levels (n = 9, median 6912 ng/mL, IQR 5808–15600) compared to patients admitted at night (P = 0.019, n = 9, median 3546 ng/mL, IQR 1668–6118) or in the afternoon (P = 0.007, n = 7, median 4224 ng/mL, IQR 1804–5790). In 184 patients, analysis of circadian variation in relation to outcome showed more deaths, amputations and need for skin grafts in patients admitted to the PICU between 6:00 am and 12:00 am than patients admitted during the rest of the day (P = 0.009). CONCLUSIONS: Circadian variation of PAI-1 levels is present in children with meningococcal sepsis and is associated with illness severity, with a peak level in the morning. Whether circadian variation is an independent risk factor for morbidity and mortality in meningococcal sepsis needs to be explored in future studies.