Differential expression of cerebrospinal fluid neuroinflammatory mediators depending on osteoarthritis pain phenotype

Low-grade systemic inflammation, but not neuroinflammation, is associated with 12-month postoperative outcome after total hip arthroplasty in patients with painful osteoarthritis

Aims

Better prediction of outcome after total hip arthroplasty (THA) is warranted. Systemic inflammation and central neuroinflammation are possibly involved in progression of osteoarthritis and pain. We explored whether inflammatory biomarkers in blood and cerebrospinal fluid (CSF) were associated with clinical outcome, and baseline pain or disability, 12 months after THA.

Methods

A total of 50 patients from the Danish Pain Research Biobank (DANPAIN-Biobank) between January and June 2018 were included. Postoperative outcome was assessed as change in Oxford Hip Score (OHS) from baseline to 12 months after THA, pain was assessed on a numerical rating scale, and disability using the Pain Disability Index. Multiple regression models for each clinical outcome were included for biomarkers in blood and CSF, respectively, including age, sex, BMI, and Kellgren-Lawrence score.

Results

Change in OHS was associated with blood concentrations of tumour necrosis factor (TNF), interleukin-8 (IL-8), interleukin-6 receptor (IL-6R), glycoprotein 130 (gp130), and IL-1β (R2 = 0.28, p = 0.006), but not with CSF biomarkers. Baseline pain was associated with blood concentrations of lymphotoxin alpha (LTα), TNFR1, TNFR2, and IL-6R (R2 = 0.37, p < 0.001) and CSF concentrations of TNFR1, TNFR2, IL-6, IL-6R, and IL-1Ra (R2 = 0.40, p = 0.001). Baseline disability was associated with blood concentrations of TNF, LTα, IL-8, IL-6, and IL-1α (R2 = 0.53, p < 0.001) and CSF concentrations of gp130, TNF, and IL-1β (R2 = 0.26, p = 0.002). Thus, preoperative systemic low-grade inflammation predicted 12-month postoperative outcome after THA, and was associated with preoperative pain and disability.

Conclusion

This study highlights the importance of systemic inflammation in osteoarthritis, and presents a possible path for better patient selection for THA in the future. Preoperative central neuroinflammation was associated with preoperative pain and disability, but not change in OHS after THA.

Brain Amyloid-β Peptide Is Associated with Pain Intensity and Cognitive Dysfunction in Osteoarthritic Patients

Considerable studies have demonstrated that osteoarthritis (OA) is a risk factor for dementia. The precise mechanisms underlying the association between OA and increased risk for cognitive dysfunction, however, remain unclear. This study aimed at exploring the associations between pro-inflammatory cytokines/chemokines, biomarkers of Alzheimer's disease (AD), pain intensity, and cognitive decline in knee joint OA patients. A total of 50 patients (26 in OA group and 24 in non-OA control group) were enrolled in this prospective, observational study. The visual analogue scale (VAS) score for pain intensity and Cognitive Abilities Screening Instrument (CASI) score for cognitive functions were examined in both groups. The plasma and cerebrospinal fluid (CSF) levels of pro-inflammatory molecules (IL-1β, IL-6, TNF-α, fractalkine, BDNF, MCP-1, and TGF-β), as well as biomarkers of AD (Aβ40, Aβ42, total-tau, and phospho-tau), were measured by multiplex immunoassay. Correlations among plasma or CSF biomarkers and questionnaire scores were assessed using Pearson's correlation coefficient and simple linear regressions. There were more patients in the OA group whose CASI cutoff percentiles were Collapse

Key Words

• amyloid β40
• amyloid β42
• cognition
• osteoarthritis
• pain
• pro-inflammatory cytokine/chemokine

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MESH Headings

• Humans
• Female
• Male
• Amyloid beta-Peptides/cerebrospinal fluid
• Amyloid beta-Peptides/blood
• Aged
• Biomarkers/blood
• Biomarkers/cerebrospinal fluid
• Cognitive Dysfunction/cerebrospinal fluid
• Cognitive Dysfunction/etiology
• Cognitive Dysfunction/blood
• Middle Aged
• Pain/cerebrospinal fluid
• Pain/etiology
• Prospective Studies
• Alzheimer Disease/cerebrospinal fluid
• Alzheimer Disease/blood
• Pain Measurement
• Osteoarthritis/cerebrospinal fluid
• Osteoarthritis/complications
• Osteoarthritis/blood
• Cytokines/cerebrospinal fluid
• Cytokines/blood
• Brain/metabolism
• Brain/diagnostic imaging
• Osteoarthritis, Knee/cerebrospinal fluid
• Osteoarthritis, Knee/complications
• Osteoarthritis, Knee/blood

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Grants

• VGHKS108-088 Kaohsiung Veterans General Hospital

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Affiliation(s)

Chun-Hsien Wen Graduate Institute of Clinical Medical Sciences, Chang Gung University, Taoyuan 33302, Taiwan; Department of Anesthesiology, Kaohsiung Veterans General Hospital, Kaohsiung 813414, Taiwan Department of Nursing, Shu-Zen Junior College of Medicine and Management, Kaohsiung 82144, Taiwan Department of Nursing, Meiho University, Pingtung 912009, Taiwan School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
Hong-Yo Kang Graduate Institute of Clinical Medical Sciences, Chang Gung University, Taoyuan 33302, Taiwan; Division of Endocrinology and Metabolism, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833401, Taiwan College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan
Julie Y.H. Chan Institute for Translational Research in Biomedicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833401, Taiwan

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Knee osteoarthritis: disease burden, available treatments, and emerging options

Osteoarthritis (OA) is a prevalent condition that affects nearly 528 million people worldwide, including 23% of the global population aged ⩾40, and is characterized by progressive damage to articular cartilage, which often leads to substantial pain, stiffness, and reduced mobility for affected patients. Pain related to OA is a barrier to maintaining physical activity and a leading cause of disability, accounting for 2.4% of all years lived with disability globally, reducing the ability to work in 66% of US patients with OA and increasing absenteeism in 21% of US patients with OA. The joint most commonly involved in OA is the knee, which is affected in about 60%-85% of all OA cases. The aging population and longer life expectancy, coupled with earlier and younger diagnoses, translate into a growing cohort of symptomatic patients in need of alternatives to surgery. Despite the large number of patients with knee OA (OAK) worldwide, the high degree of variability in patient presentation can lead to challenges in diagnosis and treatment. Multiple society guidelines recommend therapies for OAK, but departures from guidelines by healthcare professionals in clinical settings reflect a discordance between evidence-based treatment algorithms and routine clinical practice. Furthermore, disease-modifying pharmacotherapies are limited, and treatment for OAK often focuses solely on symptom relief, rather than underlying causes. In this narrative review, we summarize the patient journey, analyze current disease burden and nonsurgical therapy recommendations for OAK, and highlight emerging and promising therapies-such as cryoneurolysis, long-acting corticosteroids, and gene therapies-for this debilitating condition.

Levels of preoperative cerebrospinal fluid pro-inflammatory mediators and chronic pain after total knee arthroplasty surgery

BACKGROUND

Patients undergoing total knee arthroplasty (TKA) surgery are at high risk of chronic postsurgical pain (CPSP). Accumulating evidence suggests an active role of neuroinflammation in chronic pain. However, its role in the progression to CPSP following TKA surgery remains unanswered. Here, we examined the associations between preoperative neuroinflammatory states and pre- and postsurgical chronic pain in TKA surgery.

METHODS

The data of 42 patients undergoing elective TKA surgery for chronic knee arthralgia at our hospital were analyzed in this prospective study. Patients completed the following questionnaires: brief pain inventory (BPI), hospital anxiety and depression scale, painDETECT, and pain catastrophizing scale (PCS). Cerebrospinal fluid (CSF) samples were collected preoperatively and concentrations of IL-6, IL-8, TNF, fractalkine, and CSF-1 were measured by electrochemiluminescence multiplex immunoassay. CPSP severity was ascertained, using the BPI, 6 months postsurgery.

RESULTS

While no significant correlation was observed between the preoperative CSF mediator levels and preoperative pain profiles, the preoperative fractalkine level in the CSF showed a significant correlation with CPSP severity (Spearman's rho = -0.525; p = .002). Furthermore, multivariate linear regression analysis revealed that the preoperative PCS score (standardized β coefficient [β]: .11; 95% confidence interval [CI]: 0.06-0.16; p < .001) and CSF fractalkine level (β: -.62; 95% CI: -1.10 to -0.15; p = .012) were independent predictors of CPSP severity 6 months after TKA surgery.

CONCLUSIONS

We identified the CSF fractalkine level as a potential predictor for CPSP severity following TKA surgery. In addition, our study provided novel insights into the potential role of neuroinflammatory mediators in the pathogenesis of CPSP.

Latent characteristics and influencing factors of stigma in rheumatoid arthritis: A latent class analysis

To explore the latent classes of stigma in patients with rheumatoid arthritis, we analyzed the characteristics of the different categories. Adopting a convenient sampling method, socio-demographic and disease-related information from the outpatient clinics and wards of 3 tertiary care hospitals in China was collected. The Chinese version of the Internalized Stigma of Mental Illness scale-Rheumatoid Arthritis was used in this survey. Rheumatoid arthritis stigma was divided into 3 potential categories: Low Stigma-Strong Resistance (83, 41.5%), Medium Stigma-Strong Alienation (78, 39.0%), and High Stigma-Weak Resistance (39, 19.5%). Unordered multinomial logistic regression analysis showed that pain (OR = 1.540, P = .005; OR = 1.797, P < .001), elementary school education and below (OR = 4.051, P = .037), and duration of morning stiffness (OR = 0.267, P = .032) were risk factors for stigma, whereas family history was a protective factor against stigma (OR = 0.321, P = .046). Patients with longer morning stiffness, more severe pain, and less education have a greater risk of heavier stigma. Strong alienation is an early warning of heavy stigma. Resistance to stigma and family support can help patients overcome their psychological obstacles. More attention should be paid to constructing family centered support systems to help resist stigma.

Role of N-Methyl-D-Aspartate Receptor NR2B Subunit in Inflammatory Arthritis-Induced Chronic Pain and Peripheral Sensitized Neuropathic Pain: A Systematic Review

Arthritis is a common clinical disease that affects millions of people in the world. The most common types of arthritis are osteoarthritis and rheumatoid arthritis. Inflammatory arthritis (IA), a chronic painful disease, is characterized by synovitis and cartilage destruction in the early stages. Pathologically, IA causes inflammatory changes in the joints and eventually leads to joint destruction. Pain is associated with inflammation and abnormal regulation of the nervous system pathways involved in pain promotion and inhibition. In addition, the occurrence of pain is associated with depression and anxiety. We found that there are many factors affecting pain, in addition to inflammatory factors, glutamate receptor may be the possible cause of long-term chronic pain caused by IA. N-methyl-d-aspartate receptor subunit 2B (NR2B) has been reported to involved in IA and nervous system diseases, especially peripheral neuropathic pain. In this review, we summarized the mechanisms of the NR2B subunit of the N-methyl-D-aspartate (NMDA) receptor in peripheral nerve sensitization during IA and chronic pain.

Central nervous system monoaminergic activity in hip osteoarthritis patients with disabling pain: associations with pain severity and central sensitization

In patients with osteoarthritis undergoing total hip arthroplasty, higher cerebrospinal fluid concentrations of serotonin and dopamine metabolites are associated with increased pain severity and central sensitization.

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Diet and Chronic Non-Cancer Pain: The State of the Art and Future Directions

Nutrition plays an important role in pain management. Healthy eating patterns are associated with reduced systemic inflammation, as well as lower risk and severity of chronic non-cancer pain and associated comorbidities. The role of nutrition in chronic non-cancer pain management is an emerging field with increasing interest from clinicians and patients. Evidence from a number of recent systematic reviews shows that optimising diet quality and incorporating foods containing anti-inflammatory nutrients such as fruits, vegetables, long chain and monounsaturated fats, antioxidants, and fibre leads to reduction in pain severity and interference. This review describes the current state of the art and highlights why nutrition is critical within a person-centred approach to pain management. Recommendations are made to guide clinicians and highlight areas for future research.

Mechanistic Insight into the Effects of Curcumin on Neuroinflammation-Driven Chronic Pain

Chronic pain is a persistent and unremitting condition that has immense effects on patients' quality of life. Studies have shown that neuroinflammation is associated with the induction and progression of chronic pain. The activation of microglia and astrocytes is the major hallmark of spinal neuroinflammation leading to neuronal excitability in the projection neurons. Excessive activation of microglia and astrocytes is one of the major contributing factors to the exacerbation of pain. However, the current chronic pain treatments, mainly by targeting the neuronal cells, remain ineffective and unable to meet the patients' needs. Curcumin, a natural plant product found in the Curcuma genus, improves chronic pain by diminishing the release of inflammatory mediators from the spinal glia. This review details the role of curcumin in microglia and astrocytes both in vitro and in vivo and how it improves pain. We also describe the mechanism of curcumin by highlighting the major glia-mediated cascades in pain. Moreover, the role of curcumin on inflammasome and epigenetic regulation is discussed. Furthermore, we discuss the strategies used to improve the efficacy of curcumin. This review illustrates that curcumin modulating microglia and astrocytes could assure the treatment of chronic pain by suppressing spinal neuroinflammation.

Decreased pain sensitivity and alterations of cerebrospinal fluid and plasma inflammatory mediators after total hip arthroplasty in patients with disabling osteoarthritis

BACKGROUND

Proinflammatory mechanisms are implicated in pain states. Recent research indicates that patients with osteoarthritis (OA) with signs of central sensitization exhibit elevated cerebrospinal fluid (CSF) levels of interferon gamma-induced protein 10 (IP-10), Fms-related tyrosine kinase 1 (Flt-1), and monocyte chemoattractant protein 1 (MCP-1).

METHODS

The current prospective cohort study, including 15 patients with OA, primarily aimed to evaluate associations among alterations in CSF IP-10, Flt-1, MCP-1, and pain sensitization following total hip arthroplasty (THA). Participants provided CSF and blood samples for analysis of 10 proinflammatory mediators, and underwent detailed clinical examination and quantitative sensory testing, immediately preoperative and 18 months after surgery.

RESULTS

Neurophysiological measures of pain showed markedly reduced pain sensitivity long-term postoperative. Increases in remote site pressure pain detection thresholds (PPDTs) and decreased temporal summation indicated partial resolution of previous central sensitization. Compared to preoperative, CSF concentrations of IP-10 were increased (p = 0.041), whereas neither Flt-1 (p = 0.112) nor MCP-1 levels changed (p = 0.650). Compared to preoperative, plasma concentrations of IP-10 were increased (p = 0.006), whereas interleukin (IL)-8 was decreased (p = 0.023). Subjects who exhibited increases in arm PPDTs above median showed greater increases in CSF IP-10 compared to those with PPDT increases below median (p = 0.028). Analyses of plasma IP-10 and IL-8 indicated higher levels of peripheral inflammation were linked to decreased pressure pain thresholds (unadjusted β = -0.79, p = 0.006, and β = -118.1, p = 0.014, respectively).

CONCLUSIONS

THA leads to long-term decreases in pain sensitivity, indicative of resolution of sensitization processes. Changes in CSF and plasma levels of IP-10, and plasma IL-8, may be associated with altered pain phenotype.

Effect of perioperative use of parecoxib on chronic post-surgical pain in elderly patients after hepatectomy: a prospective randomized controlled study

Background

Chronic post-surgical pain (CPSP) has a negative impact on the recovery, quality of life, and physical functioning of elderly patients. This study aimed to test the superiority of parecoxib vs. placebo in preventing chronic post-hepatectomy pain in elderly patients under combined general-epidural anesthesia.

Methods

A total of 105 elderly patients undergoing hepatectomy under combined general-epidural anesthesia were randomized into the parecoxib or placebo group. The primary outcome was the proportion of patients with CPSP 3 months postoperatively. The secondary outcomes included the Short-Form McGill Pain Questionnaire score in CPSP-positive responders, acute pain intensity, postoperative analgesic demand, inflammatory markers change, and postoperative complications within 28 days.

Results

The parecoxib group provided a non-significant absolute 9.1% reduction in the rate of CPSP compared to the placebo group (P = 0.34). The average chronic pain visual analog scale in the parecoxib group was lower than that in the placebo group (P = 0.04). Significantly less moderate-to-severe acute pain at rest (P = 0.04) and with coughing (P < 0.001), less patient-controlled epidural analgesia (PCEA) consumption (P = 0.01), and less rescue analgesia (P < 0.001) were observed in the parecoxib group compared to the placebo group. Furthermore, no between-group difference was observed in inflammatory markers (P > 0.05) and postoperative complications (P = 0.65).

Conclusions

Parecoxib reduced the prevalence of CPSP in elderly patients after hepatectomy under combined general-epidural anesthesia from 44.4 to 35.3% with no statistical significance. Moreover, significantly alleviated CPSP intensity and improved acute pain management were observed.

Trial registration

This study was retrospectively registered in the Chinese Clinical Trial Registry (URL: http://www.chictr.org.cn/edit.aspx?pid=56961&htm=4) on August 3, 2020 (ChiCTR-2,000,035,198).

Supplementary Information

The online version contains supplementary material available at 10.1186/s40360-021-00501-1.

Chronic pain and neuroinflammation

In rheumatology, chronic pain most often sets in after a musculoskeletal injury. Its persistence is not always due to the progression of the initial injury, but in some cases to the onset of central sensitization. Much scientific data suggests that this central sensitization is caused by multiple complex interactions between the nervous system and immune system. Afferent nerve fibers carrying pain information are responsible for peripheral sensitization partly linked to inflammation molecules. These afferent fibers release neurotransmitters in the dorsal root ganglion and dorsal horn of the spinal cord, capable of activating microglia, which are the local immune cells. The activated microglia will produce pro-inflammatory cytokines, chemokines and neuropeptides capable of interacting with the second-order neuron, but also segmental and descending inhibitory neurons. This is referred to as neuroinflammation, which will amplify the hypersensitivity of second-order neurons, otherwise called central sensitization. This neuroinflammation will be able to reach the higher brain structures, which are involved in pain modulation and the emotional and cognitive aspects of pain. The aim of this update is to describe the pathophysiology of chronic pain, incorporating the latest scientific data on neuroplasticity and neuroinflammation.

Preoperative sleep quality and adverse pain outcomes after total hip arthroplasty

BACKGROUND

Sleep disturbance is thought to aggravate acute postoperative pain. The influence of preoperative sleep problems on pain control in the long-term and development of chronic postsurgical pain is largely unknown.

METHODS

This prospective, observational study aimed to examine the links between preoperative sleep disturbance (Pittsburgh Sleep Quality Index, PSQI) and pain severity (Brief Pain Inventory, BPI) 6 months postoperative (primary outcome), objective measures of pain and postoperative pain control variables (secondary outcomes). Patients (n = 52) with disabling osteoarthritis (OA) pain undergoing total hip arthroplasty (THA) were included. Quantitative sensory testing (QST) was performed preoperatively on the day of surgery to evaluate pain objectively. Clinical data, as well as measures of sleep quality and pain, were obtained preoperatively and longitudinally over a 6-month period.

RESULTS

Preoperatively, sleep disturbance (i.e., PSQI score >5) occurred in 73.1% (n = 38) of THA patients, and pain severity was high (BPI pain severity 5.4 ± 1.3). Regression models, adjusting for relevant covariates, showed that preoperative PSQI score predicted pain severity 6 months postoperative (β = 0.091 (95% CI 0.001-0.181), p = .048, R²  = 0.35). Poor sleep quality was associated with increased pressure pain sensitivity and impaired endogenous pain inhibitory capacity (R² range 0.14-0.33, all p's < 0.04). Moreover, preoperative sleep disturbance predicted increased opioid treatment during the first 24 hr after surgery (unadjusted β = 0.009 (95% CI 0.002-0.015) mg/kg, p = .007, R²  = 0.15).

CONCLUSIONS

Preoperative sleep disturbance is prevalent in THA patients, is associated with objective measures of pain severity, and independently predicts immediate postoperative opioid treatment and poorer long-term pain control in patients who have undergone THA.

SIGNIFICANCE

Poor sleep quality and impaired sleep continuity are associated with heightened pain sensitivity, but previous work has not evaluated whether preoperative sleep problems impact long-term postoperative pain outcomes. Here, we show that sleep difficulties prior to total hip arthroplasty adversely predict postoperative pain control 6 months after surgery. Given sleep difficulties robustly predict pain outcomes, targeting and improving sleep may have salutary effects on postoperative pain reports and management.