CD4 and Parkinson disease: However, in comparison to PD-dt patients treated with l-DOPA and dopamine agonists, those treated with l-DOPA alone had lower mRNA levels of DR D1 (6.0 ± 4.1 × 10−8 vs. 10.8 ± 5.4 × 10−8, P = 0.035), D5 (9.7 ± 6.9 × 10−8 vs. 20.6 ± 7.5 × 10−8, P = 0.003), and D2 (6.0 ± 4.4 × 10−8 vs. 9.4 ± 3.3 × 10−8, P = 0.050), as well as less percentage of CD4+ T cells which were DR D1+ (7.2 ± 2.5% vs. 10.3 ± 3.5%, P = 0.025) or DR D3+ (4.5 ± 1.5% vs. 6.4 ± 1.9%, P = 0.017), and of CD4+ T naive cells which were DR D3+ (3.5 ± 1.2% vs. 7.9 ± 4.6 &, P = 0.009).