Reduced T helper and B lymphocytes in Parkinson's disease

Gene association with HLA suggests involvement of immune mediated mechanisms in the pathogenesis of Parkinson's disease (PD). Only a small number of studies have found differences between circulating leukocyte populations in PD patients compared to controls, with conflicting results. To clarify whether there is a circulating leukocyte PD phenotype, we assessed the numbers of T, B and natural killer cells, and monocytes and found a small reduction (15-25%) in CD4. + T and CD19. + B cells in PD. These findings suggest some compromise in immune cells in PD and have potential implications for immune function and the progression of PD.