Reduced circulating CD4+CD25+ cell populations in Guillain–Barré syndrome

Guillain–Barré syndrome (GBS) is a monophasic inflammatory disease considered to be due to autoimmunity. In order to test the hypothesis that the disease is associated with a perturbation of the circulating lymphoid cell population, we tested the mononuclear cells from the venous blood of 21 patients with Guillain–Barré syndrome (GBS) and 20 healthy controls by flow cytometry. The proportions and numbers of B and T lymphocytes, and CD4, CD8, double negative and γδ T cell subsets and numbers of monocytes were not significantly different in the patients compared with the controls. However, the number and proportion of CD4+CD25+ cells were reduced in acute GBS (mean number 61.7 cells/μl, 95% CI 42.9–80.4 and mean percentage 4.6%, 95% CI 3.8–5.4) compared with controls (mean number 99.8 cells/μl, 95% CI 74.7–124.9, p = 0.02, and mean percentage 6.0%, 95% CI 4.9–7.1%, p = 0.037). In addition, in GBS patients, the number and proportion of CD4+ T cells expressing CD25+ and HLA-DP, DQ, DR (mean number 11.9 cells/μl, 95% CI 7.6–16.1 and mean percentage 0.8%, 95% CI 0.5–1.1%) was lower than in healthy controls (23.5 cells/μl, 95% CI 16.4–30.6, p = 0.01, and mean percentage 1.4%, 95% CI 1.1–1.8%, p = 0.005. Since CD4+CD25+ cells include cells with special immunoregulatory functions, further investigation of this phenomenon and its relation to possible loss of regulatory T cell function in GBS is warranted.