Cross-reactive antibodies against GM2 and CMV-infected fibroblasts in Guillain-Barré syndrome.

OBJECTIVE: To investigate whether anti-GM2 antibodies in patients with Guillain-Barré syndrome (GBS) are induced by molecular mimicry with cytomegalovirus (CMV).

BACKGROUND: Antibodies against ganglioside GM2 are frequently present in the serum from GBS patients with an antecedent infection with CMV.

METHODS: The authors detected inhibition of anti-GM2 reactivity after incubation of GM2-reactive serum samples with fibroblasts infected with a GBS-associated CMV strain. Control sera consisted of GQ1b-reactive samples, and control antigens included uninfected fibroblasts and fibroblasts that were infected with other herpes viruses.

RESULTS: Serum immunoglobulin M reactivity with GM2 was decreased in a dose-dependent manner after incubation with CMV-infected fibroblasts. Incubation of anti-GM2-positive serum samples with uninfected fibroblasts and fibroblasts infected with varicella zoster virus did not inhibit anti-GM2 reactivity, whereas this reactivity was slightly decreased after incubation with herpes simplex virus type 1 in one patient. Antibodies against ganglioside GQ1b did not react with CMV-infected fibroblasts.

CONCLUSIONS: CMV-infected fibroblasts express gangliosidelike epitopes that recognize specifically anti-GM2 antibodies. These results support the hypothesis that antiganglioside antibodies in CMV-infected GBS patients are induced by molecular mimicry between GM2 and antigens that are induced by a CMV infection.