ABSTRACT NUMBER: ESOC2026A712 LYMPHOCYTE-TO-MONOCYTE RATIO AND INFLAMMATORY BLOOD PROFILES IN TRANSIENT ISCHEMIC ATTACK: INSIGHTS FROM A TIA CLINIC

Abstract Background and aims The immune system plays a key role in the pathophysiology of cerebrovascular disease. Easily accessible acute blood biomarkers may represent a valuable tool in the clinical setting, providing diagnostic and prognostic information. This study aimed to compare inflammatory parameters among patients evaluated in a TIA clinic. Methods We conducted a retrospective study in a tertiary-care hospital, including patients with minor ischemic stroke (MIS, n=21), transient ischemic attack (TIA, n=90), and stroke mimics (SM, n=26) as the control group. Blood samples were obtained in the acute phase. Laboratory parameters included leukocyte subpopulations, inflammatory ratios, erythrocyte sedimentation rate (ESR), C-reactive protein, lipid profile, platelet count, and coagulation parameters. Comparisons between groups were performed using appropriate parametric and non-parametric statistical tests. Results Lymphocyte counts were significantly lower in patients with TIA compared with controls (mean ± SD: 1.93 ± 0.85 vs 2.33 ± 0.84 x109/L; p=0.037). The lymphocyte-to-monocyte ratio (LMR) was also reduced in TIA patients (median [IQR]: 3.00 [2.33-3.71] vs 3.62 [2.51-5.19]; p=0.047). Among TIA patients, those who experienced recurrence had lower monocyte counts than those without recurrence (0.51 ± 0.24 vs 0.66 ± 0.20 ×109/L; p=0.017). Additionally, ESR differed significantly between TIA etiological subtypes, being higher in lacunar than in atherothrombotic TIA (34.0 [22.0-36.0] vs 12.0 [5.0-17.0]; p=0.004). Conclusions Acute changes in lymphocyte and monocyte counts, as well as ESR, appear to reflect distinct inflammatory profiles across TIA subtypes and clinical outcomes. These parameters may provide additional diagnostic and prognostic information in the TIA clinic setting. Conflict of interest Laura Gómez-Pintado Cano: nothing to disclose.