BDNF and systemic lupus erythematosus: Only serum NGF levels and T regulatory cell counts were negatively correlated in SLE patients (Γ=0.48, p=0.01, Figure 3B), whereas there was no significant correlation between BDNF or NT-3 levels and T regulatory cell numbers (Γ=0.06, NS, Γ=0.28, NS, respectively).