Relationship between radiographic grading of osteoarthritis and the biochemical markers for arthritis in knee osteoarthritis

Decreased Synovial Fluid Ghrelin Level Is Associated With Acute Cartilage Injury in Patients With Anterior Cruciate Ligament Tear

Background

Ghrelin, an amino acid hormone secreted primarily from the stomach, can regulate bone metabolism, regulate inflammation via suppressing proinflammatory cytokines, and suppress expression of matrix metalloproteinases (MMPs).

Purpose

To measure synovial fluid levels of ghrelin in young patients with anterior cruciate ligament (ACL) tear to assess the role of ghrelin as a potential biomarker for cartilage injury.

Study Design

Controlled laboratory study.

Methods

This study included 120 patients who underwent ACL reconstructionbetween January 1, 2016, and May 31, 2021. We categorized 60 patients with acute cartilage injury (International Cartilage Regeneration & Joint Preservation Society grade 2 or 3) as the acute group and 60 patients with no acute cartilage injury as the nonacute group, with the healthy contralateral knee of each patient acting as the control group (n = 120). Synovial fluid samples were collected from the knees in the operating room before ACL reconstruction. We assessed the inflammatory biomarkers interleukin (IL)-6, MMP-1, MMP-9, and MMP-13, as well as serum ghrelin level and Mankin score, and results were compared between the 3 study groups with the Mann-Whitney U test.

Results

Lower serum ghrelin levels in the synovial fluid were found in the acute group compared with the nonacute group and healthy controls (232.4 vs 434.4 vs 421.5 pg/mL, respectively; P < .001). Ghrelin level in the synovial fluid was significantly and positively correlated with IL-6 (r = 0.4223; P < .0001), MMP-13 (r = 0.3402; P < .0001), and Mankin score (r = 0.1453; P = .0244).

Conclusion

In patients with ACL injury, ghrelin synovial fluid was significantly differently expressed in patients with cartilage injury and no cartilage injury.

Clinical Relevance

Ghrelin synovial fluid has the potential to be a biomarker to predict acute cartilage injury in patients with ACL injury.

Clinical Efficacy of Glucosamine plus Sodium Hyaluronate for Osteoporosis Complicated by Knee Osteoarthritis and Its Influence on Joint Function and Bone Metabolic Markers

Background. Osteoporosis (OP) associated with knee osteoarthritis (KOA) is common in older men and postmenopausal women, and it is important to find reliable and effective treatments for this disease to improve joint function and bone metabolism in this population. Objective. To clarify the clinical efficacy of glucosamine (GlcN) plus sodium hyaluronate (SH) for OP complicated by KOA (OP + KOA) and its influence on joint function and bone metabolic markers (BMMs). Methods. Admitted from July 2019 to July 2021, 126 patients with OP + KOA were selected, including 76 cases (observation group) treated with GlcN plus SH and 50 cases (control group) given GlcN alone. The pain, joint function, BMMs, and clinical efficacy were evaluated and compared. Pain and joint function assessments employed the Visual Analogue Scale (VAS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) plus Lysholm Knee Scoring Scale, respectively. BMMs mainly measured bone gla protein (BGP), serum tartrate-resistant acid phosphatase variant (TRACP)-5b, type I collagen cross-linked C-telopeptide (CTX-1), and bone-specific alkaline phosphatase (BALP). Results. Higher posttreatment VAS scores were determined in observation group as compared to control group; observation group showed lower WOMAC scores of joint function and higher Lysholm scores than control group; in terms of BMMs, TRACP-5b and CTX-1 were lower while BGP and BALP were higher in observation group; the curative effect was also higher in observation group. All the above differences were statistically significant. Conclusions. GlcN plus SH has definite clinical efficacy in the treatment of OP + KOA, which can not only significantly improve patients’ joint function and bone metabolism but also relieve pain, with high clinical popularization value.

Overcoming barriers for intra-articular delivery of disease-modifying osteoarthritis drugs

Despite four decades of research in intra-articular drug delivery systems (DDS) and two decades of advances in disease-modifying osteoarthritis drugs (DMOADs), there is still no clinically available disease-modifying therapy for osteoarthritis (OA). Multiple barriers compromise intra-articular DMOAD delivery. Although multiple exciting approaches have been developed to overcome these barriers, there are still outstanding questions. We make several recommendations that can help in fully overcoming these barriers. Considering OA heterogeneity, we also propose a patient-centered, bottom-up workflow to guide preclinical development of DDS-based intra-articular DMOAD therapies. Overall, we expect this review to inspire paradigm-shifting innovations for developing next-generation DDS that can enable clinical translation of intra-articular DMOADs.

Emerging microfluidics-enabled platforms for osteoarthritis management: from benchtop to bedside

Osteoarthritis (OA) is a prevalent debilitating age-related joint degenerative disease. It is a leading cause of pain and functional disability in older adults. Unfortunately, there is no cure for OA once the damage is established. Therefore, it promotes an urgent need for early detection and intervention of OA. Theranostics, combining therapy and diagnosis, emerges as a promising approach for OA management. However, OA theranostics is still in its infancy. Three fundamental needs have to be firstly fulfilled: i) a reliable OA model for disease pathogenesis investigation and drug screening, ii) an effective and precise diagnostic platform, and iii) an advanced fabrication approach for drug delivery and therapy. Meanwhile, microfluidics emerges as a versatile technology to address each of the needs and eventually boost the development of OA theranostics. Therefore, this review focuses on the applications of microfluidics, from benchtop to bedside, for OA modelling and drug screening, early diagnosis, and clinical therapy. We first introduce the basic pathophysiology of OA and point out the major unfilled research gaps in current OA management including lack of disease modelling and drug screening platforms, early diagnostic modalities and disease-modifying drugs and delivery approaches. Accordingly, we then summarize the state-of-the-art microfluidics technology for OA management from in vitro modelling and diagnosis to therapy. Given the existing promising results, we further discuss the future development of microfluidic platforms towards clinical translation at the crossroad of engineering and biomedicine.

Periprosthetic infection risks and predictive value of C-reactive protein / albumin ratio for total joint arthroplasty

Background and aim:

There are no gold standard markers to estimate the risk of developing periprosthetic infections. Our aim is to compare the risks of periprosthetic infection in patients with THA and THA and to investigate the predictive significance of the CRP / albumin ratio.

Methods:

This is a retrospective study containing data from 241 osteoarthritis patients and 19 patients with periprosthetic infections who underwent TKA and THA in our hospital from January 2014 to January 2019.12 risk factors(CRP/ albumin, albumin, CRP, age, gender, BMI, DM, ASA, nasal culture, urine culture, hospital stay, operation time) were analyzed.

Results:

In the binary logistic regression model and multivariate regression analysis, the rate of CRP / albumin was 17.161 times higher than the patients with ≤0.16 cut-off value. (CRP / albumin ratio (odds ratio (OR) = 17.16, 95% CI: 1.55-189.03, P: 0.02). High BMI increased the risk of periprosthetic infection 1.3 times. Nasal bacterial colonization (OR = 0.99, 95% CI: 0.868-1.38, P: 0.7) and bacterium in urine (OR = 0.502, 95% CI: 0.07-3.598, P: 0.703) did not pose a significant risk for periprosthetic infection.

Conclusion:

According to our findings, the CRP / albumin ratio has a more prognostic capacity than other risks in determining the risk of periprosthetic infection for total joint arthroplasty. CRP / albumin ratio is a cheap and easy to apply marker. Routine urine and nasal bacteria screening is not required before total joint arthroplasty.

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.

Level of Adiponectin, Leptin and Selected Matrix Metalloproteinases in Female Overweight Patients with Primary Gonarthrosis

The aim of this study was to assess levels of adiponectin (ACRP-30) and leptin in serum and synovial fluid (SF) of overweight females with primary gonarthrosis (GOA) and to look for their correlations with clinical status and the level of biochemical OA biomarkers: matrix metalloproteinase (MMP) 1, MMP-9 and tissue inhibitor of metalloproteinase (TIMP-1). The studied group consisted of 39 overweight females undergoing primary total knee arthroplasty as a result of GOA. The stage of GOA was evaluated according to Knee Society Score (KSS), Ahlbäck and Kellgren–Lawrence (K-L) scores. Peripheral blood and SF were obtained. Levels of selected biomarkers were assessed using ELISA kits. The mean level of ACRP-30 in serum valued were 8393.80 ng/mL and in SF, 774.33 ng/mL, the mean concentration of leptin in serum was 32,040.74 pg/mL and in SF, 27,332.12 pg/mL. Levels of leptin in serum and SF correlated with body mass index (BMI), (p = 0.0005, and p = 0.0002, respectively). Levels of ACRP-30 in serum was correlated with clinical scores (Ahlbäck: p = 0.0214; K-L: p = 0.0146). ACRP-30 in SF correlated with ACRP-30 in serum (p = 0.0003), tended to negatively correlate with MMP-1 in serum (p = 0.0598) and positively correlate with pro-MMP-1 in SF (p = 0.0600). To conclude, this study confirms the correlations between concentrations of both, leptin and ACRP-30, comparing serum and SF. In overweight females, leptin levels increase with BMI and ACRP-30 serum level increase in more advanced GOA stages. Finally, leptin levels were correlated with TIMP-1 serum concentration, one of the biochemical markers of GOA.

Serum changes in pyridinoline, type II collagen cleavage neoepitope and osteocalcin in early stage male brucellosis patients

Musculoskeletal changes are the most common clinical manifestation of brucellosis. The main objective of this study was to provide a better understanding of this disease, while also attempting to identify potential markers that can identify the early stage musculoskeletal changes associated with human brucellosis. In this case–control study, 41 male early-stage brucellosis patients (within 6 months of diagnosis) who had not received drug therapy and 44 matched controls were examined. Venous blood samples were collected and serum pyridinoline (PYD), type II collagen cleavage neoepitope (C2C) and osteocalcin (OC) levels were quantified using an enzyme-linked immunosorbent assay (ELISA). In the brucellosis group, the median serum levels of PYD (278.53 µg/L), C2C (82.23 µg/L) and OC (8.41 µg/L) were significantly elevated relative to the control group (Z = 5.686, 3.997, 3.579; P = 0.000). Serum PYD, C2C, and OC levels were increased in early-stage male brucellosis patients, and these factors appear to have promise as potential indicator biomarkers that can reflect the osteoarticular changes that occur in the early stage of human brucellosis.

Synovial Fluid Eotaxin-1 Levels May Reflect Disease Progression in Primary Knee Osteoarthritis Among Elderly Han Chinese: A Cross-Sectional Study

OBJECTIVE

The CC chemokine family member eotaxin-1, also named chemokine C-C motif ligand 11 (CCL11), has been detected in knee osteoarthritis (OA) and could induce breakdown of cartilage matrix. This study was performed to investigate the plasma and synovial fluid eotaxin-1 levels with the disease progression in elderly Han Chinese with primary knee OA.

DESIGN

A total of 143 elderly primary knee OA patients and 135 healthy controls were enrolled in the study. The Western Ontario and McMaster Universities Arthritis Index (WOMAC) was performed to evaluate the clinical severity. The radiographic severity was assessed by Kellgren-Lawrence (K-L) grading. Plasma and synovial fluid (SF) eotaxin-1 levels were explored using enzyme-linked immunosorbent assay. The SF levels of matrix metalloproteinase-3 (MMP-3) and interleukin-6 (IL-6) were also examined.

RESULTS

Elevated plasma eotaxin-1 levels were found in knee OA patients compared with healthy controls. Eotaxin-1 levels in SF of knee OA patients with K-L grade 4 were significantly elevated compared with those with K-L grades 2 and 3. Meanwhile, knee OA patients with K-L grade 3 had significantly increased SF levels of eotaxin-1 compared with those with K-L grade 2. Plasma eotaxin-1 levels in different K-L grading did not reach significant difference. Eotaxin-1 levels in SF of knee OA patients were significantly associated with disease severity evaluated by KL grading criteria. In addition, eotaxin-1 levels in SF were positively related to clinical severity illustrated by WOMAC as well as biochemical markers MMP-3 and IL-6.

CONCLUSIONS

Eotaxin-1 levels in SF instead of plasma, were independently and positively related to the disease severity in elderly knee OA patients. The inhibition of eotaxin-1 and its related signaling pathways may serve as a novel therapeutic approach for OA progression.

Decreased synovial fluid pituitary adenylate cyclase-activating polypeptide (PACAP) levels may reflect disease severity in post-traumatic knee osteoarthritis after anterior cruciate ligament injury

BACKGROUND

It has been demonstrated that anterior cruciate ligament (ACL) injury-induced cartilage degeneration is the key risk factor for post-traumatic knee osteoarthritis (PTKOA).Pituitary adenylate cyclase-activating polypeptide (PACAP), a common neuropeptide exerting a wide spectrum of functions, has been proved to inhibit inflammation and prevent cartilage degeneration.

OBJECTIVE

The current study was performed to investigate circulating and synovial fluid PACAP concentrations in ACL injury patients to determine their relationship with the disease progression of the severity of post-traumatic knee osteoarthritis (PTKOA).

METHODS

72 ACL injury patients receiving arthroscopical examination and surgery were enrolled in the study. Meanwhile, 60 gender-and-age non-traumatic patellar dislocation patients were enrolled as controls. The VAS score, Lysholm Score and International Knee Documentation Committee (IKDC) score were all recorded to evaluate the clinical severity. Serum and synovial fluid (SF) PACAP levels were investigated by enzyme-linked immunosorbent assay (ELISA).The IL-1β and TNF-α levels were also investigated. The degree of meniscus injury was assessed by MR imaging. The modified Mankin score was recorded to examine the cartilage histopathological alternations. Receiver operating characteristic (ROC) curve was performed to discuss the diagnostic value of PACAP levels for the prediction of the radiographic grading in comparison with IL-1β and TNF-α.

RESULTS

Serum PACAP levels between PTKOA patients and patellar dislocation did not reach significant differences. However, SF PACAP levels were significantly lower in PTKOA patients than controls. In addition, SF PACAP levels were negatively associated with MRI imaging grade for meniscus injury and VAS score, and were positively associated with Lysholm and IKDC scores. In addition, SF PACAP levels were negatively related to Mankin score as well as the expressions of IL-1β and TNF-α. ROC analysis curve showed that attenuated PACAP may serve as a favorable marker for the diagnosis of MRI for meniscus injury.

CONCLUSIONS

SF PACAP concentrations showed an independent and negative association with disease severity in PTKOA following ACL injury. Local treatment with PACAP may act as a possible adjuvant therapy for delaying the process of PTKOA.

The synovial fluid neuropeptide PACAP may act as a protective factor during disease progression of primary knee osteoarthritis and is increased following hyaluronic acid injection

The correlation of serum and synovial fluid (SF) pituitary adenylate cyclase-activating polypeptide (PACAP) levels with disease progression of primary knee osteoarthritis (OA) was explored. Radiographic severity of OA was determined by Kellgren-Lawrence (K-L) grades. PACAP levels were measured by ELISA before treatment, and 4 and 8 wk following hyaluronic acid (HA) injection. Levels of IL-1β and MMP-3 were also detected. The numeric pain scale (NPS), revised Oxford Knee Score (OKS), and American Knee Society Score (AKSS) were employed to evaluate to symptomatic severity. Receiver-operating-characteristic (ROC) curve analysis was carried out to compare the diagnostic value of PACAP, IL-1β, and MMP-3 for the K-L grade. PACAP concentrations in SF but not serum were significantly lower in OA patients compared with controls. SF PACAP levels were negatively associated with K-L grades and higher NPS as well as worse AKSS and OKS. Further analysis demonstrated that PACAP concentration in SF was negatively correlated with expressions of IL-1β as well as MMP-3 and may act as a marker for radiographic progression along with MMP-3. Last, we found SF PACAP levels exhibited an incremental trend after HA injection. These findings confirmed the crucial role of PACAP deficiency in the development of primary knee OA.

Preoperatively elevated serum inflammatory markers increase the risk of periprosthetic joint infection following total knee arthroplasty in patients with osteoarthritis

Background

The purpose of this study was to evaluate the prevalence of preoperatively elevated serum inflammatory markers and to determine its association with periprosthetic joint infection (PJI) in patients with osteoarthritis (OA) undergoing total knee arthroplasty (TKA).

Methods

From January 2010 to May 2014, we retrospectively reviewed 3,376 consecutive patients who were scheduled for unilateral TKA due to OA. Patients with inflammatory arthritis, posttraumatic arthritis, previous knee surgery, simultaneous surgery or arthroplasty, and comorbidity with autoimmune disease, hepatitis, renal disease, respiratory tract infections, urinary tract infection, and malignancy were excluded. One hundred and forty patients with preoperatively elevated erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP) were enrolled. The control group was matched by age, sex, body mass index, and year of index surgery in 1:1 ratio. All patients were followed for a minimum of 1 year or until the occurrence of PJI. PJI was defined based on the criteria in the International Consensus Meeting. A multivariate Cox proportional hazards model was utilized to calculate the HR and 95% CI.

Results

The prevalence of preoperatively elevated inflammatory markers was 4.1%. The rate of PJI was significantly higher in the both elevated ESR and CRP groups (12.5%, 4/32) compared with both normal group (1.4%, 2/140) and either high group (0.9%, 1/108) (P<0.001). Patients with preoperative elevated ESR and CRP had a significant risk of PJI compared to those with normal serum inflammatory markers (HR: 15.8, 95% CI: 2.57–96.7, P=0.003) after adjusting confounding factors. The cumulative rate for PJI was 6.3% (95% CI: 0%–14.27%) at 1 year and 16.5% (95% CI: 0%–30.66%) at 5 years for both high ESR and CRP groups, which was significantly higher than other 2 groups (P=0.0002).

Conclusion

Although the prevalence of preoperatively elevated ESR and CRP is low, routine examination of ESR and CRP preoperatively might be necessary to prevent subsequent PJI in patients with OA following TKA.

Meta-analysis of serum C-reactive protein and cartilage oligomeric matrix protein levels as biomarkers for clinical knee osteoarthritis

Background

The roles of C-reactive protein (CRP) and cartilage oligomeric matrix protein (COMP) in knee osteoarthritis (KOA) remain controversial, thus the present study is aimed to explore the relationships between CRP, COMP, and the incidence/progression of KOA.

Methods

A systematic search was conducted on PubMed and Embase until September, 2016 for all the relevant studies. The pooled mean difference (MD) with its 95% confidence interval (95% CI) based on fixed effects model or random effects model was calculated to assess the potential role of CRP and COMP in the incidence or progression of KOA. Heterogeneity was evaluated by Cochran’s Q and I² tests. When P < 0.05 or I² > 50%, a random effects model was chosen, otherwise, a fixed effects model was used. Moreover, the role of CRP in different degrees of pain was also analyzed. Sensitivity analysis was performed to evaluate the strength of the meta-analysis.

Results

Fourteen studies were enrolled in the meta-analysis. No difference was found between baseline CRP and CRP levels in the last follow-up period of KOA (MD = − 0.09, 95% CI: -0.30, 0.13). Pooled data showed higher CRP concentration in patients with incident KOA when compared with controls (MD = 0.33, 95% CI: 0.04, 0.63). Moreover, higher serum COMP levels were found in patients with incident KOA (MD = 1.69, 95% CI: 0.61, 2.76) Additionally, significant higher CRP concentration was observed in KOA patients with highest degree of pain (MD = 1.60, 95% CI: 0.52, 2.67).

Conclusion

CRP and COMP serum levels were both associated with the incidence of KOA. Patients with a higher CRP and COMP concentration might have an increased probability of developing KOA. However, higher CRP serum levels was not related with KOA progression. Furthermore, KOA patients with more pain had higher CRP concentrations.

The value of high-sensitivity C-reactive protein in hand and knee radiographic osteoarthritis: data from the Dong-gu Study

Due to the inconsistent association between high-sensitivity C-reactive protein (hs-CRP) and osteoarthritis (OA), we evaluated the relationship between hs-CRP and various radiographic findings in older adults with OA. This cross-sectional study recruited 2376 participants from the population-based Dong-gu cohort. The scores of radiographic features in OA on X-rays of the knees and hands were computed using a semi-quantitative grading system. The hs-CRP levels were measured using a particle-enhanced immunonephelometry assay. Correlations showing the relationship between hs-CRP and OA were calculated using multiple linear correlation analysis. The hs-CRP levels were significantly higher in older subjects (p < 0.001), those with a higher body mass index (BMI) (p < 0.001), current smokers (p < 0.001), current alcohol drinkers (p = 0.011), those who were less physically active (p = 0.002), and those with a lower level of education (p = 0.043). After adjusting for BMI and other confounders, the total OA scores (knee, p = 0.022; hand, p = 0.029) and sclerosis score (knee, p = 0.007; hand, p = 0.030) in the knees and hands were all significantly positively correlated with hs-CRP. A significant association was also observed between hs-CRP and hand erosion score (p = 0.045), hand malalignment score (p = 0.015), and tibial attrition score (p = 0.039). In this large cross-sectional study, a higher hs-CRP level was significantly associated with radiographic OA severity. Of the various types of radiographic damage, all of sclerosis, erosion, and malalignment were significantly associated with hs-CRP levels.

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.

YKL-40 and cytokines - a New Diagnostic Constellation in Rheumatoid Arthritis?

BACKGROUND

Rheumatoid arthritis (RA) causes chronic inflammation and alteration of articular tissue and joints. The pathogenesis of the disease remains unclear although it is known that proinflammatory cytokines play a major role in its induction. YKL-40 is a chitinase-like glycoprotein produced by activated macrophages, neutrophils, arthritic chondrocytes and cancer cells. It has been shown that YKL-40 is implicated in tissue remodeling, angiogenesis and inflammation.

AIM

to investigate serum and synovial YKL-40 levels in relation to IL-1β, TNF-α, and IL-6 in RA patients.

MATERIALS AND METHODS

Serum and synovial concentrations of YKL-40, TNF-α, IL- 6, and IL-1β were determined by ELISA in 39 patients (mean age 53.18 ± 16.54 yrs) with active RA.

RESULTS

Serum YKL-40 levels were increased in all patients. The highest levels were found in synovial fluid (P<0.01). Our study showed a strong association between serum and synovial levels of YKL-40 and serum TNF-α and IL-1 β (P<0.05).

CONCLUSION

This is the first study finding a significant correlation between serum TNF-α and IL-1β and YKL-40 in active RA. We suggest that these molecules together might play a dominant role in the pathogenesis and disease activity and could possibly serve as a new diagnostic constellation in rheumatoid arthritis.

Decreased synovial fluid ghrelin levels are linked with disease severity in primary knee osteoarthritis patients and are increased following laser therapy

BACKGROUND

Ghrelin has been proved to inhibit inflammation and promote cartilage growth. So far, its role in patients with primary knee osteoarthritis has not been investigated.

OBJECTIVE

The current study was performed to explore the serum and synovial ghrelin levels as well as the relationship between ghrelin levels and disease severity in primary knee OA patients.

METHODS

52 primary knee OA patients were recruited in the study. 52 sex and age-matched patients visiting our hospital for regular body check were selected as controls. The serum and synovial fluid ghrelin levels were examined by enzyme linked immunosorbent assay (ELISA) before treatment, one week and four weeks after laser therapy, respectively. The inflammation markers IL-6 and TNF-α were also investigated. The radiographic progression was assessed by Kellgren-Lawrence (K-L) grade scale and the symptomatic severity was evaluated by visual analog scale (VAS), Lequesne index and Lysholm scores. The Receiver Operating Characteristic (ROC) analysis curve was conducted to test the diagnostic value of ghrelin, IL-6 and TNF-α for radiographic progression.

RESULTS

No significant difference of serum ghrelin levels was found between knee OA patients and healthy controls. Synovial fluid ghrelin concentrations were significantly negatively correlated with K-L grading (r=-0.591, P<0.001).Attenuated synovial fluid ghrelin levels were also related to clinical severity determined by Lequesne index (r=-0.308, P=0.025),VAS scores (r=-0.591, P<0.001) and Lysholm scores (r=0.381, P=0.005).In addition, ghrelin levels were also negatively associated with TNF-α (r=-0.424, P=0.002) and IL-6 concentrations (r=-0.428, P=0.002). ROC curve analysis demonstrated that ghrelin exhibited more diagnostic value than IL-6 and TNF-α for assessing radiographic progression in medium-late stage.

CONCLUSIONS

Decreased synovial fluid ghrelin levels are related to disease severity in patients with primary osteoarthritis and are increased following laser therapy. Local application of ghrelin may serve as an adjunctive therapy for knee OA.

Low prevalence of knee chondrocalcinosis and its catabolic association with serum matrix metalloproteinase 3: A rural Japanese population study

AIM

This study aimed to elucidate the prevalence of radiographic knee chondrocalcinosis (CC) and to clarify whether CC is correlated with self-reported knee symptoms and a serum catabolic biomarker.

METHODS

A total of 1278 volunteers participated. Plain radiographs of both knees were obtained. Identification of a linear calcification in the knee joint space was defined as CC. Patients with a Kellgren-Lawrence grade of 2 or more were considered to have knee osteoarthritis (OA). Symptoms were evaluated using the Knee injury and Osteoarthritis Outcome Score (KOOS) Pain scale, and serum matrix metalloproteinase-3 (MMP-3) concentration was determined. Multiple regression analysis was conducted to determine whether CC was correlated with OA, the KOOS Pain scale and MMP-3 concentration.

RESULTS

Twenty-eight subjects were found to have CC (2.2%), and 389 had OA (30.4%). CC was correlated with OA (odds ratio: 5.797; P = 0.006). Additionally, CC was correlated with MMP-3 concentration (B = 11.415, β = 0.059, P = 0.014), but not with KOOS Pain scale.

CONCLUSIONS

The prevalence of CC was low in the Japanese population evaluated in this study. While CC was not correlated with self-reported knee symptoms, it was positively correlated with serum MMP-3 concentration.

Intra-Articular Hyaluronic Acid Compared to Traditional Conservative Treatment in Dogs with Osteoarthritis Associated with Hip Dysplasia

The purpose of this study was to compare the efficacy of the intra-articular (IA) hyaluronic acid injection to traditional conservative treatment (TCT) in dogs with osteoarthritis (OA) induced by hip dysplasia. Sixteen dogs were distributed into two groups: Hyal: IA injection of hyaluronic acid (5-10 mg), and Control: IA injection with saline solution (0.5-1.0 mL) in combination with a TCT using an oral nutraceutical (750-1000 mg every 12 h for 90 days) and carprofen (2.2 mg/kg every 12 h for 15 days). All dogs were assessed by a veterinarian on five occasions and the owner completed an assessment form (HCPI and CPBI) at the same time. The data were analyzed using unpaired t test, ANOVA, and Tukey's test (P < 0.05). Compared with baseline, lower scores were observed in both groups over the 90 days in the veterinarian evaluation, HCPI, and CPBI (P < 0.001). The Hyal group exhibited lower scores from 15 to 90 and 60 to 90 days, in the CBPI and in the veterinarian evaluation, respectively, compared to the Control group. Both treatments reduced the clinical signs associated with hip OA. However, more significant results were achieved with intra-articular hyaluronic acid injection.

Chondroprotective effects of the combination chondroitin sulfate-glucosamine in a model of osteoarthritis induced by anterior cruciate ligament transection in ovariectomised rats

CONTEXT

The efficacy of the combination chondroitin sulfate-glucosamine (CS-GlcN) in the treatment of knee osteoarthritis (OA) has been suggested in recent clinical studies. In vitro reports have also suggested anti-inflammatory and anti-resorptive effects of this combination.

OBJECTIVE

The aim of this study was to characterize the effects of CS-GlcN on joint degradation in vivo including the assessment of inflammation and bone metabolism in a model of OA.

MATERIALS AND METHODS

We have used the OA model induced by anterior cruciate ligament transection (ACLT) in ovariectomised rats. CS-GlcN was administered daily (oral gavage) from week 0 until week 12 after ovariectomy at the dose of 140 (CS)+175 (GlcN)(HCl) mg/kg. Histochemical analyses were performed, the levels of biomarkers and inflammatory mediators were measured by luminex or ELISA and bone microstructure was determined by μCT.

RESULTS

CS-GlcN protected against cartilage degradation and reduced the levels of inflammatory mediators such as interleukin-1β and tumor necrosis factor-α in the affected knee. In addition, serum biomarkers of inflammation and cartilage and bone degradation including matrix metalloproteinase-3, C-telopeptide of type II collagen and the ratio receptor activator of nuclear factor κB ligand/osteoprotegerin were significantly decreased by CS-GlcN. This treatment also tended to improve some bone microstructural parameters without reaching statistical significance.

DISCUSSION AND CONCLUSIONS

These results demonstrate the chondroprotective effects of CS-GlcN in vivo, in the experimental model of ACLT in ovariectomised rats, and suggest that this combination may be useful to control the joint catabolic effects of inflammatory stress. These findings could have clinical relevance related to the prevention of joint degradation by CS-GlcN and support the potential development of OA treatments based on this combination.

Association of follistatin-like 3 concentrations in serum and synovial fluid with the radiographic severity of knee osteoarthritis

OBJECTIVE

Follistatin-like 3 (FSTL3), a circulating glycoprotein, is correlated with obesity and inflammation, which are potential mechanisms of osteoarthritis (OA). This study aims to determine the correlation of FSTL3 concentrations in serum and synovial fluid (SF) with the radiographic severity of OA.

METHODS

This study consisted of 200 patients with knee OA and 148 healthy controls. The radiological grading of OA in the knee was performed in accordance with Kellgren-Lawrence (KL) grading system.

RESULTS

Knee OA patients had higher serum FSTL3 concentrations compared with healthy controls. Knee OA patients with KL grade 4 showed significantly elevated FSTL3 concentrations in serum and SF compared with those with KL grades 2 and 3. Moreover, knee OA patients with KL grade 3 had significantly higher FSTL3 concentrations in serum and SF compared with those with KL grade 2. FSTL3 concentrations in serum and SF of knee OA patients were significantly correlated with KL grading criteria.

CONCLUSIONS

FSTL3 concentrations in serum and SF are correlated with the radiographic severity of OA.

Elevated erythrocyte sedimentation rate and high-sensitivity C-reactive protein in osteoarthritis of the knee: relationship with clinical findings and radiographic severity

PURPOSE

We assessed erythrocyte sedimentation rate and high-sensitivity C-reactive protein concentration in knee osteoarthritis and non-knee osteoarthritis. In addition, we investigated potential relationship between the levels of erythrocyte sedimentation rate and high-sensitivity C-reactive protein with clinical findings and radiographic severity.

METHODS

We compared erythrocyte sedimentation rate and high-sensitivity C-reactive protein concentration between 104 patients with knee osteoarthritis (knee osteoarthritis group; 25 males, 79 females; mean age, 73 y) and 50 patients without knee osteoarthritis (non-knee osteoarthritis group; 16 males, 34 females; mean age, 64 y) excluding any patients with comorbid joint osteoarthritis, rheumatoid arthritis, malignant tumours or inflammatory diseases. In the knee osteoarthritis group, we assessed whether erythrocyte sedimentation rate and high-sensitivity C-reactive protein concentration differed in clinical features and Kellgren-Lawrence (KL) grades.

RESULTS

Erythrocyte sedimentation rate and high-sensitivity C-reactive protein were significantly higher in the knee osteoarthritis group than in the non-knee osteoarthritis group (P = 0.0013 and 0.00010, respectively). In the knee osteoarthritis group, erythrocyte sedimentation rate was significantly elevated in patients with tenderness and patellar ballottement (P = 0.032 and 0.038, respectively), and high-sensitivity C-reactive protein concentration was significantly elevated in patients with tenderness, swelling and patellar ballottement (P = 0.0042, 0.00030 and 0.019, respectively). Erythrocyte sedimentation rate in KL-I was lower than erythrocyte sedimentation rate in KL-III and -IV (P = 0.012 and 0.037, respectively). Erythrocyte sedimentation rate in KL-II did not significantly differ from erythrocyte sedimentation rate in the other groups. High-sensitivity C-reactive protein concentration was lower in grade I than in KL-II, -III and -IV (P = 0.044, 0.0085 and 0.049, respectively).

CONCLUSIONS

Erythrocyte sedimentation rate and high-sensitivity C-reactive protein concentration were higher in patients with knee osteoarthritis and were related to clinical features. In knee osteoarthritis, high-sensitivity C-reactive protein concentration may increase in early-stage KL-II.

Serum and synovial fluid levels of CCL18 are correlated with radiographic grading of knee osteoarthritis

Background

Chemokines are involved in the pathogenesis of osteoarthritis (OA). CCL18, a member of the chemokines family, is observed in synovial fluid (SF) of OA patients. The aim of this study was to determine the association between CCL18 levels in serum and SF with radiographic knee OA.

Material/Methods

This study was conducted in a population of 308 patients with knee OA. The radiological knee OA was graded by the Kellgren-Lawrence grading system.

Results

Serum levels of CCL18 in knee OA patients were markedly higher than those in healthy controls. Serum and SF levels of CCL18 increased with the severity of KL grades and were correlated with disease severity.

Conclusions

The CCL18 levels in serum and SF are correlated with the severity of OA.

Correlation between radiographic and arthroscopic findings in Asian osteoarthritic knees

PURPOSE

To evaluate the correlation between radiographic and arthroscopic findings for severity of knee osteoarthritis (OA) in 119 Asians.

METHODS

Medical records of 52 men and 67 women aged 33 to 70 (mean, 51) years who had complaints of chronic mechanical knee pain for >3 months and were arthroscopically diagnosed with articular cartilage degeneration of the knee were reviewed. The severity of knee OA was classified using the Kellgren-Lawrence (K&L) scale and the modified Outerbridge classification. The highest grade in any compartment of the knee was used to represent the severity of OA. The correlation between the radiographic and arthroscopic findings for severity of knee OA was evaluated.

RESULTS

17 of the 119 patients with no radiographic evidence of OA (K&L grade 0) had articular cartilage degeneration arthroscopically (mean grade, 1.14). In general, higher K&L grades correlated with more severe articular cartilage degeneration. The Pearson correlation coefficient was 0.32, indicating that the association between the radiographic and arthroscopic findings for severity of knee OA was weak.

CONCLUSION

The K&L scale correlated poorly with arthroscopic findings of articular cartilage degeneration in an Asian population with knee OA.

YKL-40 as a novel factor associated with inflammation and catabolic mechanisms in osteoarthritic joints

YKL-40 is associated with tissue injury and inflammation, and consequently to diseases in which these mechanisms lead to tissue degradation, for example, asthma and rheumatoid arthritis. The purpose of the present study was to investigate if YKL-40 is also a significant factor in osteoarthritis (OA) by assessing associations of YKL-40 with mediators related to the pathogenesis of OA: cartilage destructing matrix metalloproteinases (MMPs) and proinflammatory cytokines interleukin-6 (IL-6) and interleukin-17 (IL-17). Cartilage, synovial fluid (SF), and plasma samples were obtained from 100 OA patients undergoing total knee replacement surgery. SF levels of YKL-40 (1027.9 ± 78.3 ng/mL) were considerably higher than plasma levels (67.2 ± 4.5 ng/mL) and correlated with YKL-40 released from cartilage samples obtained from the same patients (r = 0.37, P = 0.010), indicating that YKL-40 is produced by OA cartilage. Interestingly, YKL-40 concentrations in OA SF correlated positively with MMP-1 (r = 0.36, P = 0.014), MMP-3 (r = 0.46, P = 0.001), IL-6 (r = 0.57, P < 0.001), and IL-17 (r = 0.52, P = 0.010) levels. Moreover, IL-6 and IL-17 enhanced YKL-40 production in human primary chondrocyte cultures. The present study introduces YKL-40 as a cartilage-derived factor associated with mediators of inflammation and cartilage destruction involved in the pathogenesis of OA.

Effect of swimming on clinical functional parameters and serum biomarkers in healthy and osteoarthritic dogs

This study aimed to determine whether swimming could improve function of osteoarthritic joints in canine hip OA. Fifty-five dogs were categorized into three groups. The OA with swimming group (OA-SW; n = 22), the healthy (non-OA; n = 18) with swimming group (H-SW), and the healthy (non-OA; n = 15) without swimming group (H-NSW). All animals were allowed to swim for a total of 8 weeks (2-day period, 3 cycles of swimming for 20 minutes, and resting period for 5 minutes in each cycle). Three ml of blood was collected every 2 weeks for evaluation of the levels of biomarkers for OA, including chondroitin sulfate epitope WF6 (CS-WF6) and hyaluronan (HA). Clinical evaluation of the OA-SW group found that most parameters showed improvement (P < 0.01) at week 8 compared to pretreatment, while pain on palpation was improved (P < 0.01) at week 6. The relative level of serum CS-WF6 in the OA-SW group was found to be significantly different (P < 0.01) at weeks 6 and 8 compared with the preexercise. The levels of serum HA of the H-SW group in weeks 2-8 were significantly (P < 0.01) higher than preexercise. Conclusion, swimming over 2-day period, 8 weeks continually, can improve the function of OA joint.

Knee pain and its severity in elderly Koreans: prevalence, risk factors and impact on quality of life

This study investigated the epidemiology (prevalence, risk factors, and impact on quality of life) of knee pain and its severity in elderly Koreans. The subjects (n=3,054) were participants aged ≥50 yr from the fifth Korea National Health and Nutrition Examination Survey, conducted in 2010. Knee pain was defined as pain in the knee lasting ≥30 days during the most recent 3 months; severity was categorized as mild, moderate, or severe. EQ-5D was used to measure quality of life. The prevalence of knee pain was 23.1% (11.7% in men, 31.9% in women). The prevalences of mild, moderate, and severe knee pain were 4.3%, 9.1%, and 9.7%, respectively (2.8%, 5.4%, and 3.5% in men and 5.4%, 12.0%, and 14.4% in women). Old age, female gender, a low level of education, a manual occupation, obesity, and radiographic osteoarthritis were risk factors for knee pain, and were associated with increased severity of knee pain. Excluding men with mild knee pain, people with knee pain had significantly lower quality of life than those without knee pain. Early interventional approaches are needed to reduce the medical, social, and economic burden of knee pain in elderly Koreans.

Joint space height correlates with arthroscopic grading of wrist arthritis

BACKGROUND

Osteoarthritis of the radiocarpal joints is commonly encountered by hand surgeons. To date, there is no well-defined method of radiographically grading osteoarthritis of the wrist.

METHODS

Preoperative radiographs of 48 patients undergoing wrist arthroscopy were evaluated retrospectively. Images were graded subjectively by five surgeons based on overall severity of arthritis, osteophytes, subchondral cysts, and subchondral sclerosis. The joint space height (JSH) ratio was calculated by measuring the space of the mid-radioscaphoid and mid-radiolunate joints and dividing each by the height of the capitate. Arthroscopic grading of arthritis was obtained from operative records and compared to subjective and objective grades. ANOVA testing evaluated for statistical significance with p < 0.05. Inter-rater and intra-rater reliability was determined using Pearson's correlation analysis and Cohen's kappa coefficient.

RESULTS

Objective measurement using the JSH ratio demonstrated a significant decrease as arthroscopic arthritis grade increased for both radioscaphoid and radiolunate joints. Subjective grading of radioscaphoid and radiolunate joints was able to detect moderate/severe, but not mild arthritis. Subjective grading underestimated the degree of arthritis, particularly in the radiolunate joint. Inter-rater reliability was better for objective compared to subjective grading.

CONCLUSIONS

Subjective grading of wrist arthritis can detect moderate/severe radiocarpal arthritis but poorly evaluates early arthritis and underestimates severity. Objective grading using the JSH ratio accurately grades radioscaphoid arthritis and detects early radiolunate arthritis. The JSH ratio more accurately assesses radiocarpal arthritis compared with subjective grading. As there currently is no accepted method to radiographically grade wrist arthritis, the JSH ratio represents a promising option.

Increased thymosin β4 levels in the serum and SF of knee osteoarthritis patients correlate with disease severity

OBJECTIVE

Thymosin β4, a member of a large family of thymic proteins, plays an important role in the process of articular cartilage degeneration which is a common cause of osteoarthritis (OA). This study aims to determine thymosin β4 levels in the serum and synovial fluid (SF) of patients with knee OA and analyze the correlation of thymosin β4 levels with the radiographic severity of OA.

METHODS

This study consisted of 216 patients with knee OA and 152 healthy controls. OA progression was classified based on Kellgren-Lawrence by evaluating x-ray changes observed in anteroposterior knee radiography. Thymosin β4 levels in the serum and SF were measured by enzyme-linked immunosorbent assay method.

RESULTS

The knee OA patients had higher levels of serum thymosin β4 than the healthy controls. Knee OA patients with KL grade 4 showed significantly elevated thymosin β4 levels in the serum and SF compared with those with KL grades 2 and 3. Knee OA patients with KL grade 3 had significantly higher SF levels of thymosin β4 than those with KL grade 2. Thymosin β4 levels in the serum and SF of knee OA patients were significantly correlated with disease severity according to KL grading criteria.

CONCLUSION

The thymosin β4 levels in the serum and SF may serve as effective biomarkers for the severity of OA.

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

BACKGROUND

The relationship between systemic inflammatory processes to total knee arthroplasty (TKA) outcomes remains unclear. This study investigates the relationship between serum high-sensitivity C-reactive protein (hs-CRP) and functional outcomes post-TKA.

METHODS

A total of 31 patients with osteoarthritis (OA) who underwent TKA were enrolled in the study; 15 with hs-CRP ≤1.0 mg/l (low hs-CRP group) and 16 subjects with hs-CRP ≥4.0 mg/l (high hs-CRP group). During surgery, synovium and bone sections were sequestered, formalin-fixed, and paraffin embedded for slide preparation. Tissue sections were stained with hematoxylin and eosin and analyzed using a light microscope. A total of 12 cytokines were measured in synovial fluid samples from the knee joint at time of surgery and analyzed using the Luminex Multi-Analyte Profiling System. Relationships between cytokines and hs-CRP were assessed using Spearman correlation coefficients. Student's t-tests were used to compare Short Form health outcomes survey (SF-12) health outcomes between high and low hs-CRP, and presurgical and postsurgical visits.

RESULTS

Mean ± standard deviation (SD) baseline and 1-year hs-CRP values for the low hs-CRP group were 0.55 ± 0.23 mg/l and 1.22 ± 1.32 mg/l, respectively (n = 15; p = 0.051) and for the high hs-CRP group were 7.86 ± 5.98 mg/l and 14.11 ± 38.9 mg/l, respectively (n = 13; p = 0.54). Lymphocytes were present in 10 synovium and one bone sample (all but one from high hs-CRP group). Interleukin (IL)-5 and IL-10 were significantly correlated with hs-CRP (p = 0.0137 and p = 0.0029, respectively). The low hs-CRP group exhibited significant improvement in the physical component of SF-12 at 6 and 12 months compared with baseline, whereas the high hs-CRP group exhibited significant improvement only at 6 months. Body mass index (BMI) had a significant positive correlation with presurgical hs-CRP.

CONCLUSIONS

The results of this study provide support for inflammatory mechanisms contributing to the OA progression, with hs-CRP being a possible predictive variable, combined with BMI and other comorbidities, of post-TKA function.

Relationship between sonographic parameters and YKL-40 levels in rheumatoid arthritis

YKL-40, also known as human cartilage glycoprotein 39, is a member of the "mammalian chitinase-like proteins" family without chitinase activity. Increased serum concentrations are associated with inflammatory processes and several types of cancer. In this study, we evaluated YKL-40 levels in serum and synovial fluid of patients with rheumatoid arthritis in comparison with the ultrasonographic findings. YKL-40 levels were measured by enzyme-linked immunosorbent assay in 25 patients with active rheumatoid arthritis and in 40 healthy subjects. B mode and power Doppler were performed to determine synovial thickening and vascularization. Serum YKL-40 level in patients was significantly higher than the concentration in healthy controls (P < 0.01). In patients with rheumatoid arthritis, the level of the glycoprotein in synovial fluid was remarkably elevated compared to the serum level (P = 0.003). The B mode and power Doppler scores correlated to YKL-40 in serum and synovial fluid (P = 0.07). Serum YKL-40 levels were related positively to serum markers of inflammation such as C-reactive protein (P = 0.004) and erythrocyte sedimentation rate (P = 0.003). This study is the first to demonstrate a relationship between YKL-40 levels and ultrasonographic examinations in Bulgarian patients with rheumatoid arthritis. The findings suggest that YKL-40 might be implicated in the pathogenesis of the disease and could indicate the level of joint inflammation.

No association between markers of inflammation and osteoarthritis of the hands and knees

OBJECTIVE

Local inflammation plays a prominent role in osteoarthritis (OA). This could be reflected in the presence of elevated soluble inflammatory markers. We conducted analyses to assess the association of inflammatory markers with radiographic OA of the hands and knees in a large community-based cohort.

METHODS

The Framingham Offspring cohort consists of the adult children of the original cohort and their spouses. In 1998-2001 these subjects provided blood specimens that were tested for 17 markers of systemic inflammation. In 2002-2005 these subjects had radiographs of both knees and hands. Each hand and knee joint was assigned a Kellgren and Lawrence (KL) score (0-4). We used logistic regression with generalized estimating equations and adjustment for age, sex, and body mass index to examine the association between each inflammatory marker and the presence of radiographic OA (ROA = KL grade ≥ 2) in any joint. We also constructed models for hand joints and knee joints alone.

RESULTS

Radiographs and measures of inflammation were done for 1235 subjects (56% women, mean age 65 yrs). Of that group, 729 subjects (59%) had ROA in ≥ 1 hand or knee joint: 179 (14.3%) had knee OA, and 694 (56.2%) had hand OA. There were no significant associations between any marker of inflammation and ROA.

CONCLUSION

In this large sample, in which OA was carefully assessed and multiple markers measured, we found no evidence of an association between any inflammatory marker and the presence of radiographic OA.

Correlation of plasma and synovial fluid adiponectin with knee osteoarthritis severity

BACKGROUND AND AIMS

Osteoarthritis (OA) is a chronic degenerative joint disorder of the synovial joint characterized by loss of articular cartilage, osteophyte formation, and alterations of subchondral bone. The purposes of this study were to measure adiponectin concentrations in plasma and synovial fluid of patients with knee OA and to analyze the correlation of adiponectin levels with disease severity.

METHODS

Seventy six OA patients (mean age 69.8 ± 1.1 years) and 24 healthy controls (mean age 71.2 ± 1.5 years) were enrolled in this study. OA grading was performed using the Kellgren-Lawrence (KL) criteria by evaluating x-ray changes observed in anteroposterior knee radiography. Adiponectin levels in plasma and synovial fluid were determined by commercial enzyme-linked immunosorbent assay.

RESULTS

Plasma levels of adiponectin were higher in OA patients compared to healthy individuals, but the difference did not reach statistical significance (2428.0 ± 245.1 vs. 2030.3 ± 399.4 ng/mL, p = 0.4). Adiponectin levels in plasma were remarkably higher with regard to paired synovial fluid (2428.0 ± 245.1 vs. 301.3 ± 44.9 ng/mL, p <0.001). Additionally, adiponectin concentrations in plasma and synovial fluid showed significant inverse correlation with disease severity evaluated by KL grading criteria (r = -0.68, p <0.001 and r = -0.47, p <0.001, respectively). Further analysis showed that plasma adiponectin levels positively correlated with synovial fluid adiponectin levels (r = 0.71, p <0.001).

CONCLUSIONS

Adiponectin levels in both plasma and synovial fluid decreased significantly as the severity of OA increased. These findings suggested that adiponectin may play a protective role in OA. More studies are warranted to gain insight into the potential utility of adiponectin as a biochemical determinant of disease progression and prognosis.

The potential of multiple synovial-fluid protein-concentration analyses in the assessment of knee osteoarthritis

CONTEXT

Joint trauma is a risk factor for osteoarthritis (OA), which is becoming an increasingly important orthopedic concern for athletes and nonathletes alike. For advances in OA prevention, diagnosis, and treatment to occur, a greater understanding of the biochemical environment of the affected joint is needed.

OBJECTIVE

To demonstrate the potential of a biochemical technique to enhance our understanding of and diagnostic capabilities for osteoarthritis.

DESIGN

Cross-sectional.

SETTING

Outpatient orthopedic practice.

PARTICIPANTS

8 subjects: 4 OA-knee participants (65 ± 6 y of age) and 4 normal-knee participants (54 ± 10 y) with no history of knee OA based on bilateral standing radiographs.

INTERVENTION

The independent variable was group (OA knee, normal knee).

MAIN OUTCOME MEASURES

16 knee synovial-protein concentrations categorized as follows: 4 as pro-inflammatory, or catabolic, cytokines; 5 as anti-inflammatory, or protective, cytokines; 3 as catabolic enzymes; 2 as tissue inhibitors of metalloproteinases [TIMPs]; and 2 as adipokines.

RESULTS

Two anti-inflammatory cytokines (interleukin [IL]-13 and osteoprotegerin) and a pro-inflammatory cytokine (IL-1β) were significantly lower in the OA knees. Two catabolic enzymes (matrix metalloproteinase [MMP]-2 and MMP-3) were significantly elevated in OA knees. TIMP-2, an inhibitor of MMPs, was significantly elevated in OA knees.

CONCLUSIONS

Six of the 16 synovial-fluid proteins were significantly different between OA knees and normal knees in this study. Future research using a similar multiplex ELISA approach or other proteomic techniques may enable researchers and clinicians to develop more accurate biochemical profiles of synovial fluid to help diagnose OA, identify subsets of OA or individual characteristics, guide clinical decisions, and identify patients at risk for OA after knee injury.

Knee osteoarthritis prevalence, risk factors, pathogenesis and features: Part I

Osteoarthritis (OA) a common disease of aged population and one of the leading causes of disability. Incidence of knee OA is rising by increasing average age of general population. Age, weight, trauma to joint due to repetiting movements in particular squatting and kneeling are common risk factors of knee OA. Several factors including cytokines, leptin, and mechanical forces are pathogenic factors of knee OA. In patients with knee pain attribution of pain to knee OA should be considered with caution. Since a proportion of knee OA are asymptomatic and in a number of patients identification of knee OA is not possible due to low sensitivity of radiographic examination. In this review data presented in regard to prevalence, pathogenesis, risk factors.

The effect of doxycycline on canine hip osteoarthritis: design of a 6-months clinical trial

Twenty-five dogs were included in a randomized, double-blind trial to assess the efficacy of doxycycline (DOX) orally administered twice a day at 4 mg/kg/day (n = 12) for the treatment of osteoarthritis of the hip. Chondroitin sulfate (CS; 525 mg/day) was used as a positive control (n = 13). Dogs were re-examined monthly for 6 months after initiation of treatment. The assessment protocol included clinical score, radiographic findings and serum osteoarthritis biomarkers. Dogs treated with DOX showed statistically significant improvements (p < 0.05) in lameness, joint mobility, pain on palpation, weight-bearing and overall score at 2, 6, 4, 4 and 4 months, respectively, after treatment. Biomarker levels of CS-WF6 epitope and hyaluronan were significantly increased and decreased (p < 0.05) at 2 and 3 months after treatment compared to pretreatment. These results showed that DOX had a positive therapeutic effect in dogs with osteoarthritis.

Correlation of synovial fluid leptin concentrations with the severity of osteoarthritis

Leptin is known to play an important role in the pathophysiology of osteoarthritis (OA). This study investigated whether synovial fluid (SF) leptin level is related to the radiographic severity of OA and its role as a quantitative marker for the detection of OA. SF was obtained from 42 OA patients who underwent knee surgery and 10 who had no abnormality of articular cartilage during arthroscopic examination. The progression of OA was classified by Kellgren-Lawrence grading scale. The concentrations of leptin were measured with commercial enzyme-linked-immunosorbent serologic assay kits. Median leptin concentrations in SF were significantly higher in OA patients (median 4.40 ng/ml; range 0.5-15.8) compared to controls (median 2.05 ng/ml; range 1.0-4.6; P = 0.006). SF leptin levels showed significant difference according to the severity of OA (P = 0.0125). Median SF leptin level was highest in stage IV patients (11.1 ng/ml), which was significantly higher compared to all other groups including controls (P < 0.05). Age showed a significant positive correlation with leptin concentrations in OA patients (P < 0.05), but not in controls. These results demonstrate that SF leptin concentrations were closely related to the radiographic severity of OA, suggesting that SF leptin levels could be used as an effective marker for quantitative detection of OA.

Raman spectroscopy of synovial fluid as a tool for diagnosing osteoarthritis

For many years, viscosity has been the primary method used by researchers in rheumatology to assess the physiochemical properties of synovial fluid in both normal and osteoarthritic patients. However, progress has been limited by the lack of methods that provide multiple layers of information, use small sample volumes, and are rapid. Raman spectroscopy was used to assess the biochemical composition of synovial fluid collected from 40 patients with clinical evidence of knee osteoarthritis (OA) at the time of elective surgical treatment. Severity of knee osteoarthritis was assessed by a radiologist using Kellgren/Lawrence (K/L) scores from knee joint x rays, while light microscopy and Raman spectroscopy were used to examine synovial fluid (SF) aspirates (2 to 10 microL), deposited on fused silica slides. We show that Raman bands used to describe protein secondary structure and content can be used to detect changes in synovial fluid from osteoarthritic patients. Several Raman band intensity ratios increased significantly in spectra collected from synovial fluid in patients with radiological evidence of moderate-to-severe osteoarthritis damage. These ratios can be used to provide a "yes/no" damage assessment. These studies provide evidence that Raman spectroscopy would be a suitable candidate in the evaluation of joint damage in knee osteoarthritis patients.

Chitinase 3-Like-1 (CHI3L1): a putative disease marker at the interface of proteomics and glycomics

Chitinase 3-Like-1 (CHI3L1) is a secreted 40 kDa glycoprotein that is upregulated in a number of human cancers and in non-neoplastic disease states characterized by chronic inflammation and tissue remodeling. Increased serum levels of CHI3L1 parallel disease severity, poorer prognosis, and shorter survival in many human neoplasias, including cancers of the breast, colon, prostate, ovaries, brain, thyroid, lung, and liver. Increased serum CHI3L1 also correlates with disease severity in rheumatoid arthritis, osteoarthritis, liver fibrosis, inflammatory bowel disease, and bacterial septicemia. CHI3L1 is a rheumatoid arthritis (RA) autoantigen, and MHC complexes containing specific CHI3L1 peptides have been found in RA patients; however, intranasal introduction of these same CHI3L1 peptides can induce tolerance towards them. CHI3L1 is a nonhydrolytic member of the human chitinase family that binds chitin tightly and heparin at lower affinity. Interactions with type I collagen, CHI3L1's only known protein-binding partner, helps regulate collagen fibril formation. The principal sources of CHI3L1 are activated macrophages and chondrocytes, neutrophils, and some tissue and tumor cells. CHI3L1 can act as a fibroblast mitogen and can activate several signaling pathways, however, no cell surface-binding partner for CHI3L1 has been identified. The ability of CHI3L1 to bind both proteins and carbohydrates allows potential interactions with a variety of cell-surface and extracellular-matrix proteins, proteoglycans, and polysaccharides, and thus CHI3L1 can interface between proteomics and glycomics.

Biomarkers in the development of novel disease-modifying therapies for osteoarthritis

Identification and utilization of biomarkers is vitally important for the successful development of disease-modifying osteoarthritis drugs. Biochemical and imaging platforms hold great promise to deliver such biomarkers. Studies indicate a marked increase in biochemical products arising from the breakdown and biosynthesis of collagen, extracellular matrix and bone in osteoarthritis. These molecules have been associated with disease severity and may also have prognostic value as indicators of disease progression. However, issues including biological variability and lack of tissue specificity currently hinder the utility of these molecular markers in drug development. Imaging technologies hold great potential for sensitive and accurate measurement of disease-related structural damage. Drawbacks, including expense, need for validation and limited accessibility also limit the utility of these technologies. In this article, the potential value and challenges in developing and utilizing biomarkers in disease-modifying osteoarthritis drug development will be discussed.

Biological markers in osteoarthritis

Osteoarthritis (OA) is a progressive disorder characterized by destruction of articular cartilage and subchondral bone, and by synovial changes. The diagnosis of OA is generally based on clinical and radiographic changes, which occur fairly late during disease progression and have poor sensitivity for monitoring disease progression. Progression of joint damage is likely to result primarily from an imbalance between cartilage degradation and repair, so measuring markers of these processes would seem a promising approach to improve the prediction of disease progression at the individual level. Moreover, genetic markers might be useful predictors of prognosis. The lack of fully effective, chondroprotective medications has limited the use of such potential markers to monitor the effect of treatment for OA. Nevertheless, owing to their dynamic changes in response to treatment, biological markers might provide relevant information more rapidly than imaging techniques (such as radiography and MRI) can, and should contribute to our understanding of mechanisms that underlie the clinical efficacy of OA treatments. Most of the identified genes involved in OA encode signal-transduction proteins, which provide the potential for novel therapeutic approaches. In this Review, we will use the recently proposed BIPED (i.e. burden of disease, investigative, prognostic, efficacy of intervention and diagnostic) classification of OA markers to describe the potential usage of a given marker.

Use of the plasma stromelysin (matrix metalloproteinase 3) concentration to predict joint space narrowing in knee osteoarthritis

OBJECTIVE

To determine whether baseline or serial plasma concentrations of stromelysin (matrix metalloproteinase 3 [MMP-3]) protein might distinguish subjects with progressive radiographic knee osteoarthritis (OA) from those with stable disease.

METHODS

Subjects were 120 women with unilateral knee OA who participated in a 30-month randomized, placebo-controlled trial of structure modification with doxycycline. Anteroposterior views of both knees in a semiflexed position were obtained at baseline, 16 months, and 30 months. Subjects were selected to obtain comparisons of plasma MMP-3 levels between 60 progressors (21 taking doxycycline, 39 taking placebo) and 60 nonprogressors (30 taking doxycycline, 30 taking placebo) with respect to medial joint space narrowing (JSN) in the index knee. Each group consisted of 30 subjects who exhibited significant increases in knee pain. Blood samples were obtained semiannually for MMP-3 assay.

RESULTS

Subjects in the placebo group whose MMP-3 concentration was in the upper tertile of the baseline distribution showed a 4-fold increase in the odds of progression of JSN as compared with the lower tertile (odds ratio 4.12, P = 0.037). Baseline MMP-3 levels were unrelated to knee pain. The within-subject mean of serial MMP-3 concentrations was associated with concurrent JSN in the placebo group over the 0-16-month interval (b = 0.18 mm/SD increase in the mean MMP-3, P < 0.01) and over the 16-30-month interval (b = 0.15, P < 0.05). Similar evidence of concurrent validity was found in the placebo group for the maximum of intercurrent MMP-3 values.

CONCLUSION

The baseline MMP-3 level was a significant predictor of JSN in this pilot study. Moreover, serial plasma MMP-3 levels reflected concurrent JSN in the placebo group over the 30-month period of observation.