Chemical Sympathectomy, but not Adrenergic Blockade, Improves Stroke Outcome

Evaluation of Hemoglobin and Eosinophil Count in Patients Receiving Thrombolytic Treatment

Background and aim Stroke ranks among the primary contributors to disability and mortality on a global scale. Recent advances in ischemic stroke pathophysiology emphasize the significant role of the immune system in both stroke-related damage and neuroprotection. This article investigates the relationship between hemoglobin level and white blood cell count. Materials and methods From January 1, 2019, to April 1, 2022, all patients aged 18 years and over who were diagnosed with acute ischemic stroke in the emergency department of Kanuni Sultan Süleyman Training and Research Hospital and treated with intravenous recombinant tissue plasminogen activator (r-tPA) within 4.5 hours of stroke onset were included in this cross-sectional retrospective study. Gender, age, onset of symptoms, complaints, National Institutes of Health Stroke Scale (NIHSS) score, stroke-affected area, as well as leukocyte, neutrophil, platelet, eosinophil, lymphocyte, and hemoglobin levels were recorded and compared between mortality and survivor groups. Results A total of 61 people, including 33 men and 28 women, were included in the study. Four patients died during follow-ups. The mean duration of symptoms upon admission was 86.23 ± 56.37 minutes. The mean NIHSS score of patients was found to be 9.16 ± 3.88 (minimum: 4, maximum: 18). There was a statistically significant positive correlation between age and symptom duration (p < 0.002, r: 0.391). A statistically significant negative correlation was found between eosinophil count and NIHSS score (p < 0.012, r: -0.321) and between eosinophil count and symptom duration (p < 0.042, r: -0.261). There was a negative correlation between hemoglobin levels and mortality (p < 0.013, r: -0.318). A statistically significant negative correlation was observed between the eosinophil-to-neutrophil ratio (ENR) and NIHSS score (p < 0.017, r: -0.305) as well as between ENR and symptom duration (p < 0.034, r: -0.271). Hemoglobin is a significant predictor of mortality in the logistic regression model (p < 0.05, CI: 0.253-0.942). For each one-unit increase in hemoglobin, the odds of mortality decrease by a factor of 0.488. Conclusion Certain blood cell types (neutrophils, eosinophils, and lymphocytes) play an active role in determining stroke prognosis. A detailed explanation of the role of leukocyte types lays the foundation for "immunomodulation," which could be a promising novel treatment modality for future stroke patients.

Interactions between the Autonomic Nervous System and the Immune System after Stroke

Acute stroke is one of the leading causes of morbidity and mortality worldwide. Stroke-induced immune-inflammatory response occurs in the perilesion areas and the periphery. Although stroke-induced immunosuppression may alleviate brain injury, it hinders brain repair as the immune-inflammatory response plays a bidirectional role after acute stroke. Furthermore, suppression of the systemic immune-inflammatory response increases the risk of life-threatening systemic bacterial infections after acute stroke. Therefore, it is essential to explore the mechanisms that underlie the stroke-induced immune-inflammatory response. Autonomic nervous system (ANS) activation is critical for regulating the local and systemic immune-inflammatory responses and may influence the prognosis of acute stroke. We review the changes in the sympathetic and parasympathetic nervous systems and their influence on the immune-inflammatory response after stroke. Importantly, this article summarizes the mechanisms on how ANS regulates the immune-inflammatory response through neurotransmitters and their receptors in immunocytes and immune organs after stroke. To facilitate translational research, we also discuss the promising therapeutic approaches modulating the activation of the ANS or the immune-inflammatory response to promote neurologic recovery after stroke. © 2022 American Physiological Society. Compr Physiol 12:3665-3704, 2022.

The spleen may be an important target of stem cell therapy for stroke

Stroke is the most common cerebrovascular disease, the second leading cause of death behind heart disease and is a major cause of long-term disability worldwide. Currently, systemic immunomodulatory therapy based on intravenous cells is attracting attention. The immune response to acute stroke is a major factor in cerebral ischaemia (CI) pathobiology and outcomes. Over the past decade, the significant contribution of the spleen to ischaemic stroke has gained considerable attention in stroke research. The changes in the spleen after stroke are mainly reflected in morphology, immune cells and cytokines, and these changes are closely related to the stroke outcomes. Autonomic nervous system (ANS) activation, release of central nervous system (CNS) antigens and chemokine/chemokine receptor interactions have been documented to be essential for efficient brain-spleen cross-talk after stroke. In various experimental models, human umbilical cord blood cells (hUCBs), haematopoietic stem cells (HSCs), bone marrow stem cells (BMSCs), human amnion epithelial cells (hAECs), neural stem cells (NSCs) and multipotent adult progenitor cells (MAPCs) have been shown to reduce the neurological damage caused by stroke. The different effects of these cell types on the interleukin (IL)-10, interferon (IFN), and cholinergic anti-inflammatory pathways in the spleen after stroke may promote the development of new cell therapy targets and strategies. The spleen will become a potential target of various stem cell therapies for stroke represented by MAPC treatment.