Approach to a Positive (+) Rheumatoid Factor (RF) (+) RF does not always = RA Rheumatic disorders: • Rheumatoid arthritis • SLE, Sjogren's & Mixed connective tissue (types II & III) • Mixed cryoglobulinemia • Polymyositis & Dermatomyositis Non-rheumatic disorders: • Chronic infections • Inflammatory disorders of Liver & Lung • Malignancies • Aging Andrew Sanchez M.D. @ASanchez_PS #Rheumatoid #Factor #RF #rheumatology #laboratory #differential #diagnosis
