Anti-GM1 IgG antibodies in Guillain-Barré syndrome: fine specificity is associated with disease severity

LARDONE RD,; YUKI N; ODAKA M; DANIOTTI JL; IRAZOQUI FJ; NORES GA

JOURNAL OF NEUROLOGY, NEUROSURGERY AND PSYCHIATRY

B M J PUBLISHING GROUP

Lugar: Londres; Año: 2010 vol. 81 p. 629 - 633

0022-3050

BACKGROUND: Clinical severity of Guillain-Barré syndrome (GBS) is highly variable, but the immunopathological reason is unknown. OBJECTIVE: The study was designed to show which antibody parameters are associated with disease severity in GBS patients with serum anti-GM(1) IgG antibodies. METHODS: Thirty-four GBS patients with anti-GM(1) IgG antibodies were grouped into two categories according to disease severity at nadir: mild (grades 1 to 3 by Hughes functional scale, n = 13) and severe (grades 4 and 5, n = 21). Titer, affinity, fine specificity, and cell binding of anti-GM(1) antibodies were obtained and compared between the two groups. RESULTS: No differences in antibody titer (GM(1)-ELISA) or affinity were found between the two patient groups. In contrast, the severe group showed a significantly higher frequency (95%, vs. 46% in the mild group, p < 0.003) of specific (not cross-reacting with GD(1b)) anti-GM(1) antibodies. In addition, the severe group also exhibited a higher antibody binding titer to cellular GM(1). CONCLUSIONS: Differences in fine specificity of antibodies are strong indications that different regions of the GM(1)-oligosaccharide are involved in antibody binding. High titers of specific anti-GM(1) antibody binding to cellular GM(1) can be explained by antigen exposure, i.e., GM(1) exposes or form mainly epitopes recognized by specific antibodies, and "hides" those involved in binding of cross-reacting antibodies. Thus, fine specificity of anti-GM(1) antibodies may influence disease severity by affecting antibody binding to cellular targets. Additionally, since antibody specificity