A new study suggests it may be possible to predict nonresponsiveness to antibody therapy in patients with rheumatoid arthritis (Owczarczyk K et al. Sci Transl Med. 2011;3:101ra92).
Rituximab and ocrelizumab, antibodies that target the CD20 molecule on the surface of B cells, are effective in about half of patients with rheumatoid arthritis. Previous studies have shown that a persistence of B cells in the blood following antibody therapy correlates with impaired response. Immature plasma B cells, or plasmablasts, that do not express CD20 resist B cell depletion.
Hampton T. Antibody Drugs and Arthritis. JAMA. 2011;306(17):1853. doi:10.1001/jama.2011.1574