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

Objective: To investigate whether anti-GM2 antibodies in patients with Guil lain-Barre syndrome (GBS) are induced by molecular mimicry with cytomegalov irus (CMV). Background: Antibodies against ganglioside GM2 are frequently p resent in the serum from GBS patients with an antecedent infection with CMV . Methods: The authors detected inhibition of anti-GM2 reactivity after inc ubation 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 reacti vity with GM2 was decreased in a dose-dependent manner after incubation wit h CMV-infected fibroblasts. Incubation of anti-GM2-positive serum samples w ith uninfected fibroblasts and fibroblasts infected with varicella tester v irus did not inhibit anti-GM2 reactivity, whereas this reactivity was sligh tly decreased after incubation with herpes simplex virus type 1 in one pati ent. Antibodies against ganglioside GQ1b did not react with CMV-infected fi broblasts. Conclusions: CMV-infected fibroblasts express gangliosidelike ep itopes that recognize specifically anti-GM2 antibodies. These results suppo rt the hypothesis that antiganglioside antibodies in CMV-infected GBS patie nts are induced by molecular mimicry between GM2 and antigens that are indu ced by a CMV infection.