Human peripheral blood cells (PB): Effect of Tocilizumab/MRA compared to methotrexate(MTX) treatments on rheumatoid arthritis(RA) patients.. Homo sapiens

This microarray study was conducted along with SATORI study, the clinical trial evaluated 125 patients with active RA with an inadequate response to low dose of MTX. Patients were allocated to receive either Tocilizumab(TCZ) 8 mg/kg every 4 weeks (TCZ group) or MTX 8 mg/week (MTX/control group) for 24 weeks. Gene expression profiles (GEP) of 112 patients - 54 patients from TCZ group and 58 patients from MTX group - were obtained in this study. Overall design: PB samples were collected directly into PAXGene tubes before and after the treatments. Total RNA was extracted using PAXGene Blood RNA Kit with the optimal on-column DNase digestion. Two-color microarray was used to directly compare the samples before versus after the treatment. Total RNA was amplified and amino allyl aRNA of the sample before/after treatments was further labeled with Cy3/Cy5. The labeled aRNAs (mixture of Cy3 and Cy5) was hybridized onto microarray slide. Dye swapping was done with each investigation to account for dye bias in microarray experiments.