Clinical features and response to treatment in Guillain-Barre syndrome associated with antibodies to GM1b ganglioside

GM1b is a minor ganglioside in human peripheral nerves. Serum anti-GM1b ant ibodies frequently are present in patients with Guillain-Barre syndrome (GB S). In this collaborative study, we investigated the antecedent infections, clinical features, and response to treatment of GBS patients with anti-GM1 b antibodies. Of 132 GBS patients who participated in the Dutch GBS trial t hat compared the effect of intravenous immunoglobulins and plasma exchange, 25 (19%) patients had anti-GM1b antibodies. IgM antibodies were present in 14, IgG antibodies in 15, and both isotypes in 4 patients. The 25 patients with anti-GM1b antibodies had a clinical pattern distinct from that of the other 107 GBS patients. They more often had an episode of gastrointestinal illness and frequently showed serological evidence of recent infection by Campylobacter jejuni. The anti-GM1b-positive subgroup was marked by more ra pidly progressive, more severe, and predominantly distal weakness. Cranial nerve involvement and sensory deficits were less common in the patients wit h anti-GM1b antibodies. The presence of anti-GM1b antibodies was associated with slower recovery. The clinical manifestations predominantly were assoc iated with anti-GM1b antibodies of the IgG isotype. Fourteen (56%) of the 2 5 patients with anti-GM1b antibodies also had anti-GM1 antibodies. The grou p of patients with both antibodies was clinically more homogeneous and had a more rapidly progressive, pure motor neuropathy. The subgroup of anti-GM1 b-positive GBS patients responded well to treatment with immunoglobulins bu t not to plasmapheresis. The distinctive clinical features of the patients with anti-GM1b antibodies show that acute motor neuropathy represents a spe cific subgroup within GBS and that recognizing these patients may have cons equences as to the choice of therapy.