Detection of serum anti-ganglioside antibodies by latex agglutination assay in Guillain-Barré syndrome: comparison with ELISA.

Abstract

Rapid detection of serum anti-ganglioside antibodies in Guillain-Barré syndrome (GBS) could facilitate early diagnosis and early initiation of treatment, which might shorten the term of illness and reduce sequelae. We examined serum anti-ganglioside antibodies in patients with GBS using the latex agglutination assay developed by Alaedini and Latov (J Immunoassay 21: 377-386, 2000) with some modifications. We used 75 sera from GBS patients, which exhibited IgG anti-GM1, GD1b, or GQ1b, or IgM anti-GM2 antibodies on previous enzyme-linked immunosorbent assay (ELISA). Blue latex beads (2.5% solution of 0.3 microm) were coated with 1 mg/ml of GM1, GD1b, GQ1b or GM2. Aliquots (4 microl) of serum and the ganglioside-coated particles were mixed and rocked on a glass slide for 30 to 40 seconds. The reaction was observed under a microscope and compared with the antiganglioside antibody titers determined with ELISA. Agglutination was strong in sera of which the IgM or IgG titers of anti-GM1, GD1b, GQ1b or GM2 antibodies were found to be more than 1:6,400 on ELISA except for 2 samples, but weak or absent in sera with titers of 1:3,200. Agglutination was absent in sera of which the antibody titers were less than 1:3,200 on ELISA. We could rapidly detect serum IgM and IgG anti-GM1, GD1b, GQ1b and GM2 antibodies in patients with GBS by means of the latex agglutination assay when sera exhibited high titers of the respective antibodies on ELISA. The sensitivity of our agglutination assay was much lower than that of ELISA.