Relationship between CRP and hypofibrinolysis: Is this a possible mechanism to explain the association between CRP and outcome in critically ill patients?

Abstract Background- Endothelial cell dysfunction may be implicated in the development of multiple organ failure (MOF) by a number of mechanisms. Among these, altered fibrinolysis promotes fibrin deposition, which may create microvascular alterations during inflammation. Elevated concentrations of C-reactive protein (CRP), especially when these persist over time, are correlated with an increased risk of MOF and death. CRP may inhibit fibrinolysis by inducing plasminogen activator inhibitor-1 (PAI-1) release from human aortic endothelial cells. Moreover, the administration of recombinant CRP in volunteers may increase circulating PAI-1 levels. In this study, we tested the hypothesis that CRP is associated with hypofibrinolysis in intensive care patients with and without sepsis. Methods- We studied the association of inflammation and abnormal fibrinolysis in intensive care unit (ICU) patients with (n = 11) and without (n = 21) sepsis. The inflammatory response was assessed by serum concentration of C-reactive protein (CRP), a marker of the acute phase reaction, which increase rapidly in the inflammatory response, and the plasma fibrinolytic capacity was evaluated by the Euglobulin Clot Lysis Time (ECLT), determined by a new semi-automatic method. Results- ECLT was significantly higher in septic than non-septic patients (1104 ± 439 vs 665 ± 275 min; p = 0.002) and was significantly correlated with CRP concentration (R2 = 0.45; p < 0.001). In a multivariate analysis, CRP was the strongest predictor of ECLT (R2 = 0.51, F = 25.6, p < 0.001). In addition, the overall ICU length of stay was significantly correlated with CRP (R2 = 0.264, p = 0.003) and ECLT (R2 = 0.259, p = 0.003). Conclusion- In critically ill patients a significant correlation thus exists between plasma fibrinolytic capacity and serum CRP levels. Our data were obtained in the first 24 hours of ICU admission or of sepsis, thus, the relation between CRP and hypofibrinolysis appeared very quickly. This finding is compatible with a link between inflammation and abnormal fibrinolysis, and may explain the negative prognostic value of CRP in critically ill patients.