I need opinion again. Diagnosed in March With PMR. 20mg of Prednisone. Down to 9mg a month ago pain was severe in right shoulder. Doctor sent me for MRI. MRI showed Synivitis and Effusion. Now doctor thinks possibly RA. She did 1 cortisone shot in my shoulder. And brought up the dreaded medicine Methotrexite. I got a second opinion from Orthopedic doctor. He said I might need arthscopic surgery to have fluid removed. Should I ask doctor for blood test RF, ANTI-CCP and ANA before I go on MXT? Appreciate any advice!