Abstract
Objective: Infliximab therapy effectively suppresses disease activity and improves symptoms of depression in patients with rheumatoid arthritis (RA). To elucidate the medication's mechanism, we examined changes in tumor necrosis factor (TNF)-α, interleukin (IL)-6 and dehydroepiandrosterone-salfate (DHEA-S). Method: Self-rating Depression Scale (SDS), serum concentrations of TNFα, IL-6 and delta DHEA-S were assessed in 20 patients with RA, at baseline and after 14 and 30 weeks of Infliximab treatment. (Delta DHEA-S rather than DHEA-S was measured because normal values of the latter vary depending on age and sex.) Disease activity was evaluated with the disease activity score 28 (DAS28). Quality of life was evaluated with the modified health assessment questionnaire (mHAQ). Results: Serum levels of both TNFα and IL-6 were elevated before Infliximab treatment in the patients with a moderate to high improvement in response to Infliximab treatment. Total scores on the SDS and mHAQ were improved and the serum levels of delta DHEA-S also decreased. On the other hand, patients with no response to treatment had lower TNFα and IL-6 levels at baseline and no significant change in total scores on the SDS and mHAQ. After treatment, serum levels of TNFα were slightly increased, while IL-6 showed no significant change and delta DHEA-S decreased slightly. Conclusion: Infliximab may improve depression in patients with RA by suppressing the expression of TNFα, IL-6 and DHEA-S.
