Objectives: To study the distribution of CD4+ and CD8+ T-cell subsets in cerebrospinal fluid (CSF) and peripheral blood from patients with multiple sclerosis (MS), meningitis, other neurological diseases and healthy controls.
Material and methods: The expression of markers for naive and memory cells (CD45RA+ and CD45R0+), and helper/inducer cells (CD29+) on CD4+ cells as well as CD45R0+ and killer/effector (S6F1+) on CD8+ cells was investigated in cerebrospinal fluid (CSF) and peripheral blood from patients with multiple sclerosis (n=28), meningitis (n=13), other neurological diseases (n=16), and healthy controls (n=16) by 2-color flow cytometry.
Results: The majority of T cells in the CSF of the 4 groups exhibited the phenotype of memory cells (CD45R0+) on both CD4+ and CD8+ cells. The proportion of helper/inducer (CD29+CD4+ in CD4+) cells was also larger in the CSF compared to peripheral blood in the 3 patient groups and controls investigated. In contrast, CD8+ cells with killer/effector (S6F1+) phenotype were fewer in CSF compared to peripheral blood in all 4 groups. There were no significant differences between patients and controls regarding the distribution of these activation markers in the CSF or peripheral blood.
Conclusion: Our observations support the notion that activated T cells of both CD4+ and CD8+ phenotype selectively pass the blood-brain barrier under both pathological and normal conditions.