Clinical effects of actarit in rheumatoid arthritis: improvement of early disease activity mediated by reduction of serum concentrations of nitric oxide

OBJECTIVE: We previously reported the presence of high serum concentrations of nitric oxide (NO) in patients with rheumatoid arthritis (RA). In this study we evaluated the effect of actarit on patients with early and advanced stages of RA and the relationship between RA activity and serum NO levels. METHODS: Thirty-seven RA patients who were undergoing care at Sasebo Chuo Hospital were entered into the study. Patients were divided into two groups based on the severity of their disease: group I (stages I and II) and group II (stages III and IV). NO concentrations in serum samples were measured by the chemiluminescence method. RESULTS: Morning stiffness, the number of tender and swollen joints, grip strength, pain score, modified Health Assessment Questionnaire score (mHAQ), ESR, CRP and the Lansbury index significantly improved during 24 weeks of treatment in group I. Patients in group II did not show improvement in morning stiffness, pain score, ESR or CRP during treatment. The concentrations of NO in group I were significantly reduced at 8 weeks after administration of actarit. Those in group II showed a delayed response; a significant decrease in NO occurred at 20 weeks. The improvement in the number of tender and swollen joints, grip strength, pain score, mHAQ and Lansbury index noted in group I preceded the fall in NO concentrations. CONCLUSION: Our results demonstrate that actarit improves disease activity in early phase RA by suppressing serum NO levels. The results suggest that NO is a useful marker for monitoring improvement in the early stages of RA.