Abstract TP255: Lymphocytes and Platelets in Extracted Thrombus May Indicate the Etiology of the Thrombus. Results from the Itacat Multicentric Registry.

Aim: We performed a histological and immune analysis of the clot in acute stroke patients to detect surrogates of stroke etiology. Methods: We conducted a prospective observational study of consecutive patients with acute stroke who underwent thrombectomy that obtained extracted thrombus (ITACAT study). Several staining were performed to evaluate red blood cells/fibrin (hematoxylin/eosin), platelets (CD61) and leucocytes (CD4, CD8 and CD20). All patients received CT angio to detect extra/intracranial vascular stenosis and 30-day cardiac monitoring to diagnose AF. According to TOAST classification the thrombi were classified in cardioembolic etiology CE (T-CE), due to symptomatic atherosclerosis (T-AT) and without any cause (T-CRYP). We excluded strokes due to double cause or incomplete workup. Results: Of the 117 patients: 30 were T-AT, 55 were T-CE and 32 were T-CRYP. T-AT patients were younger: T-AT 68 years (60-77) Vs. T-CE 75 years (68-80) Vs. T-CRYP 72 years (55-81) (p=0.034). T-AT group had higher percentage of CD4: T-AT 6.52% (4-13) Vs. T-CE (3.31% (12.9) Vs .T-CRYP 3.72% (1.5-12) (p=0.015) and lower percentage of CD61: T-AT 51.18% (34-68) Vs. CE 64.70% (19.56) Vs. CRYP 70.3% (19) (p=0.001). There were no correlation between CD4 and platelets. Both CD4 OR 1.05 (1-1.10) (p=0.020) and CD61 (OR 0.96 (0.94-0.98) (p=0.01) independently predicted T-AT from the age. Final analysis (n=400 cases) will be ended in September 2021. Conclusions: Patients with high percentage of CD4 and low percentage of CD61 are related to atherosclerosis etiology.