On a 3-T magnetic resonance scanner, morphologic and perfusion changes of 9 patients with rheumatoid arthritis were evaluated after start of anti-interleukin 6 receptor antibody Tocilizumab (TCZ) treatment.
Morphologic and perfusion-based magnetic resonance imaging (MRI) parameters were assessed before and 4, 12, and 24 after the start of TCZ treatment. Furthermore, serologic biomarkers and clinical assessment scores were evaluated 4, 12, 24, and 52 weeks after treatment initiation.
Results of MRI parameters showed significant group differences between responders and nonresponders for synovial volume, transfer constant, and blood plasma volume fraction already at week 12 as well as relative enhancement and rate of early enhancement at week 24.
Considering the temporal change of perfusion-derived MRI parameters (transfer constant, blood plasma volume fraction, relative enhancement, and rate of early enhancement) as well as morphologic MRI parameters (synovial volume measurements), a quantifiable assessment of response to TCZ therapy in rheumatoid arthritis seems possible at an even earlier time point compared with clinical assessment scores, whereas serologic biomarkers proved nonspecific in this respect.