Adenosine A2A receptor and IL-10 in peripheral blood mononuclear cells of patients with mild cognitive impairment

Adenosine suppresses immune responses through the A_2A receptor (A_2AR). This study investigated the interleukin 10 (IL-10) genetic profile and the expression of A_2AR in peripheral blood mononuclear cells (PBMCs) of patients with mild cognitive impairment (MCI), Alzheimer disease (AD), and age-matched controls to verify, if they may help distinguish different forms of cognitive decline. We analyzed the IL-10 genotype and the expression of A_2AR in 41 subjects with AD, 10 with amnestic MCI (a-MCI), 49 with multiple cognitive domain MCI (mcd-MCI), and 46 controls. There was a significant linear increase in A_2AR mRNA levels and A _2AR density from mcd-MCI to a-MCI, with intermediate levels being found in AD. The IL-10 AA genotype frequency was 67 in a-MCI, 46 in AD, 35 in mcd-MCI, and 20 in controls. These data suggest that the assessment of the IL-10 genotype and the expression of A_2AR in PBMCs may be a valuable means of differentiating between a-MCI and mcd-MCI.