Rituximab-treated patients had higher serum levels of IL-10 ( 101 35 pg/mL vs 41 9 pg/mL ; P < 0.01 ) and MIP-1 ( 950 418 pg/mL vs 125 32 pg/mL ; P < 0.001 ) compared to placebo-treated patients at 2 hours after start of infusion .