Markers of collagen synthesis and degradation are increased in serum in severe sepsis: a longitudinal study of 44 patients

INTRODUCTION: Sepsis-related multiple organ dysfunction is a common cause of death in the intensive care unit. The effect of sepsis on markers of tissue repair is only partly understood. The aim of this study was to measure markers of collagen synthesis and degradation during sepsis and investigate the association with disease severity and outcome. METHODS: Forty-four patients with severe sepsis participated in the study and 15 volunteers acted as controls. Blood samples were collected for 10 days after the first sepsis-induced organ dysfunction and after three and six months. Procollagen type I and III aminoterminal propeptides (PINP and PIIINP) and cross-linked telopeptides of type I collagen (ICTP) were measured. RESULTS: The PIIINP concentration was elevated in the septic patients (8.8 ug/L, 25th to 75th percentile = 6.8 to 26.0) when compared with controls (3.0 ug/L, 25th to 75th percentile = 2.7 to 3.3; P < 0.001) on day one. Maximum serum PIIINP concentrations during sepsis were higher in non-survivors compared with survivors (26.1 ug/L, 25th to 75th percentile = 18.7 to 84.3; vs. 15.1 ug/L, 25th to 75th percentile = 9.6 to 25.5; P = 0.033) and in multiple organ failure (MOF) compared with multiple organ dysfunction syndrome (MODS) (24.2 ug/L, 25th to 75th percentile = 13.4 to 48.2; vs. 8.9 ug/L, 25th to 75th percentile = 7.4 to 19.4; P = 0.002). Although the PINP values of the septic patients remained within the laboratory reference values, patients with MOF had higher values than patients with MODS (79.8, 25th to 75th percentile = 44.1 to 150.0; vs.40.4, 25th to 75th percentile = 23.6 to 99.3; P = 0.007). Day one ICTP levels were elevated in septic patients compared with the controls (19.4 ug/L, 25th to 75th percentile = 12.0 to 29.8; vs. 4.1 ug/L, 25th to 75th percentile = 3.4 to 5.0; P < 0.001). CONCLUSIONS: Markers of collagen metabolism are increased in patients with severe sepsis and can be investigated further as markers of disease severity and outcome.