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PubMed2005

Fasting serum sulfate levels before and after development of osteoarthritis in participants of the veterans administration normative aging longitudinal study do not differ from levels in participants in whom osteoarthritis did not develop.

OBJECTIVE: To determine whether the development of osteoarthritis (OA) in men over a 33-year period is related to lower sulfate levels in stored serum collected during that time interval. METHODS: Stored serum samples from participants in the Veterans Administration Normative Aging Study were assayed for sulfate by ion-exchange chromatography. Samples had been obtained every 3-5 years during part or all of a 33-year portion of the study. Sulfate levels were determined in serum from all participants who underwent knee replacement surgery and had evidence of radiographic hand OA, from some of the participants who had evidence of radiographic hand OA but had not undergone knee replacement surgery, from all participants who underwent knee replacement surgery but had no evidence of radiographic hand OA, and from age-matched participants who had no evidence of OA by history, physical examination, or hand radiography. RESULTS: Serum sulfate levels in participants, with or without radiographic hand OA and/or knee replacements, who were ages 34-72 years at the first examination, ranged from 0.21 mM to 0.51 mM over the course of a maximum of 33 years. Both the overall mean and median sulfate levels rose from 0.32 mM at age 40-50 years to 0.38 mM at age 70-80 years, and the overall mean and median for all ages was 0.36 mM. There were no significant differences in sulfate levels between subjects in any of the 4 groups. CONCLUSION: There was no evidence of a relationship between these serum sulfate levels and the development of OA. However, all samples were collected after overnight fasting, and no participant was younger than age 34 years at the initiation of the study. It remains to be determined whether differences in the time of ingestion of daily dietary protein providing sulfate are related to the development of OA, or whether sulfate levels measured at an earlier age could be a factor.

Adult↗

PubMed1989

Osteoarthritis and bone: osteologic types of osteoarthritis of the hip.

To assess prognosis and indications for allografting articular surfaces, osteological examination is of increasing importance. In this study 93 femoral heads of patients with primary osteoarthritis could be differentiated into three osteologic types using histomorphometry: (1) the osteosclerotic type (77% of cases), (2) the hyperostotic type, with excessive neogenesis of bone all over the femoral head and increased formation of osteophytes (10% of cases), and (3) the osteopenic type, with decreased bone mass and features of bone remodelling, a greater occurrence of subchondral cysts, and small osteophytes (8% of cases). Radiological and clinical features to distinguish these groups are given. The consequences for pathogenesis and clinical practice are discussed.

Female↗

PubMed2004

MRI assessment of knee osteoarthritis: Knee Osteoarthritis Scoring System (KOSS)--inter-observer and intra-observer reproducibility of a compartment-based scoring system.

OBJECTIVE: To develop a scoring system for quantifying osteoarthritic changes of the knee as identified by magnetic resonance (MR) imaging, and to determine its inter- and intra-observer reproducibility, in order to monitor medical therapy in research studies. DESIGN AND PATIENTS: Two independent observers evaluated 25 consecutive MR examinations of the knee in patients with previously defined clinical symptoms and radiological signs of osteoarthritis. We acquired on a 1.5 T system: coronal and sagittal proton density- and T2-weighted dual spin echo (SE) images, sagittal three-dimensional T1-weighted gradient echo (GE) images with fat suppression, and axial dual turbo SE images with fat suppression. Images were scored for the presence of cartilaginous lesions, osteophytes, subchondral cysts, bone marrow edema, and for meniscal abnormalities. Presence and size of effusion, synovitis and Baker's cyst were recorded. All parameters were ranked on a previously defined, semiquantitative scale, reflecting increasing severity of findings. Kappa, weighted kappa and intraclass correlation coefficient (ICC) were used to determine inter- and intra-observer variability. RESULTS: Inter-observer reproducibility was good (ICC value 0.77). Inter- and intra-observer reproducibility for individual parameters was good to very good (inter-observer ICC value 0.63-0.91; intra-observer ICC value 0.76-0.96). CONCLUSION: The presented comprehensive MR scoring system for osteoarthritic changes of the knee has a good to very good inter-observer and intra-observer reproducibility. Thus the score form with its definitions can be used for standardized assessment of osteoarthritic changes to monitor medical therapy in research studies.

Aged↗

PubMed1991

Osteoarthritis, chiropractic, and nutrition: osteoarthritis considered as a natural part of a three stage subluxation complex: its reversibility: its relevance and treatability by chiropractic and nutritional correlates.

It is proposed that chiropractic and nutritional treatment contribute to the amelioration and perhaps reversal of osteoarthritis (OA). It is further proposed that the chiropractic manipulative thrust, is in effect, treating dysfunctional bio-mechanics of joints, affecting positive cartilaginous change. The pathophysiology and multi-factorial causes of OA are reviewed. New interpretations of the literature surrounding OA are discussed which offer arguments for OA's treatment and reversal through chiropractic manipulation and nutrutional support. Presented is a new model of the chiropractic concept of subluxation (abnormal joint complex resulting in fixation or decrease in normal range of motion) and the chiropractic manipulative thrust. The associated histologic correlates are also discussed. A review of the literature of anti-inflammatory and muscle/joint complex supportive nutrients appropriate for OA is presented. Finally, a complete treatment protocol for OA is summarized.

Animals↗

PubMed2006

Surgically induced osteoarthritis in the rat results in the development of both osteoarthritis-like joint pain and secondary hyperalgesia.

OBJECTIVE: In the present study, we sought to develop/characterize the pain profile of a rat model of surgically induced osteoarthritis (OA). METHODS: OA was surgically induced in male Lewis rats (200-225 g) by transection of the medial collateral ligament and medial meniscus of the femoro-tibial joint. In order to characterize the pain profile, animals were assessed for a change in hind paw weight distribution (HPWD), development of mechanical allodynia, and the presence of thermal and mechanical hyperalgesia. Rofecoxib and gabapentin were examined for their ability to decrease change in weight distribution and tactile allodynia. RESULTS: Transection of the medial collateral ligament and medial meniscus of male Lewis rats resulted in rapid (<3 days) changes in hind paw weight bearing and the development of tactile allodynia (secondary hyperalgesia). There was, however, no appreciable effect on thermal hyperalgesia or mechanical hyperalgesia. Treatment with a single dose of rofecoxib (10 mg/kg, PO, day 21 post surgery) or gabapentin (100mg/kg, PO, day 21 post surgery) significantly attenuated the change in HPWD, however, only gabapentin significantly decreased tactile allodynia. CONCLUSION: The rat medial meniscal tear (MMT) model mimics both nociceptive and neuropathic OA pain and is responsive to both a selective cylooxygenase-2 (COX-2) inhibitor commonly utilized for OA pain (rofecoxib) and a widely prescribed drug for neuropathic pain (gabapentin). The rat MMT model may therefore represent a predictive tool for the development of pharmacologic interventions for the treatment of the symptoms associated with OA.

Amines↗

PubMed2006

High molecular weight hyaluronic acid down-regulates the gene expression of osteoarthritis-associated cytokines and enzymes in fibroblast-like synoviocytes from patients with early osteoarthritis.

OBJECTIVE: Activated synoviocytes play important roles in the progression of human osteoarthritis (OA). Intra-articular injection of high molecular weight hyaluronic acid (HMW-HA) has been used as viscosupplementation for knee OA but its effect on synoviocytes remains undisclosed. This study aims to investigate the effects of HMW-HA on the gene expression of 16 OA-associated cytokines and enzymes, including interleukin (IL)-1beta, IL-6, IL-8, leukemia inhibitory factor (LIF), tumor necrosis factor (TNF)-alpha, TNF-alpha converting enzyme (TACE), matrix metalloproteinase (MMP)-1, MMP-2, MMP-3, MMP-9, MMP-13, tissue inhibitor of metalloproteinase (TIMP)-1, TIMP-2, aggrecanase-1, aggrecanase-2, and inducible nitric oxide synthase (iNOS), in fibroblast-like synoviocytes (FLS) from patients with early stage OA. METHOD: Synovial fluid-derived FLS were obtained from the knees of 15 patients with early stage OA. IL-1-stimulated or unstimulated FLS were cultured with or without the treatment of 600-800kDa HMW-HA. Moreover, blocking experiments with anti-CD44 monoclonal antibodies (mAb) were used to examine the involvement of CD44 in HMW-HA effects. We designed and validated the real-time quantitative polymerase chain reaction (Q-PCR) assays with SYBR Green dyes for simultaneous quantification of the expression of the 16 genes. RESULTS: HMW-HA down-regulated IL-8 and iNOS gene expression in unstimulated FLS and down-regulated aggrecanase-2 and TNF-alpha gene expression in IL-1-stimulated FLS. CD44 blocking inhibited the down-regulatory effects of HMW-HA on gene expression. CONCLUSION: HMW-HA may have a structure-modifying effect for OA by down-regulation of aggrecanase-2 in FLS. HMW-HA also has an anti-inflammatory effect by down-regulation of TNF-alpha, IL-8, and iNOS in FLS. These effects may be mediated through the interaction of CD44 and HMW-HA.

ADAM Proteins↗

PubMed2005

The effect of sonication on simulated osteoarthritis. Part II: alleviation of osteoarthritis pathogenesis by 1 MHz ultrasound with simultaneous hyaluronate injection.

In our previous study, we demonstrated the effects of ultrasound (US) on the delivery of hyaluronan (HA) into the synovium, even at molecular sizes as high as 3000 kDA. We hypothesized that a combined therapy with US and HA would have synergistic effects on alleviating the pathogenesis of osteoarthritis (OA). In the present study, we evaluated the effectiveness of sonication on the progress of induced OA in rabbits. We measured the cartilage degradation and inflammation, synovial fluid amount along with protein content and, finally, performed histologic analyses of the integrity of the cartilage and synovium. Low-intensity continuous US at 1 MHz, 400 mW/cm2 was applied to the knees for 10 min bid. Combined treatment with US and HA most strikingly reduced total synovial fluid volume and also significantly alleviated the OA-induced accretion of total protein, proteoglycan and prostaglandin E2 in the synovial fluid. It also attenuated the release of collagen type II and matrix metalloproteinase-3 in the OA-induced joint to normal levels. Histopathology revealed that combined HA and US treatment also reduced the severity of OA-induced structural damages in the cartilage and synovium. The effectiveness of HA with regard to the alleviation of OA pathogenic changes can be greatly enhanced by the simultaneous treatment with HA and US.

Animals↗

PubMed1983

Influence of primary generalised osteoarthritis on development of secondary osteoarthritis.

The hands and knees of 150 patients who had undergone unilateral meniscectomy 19 or more (mean 24 . 7) years before were examined for evidence of osteoarthritis (OA). 65 had X-ray changes in the hands consistent with primary generalised OA. These patients showed more frequent and more severe knee OA, judged clinically and radiologically, in both unoperated and operated knees, than did the 85 patients without hand OA. The increased frequency in operated knees was independent of sex and age variables between the groups and remained significant after exclusion of patients with OA on the unoperated side. This study demonstrated that predisposition to "primary" OA influences the development and severity of "secondary" OA. It invalidates clear distinction between these subsets and emphasises the multifactorial nature of the disease.

Adult↗

PubMed2000

Obesity, overweight and patterns of osteoarthritis: the Ulm Osteoarthritis Study.

The objective of this study was to assess the association between obesity and osteoarthritis (OA) of the knee, hip, and hand. OA patterns were studied in 809 patients with knee or hip joint replacement due to OA. Patients with OA were categorized as having bilateral or generalized OA according to the presence of radiographic OA in the contralateral joint or different finger joints, and as normal weight, overweight, or obese according to their body mass index (BMI). Odds ratios (OR) and 95% confidence intervals (CI) for relative weight and OA patterns were estimated with multivariable logistic regression. Eighty-five percent of participants had bilateral OA, 26% had generalized OA, and 31% were obese. Obesity (BMI >/= 30 kg/m(2); OR = 8.1; 95% CI: 2.4-28) and overweight (BMI >/= 25 kg/m(2); OR = 5.9; 95% CI: 2.0-18) were strongly associated with bilateral knee OA. No association between obesity and bilateral hip OA (OR = 0.7; 95% CI: 0.3-1.7) nor generalized OA (OR = 1.1; 95% CI: 0.6-2.1) was observed. Obesity seems to be a mechanical rather than a systemic risk factor for OA with the knee joint being especially susceptible.

Aged↗

PubMed2003

Reliability and validity of the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index in Italian patients with osteoarthritis of the knee.

OBJECTIVE: The Western Ontario and McMaster Universities (WOMAC) Osteoarthritis (OA) Index is a tested questionnaire to assess symptoms and physical functional disability in patients with OA of the knee and the hip. We adapted the WOMAC for the Italian language and tested its metric properties in 304 patients with symptomatic OA of the knee. METHODS: Three hundred and four consecutive patients, attending 29 rheumatologic outpatient clinic in northern, central, and southern Italy, were asked to answer two disease-specific questionnaires (WOMAC and Lequesne algofunctional index) and one generic instrument (Medical Outcomes Study SF-36 Health Survey-MOS SF-36). A sample of 258 patients was readministered the WOMAC 7-10 days after the first visit and the structured interview, which also assessed demographic and other characteristics. Internal consistency was assessed using Cronbach's alpha, reliability using intraclass correlation coefficients (ICCs), and construct and discriminant validity using Spearman's correlations, Wilcoxon rank sum test, and Kruskal-Wallis test. RESULTS: All WOMAC subscales (pain, stiffness, and physical function) were internally consistent with Cronbach's coefficient alpha of 0.91, 0.81, and 0.84, respectively. Test-retest reliability was satisfactory with ICCs of 0.86, 0.68, and 0.89, respectively. In comparison with the SF-36, the expected correlations were found when comparing items measuring similar constructs, supporting the concepts of convergent construct validity. Very high correlations were also obtained between WOMAC scores and Lequesne OA algofunctional index. WOMAC physical function, but not WOMAC stiffness and pain subscales, was weakly associated with radiological OA severity (P=0.03). Also, WOMAC pain score was inversely correlated (P=0.01) with years of formal education. Examination of discriminant validity showed that the scores on the WOMAC and SF-36 followed hypothesized patterns: the WOMAC discriminated better among subjects with varying severity of knee problems, whereas the SF-36 discriminated better among subjects with varying levels of self-reported health status and comorbidity. CONCLUSION: The Italian version of WOMAC is a reliable and valid instrument for evaluating the severity of OA of the knee, with metric properties in agreement with the original, widely used version.

Aged↗

PubMed1998

Efficacy and tolerability of oral chondroitin sulfate as a symptomatic slow-acting drug for osteoarthritis (SYSADOA) in the treatment of knee osteoarthritis.

Patients with osteoarthritis (OA) of the knee were treated with chondroitin sulfate (CS, Condrosulf, IBSA, Lugano, CH) in a randomized, double-blind, placebo-controlled study, performed in two centres. The efficacy and tolerability of oral CS capsules 2 x 400 mg/day vs placebo was assessed in a 6-month study period. Patients with idiopathic or clinically symptomatic knee OA, with Kellgren and Lawrence radiological scores I-III, were included in this trial. Clinical controls were performed at months 0, 1, 3 and 6. Eighty patients completed the 6-month treatment period. Lequesne's Index and spontaneous joint pain (VAS) decreased constantly in the CS group; on the contrary, slight variations of the scores were reported in the placebo group. The walking time, defined as the minimum time to perform a 20-meter walk, showed a statistically significant constant reduction only in the CS group. ANOVA with repeated measures showed a statistically significant difference in favor of the CS group for these three parameters. During the study, patients belonging to the placebo group reported a higher paracetamol consumption, but this consumption was not statistically different between the two treatment groups. Efficacy judgements were significant in favor of the CS group. Both treatments were very well tolerated. All these results strongly suggest that chondroitin sulfate acts as a symptomatic slow-acting drug in knee OA.

Activities of Daily Living↗

PubMed2000

Hand osteoarthritis and generalized osteoarthritis: a need for clarification.

A proportion of patients with osteoarthritis (OA) have polyarticular involvement and are categorized as having generalized OA (GOA). However, a widely accepted definition of GOA does not exist. The topography of affected joints as well as the threshold number of affected joints used in defining GOA remain unidentified. According to number, site and clustering of affected joints, various subtypes of GOA, possibly related to different genetic factors, may exist. Such subtypes have still to be clearly identified. Among them, the association of hand and knee OA emerges as a probable subtype. Polyarticular involvement of hand joints is common, but may include various subtypes of differing significance. Further studies are needed to clarify the definition of GOA.

Diagnosis, Differential↗

PubMed2001

The development of a disease-specific quality of life measurement tool for osteoarthritis of the shoulder: The Western Ontario Osteoarthritis of the Shoulder (WOOS) index.

OBJECTIVE: The purpose of this study was to develop and validate a disease-specific quality of life measurement tool for osteoarthritis (OA) of the shoulder. METHODS: An instrument which could be used as the primary outcome measure in clinical trials involving patients with OA of the shoulder was developed using a specific methodological protocol: (1) identification of a specific patient population; (2) item generation; (3) item reduction; (4) pre-testing of the prototype questionnaire and (5) determining the validity, reliability and responsiveness of the final questionnaire. RESULTS: The final instrument contains 19 items, each with a visual analog response option for the four domains (six questions for pain and physical symptoms, five questions for sport, recreation and work, five questions for lifestyle function and three questions for emotional function). Ten of the 19 questions had not been identified previously on other shoulder measurement tools. The instrument proved to be valid by demonstrating predicted correlations with previously published shoulder measures, global health status measure and range of motion. The new instrument was also more responsive than other shoulder measurement tools, a global health status measure and range of motion. CONCLUSIONS: Since the patient's own perception of changes in health status is the most important indicator of the success of treatment we suggest that this measurement tool be used as the primary outcome in clinical evaluation of various treatments for OA of the shoulder and monitoring patients over time.

Adult↗

PubMed2002

Dimensionality and clinical importance of pain and disability in hand osteoarthritis: Development of the Australian/Canadian (AUSCAN) Osteoarthritis Hand Index.

OBJECTIVE: To develop a reliable, valid, and responsive self-administered questionnaire to probe pain, stiffness and physical disability in patients with osteoarthritis (OA) of the hand. DESIGN: In order to assess the dimensionality of the symptomatology of hand OA, a self-administered questionnaire was developed to probe various aspects of pain (10 items), stiffness (two items), and physical function (83 items). The question inventory was generated from eight existing health status measures and an interactive process involving four rheumatologists, two physiotherapists, and an orthopaedic surgeon. RESULTS: Face-to-face interviews were conducted with 50 OA hand patients; 39 females and 11 males with mean age 62.8 years and mean disease duration 9.4 years. Items retained were those which fulfilled specified selection criteria: prevalence > or =60% and mean importance score approximating or exceeding 2.0 Item exclusion criteria included low prevalence, gender-based, ambiguous, duplicates or similarities, alternatives, composite items, and items that were too restrictive. This process resulted in five pain, one stiffness and nine function items which have been proposed for incorporation in the AUSCAN Index. CONCLUSIONS: Using a traditional development strategy, we have constructed a self-administered multi-dimensional outcome measure for assessing hand OA. The next stage includes reliability, validity and responsiveness testing of the 15-item questionnaire.

Activities of Daily Living↗

PubMed2000

Serum uric acid and patterns of radiographic osteoarthritis--the Ulm Osteoarthritis Study.

OBJECTIVE: To assess the association between uric acid and patterns of osteoarthritis (OA). METHODS: OA patterns were studied in 809 patients with arthroplasty due to hip or knee OA. Patients with OA were categorized as having bilateral or generalized OA according to the presence of radiographic OA in the contralateral or different finger joints. Odds ratios (OR) and 95% confidence intervals (CI) for thirds of serum uric acid and OA patterns were estimated with multivariable logistic regression. RESULTS: Eighty-five percent of the participants had bilateral OA and 26% generalized OA. A positive association between serum uric acid and generalized OA was observed in patients with hip OA (highest versus lowest tertile OR=3.5; 95% CI: 1.3-9.1), but not among patients with knee OA (corresponding OR = 1.1). Serum uric acid was not associated with bilateral OA. CONCLUSION: Our results suggest a possible role of elevated serum uric acid in the multifactorial etiology of generalized OA.

Aged↗

PubMed1999

WOMAC osteoarthritis index. Reliability, validity, and responsiveness in patients with arthroscopically assessed osteoarthritis. Western Ontario and MacMaster Universities.

OBJECTIVE: To validate the WOMAC Osteoarthritis Index for use in Sweden. METHODS: Test-retest reliability, internal consistency, validity, and responsiveness was determined in 52 patients (mean age 48 (20-69)) with arthroscopically assessed cartilage damage of the tibio-femoral knee joint. RESULTS: All WOMAC scales were internally consistent with Cronbach's alpha coefficients of 0.83, 0.87, and 0.96 pre-operatively. Test-retest reliability was satisfactory with intraclass correlation coefficients of 0.74, 0.58, and 0.92. As hypothesized worse post-operative but not pre-operative outcomes were associated with radiographic OA. In comparison with the SF-36 the expected correlations were found when comparing items measuring similar and dissimilar constructs, supporting the concepts of convergent and divergent construct validity. Three months after arthroscopy significant mean improvement was seen in all WOMAC scales (p<0.0004). CONCLUSION: The Swedish version of WOMAC is a reliable, valid, and responsive instrument with metric properties in agreement with the original widely used version.

Adult↗

PubMedDate not supplied

Glucosamine sulfate reduces osteoarthritis progression in postmenopausal women with knee osteoarthritis: evidence from two 3-year studies.

OBJECTIVE: To investigate the effect of glucosamine sulfate on long-term symptoms and structure progression in postmenopausal women with knee osteoarthritis (OA). DESIGN: This study consisted of a preplanned combination of two three-year, randomized, placebo-controlled, prospective, independent studies evaluating the effect of glucosamine sulfate on symptoms and structure modification in OA and post-hoc analysis of the results obtained in postmenopausal women with knee OA. Minimal joint space width was assessed at baseline and after 3 years from standing anteroposterior knee radiographs. Symptoms were scored by the algo-functional WOMAC index at baseline and after 3 years. All primary statistical analyses were performed in intention-to-treat, comparing joint space width and WOMAC changes between groups by ANOVA. RESULTS: Of 414 participants randomized in the two studies, 319 were postmenopausal women. At baseline, glucosamine sulfate and placebo groups were comparable for demographic and disease characteristics, both in the general population and in the postmenopausal women subset. After 3 years, postmenopausal participants in the glucosamine sulfate group showed no joint space narrowing [joint space change of +0.003 mm (95% CI, -0.09 to 0.11)], whereas participants in the placebo group experienced a narrowing of -0.33 mm (95% CI, -0.44 to -0.22; P < 0.0001 between the two groups). Percent changes after 3 years in the WOMAC index showed an improvement in the glucosamine sulfate group [-14.1% (95%, -22.2 to -5.9)] and a trend for worsening in the placebo group (5.4% (95% CI, -4.9 to 15.7) (P = 0.003 between the two groups). CONCLUSION: This analysis, focusing on a large cohort of postmenopausal women, demonstrated for the first time that a pharmacological intervention for OA has a disease-modifying effect in this particular population, the most frequently affected by knee OA.

Dietary Supplements↗

PubMed2004

Differential adherence of osteoarthritis and rheumatoid arthritis synovial fibroblasts to cartilage and bone matrix proteins and its implication for osteoarthritis pathogenesis.

In osteoarthritis (OA), cartilage and bone fragments have been described within the synovial tissue which are surrounded by synovial cells (i.e. detritus synovitis). These cells appear to attach actively to the cartilage and bone fragments. In rheumatoid arthritis (RA), on the other hand, synovial fibroblasts (SF) have also been shown to be localized at sites of invasion into cartilage and bone and to degrade extracellular matrix (ECM) by secreting proteolytic enzymes. One prerequisite for exerting their aggressive properties is the attachment to cartilage and bone ECM. This attachment appears to be mediated by the expression of different adhesion molecules for which corresponding binding sites on ECM components are known. As it has not been addressed to which ECM proteins SF adhere and with which affinity this process takes place, we investigated the adherence of SF from patients with OA and RA to different cartilage and bone matrix proteins. Synovial tissue samples were obtained during synovectomy or arthroplastic surgery and used for isolating and culturing SF. Synovial cells attaching to cartilage/bone fragments were characterized using immunohistochemistry. The adherence of SF to ECM proteins was examined using an adhesion assay with the following proteins coated on 96-well plates: aggrecan (AGG), bone sialoprotein (BSP), cartilage oligomeric matrix protein (COMP), collagen type I, II and VI, proline arginine-rich, end leucine-rich repeat protein (PRELP), osteopontin (OPN) and recombinant chondroadherin (CHAD). Bovine serum albumin was used as negative control. In addition, adhering fibroblasts were photographed using a phase-contrast microscope. As compared with RA-SF, significantly higher numbers of OA-SF adhering to collagen type II, OPN and CHAD could be detected (P < 0.05). In contrast, RA-SF showed increased attachment to collagen type II, OPN and BSP. Adhesion to AGG, COMP and PRELP appeared not to be significantly increased and differed widely among the SF samples, and, apart from one exception (BSP), OA-SF adhered in higher numbers to the matrix proteins than did RA-SF. Using immunohistochemistry, synovial cells attached to cartilage/bone fragments could be shown to predominantly express CD68 (>/=50%). The CD68-negative population was of the fibroblast phenotype (AS02 positive). The study demonstrates that the binding pattern of OA-SF and RA-SF to ECM proteins differs considerably and therefore provides novel insights into the difficult pathophysiology of OA and RA. In general, it appeared that SF adhere primarily to ECM proteins that contain known binding sites for adhesion molecules (e.g. integrins: collagen/integrin alpha(2)beta(1)) and that higher numbers of OA-SF adhered to the cartilage and bone matrix proteins than did RA-SF.

Arthritis, Rheumatoid↗