Immunological indices in presenile Alzheimer's disease.

Immunological indices, both T- and B-dependent, were studied in 11 patients affected by presenile Alzheimer's disease. The data obtained were compared with those from a group of normal adults of similar age and from a group of normal young subjects. Furthermore, antisera were produced in rabbits against Alzheimer's serum and compared to antisera against normal human serum. The following results were obtained: decrease of serum IgM levels; no monoclonal aspects or auto-antibodies were detected in our patients. The kappa/lambda ratio was also normal. The T cell system was functionally normaly, but with a slight decrease of the T cell number and with an increase of the Null lymphocytes. No specific serum proteins were found in the anti-Alzheimer antisera. The data are discussed in correlation to the possible genesis of senile plaques.