Significance of C-reactive protein in osteoarthritis and total knee arthroplasty outcomes

The Potential Role of Probiotics in the Management of Osteoarthritis Pain: Current Status and Future Prospects

PURPOSE OF REVIEW

This narrative review article comprehensively explains the pathophysiology of osteoarthritis (OA) pain perception, how the gut microbiota is correlated with it, possible molecular pathways involved in probiotics-mediated OA pain reduction, limitations in the current research approaches, and future perspectives.

RECENT FINDINGS

The initiation and progression of OA, including the development of chronic pain, is intricately associated with activation of the innate immune system and subsequent inflammatory responses. Trauma, lifestyle (e.g., obesity and metabolic disease), and chronic antibiotic treatment can disrupt commensal homeostasis of the human microbiome, thereby affecting intestinal integrity and promoting leakage of bacterial endotoxins and metabolites such as lipopolysaccharides (LPS) into circulation. Increased level of LPS is associated with knee osteophyte severity and joint pain. Both preclinical and clinical studies strongly suggest that probiotics may benefit patients with OA pain through positive gut microbiota modulation and attenuating low-grade inflammation via multiple pathways. Patent data also suggests increased interest in the development of new innovations that involve probiotic use for reducing OA and joint pain. Recent data suggest that probiotics are attracting more and more attention for OA pain management. The advancement of knowledge in this area may pave the way for developing different probiotic strains that can be used to support joint health, improve treatment outcomes in OA, and reduce the huge impact of the disease on healthcare systems worldwide.

The Relationship Between Echocardiographic Calcification Score and Grade of Knee Osteoarthritis

Background and objective It has been suggested that knee osteoarthritis (KOA) is associated with the development of calcification and an increased risk of cardiovascular (CV) disease, while the contribution of KOA grade is not clearly known enough. This study aimed to investigate the relationship between the grade of KOA, the echocardiographic calcification score (echo-CCS), and CV risk assessment. Methods This cross-sectional study involved 204 patients diagnosed with KOA and classified according to the Kellgren-Lawrence staging criteria. Echo-CCS was obtained according to the presence of calcification in the aortic valve, aortic root, mitral ring, papillary muscle and ventricular septum. Framingham risk score (FRS) was used for CV risk assessment. Results Calcification was detected in 79.4% of patients. The median FRS, echo-CCS, and high-sensitivity C-reactive protein (hs-CRP) levels increased as the KOA grade increased (p<0.05). A one-grade increase in KOA increased the odds of echo-CCS 1-2 group by 5.15 fold (vs. no calcification group) (OR=5.15, p=0.003), while it increased the odds of echo-CCS ≥3 group by 4.61 fold (vs. echo-CCS 1-2 group) (OR=4.61, p=0.003). Median echo-CSS and hs-CRP were higher in the high CV risk group than in the moderate and low CV risk groups. Conclusion The majority of patients with KOA had intracardiac calcification. An increased KOA grade was associated with higher echo-CSS and FRS. These findings indicate that patients with higher grades of KOA may be predisposed to developing subclinical atherosclerosis.

C-Reactive Protein: Pathophysiology, Diagnosis, False Test Results and a Novel Diagnostic Algorithm for Clinicians

The current literature provides a body of evidence on C-Reactive Protein (CRP) and its potential role in inflammation. However, most pieces of evidence are sparse and controversial. This critical state-of-the-art monography provides all the crucial data on the potential biochemical properties of the protein, along with further evidence on its potential pathobiology, both for its pentameric and monomeric forms, including information for its ligands as well as the possible function of autoantibodies against the protein. Furthermore, the current evidence on its potential utility as a biomarker of various diseases is presented, of all cardiovascular, respiratory, hepatobiliary, gastrointestinal, pancreatic, renal, gynecological, andrological, dental, oral, otorhinolaryngological, ophthalmological, dermatological, musculoskeletal, neurological, mental, splenic, thyroid conditions, as well as infections, autoimmune-supposed conditions and neoplasms, including other possible factors that have been linked with elevated concentrations of that protein. Moreover, data on molecular diagnostics on CRP are discussed, and possible etiologies of false test results are highlighted. Additionally, this review evaluates all current pieces of evidence on CRP and systemic inflammation, and highlights future goals. Finally, a novel diagnostic algorithm to carefully assess the CRP level for a precise diagnosis of a medical condition is illustrated.

Biomonitoring the skeletal muscle metabolic dysfunction in knee osteoarthritis in older adults: Is Jumpstart Nutrition® Supplementation effective?

Background

This study aimed to investigate the efficacy of Jumpstart Nutrition® dietary supplement (JNDS) for enhancing the skeletal muscle metabolism and function of older adults with knee osteoarthritis (KOA) by evaluating the biomarkers of aberrant levels of serum tumor necrosis factor-alpha (TNF-α), interleukin-10 (IL-10), C-reactive protein (CRP), creatine kinase-muscle (CK-MM), and aldolase-A (Aldo-A).

Methods

This twelve-week registry included 54 patients treated with JNDS mainly comprised of calcium, phosphorus, vitamin-K2, coenzyme-Q10, boswellic acid, and curcumin mixed with soy and whey protein (experimental group) and 51 patients treated with symptomatic slow-acting drugs for osteoarthritis (SYSADOA) (control group) for KOA confirmed with radiological images. At week 0 and week 12 for both the groups evaluated, the non-fasting serum levels of TNF-α, IL-10, CRP, CK-MM, and Aldo-A by using appropriate kits.

Results

At week-twelve, the respective values of area under the ROC curves of the studied biomarkers for pooled experimental cohorts were 0.928, 0.907, 0.908, 0.927, and 0.988 having the significance of accuracy (R-square):66.28%, 47.25%, 70.39%, 65.13%, and 68.00%, indicating a satisfactory treatment policy, their mean± SD, and risk ratio, all exhibited highly significant differences (p<0.0001) and KOA-gradation was upgraded between≥2 and ≥3 from≥4 as per the Kellgren-Lawrence scale compared to the control. Fewer patients had to use emergency medications (p<0.05).

Conclusions

Results suggest that JNDS may be effectively used to strengthen the skeletal muscle metabolism and function of elderly patients with KOA confirmed with the stabilization of studied biomarkers as an alternative to the treatment of SYSAD correlated with ROC curves and the Kellgren-Lawrence scale.

Correlation of Womac Index and Cytokine Values in Patients with OA Knee

Osteoarthritis (OA) of the knee (gonarthrosis) is a degenerative rheumatic disease, which is the most common rheumatic disease. Numerous factors, such as mechanical, enzymatic, and biological, are responsible for the development of this complex, multifactorial disease. The connection between inflammation and the development of knee OA is being investigated more and more. Cytokines are thought to be one of the main causes of disturbances in normal cartilage metabolism.

This study, designed as a prospective cohort study included 60 patients with knee OA. The examinees were recruited from total population of patients with knee OA, hospitalized or treated as outpatients at Department of Physical Medicine and Rehabilitation, University Clinical Centre Kragujevac. After the consent was obtained, anamnestic data were collected, blood samples were taken and functional testing was done together with anthropometric measurements. The values of the following cytokines were determined from a blood sample: IL-6, TNF-α, IL-10, IL-17. The average age of patients was 69.10±9.06 years, most of whom were females (78,3%). Both IL-6 and TNF-α correlated positively with WOMAC scores. WOMAC index subscales showed different association with cytokines. In our studies the level of cytocines in the serum of pacients with OA knee is show not correlation with radiographic image.

The present study demonstrated than the concentrations of proinflammatory cytokines (TNF-α IL-6) can be correlated with WOMAC scores of knee OA patients. The results indicate that concentrations of TNF-α and IL-6 may affect knee joint function in patients with knee OA.

Biochemical, clinical, demographic and imaging biomarkers for disease progression in knee osteoarthritis

Aim: To identify prognostic biomarker(s) for knee osteoarthritis (OA) in the Osteoarthritis Initiative (OAI) cohort. Methods: Multilevel regression was used to determine the association between baseline biomarkers and change in biomarkers from baseline to 24 months with clinical and radiographic OA progression over 48 months of follow-up. Results: Higher values of baseline urinary CTXII were consistently associated with an increased risk of OA disease progression outcomes: Kellgren & Lawrence grade (odds ratio [OR]: 1.15, 95% CI: 1.03-1.28); medial joint space narrowing (OR: 1.06, 95% CI: 1.02-1.10); lateral osteophytes (OR: 1.05, 95% CI: 1.01-1.10); joint space width (regression coefficient: -0.005, 95% CI: -0.008-0.001); and Western Ontario and McMaster Universities Arthritis Index pain scores (OR: 1.02, 95% CI: 1.01-1.04). Changes in serum PIIANP and serum COMP over 24 months were associated with clinical disease progression. Conclusion: Urinary CTXII showed stronger associations with radiographic OA and appears to be a reliable prognostic marker, while changes in other biomarkers were found in early symptomatic OA, supporting the phasic nature of OA.

Delayed normalization of C-Reactive protein and erythrocyte sedimentation rate was not associated with inferior clinical outcomes after total knee arthroplasty

BACKGROUND

The purpose of this study aimed to identify the proportion of patients with delayed normalization of C-reactive protein (CRP) and Erythrocyte sedimentation rate (ESR) after TKA, to determine postoperative thresholds predictive of prolonged elevation. Further, we aimed to determine if the clinical outcomes of patients with prolonged elevation were inferior to those without prolonged elevation.

METHODS

The records of 211 unilateral and 320 bilateral TKA were reviewed. Patients were divided into the normal and elevation group based on CRP and ESR levels at 6 weeks and 3 months. The temporal pattern of CRP and ESR change in both groups was compared, and thresholds predictive of elevation at 6 weeks and 3 months were identified. Further, the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index and Tegner activity scale of both groups at 6 months, 1 year, and 2 years after TKA were compared.

RESULTS

The proportion of patients with elevated CRP and ESR at 6 weeks and 3 months was CRP: 24.2%, 10%, ESR: 51.6%, 29.9% in unilateral and CRP: 31.5%, 10.6%, ESR: 58.1%, 42.7% in bilateral TKA. The thresholds for elevation at 6 weeks and 3 months were 9.5 mg/dL, 11.4 mg/dL (CRP at 6 weeks) and 81.5 mm/h, 74.5 mm/h (ESR at 3 months). There was no difference in the WOMAC score and Tegner activity scale between both groups.

CONCLUSIONS

CRP and ESR are often elevated for a prolonged period even in the absence of infection after TKA. Such cases show distinct temporal patterns, which are predictable, and do not appear to have a significant effect on clinical outcome.

Osteoarthritis is not a disease, but rather an accumulation of predisposing factors. A systematic review

Introduction: Although they do not endanger the life of the individual, the major symptoms of osteoarthritis (OA), such as pain, inflammation and dysfunction, it will slowly decrease quality of life and performance, leading finally to disabilities. Due to the fact that this disease has no cure, strategies are still being sought to slow its evolution. The lack of understanding of the predisposing and triggering factors of OA, has led to different approaches to this pathology so discussed, but with modest results. This systematic review aims to debate the main phenomena underlying joint destruction in OA, and etiopathogenic theories. Materials and Methods: In this study were included 58 bibliographic sources, of which title 39 refers to OA, 6 with inflammation, 28 with cartilage, 3 with chondrocytes, and 5 with synovitis. In this study were discussed the etiopathogenic theories of OA which include: age, alteration of the cartilaginous matrix, alteration of chondrocyte metabolism, microtrauma and major trauma, inflammation of the joints - synovitis and obesity. Results: Increasing the level of understanding of predisposing factors, the occurrence of acute inflammatory phenomenon and the perpetuation of mechanisms that latently maintain chronic inflammation that over time develops a destructive effect on articular cartilage, would limit the negative effects of OA, delay the evolution and optimally combat that maintain the vicious circle: inflammation → production of enzymes → chondrolysis → inflammation. Conclusions: These studies contribute significantly to the understanding of destructive phenomena in OA. More studies are needed on the risk factors of OA and its production mechanisms, to find increasingly effective therapies that limiting its progression. Keywords: Osteoarthritis, etiopathogenic theories, chronic inflammation, age, obesity, cartilaginous matrixm, chondrocyte metabolism

Patients With High Chronic Postoperative Knee Pain 5 Years After Total Knee Replacement Demonstrate Low-grad Inflammation, Impairment of Function, and High Levels of Pain Catastrophizing

OBJECTIVES

Total knee replacement (TKR) normally provides improvements of physical function and reduces pain. However, ∼20% of the patients report chronic postoperative knee pain. The aims of the present study were to assess the pain, physical function, and physiological characteristics 5 years after TKR surgery.

MATERIALS AND METHODS

Eighty patients were recruited 5 years after TKR and divided into 2 groups based on their average 24-hour knee pain intensity assessed on a visual analog scale (VAS 0 to 10) ("high pain group": VAS≥3; "low pain group": VAS<3). The patients completed the PainDETECT Questionnaire (PDQ), Oxford Knee Score (OKS), Pain Catastrophizing Scale, and Forgotten Joint Score-12. Furthermore, the patients underwent a clinical examination of the knees and high-sensitivity serum C-reactive protein was measured as an inflammatory marker.

RESULTS

A total of 53% of the patients in the high pain group were not satisfied with the outcome, while only 11% of the patients in the low pain group was not satisfied, and the pain intensities in the 2 groups were 5.1 (4.6 to 5 to 6) and 1.1 (0.6 to 1.5) (P<0.001), respectively. Furthermore, the high pain group demonstrates worse scores in: Forgotten Joint Score-12 (P=0.001), OKS function (P<0.001), OKS pain (P<0.001), and Pain Catastrophizing Scale (P<0.001).The high pain group demonstrated increased level of high-sensitivity serum C-reactive protein (4.3 mg/L [3.2 to 5.5] vs. 1.7 mg/L [1.2 to 2.2], P<0.001), and decreased range of motion in the knee (110 vs. 119-degree range of motion, P=0.013).

DISCUSSION

Patients with high chronic postoperative knee pain 5 years after TKR demonstrate decreased physical function, higher levels of catastrophizing thoughts, and increased levels of inflammation.

A warning machine learning algorithm for early knee osteoarthritis structural progressor patient screening

Aim

In osteoarthritis (OA) there is a need for automated screening systems for early detection of structural progressors. We built a comprehensive machine learning (ML) model that bridges major OA risk factors and serum levels of adipokines/related inflammatory factors at baseline for early prediction of at-risk knee OA patient structural progressors over time.

Methods

The patient- and gender-based model development used baseline serum levels of six adipokines, three related inflammatory factors and their ratios (36), as well as major OA risk factors [age and bone mass index (BMI)]. Subjects (677) were selected from the Osteoarthritis Initiative (OAI) progression subcohort. The probability values of being structural progressors (PVBSP) were generated using our previously published prediction model, including five baseline structural features of the knee, i.e. two X-rays and three magnetic resonance imaging variables. To identify the most important variables amongst the 47 studied in relation to PVBSP, we employed the ML feature classification methodology. Among five supervised ML algorithms, the support vector machine (SVM) demonstrated the best accuracy and use for gender-based classifiers development. Performance and sensitivity of the models were assessed. A reproducibility analysis was performed with clinical trial OA patients.

Results

Feature selections revealed that the combination of age, BMI, and the ratios CRP/MCP-1 and leptin/CRP are the most important variables in predicting OA structural progressors in both genders. Classification accuracies for both genders in the testing stage (OAI) were >80%, with the highest sensitivity of CRP/MCP-1. Reproducibility analysis showed an accuracy ⩾92%; the ratio CRP/MCP-1 demonstrated the highest sensitivity in women and leptin/CRP in men.

Conclusion

This is the first time that such a framework was built for predicting knee OA structural progressors. Using this automated ML patient- and gender-based model, early prediction of knee structural OA progression can be performed with high accuracy using only three baseline serum biomarkers and two risk factors.

Plain language summary

Machine learning model for early knee osteoarthritis structural progression Knee osteoarthritis is a well-known debilitating disease leading to reduced mobility and quality of life - the main causes of chronic invalidity. Disease evolution can be slow and span many years; however, for some individuals, the progression/evolution can be fast. Current treatments are only symptomatic and conventional diagnosis of osteoarthritis is not very effective in early identification of patients who will progress rapidly. To improve therapeutic approaches, we need a robust prediction model to stratify osteoarthritis patients at an early stage according to risk of joint structure disease progression.We hypothesize that a prediction model using a machine learning system would enable such an early identification of individuals for whom osteoarthritis knee structure will degrade rapidly. Data were from the Osteoarthritis Initiative, a National Institute of Health (United States) databank, and the robustness and generalizability of the developed model was further evaluated using osteoarthritis patients from an external cohort. Using the supervised machine learning system (support vector machine), we developed an automated patient- and gender-based model enabling an early clinical prognosis for individuals at high risk of structural progressive osteoarthritis. In brief, this model employed at baseline (when the subject sees a physician) easily obtained features consisting of the two main osteoarthritis risk factors, age and bone mass index (BMI), in addition to the serum levels of three molecules. Two of these molecules belong to a family of factors names adipokines and one to a related inflammatory factor. In brief, the model comprising a combination of age, BMI, and the ratios CRP/MCP-1 and leptin/CRP were found very robust for both genders, and the high accuracy persists when tested with an external cohort conferring the gender-based model generalizability. This study offers a new automated system for identifying early knee osteoarthritis structural progressors, which will significantly improve clinical prognosis with real time patient monitoring.

Effect Of E-OA-07 On Improving Joint Health And Mobility In Individuals With Knee Osteoarthritis: A Randomized, Double-Blind, Placebo-Controlled, Parallel Group Study

AIM

The aim of the present study was to evaluate the effect of E-OA-07 on individuals having osteoarthritis of the knee.

BACKGROUND

Lanconone® (E-OA-07) is a widely marketed dietary supplement which has been previously studied in different clinical settings for managing chronic joint pain. This was a confirmatory study planned at a lowered dose regimen with the purpose of improving compliance and reducing consumer cost.

METHODS

Male and female participants aged between 40 and 65 years, with history of joint pain for at least 3 years, were recruited. Knee joint dysfunction of grade II/III was radiographically characterized as per Kellgren-Lawrence system of classification. Enrolled participants were randomized to receive E-OA-07 at a dose of 1000 mg/day or placebo over a period of 8 weeks. The primary efficacy parameter was assessment of change in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain score. Whereas, the secondary parameters explored in the study included WOMAC subscales of stiffness and physical function, EQ-5D-5L questionnaire, systemic inflammatory marker (hs-CRP) and self-assessment of treatment satisfaction.

RESULTS

At the end of 8 weeks, joint pain severity as per WOMAC was found to be significantly reduced in the E-OA-07 group as compared to placebo (p<0.001). Similar improvement was observed in the subscales of stiffness and physical function which corresponds to significant improvement in the quality-of-life standards of E-OA-07 participants (p<0.001), reporting higher treatment satisfaction (p<0.001).

CONCLUSION

E-OA-07 at a dose of 1000 mg/day was able to significantly reduce joint pain and thereby improve joint mobility in study participants. At the end of the study period, there was a clinically relevant change of 45.55%, 45.91% and 38.19% for pain, stiffness and physical function, respectively. Moving forward, studies could be planned for understanding the cartilage regenerative properties of E-OA-07.

Dietary magnesium intake, serum high sensitivity C-reactive protein and the risk of incident knee osteoarthritis leading to hospitalization-A cohort study of 4,953 Finns

Objectives

To study whether low dietary magnesium (Mg) intake and serum high sensitivity C-reactive protein (hs-CRP) predict the development of clinical knee osteoarthritis (OA).

Methods

The cohort consisted of 4,953 participants of a national health examination survey who were free of knee and hip OA at baseline. Information on the incidence of knee OA leading to hospitalization was drawn from the National Care Register for Health Care. During the follow-up of 10 years, 123 participants developed incident knee OA. Dietary magnesium intake was assessed on the basis of a food frequency questionnaire from the preceding year. We used Cox’s proportional hazards model to estimate the strength of the association between the tertiles of dietary Mg intake and incident knee OA, adjusted for baseline age, gender, energy intake, BMI, history of physical workload, leisure time physical activity, injuries, knee complaints, the use of Mg supplements, and serum hs-CRP levels.

Results

At baseline, dietary Mg intake was inversely associated with serum hs-CRP even after adjustment for all the potential confounding factors. During the follow-up, the adjusted hazard ratios (with their 95% confidence intervals) for incident knee OA in dietary Mg intake tertiles were 1.00, 1.28 (0.78–2.10), and 1.38 (0.73–2.62); the p value for trend was 0.31. Serum hs-CRP level at baseline did not predict incident knee OA.

Conclusions

The results do not support the hypothesis that low dietary Mg intake contributes to the development of clinical knee OA, although Mg intake is inversely associated with serum hs-CRP level.

Association between serum magnesium concentration and metabolic syndrome, diabetes, hypertension and hyperuricaemia in knee osteoarthritis: a cross-sectional study in Hunan Province, China

OBJECTIVES

To examine the associations between serum magnesium (Mg) concentration with the prevalence of metabolic syndrome (MetS), diabetes mellitus (DM), hypertension (HP) and hyperuricaemia (HU) in patients with radiographic knee osteoarthritis (OA).

METHODS

The present study was conducted at the Health Management Center of Xiangya Hospital. Radiographic OA was evaluated for patients aged over 40 years with basic characteristics and blood biochemical assessment. Serum Mg concentration was measured using the chemiluminescence method. MetS, DM, HP and HU were diagnosed based on standard protocols. The associations between serum Mg concentration with MetS, DM, HP and HU were evaluated by conducting multivariable adjusted logistic regression.

RESULTS

A total of 962 patients with radiographic knee OA were included. Compared with the lowest quintile, the multivariable adjusted ORs and related 95% CIs of DM were 0.40 (95% CI 0.23 to 0.70, p=0.001), 0.33 (95% CI 0.18 to 0.60, p<0.001), 0.27 (95% CI 0.14 to 0.52, p<0.001) and 0.22 (95% CI 0.11 to 0.44, p<0.001) in the second, third, fourth and highest quintiles of serum Mg, respectively (p for trend <0.001); the multivariable adjusted ORs of HU were 0.33 (95% CI 0.19 to 0.59, p<0.001), 0.52 (95% CI 0.30 to 0.91, p=0.022) and 0.39 (95% CI 0.22 to 0.70, p=0.001) in the third, fourth and highest quintiles of serum Mg, respectively (p for trend <0.001); and the multivariable adjusted ORs of MetS were 0.59 (95% CI 0.36 to 0.94, p=0.027) in the second and 0.56 (95% CI 0.34 to 0.93, p=0.024) in the highest quintiles of serum Mg. However, the inverse association between serum Mg and the prevalence of MetS was non-linear (p for trend=0.067). There was no significant association between serum Mg and HP in patients with OA.

CONCLUSIONS

The serum Mg concentration was inversely associated with the prevalence of MetS, DM and HU in patients with radiographic knee OA.

LEVEL OF EVIDENCE

Level III, cross-sectional study.

The effect of probiotic Lactobacillus casei Shirota on knee osteoarthritis: a randomised double-blind, placebo-controlled clinical trial

Knee osteoarthritis (OA) treatment is challenging due to inefficacy and adverse effects of current medications. Probiotic treatment has been shown to promote bone metabolism, reduce pain and inflammatory responses of age-related musculoskeletal disorders, including OA. We aimed to investigate the effect of probiotic Lactobacillus casei Shirota (LcS) on patients with knee OA. 537 patients with knee OA were enrolled in this double-blind, placebo-controlled trial, who were randomised to receive skimmed milk containing either LcS or placebo daily for 6 months. Primary outcome was defined as changes in WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) and VAS (visual analog scale) scores. Secondary outcome was defined as changes in serum levels of high sensitivity C-reactive protein (hs-CRP). After 6 months of treatment, both WOMAC and VAS scores were significantly improved in the LcS groups of patients compared to the placebo group. Serum levels of hs-CRP were also significantly lower in patients receiving LcS than placebo. Strong linear correlations were observed between serum hs-CRP levels and WOMAC and VAS scores. LcS consumption could serve as a novel therapeutic option in the clinical management of knee OA, improving treatment outcome likely through reducing serum hs-CRP levels.

Levels of serum biomarkers from a two-year multicentre trial are associated with treatment response on knee osteoarthritis cartilage loss as assessed by magnetic resonance imaging: an exploratory study

Background

There is an obvious need to identify biomarkers that could predict patient response to an osteoarthritis (OA) treatment. This post hoc study explored in a 2-year randomized controlled trial in patients with knee OA, the likelihood of some serum biomarkers to be associated with a better response to chondroitin sulfate in reducing cartilage volume loss.

Methods

Eight biomarkers were studied: hyaluronic acid (HA), C reactive protein (CRP), adipsin, leptin, N-terminal propeptide of collagen IIα (PIIANP), C-terminal crosslinked telopeptide of type I collagen (CTX-1), matrix metalloproteinase-1 (MMP-1), and MMP-3. Patients were treated with chondroitin sulfate (1200 mg/day; n = 57) or celecoxib (200 mg/day; n = 62). Serum biomarkers were measured at baseline. The cartilage volume at baseline and its loss at 2 years were assessed by quantitative magnetic resonance imaging (MRI). Statistical analysis included analysis of covariance.

Results

As data from the original MOSAIC trial showed no differences in cartilage volume and loss in the lateral compartment of the knee joint between the two treatment groups in any comparison, only the medial compartment and its subregions were studied. Stratification according to the median biomarker levels was used to discriminate treatment effect. In patients with levels of biomarkers of inflammation (HA, leptin and adipsin) lower than the median, those treated with chondroitin sulfate demonstrated less cartilage volume loss in the medial compartment, condyle, and plateau (p ≤ 0.047). In contrast, patients treated with chondroitin sulfate with higher levels of MMP-1 and MMP-3, biomarkers of cartilage catabolism, had less cartilage volume loss in the medial compartment, condyle, and plateau (p ≤ 0.050). Patients with higher levels of PIIANP and CTX-1, biomarkers related to collagen anabolism and bone catabolism, respectively, had reduced cartilage volume loss in the medial condyle (p ≤ 0.026) in the chondroitin sulfate group.

Conclusion

This study is suggestive of a potentially greater response to chondroitin sulfate treatment on cartilage volume loss in patients with knee OA with low level of inflammation and/or greater level of cartilage catabolism.

Trial registration

This is a post hoc study. Original trial registration: ClinicalTrials.gov, NCT01354145. Registered on 13 May 2011. 

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-017-1377-y) contains supplementary material, which is available to authorized users.

Alteration of inflammatory cytokine production in primary total knee arthroplasty using antibiotic-loaded bone cement

Background

The aim was to compare serum levels of interleukin-6 (SIL6), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and joint fluid IL-6 (JIL-6) level between total knee arthroplasty (TKA) that used bone cement (BC group) and antibiotic-loaded bone cement (ALBC group).

Materials and methods

Thirty-nine patients (40 TKAs) with a mean age of 69.6 years were non-randomly assigned to the BC or ALBC groups. Samples of SIL6, ESR, and CRP were collected at baseline and at 24 h, 72 h, and 4 weeks after surgery. JIL-6 levels were collected intraoperatively before joint arthrotomy, before finishing the procedure and 24 h after surgery. Postoperative mediator levels were compared with baseline levels within the same group and between groups at each time point. Knee Society Score-knee (KSSK) and Knee Society Score-function (KSSF) scores were evaluated.

Results

SIL-6, ESR, and CRP levels were significantly elevated at 24 and 72 h, compared to baseline. Only SIL-6 levels at 72 h in the ALBC group showed a significantly lower level than those in the BC group. JIL-6 levels were not different between groups. There were no significant differences in KSSK or KSSF scores between groups at 4 weeks and the most recent follow-up (1.4 ± 0.6 years) evaluation. No correlations were identified among SIL-6 and JIL-6 levels at 24 and 72 h, and KSSK and KSSF scores at 4 weeks and at the most recent evaluation.

Conclusions

ALBC showed a favorable immunomodulatory effect and lower SIL-6 level at 72 h following TKA compared to BC, although functional benefits require further investigation.

Level of evidence

OCEBM, Level 3.

Towards an understanding of the painful total knee: what is the role of patient biology?

Total knee arthroplasty (TKA) remains the treatment of choice for end-stage osteoarthritis of the knee. With an aging population, the demand for TKA continues to increase, placing a significant burden on a health care system that must function with limited resources. Although generally accepted as a successful procedure, 15-30 % of patients report persistent pain following TKA. Classically, pain generators have been divided into intra-articular and extra-articular causes. However, there remains a significant subset of patients for whom pain remains unexplained. Recent studies have questioned the role of biology (inflammation) in the persistence of pain following TKA. This article aims to serve as a review of previously identified causes of knee pain following TKA, as well as to explore the potential role of biology as a predictor of pain following knee replacement surgery.

Associations of cigarette smoking, betel quid chewing and alcohol consumption with high-sensitivity C-reactive protein in early radiographic knee osteoarthritis: a cross-sectional study

OBJECTIVES

High-sensitivity C-reactive protein (hsCRP) is possibly related to osteoarthritis (OA) progression and a variety of OA-related symptoms. This study aimed to examine associations between cigarette smoking, betel quid chewing and alcohol consumption and hsCRP in early radiographic knee OA.

DESIGN

Cross-sectional health examination survey.

SETTING

This primary study was conducted in a health examination centre in China.

PARTICIPANTS

936 (656 men and 280 women) patients with early radiographic knee OA were included in this cross-sectional study.

PRIMARY AND SECONDARY OUTCOME MEASURES

Smoking status was classified into four levels based on daily smoking habit: 0/day, 1-10/day, 11-20/day and >20/day. Betel quid chewing and alcohol consumption status was divided into 'Yes' or 'No'. Early radiographic knee OA was defined as Kellgren Lawrence (K-L) grade 1 or 2 in at least one leg, and elevated hsCRP was assessed as ≥ 3.0 mg/L.

RESULTS

After adjustment for a number of potential confounding factors, a significant positive association between cigarette smoking and hsCRP was observed in the multivariable model. The multivariable-adjusted ORs (95% CI) of elevated hsCRP (≥ 3.0 mg/L) in the second (1-10/day, n=133), third (11-20/day, n=59) and highest (>20/day, n=104) cigarette smoking categories were 1.54 (95% CI 0.91 to 2.61), 1.27 (95% CI 0.57 to 2.79) and 2.09 (95% CI 1.20 to 3.64), respectively, compared with the non-smoker category (n=640). In addition, there was a positive dose-response relationship between cigarette smoking and elevated hsCRP (p for trend=0.01). No significant associations between betel quid chewing and alcohol consumption and hsCRP were observed in the multivariable model.

CONCLUSIONS

This study indicated that cigarette smoking was positively associated with serum hsCRP level in patients with early radiographic knee OA. However, in view of the nature of cross-sectional designs, the results need to be confirmed by further prospective studies.

Determinants of pain in patients with symptomatic knee osteoarthritis

BACKGROUND

Several factors are associated with the development or exacerbation of pain in knee osteoarthritis (KOA). In this study, we reviewed this context based on relevant studies.

METHODS

Recent published studies which have addressed the relationship between pain and KOA were summarized.

RESULTS

Correlates of the clinical, demographic features, laboratory tests and abnormalities on radiographic as well as magnetic resonance imaging (MRI) with the knee pain have been discussed. The results indicated that many factors such as synovitis, synovial effusion, obesity, as well as structural lesions determined by MRI or radiographic examination, serum cytokines, inflammatory markers are determinants of pain in KOA.

CONCLUSION

This context requires further investigations for identification of additional factors which initiate pain in asymptomatic KOA.

Development of an Experimental Animal Model for Lower Back Pain by Percutaneous Injury-Induced Lumbar Facet Joint Osteoarthritis

We report generation and characterization of pain-related behavior in a minimally invasive facet joint degeneration (FJD) animal model in rats. FJD was produced by a non-open percutaneous puncture-induced injury on the right lumbar FJs at three consecutive levels. Pressure hyperalgesia in the lower back was assessed by measuring the vocalization response to pressure from a force transducer. After hyperalgesia was established, pathological changes in lumbar FJs and alterations of intervertebral foramen size were assessed by histological and imaging analyses. To investigate treatment options for lumber FJ osteoarthritis-induced pain, animals with established hyperalgesia were administered with analgesic drugs, such as morphine, a selective COX-2 inhibitor, a non-steroidal anti-inflammatory drug (NSAID) (ketorolac), or pregabalin. Effects were assessed by behavioral pain responses. One week after percutaneous puncture-induced injury of the lumbar FJs, ipsilateral primary pressure hyperalgesia developed and was maintained for at least 12 weeks without foraminal stenosis. Animals showed decreased spontaneous activity, but no secondary hyperalgesia in the hind paws. Histopathological and microfocus X-ray computed tomography analyses demonstrated that the percutaneous puncture injury resulted in osteoarthritis-like structural changes in the FJs cartilage and subchondral bone. Pressure hyperalgesia was completely reversed by morphine. The administration of celecoxib produced moderate pain reduction with no statistical significance while the administration of ketorolac and pregabalin produced no analgesic effect on FJ osteoarthritis-induced back pain. Our animal model of non-open percutanous puncture-induced injury of the lumbar FJs in rats shows similar characteristics of low back pain produced by human facet arthropathy.

Current and future trends in biomarker discovery and development of companion diagnostics for arthritis

Musculoskeletal diseases such as rheumatoid arthritis are complex multifactorial disorders that are chronic in nature and debilitating for patients. A number of drug families are available to clinicians to manage these disorders but few tests exist to target these to the most responsive patients. As a consequence, drug failure and switching to drugs with alternate modes of action is common. In parallel, a limited number of laboratory tests are available which measure biological indicators or 'biomarkers' of disease activity, autoimmune status, or joint damage. There is a growing awareness that assimilating the fields of drug selection and diagnostic tests into 'companion diagnostics' could greatly advance disease management and improve outcomes for patients. This review aims to highlight: the current applications of biomarkers in rheumatology with particular focus on companion diagnostics; developments in the fields of proteomics, genomics, microbiomics, imaging and bioinformatics and how integration of these technologies into clinical practice could support therapeutic decisions.

Republished: Value of biomarkers in osteoarthritis: current status and perspectives

Osteoarthritis affects the whole joint structure with progressive changes in cartilage, menisci, ligaments and subchondral bone, and synovial inflammation. Biomarkers are being developed to quantify joint remodelling and disease progression. This article was prepared following a working meeting of the European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis convened to discuss the value of biochemical markers of matrix metabolism in drug development in osteoarthritis. The best candidates are generally molecules or molecular fragments present in cartilage, bone or synovium and may be specific to one type of joint tissue or common to them all. Many currently investigated biomarkers are associated with collagen metabolism in cartilage or bone, or aggrecan metabolism in cartilage. Other biomarkers are related to non-collagenous proteins, inflammation and/or fibrosis. Biomarkers in osteoarthritis can be categorised using the burden of disease, investigative, prognostic, efficacy of intervention, diagnostic and safety classification. There are a number of promising candidates, notably urinary C-terminal telopeptide of collagen type II and serum cartilage oligomeric protein, although none is sufficiently discriminating to differentiate between individual patients and controls (diagnostic) or between patients with different disease severities (burden of disease), predict prognosis in individuals with or without osteoarthritis (prognostic) or perform so consistently that it could function as a surrogate outcome in clinical trials (efficacy of intervention). Future avenues for research include exploration of underlying mechanisms of disease and development of new biomarkers; technological development; the ‘omics’ (genomics, metabolomics, proteomics and lipidomics); design of aggregate scores combining a panel of biomarkers and/or imaging markers into single diagnostic algorithms; and investigation into the relationship between biomarkers and prognosis.

Type X collagen levels are elevated in serum from human osteoarthritis patients and associated with biomarkers of cartilage degradation and inflammation

Background

Osteoarthritis (OA) is the most common degenerative joint disease, of which the pathogenesis is inadequately understood. Hypertrophy-like changes have been observed as part of the progression of OA. The aim of the study was to develop and characterize a novel biomarker of chondrocytes hypertrophy and investigate how this marker was associated with cartilage degradation and inflammation in patients with various degrees of OA.

Methods

A competitive ELISA, C-Col10, applying a well-characterized monoclonal antibody was developed as a biomarker of chondrocyte hypertrophy through measurement of type X collagen (ColX). The levels of C-Col10, C2M (matrix metalloproteinase-derived fragments of type II collagen) and hsCRP (high sensitive C-reactive protein) were quantified by ELISAs in serum of 271 OA patients stratified by Kellgren-Lawrence (KL) score 0–4. Associations between serum levels of the three biomarkers (log transformed) were analyzed by Pearson’s correlation and differences in C-Col10 levels between patients with high and low levels of inflammation measured by hsCRP were analyzed by ANOVA.

Results

We developed a C-Col10 assay measuring the C-terminus of ColX. We found significantly higher levels of ColX in patients with KL score 2 compared to patients with no radiographic evidence of OA (KL0) (p = 0.04). Levels of ColX were significantly elevated in OA patients with above normal hsCRP levels (p < 0.0001), as well as significantly correlated with levels of C2M (r = 0.55, p < 0.0001), which suggested that chondrocyte hypertrophy was associated with inflammation and cartilage degradation. There was no correlation between C2M and hsCRP. Age and BMI adjustment didn’t change the results. Immuno-staining revealed that ColX was predominately located around the hypertrophic chondrocytes and the clustered chondrocytes indicating that C-Col10 measures may be linked to cartilage hypertrophic changes.

Conclusions

We developed a novel assay, C-Col10, for measurement of chondrocyte hypertrophy and found its levels significantly elevated in OA patients with KL score of 2, and also in OA patients with above normal hsCRP levels. Concentration of C-Col10 strongly correlated with levels of C2M, a marker of cartilage destruction. The data suggest that chondrocyte hypertrophy and subsequent collagen X fragmentation seem to be increased in a subset of patients with inflammatory OA.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2474-15-309) contains supplementary material, which is available to authorized users.

Converting between high- and low-sensitivity C-reactive protein in the assessment of periprosthetic joint infection

Although low-sensitivity CRP (Ls-CRP) is an important tool for evaluating infected orthopedic prostheses, no clinical studies have evaluated whether Hs-CRP is a suitable surrogate for Ls-CRP or other traditional infection biomarkers. The laboratory data of 98 arthroplasty patients with suspected prosthetic infection were reviewed. Hs-CRP was highly correlated with Ls-CRP (R = 0.93). ROC analysis generated 100% sensitivity and 97% specificity for both Hs-CRP and Ls-CRP at optimal cutoffs of 28.6 and 2.6 mg/dL, respectively. Both CRP tests were more accurate than serum erythrocyte sedimentation rate, neutrophil differential, and white blood cell count. Hs-CRP was no different from Ls-CRP after unit conversion, and regression analyses suggested conversion factors that approximated 10. Hs-CRP and Ls-CRP have equivalent utility in the diagnosis of infected joint arthroplasty.

Calcium fructoborate helps control inflammation associated with diminished bone health

Inflammation has been identified as a possible contributory factor to disruption of the normal bone remodeling process, a process essential to healthy bone mineral density. Several large population-based clinical studies have specifically shown that levels of C-reactive protein, an immune recognition protein that is a sensitive marker of inflammation, are inversely and independently associated with total bone mineral density. The evidence suggests that control of C-reactive protein levels may contribute to bone health by protecting against inflammation's disruption of the equilibrium between bone resorption and bone deposition. Calcium fructoborate, a patented complex of calcium, fructose, and boron found naturally in fresh and dried fruits, vegetables and herbs, and wine, is a sugar-borate ester. A growing body of peer-reviewed, published clinical research indicates that the calcium fructoborate significantly reduces serum levels of the C-reactive protein in humans, suggesting that this unique plant-mineral complex may contribute to bone health by controlling the inflammation associated with loss of bone mineral density.

Joint and bone assessment in hand osteoarthritis

Hand osteoarthritis (OA) is a common disease frequently affecting middle-aged women. Prevalence estimates for OA vary widely depending on the age and sex of the population studied, the assessment tools used, and the specific joint sites analyzed OA is characterized by the degradation of articular cartilage, subchondral bone changes and osteophyte formation at the joint margins leading to joint failure. The pathogenesis of the disease and its evolution are multifactorial involving biomechanical, metabolic, hormonal, and genetic factors. Moreover, the role of inflammation has recently been advanced as pivotal in OA onset and progression. In particular, an uncommon variant of hand OA, erosive hand OA, is characterized by inflammatory and degenerative interphalangeal proximal and distal joints. The diagnosis of different types of hand OA is centered on clinical and laboratory investigations which can distinguish the peculiar aspects of these forms. Joint and bone assessments in hand OA are widely studied but there is no agreement with regard to established parameters to make a definitive diagnosis. This report focuses on the laboratory and clinimetric assessments that can be used to distinguish hand OA subtypes and addresses the debatable association with low bone mineral density in osteoporosis.

Value of biomarkers in osteoarthritis: current status and perspectives

Osteoarthritis affects the whole joint structure with progressive changes in cartilage, menisci, ligaments and subchondral bone, and synovial inflammation. Biomarkers are being developed to quantify joint remodelling and disease progression. This article was prepared following a working meeting of the European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis convened to discuss the value of biochemical markers of matrix metabolism in drug development in osteoarthritis. The best candidates are generally molecules or molecular fragments present in cartilage, bone or synovium and may be specific to one type of joint tissue or common to them all. Many currently investigated biomarkers are associated with collagen metabolism in cartilage or bone, or aggrecan metabolism in cartilage. Other biomarkers are related to non-collagenous proteins, inflammation and/or fibrosis. Biomarkers in osteoarthritis can be categorised using the burden of disease, investigative, prognostic, efficacy of intervention, diagnostic and safety classification. There are a number of promising candidates, notably urinary C-terminal telopeptide of collagen type II and serum cartilage oligomeric protein, although none is sufficiently discriminating to differentiate between individual patients and controls (diagnostic) or between patients with different disease severities (burden of disease), predict prognosis in individuals with or without osteoarthritis (prognostic) or perform so consistently that it could function as a surrogate outcome in clinical trials (efficacy of intervention). Future avenues for research include exploration of underlying mechanisms of disease and development of new biomarkers; technological development; the ‘omics’ (genomics, metabolomics, proteomics and lipidomics); design of aggregate scores combining a panel of biomarkers and/or imaging markers into single diagnostic algorithms; and investigation into the relationship between biomarkers and prognosis.