Inflammatory Blood Signature Related to Common Psychological Comorbidity in Chronic Pain

The impact of adverse childhood experiences on pain and subjective cognitive decline in patients treated for localized breast cancer: The mediating role of sense of coherence, sense of danger and psychosocial distress and danger

BACKGROUND

Pain and subjective cognitive decline (SCD) are common sequala of breast cancer (BC) treatment. Adverse childhood experiences (ACEs) are associated with pain and adverse health outcomes in noncancer population. Sense of coherence (SOC) reflects the disposition that life is manageable and predictable. Sense of danger (SOD) is the extent of perceived danger to oneself and family from a specific stressor. We aimed to assess if ACEs are associated with pain and SCD in patients treated for localized BC, and whether decreased SOC, increased SOD from BC, and increased psychological distress mediate these links.

METHODS

This study is a primary analysis of an on-going prospective trial, recruiting patients with localized BC before (neo) adjuvant oncological therapy. Patients completed validated questionnaires on ACEs, pain, SCD, SOC, SOD, and psychosocial distress. Demographic and clinical data were also collected.

RESULTS

We performed an analysis of baseline assessments in 127 patients. After controlling for demographic and clinical factors that correlated with study variables, serial mediation analyses confirmed that ACEs were associated with increased pain and SCD. These links were mediated by decreased SOC, followed by increased SOD, followed by increased psychosocial distress (all p's < 0.001). The models explained 50.14 % of the variance in pain and 43.37 % of the variance in SCD.

CONCLUSION

Our study suggests that ACEs increase the risk of pain and SCD in patients with localized BC, mediated by SOC, SOD, and psychosocial distress. These factors should be addressed when aiming to reduce symptom burden in BC patients.

Race-based differences in serum biomarkers for cancer-associated cachexia in a diverse cohort of patients with pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma is projected to become the second leading cause of cancer-related deaths by 2040, with the highest disease burden expected amongst Non-Hispanic Blacks. One of the most significant predictors of poor outcomes is the presence of cancer-associated cachexia (CCa). Yet, race- and ethnicity-specific biomarkers for early CCa diagnosis are lacking. Thus, evaluated a panel of candidate biomarkers of CCa in a diverse cohort of pre-treatment serum. Our study shows that GDF-15 was associated with cachexia severity, was superior to standard CCa-associated biomarkers at classifying cachexia, and differentiated between non-cachexia and pre-cachexia status, but only among Hispanic/Latinx and non-Hispanic Whites. Furthermore, high GDF-15 levels at diagnosis were associated with a ~ 2-fold increase in weight loss over the 6 months post-diagnosis. Thus, GDF-15 may be a potential biomarker for pre-cachexia (prior to weight loss) in the White and the Hispanic population, but not Black individuals. These findings underscore the fact that enrollment of minority individuals in clinical trials to evaluate treatments for CCa is of utmost importance.

Why PNI scientists need to engage in exploratory hypothesis-generating biomarker studies

Multi-omics research is developing rapidly, offering extensive sample analysis options and advanced statistical solutions to identify and understand complex networks of biomarkers. This review encourages groups in the psychoneuroimmunology field with limited experience in omics research to embrace these advances. Cross-sectional studies can leverage existing sample collections to provide unique information that complements longitudinal studies, providing insights into which biological systems may warrant further investigation and building fundamental mechanistic knowledge of biological networks. The understanding of immune-brain interactions should inform ongoing developments in exploratory, hypothesis-generating research. Disregarding psychoneuroimmunological aspects may have led to challenges in some prior biomarker research. Moving forward, a more nuanced perspective on inflammation and psychological comorbidity is needed. The first steps in the conceptualization of an explorative cross-sectional omics study are discussed from a pragmatic perspective, highlighting who we choose to study and what we choose to measure.

Methods and clinical biomarker discovery for targeted proteomics using Olink technology

PURPOSE

This paper is to offer insights for designing research utilizing Olink technology to identify biomarkers and potential therapeutic targets for disease treatment.

EXPERIMENTAL DESIGN

We discusses the application of Olink technology in oncology, cardiovascular, respiratory and immune-related diseases, and Outlines the advantages and limitations of Olink technology.

RESULTS

Olink technology simplifies the search for therapeutic targets, advances proteomics research, reveals the pathogenesis of diseases, and ultimately helps patients develop precision treatments.

CONCLUSIONS

Although proteomics technology has been rapidly developed in recent years, each method has its own disadvantages, so in the future research, more methods should be selected for combined application to verify each other.

Associations between sickness behavior, but not inflammatory cytokines, and psychiatric comorbidity in chronic pain

OBJECTIVES

Approximately one in five adults experiences chronic pain, often in co-occurrence with depression, insomnia, anxiety, and lower self-rated health. Elevated levels of cytokines, e.g. tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), interleukin 8 (IL-8), and interleukin 10 (IL-10), have been identified in patients with chronic pain. Depression, insufficient sleep, poor self-rated health, and pain intensity have also been associated with inflammatory biomarkers. This study aimed to investigate the interrelationships between inflammatory biomarkers and depression, insomnia, anxiety, self-rated health, sickness behavior, and pain intensity in patients with chronic pain.

METHODS

Self-report questionnaires and blood samples analyzed for plasma levels of inflammatory biomarkers were collected from 80 adult patients with chronic pain. Associations between inflammatory biomarkers (TNF-α, IL-6, IL-8, IL-10, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR)) and depression, insomnia, anxiety, self-rated health, sickness behavior, and pain intensity, were analyzed using bivariate Spearman rank correlation coefficients and regression analyses.

RESULTS

Participants were mainly women (72.5 %), with a mean age of 50.8 years, and a reported mean pain duration of 16.7 years. There were significant correlations between insomnia and CRP (rs =.26, p <.05); sex and ESR (rs =.29, p <.05); age and IL-6 (rs =.29, p <.05) and IL-8 (rs =.30, p <.05); BMI and IL-6 (rs =.50, p <.001), CRP (rs =.63, p <.001) and ESR (rs =.42, p <.001). Ratings of depression were positively and significantly related to ratings of sickness behavior and anxiety (β =.32 and β =.40, respectively), explaining 49 % of the total variance in depression ratings. Insomnia was positively and significantly related to sickness behavior (β =.37) explaining 31 % of the total variance in insomnia ratings. Inflammatory biomarkers, however, did not contribute significantly to the models.

CONCLUSIONS

Participants reported high levels of symptoms, yet the associations between these ratings and the inflammatory biomarkers were either absent or weak. Also, despite high levels of self-reported sickness behavior, overall the inflammatory status remained within the normal range. Ratings of sickness behavior contributed more than inflammatory markers in explaining ratings of depression and insomnia. The present results point to the complexity of chronic pain, and the challenges of identifying biomarkers that explain symptomatology.

Pain and the biochemistry of fibromyalgia: patterns of peripheral cytokines and chemokines contribute to the differentiation between fibromyalgia and controls and are associated with pain, fat infiltration and content

Objectives

This explorative study analyses interrelationships between peripheral compounds in saliva, plasma, and muscles together with body composition variables in healthy subjects and in fibromyalgia patients (FM). There is a need to better understand the extent cytokines and chemokines are associated with body composition and which cytokines and chemokines differentiate FM from healthy controls.

Methods

Here, 32 female FM patients and 30 age-matched female healthy controls underwent a clinical examination that included blood sample, saliva samples, and pain threshold tests. In addition, the subjects completed a health questionnaire. From these blood and saliva samples, a panel of 68 mainly cytokines and chemokines were determined. Microdialysis of trapezius and erector spinae muscles, phosphorus-31 magnetic resonance spectroscopy of erector spinae muscle, and whole-body magnetic resonance imaging for determination of body composition (BC)-i.e., muscle volume, fat content and infiltration-were also performed.

Results

After standardizing BC measurements to remove the confounding effect of Body Mass Index, fat infiltration and content are generally increased, and fat-free muscle volume is decreased in FM. Mainly saliva proteins differentiated FM from controls. When including all investigated compounds and BC variables, fat infiltration and content variables were most important, followed by muscle compounds and cytokines and chemokines from saliva and plasma. Various plasma proteins correlated positively with pain intensity in FM and negatively with pain thresholds in all subjects taken together. A mix of increased plasma cytokines and chemokines correlated with an index covering fat infiltration and content in different tissues. When muscle compounds were included in the analysis, several of these were identified as the most important regressors, although many plasma and saliva proteins remained significant.

Discussion

Peripheral factors were important for group differentiation between FM and controls. In saliva (but not plasma), cytokines and chemokines were significantly associated with group membership as saliva compounds were increased in FM. The importance of peripheral factors for group differentiation increased when muscle compounds and body composition variables were also included. Plasma proteins were important for pain intensity and sensitivity. Cytokines and chemokines mainly from plasma were also significantly and positively associated with a fat infiltration and content index.

Conclusion

Our findings of associations between cytokines and chemokines and fat infiltration and content in different tissues confirm that inflammation and immune factors are secreted from adipose tissue. FM is clearly characterized by complex interactions between peripheral tissues and the peripheral and central nervous systems, including nociceptive, immune, and neuroendocrine processes.

How Can Experimental Endotoxemia Contribute to Our Understanding of Pain? A Narrative Review

The immune system and the central nervous system exchange information continuously. This communication is a prerequisite for adaptive responses to physiological and psychological stressors. While the implicate relationship between inflammation and pain is increasingly recognized in clinical cohorts, the underlying mechanisms and the possibilities for pharmacological and psychological approaches aimed at neuro-immune communication in pain are not fully understood yet. This calls for preclinical models which build a bridge from clinical research to laboratory research. Experimental models of systemic inflammation (experimental endotoxemia) in humans have been increasingly recognized as an approach to study the direct and causal effects of inflammation on pain perception. This narrative review provides an overview of what experimental endotoxemia studies on pain have been able to clarify so far. We report that experimental endotoxemia results in a reproducible increase in pain sensitivity, particularly for pressure and visceral pain (deep pain), which is reflected in responses of brain areas involved in pain processing. Increased levels of blood inflammatory cytokines are required for this effect, but cytokine levels do not always predict pain intensity. We address sex-dependent differences in immunological responses to endotoxin and discuss why these differences do not necessarily translate to differences in behavioral measures. We summarize psychological and cognitive factors that may moderate pain sensitization driven by immune activation. Together, studying the immune-driven changes in pain during endotoxemia offers a deeper mechanistic understanding of the role of inflammation in chronic pain. Experimental endotoxemia models can specifically help to tease out inflammatory mechanisms underlying individual differences, vulnerabilities, and comorbid psychological problems in pain syndromes. The model offers the opportunity to test the efficacy of interventions, increasing their translational applicability for personalized medical approaches.