Blood γδ T cells, Campylobacter jejuni, and GM1 titers in Guillain-Barré syndrome

The γδ T cells participate in microbial defense, are prevalent in intestinal epithelia, and are activated in autoimmune diseases. We studied whether peripheral blood γδ cells and γδ subsets are increased in Guillain-Barré syndrome (GBS) and whether elevations are associated with Campylobacter jejuni infection or GM1 elevations. In 20 GBS patients, we performed serial flow cytometry studies of blood γδ, Vδ1, and Vδ2 cells (±CD8⁺), C jejuni, and ganglioside titers. There was no significant difference in median γδ T-cell percentages between GBS patients and controls at onset and at convalescence. However, 5 patients had marked Vδ1/Cδ8⁺ elevations. Elevated Vδ1 or Vδ1/Cδ8⁺ cells occurred in 3 of 6 patients with C jejuni or GM1 titer elevations. A minority of GBS patients have elevations of Vδ1/CD8⁺ cells, possibly associated with elevated Cjejuni or GM1 titers. The γδ T cells may have a cytotoxic (or suppressor) role in the disease.