Urinary neopterin quantification indicates altered cell-mediated immunity in healthy subjects under psychological stress

Urinary neopterin levels increase and predict survival during a respiratory outbreak in wild chimpanzees (Taï National Park, Côte d'Ivoire)

Monitoring immune system activation of wild animals has garnered increasing interest within the field of ecological immunology, leading to an urgent need for non-invasive biomarkers measuring these changes. Urinary neopterin, a marker of the cell-mediated immune response, is validated as an immune-related biomarker in captive and laboratory animals. However, wild animals naturally host higher and chronic pathogen loads. Therefore, detection and quantification of additional infections via neopterin might not be possible against the background of a chronically challenged immune system. To assess the suitability of urinary neopterin in wild animals, we measured neopterin corrected for specific gravity with an enzyme immunoassay in 185 samples collected before, during and after a respiratory disease outbreak in 28 individuals from a group of wild chimpanzees (Taï National Park, Côte d'Ivoire). Urinary neopterin levels were significantly higher during periods when individuals showed respiratory symptoms versus before and after the outbreak. Furthermore, urinary neopterin levels were significantly higher in individuals that died, with higher levels already apparent before the outbreak, suggesting individuals may have an already activated immune system. Measuring urinary neopterin levels, with other biomarkers of energetic condition, stress challenges, and reproduction will contribute towards a deeper understanding of life-history trade-offs in wild animals.

An Intervention to Reduce Psychosocial and Biological Indicators of Stress in African American Lupus Patients: The Balancing Lupus Experiences with Stress Strategies Study

OBJECTIVE

Very little is known about the impact of psychosocial stress on African American lupus patients. Due to the exposure of African Americans to a unique trajectory of stressors throughout life, it may be critical to understand the relationship between psychosocial stress and underlying biological mechanisms that influence disease activity and pathology in this high risk group.

METHODS

The Balancing Lupus Experiences with Stress Strategies (BLESS) study piloted the validated "Better Choices, Better Health" Chronic Disease Self-Management Program (CDSMP) in 30 African-American lupus patients participating in the SLE Clinic Database Project at the Medical University of South Carolina (MUSC). Measures of psychosocial and biological indicators of stress were collected in all of the patients in each of the study conditions before and after intervention activities, as well as four months post-intervention, to assess the effectiveness of the program in reducing perceived and biological indicators of stress.

RESULTS

Participation in the workshops had large effects upon depression (d=1.63 and d = 1.68), social/role activities limitations (d =1.15), health distress (d =1.13 and d = 0.78), fatigue (d =1.03), pain (d =0.96), and lupus self-efficacy (d =0.85). Neither the differences in cortisol or DHEA levels pre- and post-intervention were found to be significantly different between intervention participants and controls.

CONCLUSION

The intervention workshops acted to reduce perceived stress and improve quality of life. Our findings imply that comparable, if not more significant gains in relevant health indicators are possible in African American patients when provided the opportunity to participate in CDSMP's.

Stress system dynamics during "life as it is lived": an integrative single-case study on a healthy woman

Little is known about the dynamic characteristics of stress system activity during "life as it is lived". Using as representative a study design as possible, this investigation sought to gain insights into this area. A healthy 25-year-old woman collected her entire urine over a period of 63 days in 12-h intervals (126 measurements) to determine cortisol and neopterin (immune activation marker) levels. In addition, she filled out questionnaires on emotional state and daily routine in 12-h intervals, and was interviewed weekly to identify emotionally negative and positive everyday incidents. Adjusted cross-correlational analyses revealed that stressful incidents were associated with cyclic response patterns in both urinary cortisol and urinary neopterin concentrations. Urinary cortisol levels first decreased 12-24 h after stressful incidents occurred (lag 1: -.178; p = 0.048) and then increased a total of 72-84 h later (lag 6: +.224; p = 0.013). Urinary neopterin levels first increased 0-12 h before the occurrence of stressful incidents (-lag 1: +.185; p = 0.040) and then decreased a total of 48-60 h following such stressors (lag 4: -.181; p = 0.044). Decreases in urinary neopterin levels were also found 24-36 and 48-60 h after increases in pensiveness (lag 2: -.215; p = 0.017) and depressiveness (lag 4: -.221; p = 0.014), respectively. Findings on emotionally positive incidents sharply contrasted with those dealing with negative experiences. Positive incidents were followed first by urinary cortisol concentration increases within 12 h (lag 0: +.290; p = 0.001) and then by decreases after a total of 60-72 h (lag 5: -.186; p = 0.039). Urinary neopterin levels first decreased 12-24 h before positive incidents occurred (-lag 2: -.233; p = 0.010) and then increased a total of 12-24 h following these incidents (lag 1: +.222; p = 0.014). As with previous investigations on patients with systemic lupus erythematosus (SLE), this study showed that stress system response can be considerably longer and more complex and differentiated than findings from conventional group studies have suggested. Further integrative single-case studies will need to be conducted in order to draw firm conclusions about stress system dynamics under real-life conditions.

Mid-life stress is associated with both up- and down-regulation of markers of humoral and cellular immunity

Perception of stress with consequent activation of a neuroendocrine cascade causes changes in immune function that may be bi-directional, with alterations in basal levels of biological parameters outside the optimal range. In this cross-sectional study of 302 healthy persons (males 56.3%, females 43.7%) aged 41-46 years, higher stress levels, as assessed by questionnaire measures of recurrent and recent perceived stress, were associated with a 4-fold greater risk of having a high compared to mid-range serum neopterin concentration, indicating activation of cellular immune mechanisms [adjusted odds ratio, OR; (95% confidence intervals, CI): Low stress=1.00 (reference group); Medium stress=4.13 (1.51, 11.29); High stress=4.63, (1.35, 15.83), p for trend=0.01]. Higher stress levels were associated with a 3-fold greater risk of having signs of humoral immune activation, as indicated by salivary IgA concentration [high compared to mid-range salivary IgA: Low stress=1.00 (reference group); Medium stress=1.06 (0.48, 2.34); High stress=3.62 (1.26, 10.39), p for trend=0.02], but also a 4-fold greater risk of humoral immune depression [low compared to mid-range IgA: Low stress=1.00 (reference group); Medium stress=1.72 (0.74, 3.99); High stress=4.38 (1.47, 13.00), p for trend=0.02]. In conclusion, in this cross-sectional study, higher stress levels were associated with higher serum neopterin and both elevated and depressed salivary IgA levels. These findings emphasise the importance of considering that stress may have bi-directional effects on immune mechanisms, and are consistent with an activational effect of chronic, perceived stress on cellular immunity, and a bi-directional effect on IgA levels, one aspect of humoral immunity.

Immune dysfunction associated with chronic professional stress in nurses

The relationship between chronic professional stress in nurses and immunity as well as the possible impact of psychopathology upon this relationship have been examined. Sixty subjects were selected on the basis of high/low scores on professional stress and psychopathology. Chronic professional stress appeared to be associated with immune dysfunction including signs of immune activation (increased numbers of cells expressing the interleukin-2 receptor, especially CD4+CD25+ cells) and possibly immune suppression (decrease in percentage of natural killer cells). The increase in activation markers, CD3+CD16CD56+ cells and serum neopterin was most pronounced in the group with high stress/low psychopathology whereas the decrease in CD8+CD11b+ cells was most pronounced in the group with high stress/high psychopathology. It is hypothesized that in the presence of chronic stress distinct psychological mechanisms are associated with specific immune dysfunctions.