Abnormal erythrocyte choline and influx in Alzheimer's disease.

Choline transport and levels were studied in erythrocytes from patients with Alzheimer's disease and age-matched controls using stable isotopic tracer techniques. The mean erythrocyte choline in the Alzheimer group was 50.1 nmol ml-1 compared to 15.5 nmol ml-1 in the controls. This was significant using a Student's t test at a P of less than 0.0005. Influx of choline into the erythrocyte correlated inversely with erythrocyte choline with high significance. This study suggests that erythrocyte choline is elevated in a subset of patients with Alzheimer's disease and that the low affinity transport system is also abnormal in these patients. This abnormality of choline transport may play a role in the pathogenesis of Alzheimer's disease in some patients.