IFNAR1 and nephritis: Thus, mBLyS and IFNAR1 levels on monocytes were related to the frequency of nephritis (β = 0.275, p = 0.032 and β = 0.270, p = 0.027, respectively) and serositis (β = 0.316, p = 0.012 and β = 0.283, p = 0.028), whereas expression on B cells were associated to the frequency of serositis (β = 0.257, p = 0.025 and β = 0.209, p = 0.021) and neurologic disease (β = 0.336, p = 0.005 and β = 0.289, p = 0.017).