Variability of immunologic and clinical features in patients with rheumatoid arthritis studied over 24 hours.

Disease activity measures in patients with rheumatoid arthritis (RA) are influenced by many factors. Bedrest has been long recognized to effect decreased disease activity. In addition, most patients note maximal levels of pain and stiffness in the early morning hours with improvement in the afternoon. Cytokines and hormones with circadian rhythms may also contribute to variability in disease status during the day. Our purpose was to investigate variability of clinical and immunologic measures over a 24-h period of hospitalization in patients with RA. Production of rheumatoid factors and immunoglobulins, joint counts and questionnaire evaluations were measured 3 to 6 times over a 24-h period of hospitalization in 10 patients with RA who were not receiving steroids or second line drugs. Total joint counts were significantly decreased as soon as 4 h after admission, and continued to decrease during the 24-h period of observation. Significant decreases in mononuclear cell proliferation and antibody synthesis were also observed. Our findings are consistent with the presence of decreased levels of immunostimulatory mediators in hospitalized patients especially during late afternoon or evening hours.