GUAMANIAN NEURODEGENERATIVE DISEASE - ARE DIABETES-MELLITUS AND ALTERED HUMORAL IMMUNITY CLUES TO PATHOGENESIS

On the western Pacific island of Guam, parkinsonism, dementia, and amy otrophic lateral sclerosis are highly prevalent but the cause is not k nown. To assess the possibility that the pathologic process extends be yond the nervous system, we studied patients with Guamanian neurodegen erative disease (N = 16) and Guamanian Chamorro control subjects (N = 16) in the Clinical Research Center of the Mayo Clinic, Rochester, MN. The principal abnormalities found in those with neurodegenerative dis ease included diabetes mellitus in 44%, elevated levels of serum immun oglobulin A (IgA) in 50%, and elevated IgG in 44%. The mean serum IgM level in the patient group was significantly lower than in the control group. Diabetes mellitus and elevated IgA and IgG levels were also pr esent in 31% of neurologically normal Guamanian subjects. Some of thes e control subjects, however, probably have preclinical neurodegenerati ve disease, as found in previously published postmortem studies. Exten sive serologic testing did not reveal any consistent profile of autoim munity. Other blood and urine studies failed to identify hematologic, nutritional, renal, hepatic, or metabolic abnormalities that distingui shed patients. Whether diabetes mellitus or abnormalities of immune re gulation share common etiopathology with Guamanian neurodegenerative d isease deserves further study.