Serum hyaluronan levels increase with the total number of osteoarthritic joints and are strongly associated with the presence of knee and finger osteoarthritis

Sex-specific effects of calving season on joint health and biomarkers in Montana ranchers

BACKGROUND

Agricultural workers have a higher incidence of osteoarthritis (OA), but the etiology behind this phenomenon is unclear. Calving season, which occurs in mid- to late-winter for ranchers, includes physical conditions that may elevate OA risk. Our primary aim was to determine whether OA biomarkers are elevated at the peak of calving season compared to pre-season, and to compare these data with joint health survey information from the subjects. Our secondary aim was to detect biomarker differences between male and female ranchers.

METHODS

During collection periods before and during calving season, male (n = 28) and female (n = 10) ranchers completed joint health surveys and provided samples of blood, urine, and saliva for biomarker analysis. Statistical analyses examined associations between mean biomarker levels and survey predictors. Ensemble cluster analysis identified groups having unique biomarker profiles.

RESULTS

The number of calvings performed by each rancher positively correlated with plasma IL-6, serum hyaluronic acid (HA) and urinary CTX-I. Thiobarbituric acid reactive substances (TBARS), a marker of oxidative stress, was significantly higher during calving season than pre-season and was also correlated with ranchers having more months per year of joint pain. We found evidence of sexual dimorphism in the biomarkers among the ranchers, with leptin being elevated and matrix metalloproteinase-3 diminished in female ranchers. The opposite was detected in males. WOMAC score was positively associated with multiple biomarkers: IL-6, IL-2, HA, leptin, C2C, asymmetric dimethylarginine, and CTX-I. These biomarkers represent enzymatic degradation, inflammation, products of joint destruction, and OA severity.

CONCLUSIONS

The positive association between number of calvings performed by each rancher (workload) and both inflammatory and joint tissue catabolism biomarkers establishes that calving season is a risk factor for OA in Montana ranchers. Consistent with the literature, we found important sex differences in OA biomarkers, with female ranchers showing elevated leptin, whereas males showed elevated MMP-3.

Biomarkers for Osteoarthritis Diseases

Growing evidence has revealed the pivotal role of inflammatory biomarkers in the pathogenesis of osteoarthritis. There is significant interest in the prognostic value of select biomarkers, given the potential for early identification and treatment of patients at risk of osteoarthritis prior to the development of irreversible clinical disease. Clinical trials of novel therapeutics that disrupt the inflammatory pathways of osteoarthritis are also ongoing. The purpose of this review is to summarize the current literature on key biomarkers within the context of osteoarthritis pathogenesis, clinical symptom development, and treatment capabilities. Multiple recent studies have established biomarkers that signal the existence of osteoarthritis pathology and the development of clinical symptomology. However, prior to implementation in clinical practice, additional research is required to precisely define the prognostic value for numerous biomarkers and standardize their measurement. Biomarker-driven investigations represent a promising avenue for the early diagnosis and treatment of osteoarthritis.

A comprehensive review of intraarticular knee injection therapy, geniculate injections, and peripheral nerve stimulation for knee pain in clinical practice

The knee is the most common joint in adults associated with morbidity. Many pathologies are associated with knee damage, such as gout or rheumathoid arthritis, but the primary condition is osteoarthritis (OA). Not only can osteoarthritis cause significant pain, but it also can result in signficant disability as well. Treatment for this condition varies, starting off with oral analgesics and physical therapy to surgical total knee replacmenet. In the gamut of this various treatments, a conservative approach has included intra articular steroid injections. With time, researchers and clinicians determined that other components injected to the knee may additionally provide relief of this condition. In this investigation, we describe different types of knee injections such as platelet-rich plasma (PRP), hyaluronic acid, stem cells, and prolotherapy. Additionally, we describe the role of geniculate knee injections, radiofrequency, and periopheral nerve stimulation. These treatments should be considered for patients with knee pain refractory to conservative therapies.

Association of Biomarkers with Individual and Multiple Body Sites of Pain: The Johnston County Osteoarthritis Project

Introduction

Biochemical biomarkers may provide insight into musculoskeletal pain reported at individual or multiple body sites. The purpose of this study was to determine if biomarkers or pressure-pain threshold (PPT) were associated with individual or multiple sites of pain.

Methods

This cross-sectional analysis included 689 community-based participants. Self-reported symptoms (ie, pain, aching, or stiffness) were ascertained about the neck, upper back/thoracic, low back, shoulders, elbows, wrist, hands, hips, knees, ankles, and feet. Measured analytes included CXCL-6, RANTES, HA, IL-6, BDNF, OPG and NPY. A standard dolorimeter measured PPT. Logistic regression was used determine the association between biomarkers and PPT with individual and summed sites of pain.

Results

Increased IL-6 and HA were associated with knee pain (OR=1.30, 95% CI 1.03, 1.64) and (OR=1.32, 95% CI 1.01, 1.73) respectively; HA was also associated with elbow/wrist/hand pain (OR=1.60, 95% CI 1.22, 2.09). Those with increased NPY levels were less likely to have shoulder pain (OR=0.56, 95% CI 0.33, 0.93). Biomarkers HA (OR=1.50, 95% CI 1.07, 2.10), OPG (OR=1.74, 95% CI 1.00, 3.03), CXCL-6 (OR=1.75, 95% CI 1.02, 3.01) and decreased PPT (OR=3.97, 95% CI 2.22, 7.12) were associated with multiple compared to no sites of pain. Biomarker HA (OR=1.57, 95% CI 1.06, 2.32) and decreased PPT (OR=3.53, 95% CI 1.81, 6.88) were associated with multiple compared to a single site of pain.

Conclusion

Biomarkers of inflammation (HA, OPG, IL-6 and CXCL-6), pain (NPY) and PPT may help to understand the etiology of single and multiple pain sites.

Small fragments of hyaluronan are increased in individuals with obesity and contribute to low-grade inflammation through TLR-mediated activation of innate immune cells

Background and aim

Extracellular matrix (ECM) components released during excessive fat mass expansion are considered potential endogenous danger/alarm signals contributing to innate immune system activation. The aim of the current study was to specifically measure plasma levels of low molecular weight (LMW) hyaluronan (HA) and to evaluate its role as pro-inflammatory damage-associated molecular pattern (DAMP) on leukocyte response in the context of human obesity.

Subjects and methods

Participants were selected according to their body mass index (BMI, kg/m²) as non-obese (BMI < 29.9, n = 18) and obese (BMI > 29.9, n = 33). Plasma samples were size-dependent fractionated using ion-exchange chromatography to specifically obtain LMW HA fractions that were subsequently quantified by ELISA. Cell incubation experiments with synthetic HA molecules were performed on freshly Ficoll-isolated neutrophils (PMN) and peripheral blood monocytes (PBMC). Leukocyte and adipose tissue gene expression was assessed by real-time PCR and NF-κB activation by western blot. Plasma cytokine levels were measured by fluorescent bead-based (Luminex) immunoassay.

Results

We observed a statistically significant increase in the circulating levels of HA fragments of LMW in individuals with obesity which were consistent with significant up-regulated expression of the LMW HA synthesizing enzyme hyaluronan synthase-1 (HAS-1) in obese adipose tissue. Gene expression assessment of HA receptors revealed up-regulated levels for TLR2 in both obese PMN and PBMC. Synthetic HA molecules of different sizes were tested on leukocytes from healthy donors. LMW HA fragments (15–40 kDa) and not those from intermediate molecular sizes (75–350 kDa) induced a significant up-regulation of the expression of major pro-inflammatory cytokines such as IL-1β, MCP-1 and IL-8 in PBMC. Importantly, LMW HA was able to induce the phosphorylation of IKK α/β complex supporting its pro-inflammatory role through NF-κB activation.

Conclusion

Circulating LMW HA molecules are elevated in obesity and may play an important role in triggering low-grade inflammation and the development of metabolic complications.

Associations between serum biomarkers of cartilage metabolism and serum hyaluronic acid, with risk factors, pain categories, and disease severity in knee osteoarthritis: a pilot study

BACKGROUND

Specific serum biomarkers of cartilage metabolism such as cartilage oligomeric matrix protein (sCOMP) and procollagen type II C-terminal propeptide (sPIICP) as well as hyaluronan (sHA), a biomarker of synovitis, have been implicated in the pathophysiology of knee osteoarthritis (OA). However, the associations of these biomarkers with the severity of the disease and OA risk factors, including age and obesity remain inconclusive. This analysis examines the associations between these serum biomarkers and the radiographic severity of OA and knee pain, as wells as obesity, the age and gender of the participants, and other OA risk factors.

METHODS

From 44 patients with early knee OA and 130 patients with late knee OA we analyzed the radiographic severity of the disease using the Kellgren and Lawrence (KL) grading system. Moreover, 38 overweight healthy individuals were used as a control group. Specific information was collected from all participants during their recruitment. The levels of the three serum biomarkers were quantified using commercially available ELISA kits. Serum biomarkers were analyzed for associations with the average KL scores and pain in both knees, as well as with specific OA risk factors.

RESULTS

The levels of sCOMP were elevated in patients with severe late OA and knee pain and correlated weakly with OA severity. A weakly correlation of sHA levels and OA severity OA was observed. We demonstrated that only sPIICP levels were markedly decreased in patients with late knee OA suggesting the alterations of cartilage metabolism in this arthritic disease. Moreover, we found that sPIICP has the strongest correlation with obesity and the severity of OA, as well as with the knee pain at rest and during walking regardless of the severity of the disease. ROC analysis showed that the area under the ROC curve (AUC) was 0.980 (95% CI: 0.945-0.995; p < 0.0001), suggesting high diagnostic accuracy of sPIICP. Interestingly, gender and age had also an effect on the levels of sPIICP.

CONCLUSION

This study revealed the potential of serum PIICP to be used as a biomarker to monitor the progression of knee OA, however, further studies are warranted to elucidate its clinical implication.

Usefulness of serum hyaluronic acid levels as a predictor of incidence of hand osteoarthritis analyzed by longitudinal analysis from the Iwaki cohort

The factors predicting hand osteoarthritis (HOA) in patients remain unknown. We aimed to investigate the usefulness of serum hyaluronic acid (sHA) levels in predicting HOA progression from a 6-year longitudinal epidemiological study. A total of 417 participants in the Iwaki cohort were followed-up over 6 years. Hand and knee radiographs taken at baseline and follow-up were scored according to Kellgren–Lawrence grades and Kallman score. Participants were classified into the HOA group and the non-HOA group. sHA levels at baseline were determined by ELISA. Correlations between sHA levels, the number of involved joints, and Kallman score were estimated. Factors related to the incidence or progression of HOA over 6 years were analyzed. The prevalence of HOA was 19.9% at baseline, and 3.6 ± 2.1 joints were involved. sHA levels in the HOA group at baseline were significantly higher than in the non-HOA group (p < 0.001) and correlated with the number of involved joints (r = 0.399, p < 0.001) and Kallman score (r = 0.540, p < 0.001). The incidence rate was 14.5%, and the progression rate was 46.1% over 6 years. Higher sHA levels at baseline were the risk factor of HOA incidence. Thus, sHA levels predicted the incidence of HOA over 6 years.

Mass Spectrometry Imaging as a Potential Tool to Investigate Human Osteoarthritis at the Tissue Level

Osteoarthritis (OA) is the most common degenerative joint disease, predicted to increase in incidence year by year due to an ageing population. Due to the biological complexity of the disease, OA remains highly heterogeneous. Although much work has been undertaken in the past few years, underlying molecular mechanisms leading to joint tissue structural deterioration are not fully understood, with only few validated markers for disease diagnosis and progression being available. Discovery and quantitation of various OA-specific biomarkers is still largely focused on the bodily fluids which does not appear to be reliable and sensitive enough. However, with the advancement of spatial proteomic techniques, several novel peptides and proteins, as well as N-glycans, can be identified and localised in a reliable and sensitive manner. To summarise the important findings from OA biomarker studies, papers published between 2000 and 2020 were searched via Google Scholar and PubMed. Medical subject heading (MeSH) terms ‘osteoarthritis’, ‘biomarker’, ‘synovial fluid’, ‘serum’, ‘urine’, ’matrix-assisted laser desorption/ionisation’, ‘mass spectrometry imaging’, ‘proteomic’, ‘glycomic’, ‘cartilage’, ‘synovium’ AND ‘subchondral bone’ were selectively used. The literature search was restricted to full-text original research articles and written only in English. Two main areas were reviewed for OA biomarker studies: (1) an overview of disease-specific markers detected from different types of OA bio-samples, and (2) an up-to-date summary of the tissue-specific OA studies that have utilised matrix-assisted laser desorption/ionisation mass spectrometry imaging (MALDI-MSI). Overall, these OA biomarkers could provide clinicians with information for better the diagnosis, and prognosis of individual patients, and ultimately help facilitate the development of disease-modifying treatments.

Early knee osteoarthritis prevalence is highest among middle-aged adult females with obesity based on new set of diagnostic criteria from a large sample cohort study in the Japanese general population

PURPOSE

A few new criteria for early detection and prevention of early knee osteoarthritis (EKOA) have been proposed. However, its prevalence, risk factors, relationship with function and prognosis have not been clarified. The purpose of this study was to investigate the prevalence of EKOA and its risk factors in the Japanese general population.

METHODS

A total of 1104 volunteers (443 males, 661 females) who participated in the Iwaki cohort study in Japan were enrolled in this cross-sectional study. Their bilateral weight-bearing anterior-posterior knee radiographs were classified by Kellgren-Lawrence (KL) grade. EKOA (KL grade 0/1) was defined according to the following criteria: knee injury and osteoarthritis outcome score < 85%, joint line tenderness, and crepitus and its prevalence among age-sex groups was calculated. Logistic regression analyses were performed to determine the risk factors for EKOA.

RESULTS

Eight hundred and twenty-two participants had KL grade 0/1, and the EKOA prevalence was 9.5% in males and 15.0% in females (p = 0.011). The prevalence of EKOA increased with age. The highest prevalence was noted in females aged 50-59 years. Logistic regression analysis showed that the risk factors for EKOA were age (p < 0.001, odds ratio (OR) 1.1), female sex (p = 0.002, OR 2.5), high body mass index (p < 0.001, OR 1.2), and history of knee injury (p < 0.001, OR 21.7).

CONCLUSIONS

The highest EKOA prevalence was observed in middle adult females (50-59 years old). The risk factors for EKOA were female sex, ageing, obesity and knee injury history, which were extremely similar to those of definitive knee osteoarthritis.

LEVEL OF EVIDENCE

Level I in diagnostic studies-investigating a diagnostic test.

Investigating lubricin and known cartilage-based biomarkers of osteoarthritis

Introduction: Osteoarthritis (OA) is a degenerative disease which primarily affects hyaline cartilage, leading to pain, stiffness and loss of mobility of the entire articulation. Diagnosis is commonly based on symptoms and radiographs, but there is a growing interest in detecting novel biomarkers, in serum, urine and synovial fluid, which can be predictors of disease onset and progression.Areas covered: This review provides an overview of the main biomarkers currently used in OA clinical practice, with a focus on lubricin, a surface glycoprotein secreted in the synovial fluid that lubricates the cartilage and reduces the coefficient of friction within the joint. Key findings of the last years are presented throughout the article.Expert opinion: Analysis of biomarkers might suggest personalized protocols of treatment, guide the classification of OA phenotypes, contribute to precision medicine, avoid further unnecessary exams, facilitate drug discovery or refine treatment guidelines. For all these reasons, the investigation of novel cartilage-based biomarker of osteoarthritis needs to be promoted and improved.

Joint hypermobility is not positively associated with prevalent multiple joint osteoarthritis: a cross-sectional study of older adults

BACKGROUND

This cross-sectional study evaluated associations of joint hypermobility and multiple joint osteoarthritis (MJOA) in a community-based cohort of adults 45+ years of age.

METHODS

MJOA and joint hypermobility data were from 1677 participants (mean age 69 years, 68% women) who completed research clinic visits during 2003-2010. Prevalent MJOA was defined in four ways. Radiographic OA (rOA) was defined as Kellgren-Lawrence (KL) > 2 at any included study joint; symptomatic OA (sxOA) required both symptoms and rOA in a joint. Joint hypermobility was defined as a Beighton score of > 4. Separate logistic regression models were used to estimate odds ratios (OR) between joint hypermobility and each MJOA definition, adjusting for age, sex, race, body mass index, and baseline visit.

RESULTS

In this cohort, 4% had Beighton score > 4 and 63% met any definition of MJOA. Joint hypermobility was associated with significantly lower odds of radiographic and symptomatic MJOA-1 (multiple joint OA-definition 1: involvement of > 1 IP (interphalangeal) nodes and > 2 sites of hip, knee, and spine; 74 and 58% lower, respectively). However, for the other MJOA definitions (i.e., MJOA-2:involvement of > 2 IP joints, > 1 carpometacarpal [CMC] joints, and knee or hip sites; MJOA-3: involvement of > 5 joint sites from among distal interphalangeal, proximal interphalangeal, CMC, hip, knee, or spine sites; and MJOA-4:involvement of > 2 lower body sites (hip, knee, or spine), there were no statistically significant associations. For associations between site-specific hypermobility and any MJOA definition, most adjusted ORs were less than one, but few were statistically significant.

CONCLUSIONS

Overall, joint hypermobility was not positively associated with any definition of prevalent MJOA in this cohort, and an inverse association existed with one definition of MJOA. Longitudinal studies are needed to determine the contribution of hypermobility to the incidence and progression of MJOA outcomes.

Age-related reduction of trunk muscle torque and prevalence of trunk sarcopenia in community-dwelling elderly: Validity of a portable trunk muscle torque measurement instrument and its application to a large sample cohort study

Trunk muscle weakness and imbalance are risk factors for postural instability, low back pain, and poor postoperative outcomes. The association between trunk muscle strength and aging is poorly understood, and establishing normal reference values is difficult. We aimed to establish the validity of a novel portable trunk muscle torque measurement instrument (PTMI). We then estimated reference data for healthy young adults and elucidated age-related weakness in trunk muscle strength. Twenty-four university students were enrolled to validate values for PTMI, and 816 volunteers from the general population who were recruited to the Iwaki Health Promotion Project were included to estimate reference data for trunk muscle strength. Trunk flexion and extension torque were measured with PTMI and KinCom, and interclass correlation coefficients (ICC) were estimated to evaluate the reliability of PTMI values. Furthermore, from the young adult reference, the age-related reduction in trunk muscle torque and the prevalence of sarcopenia among age-sex groups were estimated. The ICC in flexion and extension torque were 0.807 (p<0.001) and 0.789 (p<0.001), respectively. The prevalence of sarcopenia increased with age, and the prevalence due to flexion torque was double that of extension torque. Flexion torque decreased significantly after 60 years of age, and extension torque decreased after 70 years of age. In males over age 80, trunk muscle torque decreased to 49.1% in flexion and 63.5% in extension. In females over age 80, trunk muscle torque decreased to 60.7% in flexion and 68.4% in extension. The validity of PTMI was confirmed by correlation with KinCom. PTMI produced reference data for healthy young adults, and demonstrated age-related reduction in trunk muscle torque. Trunk sarcopenia progressed with aging, and the loss of flexion torque began earlier than extension torque. At age 80, trunk muscle torque had decreased 60% compared with healthy young adults.

Quantitative genetics of circulating Hyaluronic Acid (HA) and its correlation with hand osteoarthritis and obesity-related phenotypes in a community-based sample

BACKGROUND

One of the potential molecular biomarkers of osteoarthritis (OA) is hyaluronic acid (HA). HA levels may be related to the severity and progression of OA. However, little is known about the contribution of major risk factors for osteoarthritis, e.g. obesity-related phenotypes and genetics to HA variation.

AIM

To clarify the quantitative effect of these factors on HA.

SUBJECTS AND METHODS

An ethnically homogeneous sample of 911 apparently healthy European-derived individuals, assessed for radiographic hand osteoarthritis (RHOA), HA, leptin, adiponectin, and several anthropometrical measures of obesity-related phenotypes was studied. Model-based quantitative genetic analysis was used to reveal genetic and shared environmental factors affecting the variation of the study's phenotypes.

RESULTS

The HA levels significantly correlated with the age, RHOA, adiponectin, obesity-related phenotypes, and the waist-to-hip ratio. The putative genetic effects contributed significantly to the variation of HA (66.2 ± 9.3%) and they were also significant factors in the variations of all the other studied phenotypes, with the heritability estimate ranging between 0.122 ± 4.4% (WHR) and 45.7 ± 2.2% (joint space narrowing).

CONCLUSIONS

This is the first study to report heritability estimates of HA variation and its correlation with obesity-related phenotypes, ADP and RHOA. However, the nature of genetic effects on HA and its correlation with other study phenotypes require further clarification.

Review of Prospects of Biological Fluid Biomarkers in Osteoarthritis

Osteoarthritis (OA) is a degenerative disease of the joints and is one of the leading causes of disability in adults. However, there are no key therapeutics for OA and medical treatment is based on managing the symptoms and slowing down progression of the disease. Diagnostics based on clinical examination and radiography have provided little information about metabolic changes in joint tissues, disease onset and progression. Due to lack of effective methods for early detection and evaluation of treatment outcome, the measurement of biochemical markers (biomarkers) shows promise as a prospective method aiding in disease monitoring. OA biomarkers that are present in biological fluids such as blood, urine and synovial fluid, sources that are easily isolated from body, are of particular interest. Moreover, there are increasingly more studies identifying and developing new biomarkers for OA. In this review, efforts have been made to summarize the biomarkers that have been reported in recent studies on patients. We also tried to classify biomarkers according to tissue metabolism (bone, cartilage and synovial metabolism markers), pathological pathways (inflammatory and genetic markers) and biological function (chemokines, growth factors, acute phase proteins, etc.).

Systemic inflammation and painful joint burden in osteoarthritis: a matter of sex?

OBJECTIVE

We investigated the association between serum levels of C-reactive protein (CRP) and the extent of multijoint pain among individuals with hip/knee osteoarthritis (OA) and determined whether the association differs by sex.

DESIGN

Serum CRP and cartilage oligomeric matrix protein (COMP) were determined by enzyme-linked immunosorbent assay (ELISA) in 189 individuals (101 female, 88 male) scheduled for total hip/knee arthroplasty for OA. Patients indicated on a homunculus all painful joints; a summed count was derived. A series of negative binomial regression models was used to investigate the cross-sectional association between painful joint count (outcome) and serum CRP concentrations, adjusting for age, sex, body mass index (BMI), comorbidity count and COMP. An interaction between sex and these biomarkers was tested.

RESULTS

Mean age: 66 among women, 65 among men. Women had higher mean joint count (3.7 vs 2.5, P < 0.01; 4+ joint count reported by 37% women, 25% men). Median CRP concentration was higher in women (15.4 mg/l vs 9.3, P = 0.07). From adjusted analyses, the effects of both ln(CRP) and ln(COMP) were modified by sex (P < 0.05). Increasing ln(CRP) was associated with greater painful joint count among women, but not men.

CONCLUSIONS

There may be a dose-response association between painful joint burden in OA and systemic inflammation, and it appears the association is sex-specific, which may in part explain inconsistent findings in the literature. Our results underline the importance of showing sex-specific associations in OA, especially when studying the influence of inflammation.

Association of clinical and radiographic signs of femoroacetabular impingement in the general population

BACKGROUND

The relationships between the clinical and radiographic signs of femoroacetabular impingement (FAI) are unknown. The purpose of this study was to assess the relationship between hip pain, a positive anterior impingement sign (AIS), and radiographic signs of FAI in a general Japanese population.

METHODS

A total of 616 individuals participated in this study. Hip pain was assessed using the Japanese Orthopaedic Association Hip-Disease Evaluation Questionnaire (JHEQ) pain category score and the AIS was used as a provocation test. Participants were divided into a positive AIS group (at least one positive hip) and a negative AIS group. Radiographs were assessed for the cross-over sign (COS), ischial spine sign (ISS), posterior wall sign (PWS), and pistol grip deformity (PGD). Then, the relationships between the clinical and radiographic signs of FAI were evaluated.

RESULTS

JHEQ pain scores did not differ between men and women. Seven men (3.4%) and 29 women (7.1%) had a least one hip with a positive AIS. The mean JHEQ pain scores were 22.9 ± 7.2 for the positive and 27.3 ± 2.2 for the negative AIS group (P < 0.01). The prevalences of COS, ISS, PWS, and PGD were 8.9%, 17.2%, 21.8%, and 1.9%, respectively. There were no significant associations between degree of hip pain, AIS, and each radiographic finding.

CONCLUSIONS

Radiographic signs of FAI were not associated with the degree of hip pain or a positive AIS, which suggests that radiographic findings may not be important in the clinical diagnosis of FAI.

Serum Collagen Type II Cleavage Epitope and Serum Hyaluronic Acid as Biomarkers for Treatment Monitoring of Dogs with Hip Osteoarthritis

The aim of this study was to evaluate the use of serum type II collagen cleavage epitope and serum hyaluronic acid as biomarkers for treatment monitoring in osteoarthritic dogs. For this purpose, a treatment model based on mesenchymal stem cells derived from adipose tissue combined with plasma rich in growth factors was used. This clinical study included 10 dogs with hip osteoarthritis. Both analytes were measured in serum at baseline, just before applying the treatment, and 1, 3, and 6 months after treatment. These results were compared with those obtained from force plate analysis using the same animals during the same study period. Levels of type II collagen cleavage epitope decreased and those of hyaluronic acid increased with clinical improvement objectively verified via force plate analysis, suggesting these two biomarkers could be effective as indicators of clinical development of joint disease in dogs.

Serum hyaluronic acid concentration predicts the progression of joint space narrowing in normal knees and established knee osteoarthritis - a five-year prospective cohort study

Introduction

Serum hyaluronic acid (sHA) is a serum biomarker for knee osteoarthritis (OA). Although sHA concentration is elevated in patients with knee OA, the relationship between serum concentration and disease progression remains unclear. We examined the relationship between sHA concentration and radiographic progression of knee OA in a cohort of individuals followed for 5 years.

Methods

We prospectively enrolled 444 individuals and measured their sHA concentrations at baseline. Anterior-posterior weight bearing knee radiographs were obtained at baseline and the 5-year endpoint. Osteoarthritic knee changes were classified according to Kellgren–Lawrence (KL) grade, and joint space narrowing (JSN) was measured using a Knee Osteoarthritis Computer-Aided Diagnosis (KOACAD) system. Correlations between sHA concentration, progression in KL grade, and JSN were assessed using regression models, taking into account potentially confounding factors.

Results

OA progressed from KL grades 0 or 1 in 129 of the 323 knees, and from KL grades 2 or 3 in 61 of the 119 knees. Higher sHA concentrations were correlated with KL grade progression (p = 0.004). The mean JSN, as assessed by KOACAD over 5 years, was 0.23 ± 0.55 mm, and sHA concentration was positively correlated with progression of JSN in KL grades 0 or 1 (p = 0.021) and KL grades 2 or 3 (p = 0.008) knees.

Conclusion

Serum HA concentration was positively correlated with progression of KL grade. sHA was also positively correlated with progression of JSN in knees with and without OA, suggesting that sHA concentration may be a useful predictor of knee OA progression.

Detection of urine C2C and trace element level in patients with knee osteoarthritis

The objective is to determine the relation between severity of knee osteoarthritis (KOA) and levels of Collagen type II metabolite (C2C) and trace elements in the urine. The urine sample and knee joint films (anteroposterior and lateral) from the KOA patients and control subjects were collected. The KOA patients were divided into five groups (controls and grades I-IV) according to the Kellgren-Lawrence radiographic grading standards. Urine levels of C2C and trace elements were detected by enzyme-linked immunosorbent assay and inductively coupled plasma atomic emission spectrometry, respectively. Urine C2C levels in the KOA subjects (261.235 ± 39.944 pg/ml) were higher than those of the control group (218.341 ± 22.270 pg/ml). The Fe content in KOA groups was significantly lower than that of control group (group IV > group III > group II > group I or controls). The contents of Cu and Zn were also significantly higher in the KOA patients than in the control group (p < 0.05). However, Cr, Al, Cd, Ni, and Se levels of KOA patients were not significantly different from those of the controls (p > 0.05). Determination of the urine levels of C2C and trace elements may prove to be informative for an early diagnosis of KOA. It can also assist in the prognosis judgment of the disease and selecting an appropriate therapeutic regimen.

The Difference between Growth Factor Expression after Single and Multiple Fractures: Preliminary Results in Human Fracture Healing

Objectives. Circulating levels of VEGF-A (Vascular Endothelia Growth Factor-A), TGF-β1 (Transforming Growth Factor-beta 1), and M-CSF (Macrophage-Colony Stimulating Factor) were found to be predictors of bone healing and therefore prognostic criteria of delayed bone healing or nonunion. The aim of this study was to evaluate a potential rise of these markers in patients with multiple fractures of long bones compared to patients with single fractured long bone. Methods. 92 patients were included in the study and finally after excluding all female patients 45 male patients were left for final analysis and divided into the single or multiple fracture group. TGF-β1, M-CSF, and VEGF-A serum levels were analysed over a time period of two weeks. Results. MCSF serum concentrations were higher in the group with multiple fractures as also TGF-β1 serum concentrations were at one and two weeks after trauma. No statistically significant difference was observed in the VEGF-A serum concentrations of both groups at either measurement point. Conclusion. We did observe a correlation between the quantity of the M-CSF and TGF-β1 expressions in serum and the number of fractured bones; surprisingly there was no statistically significant difference in the serum levels between patients with single and multiple fractures of long bones.

Dietary hyaluronic acid migrates into the skin of rats

Hyaluronic acid is a constituent of the skin and helps to maintain hydration. The oral intake of hyaluronic acid increases water in the horny layer as demonstrated by human trials, but in vivo kinetics has not been shown. This study confirmed the absorption, migration, and excretion of ¹⁴C-labeled hyaluronic acid (¹⁴C-hyaluronic acid). ¹⁴C-hyaluronic acid was orally or intravenously administered to male SD rats aged 7 to 8 weeks. Plasma radioactivity after oral administration showed the highest level 8 hours after administration, and orally administered ¹⁴C-hyaluronic acid was found in the blood. Approximately 90% of ¹⁴C-hyaluronic acid was absorbed from the digestive tract and used as an energy source or a structural constituent of tissues based on tests of the urine, feces, expired air, and cadaver up to 168 hours (one week) after administration. The autoradiographic results suggested that radioactivity was distributed systematically and then reduced over time. The radioactivity was higher in the skin than in the blood at 24 and 96 hours after administration. The results show the possibility that orally administered hyaluronic acid migrated into the skin. No excessive accumulation was observed and more than 90% of the hyaluronic acid was excreted in expired air or urine.