Introduction: Cerebral ischaemia triggers a very intense inflammatory response that is characterised by the infiltration of leukocytes in the brain parenchyma. The first of these cells to reach the brain are the neutrophils. Nevertheless, the role played by neutrophils and the expression of their innate immunity receptors TLR2 and TLR 4 (toll-like receptors 2 and 4) in cerebral ischaemia is still not fully understood.
Aim: To examine the association between the levels of neutrophils and the expression of TLR2 and TLR4 in those cells and the prognosis of ischaemic stroke patients.
Patients and methods: The study involved a sample of 110 patients with an ischaemic stroke that had started less than 12 hours earlier. The main variables that were taken into account were the modified Rankin scale at three months (poor prognosis > 2) and the volume of the infarction (measured by means of computerised tomography between days 4 and 7). We analysed the percentage of neutrophils and the mean expression of TLR2 and TLR4 in neutrophils by means of flow cytometry on admission, at 24 h, at 72 h and at 7 days.
Results: The TLR4 expression in neutrophils at 72 h (odds ratio, OR = 2.1; confidence interval of 95%, CI 95% = 1.4-3.2) and at 7 days (OR = 3.2; CI 95% = 1.7-6.1) was associated independently with the patients' prognosis and with the volume of the infarction at 72 h (B = 5.4; CI 95% = 2.9-7.8) and at 7 days (B = 7.0; CI 95% = 4.5-9.6).
Conclusions: Neutrophils are associated with the prognosis of patients with ischaemic stroke through the expression of their TLR4.