Autosomal dominant cerebrovascular amyloidosis: properties of peripheral blood lymphocytes

Selected properties of peripheral blood lymphocytes (PBLs) from five ambulatory affected individuals of a kindred with autosomal dominant cerebrovascular amyloidosis were studied. The percentage of PBLs bearing surface membrane immunoglobulin (SmIg+ cells) was increased in the patient group (30 +/- 3% versus 20 +/- 2%; p less than 0.05). The percentage of PBLs forming early and total E-rosettes was comparable in patient and control groups. Mitogenic response to concanavalin A (Con A) was suggestively reduced in the patient group, measured both by total 3H-thymidine incorporation and by comparison of stimulation indices. Mitogenic response to phytohemagglutinin and pokeweed was comparable in the two groups. Capping of Con A by PBLs was significantly reduced in the patient group compared with the controls (13 +/- 1% versus 26 +/- 2%; p less than 0.01). The findings of reduced Con A response and increased SmIg+ cells support the hypothesis that immune dysfunction contributes to the development of amyloidosis. The reduced capping suggests altered membrane properties in this autosomal dominant disorder.