The Relationship between Protein C, Protein S and Cytokines in Acute Ischemic Stroke

Abstract

Objective: The role of inflammation in the pathogenesis of acute ischemic stroke is well known, but its association with the clinical picture is as yet unclear. Material and Methods: In our study, we measured the serum levels of the proinflammatory cytokines interleukin-1β (IL-1β), tumor necrosis factor α (TNFα) and interleukin-6 (IL-6) within the first 50 h of stroke in 60 acute stroke patients, and examined the association with the natural anticoagulants protein C and free protein S. We compared the results with a control group that consisted of 30 volunteers. We also correlated their levels with the clinical outcomes by using the Canadian Neurological Scale (CNS). Results: Neither stroke patients nor the control group had any elevations in IL-1β serum levels. However, the levels of serum IL-6 were significantly higher in stroke patients (13.7 ± 19.46 vs. 4.3 ± 15.88, p = 0.002). In addition, the protein S levels of patients were lower than those of the controls (84.36 ± 27.97 vs. 95.9 ± 25.64, p = 0.007). Although IL-6 showed negative correlation with protein S (r = –0.504, p = 0.000), the other studied cytokines TNFα and IL-1β did not correlate with these natural anticoagulants. Another negative correlation was found between IL-6 and CNS scores (r = –0.451, p = 0.000). In addition, both protein C and protein S positively correlated with CNS (r = 0.263, p = 0.042; r = 0.381, p = 0.003). There was also a positive correlation between protein C and protein S (r = 0.408, p = 0.001). Conclusions: Our results suggest that TNFα and IL1β serum levels are not elevated in the acute phase of stroke and have no correlation with the natural anticoagulants protein C and protein S. However, a decrease in free protein S may be related to elevated IL-6 levels. In addition, increased levels of IL-6 and reduced levels of protein C and protein S may play a role in acute ischemic stroke severity.