TPO and rheumatoid arthritis: First, although autoimmune markers (e.g., anti-nuclear antibodies [ANA], rheumatoid factor [RF], IgG, IgM, anti-thyroid peroxidase antibodies (anti-ThyPeroxAb), anticardiolipin antibodies [ACL], and lupus anticoagulant [LAC]) are usually present in patients with autoimmune disorders (e.g., scleroderma, Sjögren’s syndrome, myositis, SLE, RA, myasthenia gravis, and ITP), they may also be detected in patients with non-autoimmune diseases and in healthy individuals who may never develop an autoimmune disease (72, 73).