Abstract
Rheumatoid arthritis (RA) is a systemic autoimmune disorder that involves inflammation and pain of joints and has been treated by steroid hormones. However, long-term use of steroid often causes side effects. Low-level laser irradiation (LLLI) is being evaluated for treating RA, and no side effects have been reported. LLLI reduced inflammation in collagen-induced RA rats. Linearly polarized infrared light irradiation (IPIL) and steroid reduced the expression of IL-8 in human RA synoviocyte MH-7A cells. GeneChip analysis coupled with a signal pathway database showed that steroid randomly altered the expression of many genes including unwanted genes, whereas IPIL reduced genes which are useful for anti-inflammation.
