DELAYED APPEARANCE OF ANTI-MYELIN-ASSOCIATED GLYCOPROTEIN ANTIBODIES IN A PATIENT WITH CHRONIC DEMYELINATING POLYNEUROPATHY

A patient who had a polyneuropathy compatible with a chronic inflammat ory demyelinating polyneuropathy and was initially negative for anti-m yelin-associated glycoprotein (MAG) antibodies developed a double mono clonal gammopathy, IgM kappa and IgM lambda, two years after the diagn osis. The IgM kappa, but not the IgM lambda, exhibited strong anti-MAG antibody activity. The late appearance of the anti-MAG immunoreactivi ty suggests that in patients with an initial diagnosis of chronic infl ammatory demyelinating polyneuropathy, the search for anti-MAG antibod ies should be repeated during the course of the neuropathy.