Protein Carbonylation Contributes to Prothrombotic Fibrin Clot Phenotype in Acute Ischemic Stroke: Clinical Associations

BACKGROUND: Acute ischemic stroke (AIS) is associated with enhanced oxidative stress and unfavorably altered fibrin clot properties. We investigated determinants of plasma protein carbonylation (PC) in AIS, its impact on the prothrombotic state, and prognostic value during follow-up. METHODS: We included 98 consecutive AIS patients aged 74±12 years (male:female ratio, 50:48 [51%:49%]) at the Neurology Center in Warsaw, Poland, between January and December 2014. As many as 74 (75.5%) patients underwent thrombolysis, and 24 were unsuitable for thrombolysis. We determined plasma PC, along with thrombin generation, fibrin clot permeability, and clot lysis time on admission, at 24 hours, and 3 months. Stroke severity was assessed using the National Institutes of Health Stroke Scale and stroke outcome with the modified Rankin Scale. Hemorrhagic transformation was assessed on the computed tomography scan within 48 hours from the symptom onset, while stroke-related mortality was evaluated at 3 months. RESULTS: On admission, PC levels (median, 4.61 [3.81–5.70] nM/mg protein) were associated with the time since symptom onset (r=0.41; P <0.0001) and with the National Institutes of Health Stroke Scale score ( P =0.36; P =0.0003). Higher PC levels on admission correlated with denser fibrin clot formation and prolonged clot lysis time but not with thrombin generation. In thrombolysed patients, lower PC levels were observed after 24 hours (−34%) and at 3 months (−23%; both P <0.001). PC levels at baseline and after 24 hours predicted the modified Rankin Scale score >2 at 3 months (OR, 1.90 [95% CI, 1.21–3.00]; OR, 2.19 [95% CI, 1.39–3.44], respectively). Higher PC at baseline predicted hemorrhagic transformation of stroke (OR, 1.95 [95% CI, 1.02–3.74]) and stroke-related mortality (OR, 2.02 [95% CI, 1.08–3.79]), while higher PC at 24 hours predicted solely stroke-related mortality (OR, 2.11 [95% CI, 1.28–3.46]). CONCLUSIONS: Elevated plasma PC levels in patients with AIS, related to prothrombotic fibrin clot properties, are associated with stroke severity. Thrombolysis reduces the extent of PC. The current study suggests a prognostic value of PC in AIS.