Unusual presence of anti-GM1 IgG-antibodies in a healthy individual, and their possible involvement in the origin of disease-associated anti-GM1 antibodies.

LARDONE RICARDO DANTE; ALANIZ MARIA EUGENIA; IRAZOQUI FERNANDO JOSE; NORES GUSTAVO ALEJANDRO

JOURNAL OF NEUROIMMUNOLOGY

Elsevier

Lugar: Amsterdam; Año: 2006 vol. 173 p. 174 - 174

0165-5728

p class="abstract">Anti-GM1 antibodies of the IgG isotype are found in serum from patients with Guillain-Barre syndrome. In normal human sera, anti-GM1 IgM-antibodies are commonly present, but their IgG counterpart has not been previously demonstrated. During routine screening, we found a normal human serum with a high titer of anti-GM1 IgG-antibodies (IgG1 subclass). Affinity estimation by soluble antigen-binding inhibition indicated that they are low-affinity antibodies with IC50 values between one and two orders of magnitude higher than those of anti-GM1 IgG-antibodies from Guillain-Barre patients. Various antibody parameters remained fairly constant for 1 year, in additional serum samples taken at 4-month intervals. Such anti-GM1 IgG1-antibodies were not detected in > 100 other normal serum samples tested, indicating a very low frequency in the general population. The low affinity of these unusually present antibodies could explain the absence of disease, despite their relative