Effect of IQ on plasma PDI antigen and plasma PDI activity. (A) Mean change from baseline in plasma PDI antigen was not different between the patients treated with IQ and those treated with placebo (ANCOVA, P = .52; IQ, n = 22; placebo, n = 22). (B) PDI reductase activity (mean change from the baseline value) is significantly decreased in the patients treated with IQ compared with those treated with placebo (ANCOVA, ∗P = .02; IQ, n = 22; placebo, n = 22).