Increase in platelet immunoglobulin in Alzheimer's disease is normalised following cholinesterase inhibitor treatment: preliminary results.

We report a 16.5% increase in platelet immunoglobulin (Ig) content in subjects with Alzheimer's disease (AD) in relation to cognitively intact individuals (p = 0.021), whereas the plasma Ig levels were unaltered (p = 0.428). The upregulation of platelet Ig was not explained by age, duration of dementia, or degree of cognitive impairment. However, AD subjects treated with cholinesterase inhibitors (n = 21) had lower levels of platelet Ig (p = 0.009) than AD subjects not treated with anti-dementia drugs (n = 4) and similar to those of control subjects (n = 24; p = 0.069). The anti-dementia treatment did not influence the plasma Ig levels (p = 0.177). These preliminary findings require further confirmation in studies on larger number of AD subjects with various stages of cognitive impairment, and who would be assessed prior to initiation of and during cholinesterase inhibitor treatment.