Background LM1 is the predominant glycolipid in human peripheral nerve myelin and antibodies to LM1 and LM1-containing ganglioside complexes are detected in some patients with chronic inflammatory demyelinating polyneuropathy (CIDP). The clinical features of patients with such antibodies have not yet been investigated.

Methods Serum antibodies to LM1, a mixture of GM1 and LM1 (GM1/LM1), and that of GD1b and LM1 (GD1b/LM1) were examined in 75 consecutive patients with CIDP. The clinical features of the CIDP patients with such antibodies in the present series and those in the previous reports were investigated and compared with those of antibody-negative patients.

Results Of the 75 patients with CIDP, two had antibodies to LM1, three had anti-GM1/LM1 complex antibody, one had anti-GD1b/LM1 complex antibody and two had antibodies to both the GM1/LM1 and GD1b/LM1 complexes. Patients with the LM1-associated antibodies did not have cranial nerve deficits (p<0.05) and exhibited ataxia more frequently than the antibody-negative patients (p<0.01).

Conclusion In humans, LM1 is contained more in the dorsal root than in the cranial nerves. The clinical features of CIDP patients with antibodies to LM1 and LM1-containing complexes may be associated with the distribution of the LM1 antigen. LM1-associated antibodies are possible markers for a subclass of CIDP.