Role of specific clone of lymphocytes, [CD4[+] and CD8[+]] and the sympathetic activity in pathophysiology of altered immunity in ischemic stroke

ABSTRACT

Ischemic stroke is one of the major causes of high morbidity and mortality allover the world. The understanding of the pathophysiology of post-ischemic immune response is very limited. Cerebral ischemic stroke affects the normally well-balanced interplay of the 2 super systems the nervous and the immune system. T-cell lymphocytes, [CD4[-], CD8[-]], may contribute to altered immunity associated with stroke. Increased sympathetic activity during ischemic stroke may have a role in altered lymphocytes function. The present study investigated the contribution of CD4[-] and CD8[-] and the sympathetic activity in altered immunity in ischemic stroke. Determination of CD4[-] and CD8[-] percentage in patient's blood was done by flowcytometry. Evaluation of sympathetic activity done by measuring urinary vanilmandelic acid [VMA] levels by spectrophotometry. The study also correlated the changes of these parameters with specific clinical and diagnostic variables in stroke. The study showed that CD4[-] and CDS percentage were significantly lower [p<0.001], while CD4[-] /CD8[-] ratio was significantly higher [p<0.001] in patients than controls. There was also significantly increased [p<0.001] mean urinary VMA excretion levels [mg/day] in patients compared to control group. Significantly lower CD4[-]% and CD4[-] /CD8[-] ratio and higher CD8[-]% were found in patients with recurrent stroke or history of transient ischemic attacks, progressive strokes and large size of infarction in comparison to other comparable patients. The study indicated that patients with ischemic strokes may have altered immunity and sympathetic over-activity which may be one of the mechanisms by which modulation of immune response can be induced after stroke. This brain-immune interaction after stroke may have protective, destructive, or regenerative effects in the brain, therefore the development of therapeutic strategies is not straightforward, and must take all these factors into consideration