|Systemic Juvenile Idiopathic Arthritis (SJIA)|
People with Systemic Juvenile Idiopathic Arthritis (SJIA) can have recurrent fevers, a macular rash, joint pain, joint deformities, an enlarged liver and/or spleen, and can occasionally have polyserositis or pericardial effusions. |
The more commonly known forms of JIA are considered to be autoimmune diseases, but there are new findings that suggest that Systemic JIA (SJIA) -a rare subtype of JIA should be classified as an autoinflammatory disease instead of an autoimmune disease. Systemic JIA is also known as Still's disease. Systemic JIA patients show signs that there are abnormalities in the innate immune system. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2774820/
There are some significant differences between JIA, an autoimmune disease (the body attacks itself due to many other factors), versus that of Systemic JIA or other autoinflammatory diseases. CAPS is an autoinflammatory syndrome, which is caused by a mutation of a gene in the cryopyrin protein.
With CAPS, the rash is different, is present at birth or early infancy, and the joints of CAPS patients can have non-specific joint pain. With NOMID, 50% of patients have bony changes on X rays, often with enlarged kneecaps. These symptoms are NOT present with autoimmune JIA. However, patients with Systemic JIA can have bony changes to their joints, especially at the cervical spine, wrists and middle of the foot.
JIA patients usually have inflammation in their synovial joints, such as the shoulders or knees, with increased fluid levels in the joints from inflammation that caused JIA sufferers to have warm, swollen and stiff joints. Also, JIA patients do not have the multisystemic inflammatory involvement of the brain tissue, eyes, hearing, and other problems present in NOMID, or cold induction of symptoms seen with FCAS, or adolescent hearing loss and amyloidosis seen with MWS.
For more information on JIA Systemic JIAor other autoimmune diseases, please go to http://www.arthritis.org/disease-center.php?disease_id=38