Psychoimmunology and rheumatoid arthritis: concepts and methodologies

Stress-vulnerability factors as long-term predictors of disease activity in early rheumatoid arthritis

OBJECTIVE

Stress-vulnerability factors were studied for their ability to predict long-term disease activity in early rheumatoid arthritis.

METHODS

In a prospective study involving 78 recently diagnosed rheumatoid arthritis (RA) patients, the role of personality characteristics (neuroticism, extraversion), physical and psychological stressors (chronic, disease-related stressors of functional disability, pain, disease impact on daily life, as well as major life events), coping and social support at the time of diagnosis was examined to predict changes in clinical indicators of disease activity 1, 3 and 5 years later.

RESULTS

While stress-vulnerability factors failed to predict disease activity at the 1-year follow-up, disease activity at the 3- and 5-year follow-ups was predicted by coping and social support at the time of diagnosis, after adjusting for disease activity at first assessment, other biomedical and psychosocial factors and use of medication. Low levels of social support predicted increased disease activity at the 3-year follow-up, and high avoidance coping predicted increased disease activity at the 3- and 5-year follow-ups.

CONCLUSION

Findings indicate the potential prognostic value of avoidance coping and social support for the long-term course of disease activity in early RA and suggest that the effects of these vulnerability factors predominantly operate in the long term.

Biopsychosocial mediators and moderators of stress-health relationships in patients with recently diagnosed rheumatoid arthritis

OBJECTIVE

To investigate the mediating and moderating roles of social support, coping, and physiological variables in the relationship between life events and health status.

METHODS

Psychological and biological measurements were taken in 54 patients (38 women, 16 men, mean age +/- SD 56 +/-14.4 years) with recently diagnosed rheumatoid arthritis (RA).

RESULTS

Life events were correlated with psychological distress, but not with disease activity. No mediators for the relationship of life events with psychological well-being and disease activity were observed. In 40 tests, 4 moderators were found: Problem-focused coping, perceived support, diastolic blood pressure, and total number of lymphocytes were moderators of the relationship between daily hassles and health status (P < or = 0.05).

CONCLUSION

Our study provides limited support for the notion that the interactions of life stress with biopsychosocial variables have an impact on health. None of these variables were found to be crucial mediators of stress-health associations in recently diagnosed patients with RA, but some provocative evidence was given that biopsychosocial variables may have a minor impact on stress-health relationships.

A dual pathway model of daily stressor effects on rheumatoid arthritis

This study evaluated the initial promise of a dual-pathway conceptual model linking daily event stressors to rheumatoid arthritis (RA) disease activity through changes in immune system activation and mood. Fifty individuals, who were studied on five occasions two weeks apart, reported daily event stressors on the Daily Life Experience Checklist, daily mood on an abbreviated version of the Profile of Mood States-B, and daily joint pain on the Rapid Assessment of Disease Activity in Rheumatology. Serial clinical examinations comprised ratings of joint tenderness and swelling, and blood drawn during exams was analyzed for sedimentation rate (an indicator of systemic inflammation) and soluble interleukin-2 receptors (a marker of immune system activation known to correlate with RA disease activity). Across-person analyses failed to establish links from daily event stressors to either disease activity or composites of joint pain and joint inflammation when associations were adjusted for the effect of neuroticism on self-report measures. Pooled within-person analyses, however, were generally consistent with the relations predicted by the dual-pathway model. Increases in daily event stressors during the week preceding each clinical exam were associated with increased joint pain (regardless of changes in mood). At the same time, increased daily stressors were indirectly associated with decreased joint inflammation through reduction in levels of soluble interleukin-2 receptors. The dual-pathway model, which may be limited to short-term psychological and psychoimmunologic processes, underscores the importance of distinguishing potentially opposing effects of stress on pain versus inflammation in individuals with rheumatoid arthritis.

Susceptibility to adjuvant arthritis: relative importance of adrenal activity and bacterial flora

Previous studies on the regulation of bacterial-induced arthritis in rats have focused on endocrine aspects as well as differences in T cell immunity against bacterial epitopes. We analysed the role of both adrenal activity and bacterial flora in determining susceptibility to bacterial-induced arthritis. Outbred Wistar rats show a low incidence of adjuvant arthritis. Moderate sensitivity to adjuvant arthritis was found in a selected, stress-resistant line of the Wistar rat, whereas no arthritis was found in a stress-susceptible Wistar line. Plasma corticosterone responses after IL-1 alpha exposure were, however, identical in these two lines, excluding a direct correlation between susceptibility and corticosterone levels. In line with previous findings in germ-free (GF) F344 rats, GF Wistars also appeared highly susceptible to arthritis. We further analysed the corticosterone responses in GF and conventional (CV) rats. Administration of IL-1 alpha induced identical corticosterone responses in both CV and GF F344 rats. In addition, plasma corticosterone levels were measured around the time of onset of arthritis. Whereas no rise was seen in the arthritis-resistant CV rats, a significant increase was observed from day 14 in GF rats, at the moment of onset of arthritis. Although this corticosterone response was insufficient to prevent arthritis, it may have ameliorated disease expression in the GF F344 rats. Our data indicate that the bacterial flora, and therefore T cell tolerance, is of prime importance in determining susceptibility, whereas the activity of the hypothalamus-pituitary-adrenal (HPA) axis may modulate disease severity.

Temporal covariation of soluble interleukin-2 receptor levels, daily stress, and disease activity in rheumatoid arthritis

OBJECTIVE

To examine synchronous changes in soluble interleukin-2 receptor (sIL-2R) levels, daily indicators of emotional stress, joint inflammation, and reported pain in patients with rheumatoid arthritis (RA).

METHODS

Fourteen patients were studied on each of 6 occasions, 2 weeks apart. Measures included daily ratings of mood disturbance, undesirable events, and joint pain; clinical examination of joint swelling; and serum assays of sIL-2R. Pooled within-person correlations among these variables were calculated.

RESULTS

Consistent with the results of previous research, joint inflammation covaried directly with sIL-2R levels. Changes in mood disturbance were unrelated to changes in joint inflammation, but increases in mood disturbance were linked with decreases in sIL-2R levels and increases in reported joint pain.

CONCLUSION

These findings provide preliminary evidence that psychoimmune processes may be implicated in short-term changes in RA disease activity.

Timed treatment of the arthritic diseases: a review and hypothesis

Evidence has been accumulating regarding the importance of biological rhythms in the diagnosis and treatment of a variety of diseases and disorders. Increasingly, the arthritides have shown statistically quantifiable rhythmic parameters. Included in the latter group are joint pain and joint size. In addition, a number of drugs used to treat rheumatic diseases have varying therapeutic and toxic effects based on the time of day of administration. Among these drug classes are nonsteroidal antiinflammatory drugs, glucocorticoids, and a number of cytostatic agents. In the last group of agents, experience in treating malignant disease suggests that time-specified treatment may reduce the toxic effects of low-dose cytostatic treatment of rheumatoid arthritis (RA) and related diseases. This article reviews that evidence and suggests a rationale for the timed treatment of RA with methotrexate.