In Vitro Synthesis of Prostaglandin E 2 by Synovial Tissue after Helium–Neon Laser Radiation in Rheumatoid Arthritis

This paper reports the effect of helium–neon laser radiation (power of 5 mW and 632.8 nm wave length) on the synthesis of PGE₂ in vitro in synovial tissue of biopsy samples of knee joints in patients with chronic rheumatoid arthritis stages II or III. Twelve patients were studied. Each patient received 15 applications of He–Ne laser. Eleven points for He–Ne laser applications were selected in one of the affected knees. The energy density used was 8 J/cm² per application point. The He–Ne laser therapy reduced the synthesis of PGE₂. The analysis of the data revealed a statistically significant difference between the levels of the synthesis of PGE₂ before treatment (17.69 ± 2.65 ng mg⁻¹ of dry tissue h⁻¹) and after treatment (13.85 ± 2.73 ng mg⁻¹ of dry tissue h⁻¹), with p < 0.01 comparing mean values. This was also accompanied by relief of pain (91.6%), and a favorable subjective report from the patient. We conclude that PGE₂ is a quantifiable parameter that could explain what causes pain relief in patients with rheumatoid arthritis that are treated with He–Ne laser.