Sixteen patients with meningopolyneuritis of Garin-Bujadoux-Bannwarth (MPN-GBB) were examined for HLA-DR antigens. In contrast to data in Lyme disease (LD), which is caused by an identical or closely related spirochete, no significant association was found between the neurological disease and HLA-DR. The reported association between neurological disease and HLA-DR2 in LD may be due to the inclusion of cases with neurological disease and arthritis, since chronic arthritis in LD seems to be well correlated with HLA-DR2.