Background B cell depletion by rituximab requires cross linking of CD20, which induces redistribution of CD20 to lipid rafts. This redistribution is correlated with efficiency of CDC and ADCC in previous studies. The integrity of the lipid rafts may also be important in induction of apoptosis. Statins interfere with the formation of cholesterol-rich micro domains within the plasma membrane- the lipid rafts1. Statins were recently reported to inhibit rituximab’s clinical efficacy in rheumatoid arthritis (RA)2.
Objectives To study the effect of statin on rituximab’s clinical efficacy and B cell depletion in RA.
Methods 119 patients pooled from three clinical trials were treated with 2×1000mg of rituximab. DAS28 and EULAR response were calculated at baseline and 6 months. B cell naïve, memory and plasmablast subsets were measured by flow cytometry.
Results Among 119 patients, 26 patients received a statin. Baseline characteristics are summarised in table 1.
At baseline, mean (SEM) DAS28-CRP were; 5.84 (0.23) and 5.52 (0.12) for SG and NSG respectively. At 6 months this improved to 3.92 (0.31) and 3.99 (0.14). Delta DAS28 was 1.92 (0.33) for SG vs. 1.52 (0.16) for NSG, p=0.590. EULAR response rates were as follows. SG: NON 23.1% (6), MOD 42.3% (11), GOOD 34.6% (9); in NSG: NON 34.4% (32), MOD 38.7% (36), GOOD 26.9% (25). There was no difference in the complete B cell depletion data at 2 weeks timepoint among the groups (SG-60% (15), NSG-52.9% (42), p=0.650). No difference in B cell subsets before or after rituximab was observed according to statin use.
Conclusions We found no evidence that clinical response to rituximab or degree of B cell depletion was influenced by use of statins.
Winiarska M, PLoS Med 2008;5:e64
EEA Arts, Ann Rheum Dis 2011; 70(5)
Disclosure of Interest S. Das: None Declared, M. Fernandez Matilla: None Declared, S. Dass Grant/Research support from: Honorarium Roche, Speakers Bureau: Roche, E. Vital Grant/Research support from: Honararium Roche, P. Emery Grant/Research support from: Roche, Consultant for: Roche, Speakers Bureau: Roche