The effect of homocysteine on the clinical outcomes of ventilated patients with severe sepsis

Abstract

Background. There is considerable evidence that elevated plasma homocysteine levels are associated with a prothrombotic milieu, whereas activation of the coagulation cascade is an important component of the pathogenesis of sepsis. The protein C pathway has been reported to play a central role both in the propagation of sepsis and a hyperhomocysteinemia-induced hypercoagulable state. Our primary aim was to measure plasma homocysteine levels in mechanically ventilated patients with severe sepsis/septic shock and to assess the association of these levels with relevant clinical outcomes. Methods. The study cohort included 102 mechanically ventilated patients with severe sepsis or septic shock. Demographics, comorbidities, clinical data and severity scores were recorded. Plasma homocysteine, vitamin B12, folate, creatinine, and protein C levels were measured in all study subjects upon enrollment, and genotyping for the C677T and A1298C polymorphisisms of the methylenetetrahydrofolate reductase (MTHFR) gene and for factor V Leiden (FVL) mutations was performed as well. The primary outcomes were mortality at 28 and 90 days; secondary outcomes included the number of days without renal or cardiovascular failure and the ventilator-free days during the study period. Results. Homocysteine levels were not significantly associated with any primary or secondary outcomes in the multivariable analysis. In addition, a synergistic effect of homocysteine with protein C levels was not detected. Conclusion. Our data suggest that plasma homocysteine levels may not inform the prognosis of mechanically ventilated patients with severe sepsis/septic shock.