Clinical and radiological factors associated with erosive radiographic progression in hand osteoarthritis.

OBJECTIVE: To identify prognostic factors of erosive progression in hand osteoarthritis (OA). METHOD: One hundred and fifty-four patients with hand OA were selected from an earlier cohort. X-rays, clinical and demographic data at baseline were present. All patients were seen for a follow-up between January and March 2014. Interphalangeal (IP) finger joints were scored on both radiographs using the anatomical scoring system. Radiographic progression was defined as a joint progressing from at least one anatomical phase, excluding the progression from a 'Normal' to 'Stationary' phase. Odds ratios (OR) and 95% confidence intervals (95% CI) of potential clinical and radiographic prognostic factors were calculated on joint, hand and patient level with a generalized estimating equation (GEE) model. RESULTS: Radiographic progression, including progression from 'N' to 'S' phase, was present in 1014 of 2750 joints (36.9%) after a mean follow-up of 5.8 years. On joint level, the following clinical factors were associated with radiographic progression (OR [95% CI]): presence of pain (1.48 [1.01-2.15]), tenderness (2.18 [1.56-3.05]), and soft tissue swelling (2.56 [1.54-4.24]). The following radiographic variables were significantly associated with erosive progression: presence of 'J' (16.74 [9.09-30.83]) and 'E' phase (76.34 [42.17-138.23]). On hand and patient level, soft tissue swelling, 'J' and 'E' phase were retained as prognostic factors. CONCLUSION: Pain, tenderness, soft tissue swelling, 'J' and 'E' phase were significantly associated with erosive progression in hand OA. These prognostic factors should be confirmed in further studies and considered when selecting patients for therapeutic trials with potential disease-modifying osteoarthritis drugs (DMODs).

3 T DCE-MRI assessment of synovitis of the interphalangeal joints in patients with erosive osteoarthritis for treatment response monitoring.

OBJECTIVE: To study the value of 3 T dynamic contrast-enhanced (DCE)-MRI for assessment of synovitis of the interphalangeal joints in patients with erosive osteoarthritis (EOA) for treatment response monitoring. MATERIALS AND METHODS: The interphalangeal joints of fingers two to five were examined at 3 T MRI in nine patients with EOA. Two musculoskeletal radiologists recorded erosions, bone marrow oedema (BME), synovitis and osteophytes. Interobserver reliability was calculated using κ statistics. In six patients, DCE-MRI time intensity curves of synovitis in two affected joints were analysed. The maximum upslope, absolute and relative enhancement of synovitis were compared with MRI after 12 months of anti-tumour necrosis factor treatment. Intraobserver reproducibility was calculated using intra-class correlation coefficient. RESULTS: Interobserver reliability was 'good' for detection of erosions (κ = 0.70), BME (κ = 0.77) and synovitis (κ = 0.77), but 'poor' for osteophytes (κ = 0.12). Post-treatment DCE-MRI showed decreasing maximum upslope (p = 0.002) and absolute (p = 0.002) and relative (p = 0.01) enhancement compared to the initial scan. Intraobserver reproducibility of DCE-MRI was 'almost perfect' or 'strong' for all parameters. CONCLUSIONS: 3 T DCE-MRI demonstrates changes in time intensity curves of synovitis in EOA of the interphalangeal joints in a longitudinal study, indicating this technique is promising for monitoring therapy response.

First insights into human acetabular labrum cell metabolism.

OBJECTIVE: Hip labrum pathology has only begun to emerge as a significant source of groin pain in the last decade since the development of hip arthroscopy. Few data are available on the anatomy, histology and function of this structure. Moreover, no metabolic data exist at cellular level. The aim of this study was to characterize extracellular matrix (ECM) genes and pro-inflammatory mediators expressed by these cells. METHODS: Isolated human acetabular labrum cells were cultured in alginate beads for 10 days and additionally stimulated with interleukin (IL)-1 for 24 h. Gene expression levels and secretion of different ECM genes, enzymes and cytokines were examined by quantitative polymerase chain reaction (qPCR) and enzyme-linked immunosorbent assay (ELISA) to assess the metabolic characteristics of labrum cells. Articular chondrocytes and meniscus cells served as controls. RESULTS: Labrum cells expressed high levels of COL1A1 and low levels of COL2A1, aggrecan and SOX-9 compared to chondrocytes. However, COL2A1 was more expressed by labrum cells than by meniscus cells. The expression of matrix metalloproteinase (MMP)-1/-2/-9, ADAMTS-4 and IL-6 was significantly higher in labrum cells than in chondrocytes. IL-1 suppressed the ECM gene expression levels of labrum cells, but increased the expression levels and release of MMP-1/-3/-9/-13 and ADAMTS-4 and IL-6 by these cells. Remarkably, MMP-9 was only significantly upregulated in acetabular labrum cells. CONCLUSIONS: The findings in this study demonstrated that the acetabular labrum is populated with unique highly active fibrochondrocyte-like cells. These cells are capable of expressing and releasing pro-inflammatory enzymes and cytokines and react to a pro-inflammatory stimulus. In this way, they contribute obviously to disturbed tissue function in hip labrum pathology.

The combination of microfracture and a cell-free polymer-based implant immersed with autologous serum for cartilage defect coverage.

PURPOSE: The purpose of this short-term pilot study was to determine the clinical and MRI outcome of a combination of microfracture with a cell-free polymer-based matrix for the treatment of cartilage defects in the knee. METHODS: The technique was used for treatment of symptomatic cartilage defects in the knee. Five patients were prospectively evaluated during 2 years with use of the Knee injury and Osteoarthritis Outcome Score (KOOS), the Tegner activity scale and the visual analog scale (VAS). MRI data were analyzed based on the original and modified MOCART (Magnetic Resonance Observation of Cartilage Repair Tissue) scoring system at 6, 12 and 24 months of follow-up. RESULTS: A gradual clinical improvement was observed during the follow-up. Adverse reactions to the matrix were not observed. The scaffold was firmly fixed with the use of bioresorbable pins. Both MOCART scoring systems revealed no significant deterioration or improvement in the repair tissue during the follow-up period. However, the majority of the patients exhibited subchondral lamina and bone changes. The formation of an intralesional osteophyte was observed in one case. CONCLUSIONS: The key finding in this study was that this procedure is safe for the treatment of cartilage defects in the knee. The patients showed a gradual clinical improvement postoperatively. Sixty percent (3/5) of the defects were adequately (complete or hypertrophic) filled with repair tissue at 2 years of follow-up. LEVEL OF EVIDENCE: IV.

Short-term outcome of the second generation characterized chondrocyte implantation for the treatment of cartilage lesions in the knee.

PURPOSE: To evaluate short-term clinical and MRI outcome of the second generation characterized chondrocyte implantation (CCI) for the treatment of cartilage defects in the knee. METHODS: Thirty-two patients aged 15-51 years with single International Cartilage Repair Society (ICRS) grade III/IV symptomatic cartilage defects of different locations in the knee were treated with CCI using a synthetic collagen I/III membrane to cover the defect. Clinical outcome was measured over 36 months by the Knee injury and Osteoarthritis Outcome Score (KOOS) and Visual Analogue Scale (VAS) for pain. Serial magnetic resonance imaging (MRI) scans of 22 patients were scored using the original and modified Magnetic resonance Observation of Cartilage Repair Tissue (MOCART) system. RESULTS: The patients included in this study showed a significant gradual clinical improvement after CCI. The MRI findings of this pilot study were considered to be promising. No signs of deterioration were observed. A complete or hypertrophic filling was observed in 76.5% of the cases at 24 months of follow-up. No preventive effect of an avital membrane on the occurrence of hypertrophic repair tissue was observed on MRI. Three failures were observed among the 32 patients until now (9.4%). CONCLUSIONS: This investigation provided useful information on the efficacy of this treatment. The short-term clinical and MRI outcome are promising. Large-scale and long-term trials are mandatory to confirm the results and the reliability of this procedure. LEVEL OF EVIDENCE: IV.

Autologous matrix-induced chondrogenesis combined with platelet-rich plasma gel: technical description and a five pilot patients report.

PURPOSE: This pilot study was designed to describe the technical details and to present the preliminary outcome of autologous matrix-induced chondrogenesis (AMIC) combined with platelet-rich plasma gel, the so called AMIC plus technique, for the treatment of patellar cartilage defects in the knee. METHODS: The AMIC plus technique was used for the treatment of (osteo) chondral patellar lesions in the knee. The surgical technique is extensively described. Five patients were clinically prospectively evaluated during 2 years. MRI data were analysed based on the original MOCART (Magnetic Resonance Observation of Cartilage Repair Tissue) and modified MOCART scoring system. RESULTS: A clinical improvement became apparent after 24 months of follow-up. Both MOCART scoring systems revealed no significant deterioration or improvement of the repair tissue between one and 2 years of follow-up. However, all cases showed subchondral lamina and bone changes. The formation of intralesional osteophytes was observed in 3 of the 5 patients during the 2 years of follow-up. CONCLUSIONS: AMIC plus is feasible for the treatment of symptomatic patellar cartilage defects and resulted in a clinical improvement in all patients. The favourable clinical outcome of the AMIC plus technique was not confirmed by the MRI findings. LEVEL OF EVIDENCE: IV.

Proteome characterization of human articular chondrocytes leads to novel insights in the function of small heat-shock proteins in chondrocyte homeostasis.

OBJECTIVE: In recent years, studies have been initiated to disclose the proteome of human chondrocytes and cartilage. Despite these studies, comprehensive information of the chondrocyte proteome remains limited. This study aimed to further explore the proteome expressed by human knee chondrocytes, and to study the functional aspects of heat-shock protein 27 (HSP27), a protein related to the previously described alphaBcrystallin, in chondrocyte biology. METHODS: Chondrocytes isolated from human knee articular cartilage were cultured in a three-dimensional alginate culture system. To simplify the protein mixtures, proteins extracted from chondrocyte cell lysates were fractionated based on hydrophobicity and molecular weight. Proteins were digested and the resulting peptides were separated and identified by an on-line two-dimensional (2-D) nanoliquid chromatography (nanoLC)-system coupled to a quadrupole time-of-flight (Qq-TOF) mass spectrometer. Differential expression analysis of HSP27 was performed by Western Blotting and quantitative polymerase chain reaction (QPCR). The effects of HSP27 on chondrocyte biology were explored by suppression of HSP27 expression induced by RNA interference (RNAi). RESULTS: In this study, we identified proteins with unknown functions together with membrane proteins, transcription factors and other low abundant proteins, which have not yet been described in chondrocytes. Based on previous knowledge on the related protein alphaBcrystallin, we selected HSP27 from the chondrocyte proteome database. Differential expression analysis revealed a decreased expression of HSP27 in Osteoarthritic (OA) chondrocytes. RNAi experiments revealed that HSP27 is involved in interleukin-1beta (IL-1beta) induced IL-6 secretion. CONCLUSION: These findings highlight that small HSPs, especially HSP27, play a prominent role in the maintenance of human articular chondrocyte homeostasis.

Reversible changes in serum immunoglobulin galactosylation during the immune response and treatment of inflammatory autoimmune arthritis.

OBJECTIVES: Improved DNA sequencer-aided fluorophore-assisted carbohydrate electrophoresis (DSA-FACE) technology was used to monitor the changes in the galactosylation status of serum immunoglobulins during the immune response and therapy of autoimmune arthritis. METHODS: Collagen-induced arthritis (CIA) was induced in susceptible DBA/1 mice and the undergalactosylation status (UGS) of serum immunoglobulins was determined using the improved DSA-FACE technology. Prophylactic intravenous tolerisation with type II collagen as well as semitherapeutic treatment with dexamethasone (DEX) were performed and UGS was analysed. Next, the serum immunoglobulin glycosylation profiles of patients with rheumatoid arthritis (RA) and spondyloarthropathy (SpA) were studied and changes in the UGS scores during anti-tumour necrosis factor (TNF)alpha therapy followed. RESULTS: In the longitudinal CIA study, the undergalactosylation state of immunoglobulins was found to be significantly correlated with the clinical arthritis scores. Upon collagen-specific tolerisation as well as glucocorticoid semitherapeutic treatment, improvement of the clinical arthritis scores correlated with decreased levels of UGS. It was also demonstrated that withdrawal of DEX was associated with an increased UGS score. Interestingly, reversibility in the UGS was also shown during treatment of patients with RA and SpA with anti-TNFalpha. CONCLUSIONS: These findings demonstrate that the UGS of serum immunoglobulins changes during the disease course of CIA and that this UGS is inhibited by antigen-specific and antigen-independent treatment procedures. The observation that Ig galactosylation is a reversible process is also documented during treatment of patients with RA and SpA with anti-TNFalpha.

EULAR evidence-based recommendations for the diagnosis of hand osteoarthritis: report of a task force of ESCISIT.

OBJECTIVES: To develop evidence-based recommendations for the diagnosis of hand osteoarthritis (OA). METHODS: The multidisciplinary guideline development group, representing 15 European countries, generated 10 key propositions regarding diagnosis using a Delphi consensus approach. For each recommendation, research evidence was searched for systematically. Whenever possible, the sensitivity, specificity and likelihood ratio (LR) were calculated; relative risk and odds ratios were estimated for risk factors for hand OA. Quality of evidence was categorised using the European League Against Rheumatism (EULAR) hierarchy, and strength of recommendation was assessed by the EULAR visual analogue scale. RESULTS: Diagnostic topics included clinical manifestations, radiographic features, subgroups, differential diagnosis, laboratory tests, risk factors and comorbidities. The sensitivity, specificity and LR varied between tests depending upon the cut-off level, gold standard and controls. Overall, no single test could be used to define hand OA on its own (LR <10) but a composite of the tests greatly increased the chance of the diagnosis. The probability of a subject having hand OA was 20% when Heberden nodes alone were present, but this increased to 88% when in addition the subject was over 40 years old, had a family history of nodes and had joint space narrowing in any finger joint. CONCLUSION: Ten key recommendations for diagnosis of hand OA were developed using research evidence and expert consensus. Diagnosis of hand OA should be based on assessment of a composite of features.

Cross-cultural adaptation of the Dutch version of the Functional Index for Hand Osteoarthritis (FIHOA) and a study on its construct validity.

OBJECTIVE: To validate a cross-culturally translated and adapted Dutch version of the Functional Index for Hand Osteoarthritis (FIHOA) in patients with osteoarthritis (OA) of the hands and to evaluate its construct validity by comparing with the Australian/Canadian Osteoarthritis Hand Index (AUSCAN). METHODS: The FIHOA was translated into Dutch and cross-culturally adapted. The questionnaire was administered to 72 patients with hand OA (female/male ratio: 64/8, handedness: right: 62/left: 7/both: 3). A visual analogue scale (VAS) pain scale (100mm) and the AUSCAN questionnaire were also recorded. An item-item analysis was performed. Test-retest reliability (time interval: 5 days) was assessed in 21 patients with intraclass correlation coefficient (ICC) and Bland and Altman graphical method. Construct validity was assessed by Spearman rank correlation coefficient between the FIHOA and AUSCAN. RESULTS: Internal consistency was high (Cronbach's alpha=0.89). All items, except for one ('Are you able to clench the fist?'), and the mean total FIHOA scores were statistically different between the subgroups based on the VAS (mean total score=7.46 and 14.19, in a-/mild symptomatic and symptomatic group, respectively (P<0.001)). The Spearman's correlation between all subscales of the AUSCAN (pain, stiffness, functionality) and the FIHOA was good, especially with the subscale functionality (r=0.81, P<0.01). Test-retest reliability was excellent with an ICC of 0.96 for the total score and the Bland and Altman plot showing a homogeneous distribution of the differences. CONCLUSION: The psychometric properties of the Dutch version of the FIHOA are excellent. There is a good correlation between the FIHOA and all subscales of the AUSCAN, especially the subscale functionality.

Sensitivity and specificity of criteria for spondyloarthritis in children with late onset pauciarticular juvenile chronic arthritis as well as their characteristics.

OBJECTIVE: To evaluate the sensitivity and specificity of criteria designed for spondyloarthritis in a university hospital treated population of children with late onset pauciarticular juvenile chronic arthritis and a control population. METHODS: Four sets of criteria especially designed for juvenile patients: Garmisch-Partenkirchen juvenile spondylitis criteria (= Garmisch), SEA (=seronegative enthesopathy and arthritis) syndrome, Enthesitis Related Arthritis (ERA), Atypical spondyloarthritis for children and two sets of criteria for patients without age specification (European spondyloarthropathy Study Group - ESSG and Amor) were evaluated in a cross-sectional way in a group of 43 consecutive patients with late onset pauciarticular juvenile chronic arthritis (LOPA) seen over a six-month period in the outpatient clinic. These criteria were analysed in 69 patients with other forms of juvenile chronic arthritis as well. The sensitivity and specificity were calculated for each set, as well as positive predictive value and likelihood ratio. The characteristics described in the different sets of criteria were separately evaluated in the LOPA patients and the other patients. RESULTS: For sensitivity, the Garmisch criteria scored the highest value (97.7%). However, sensitivity was significantly lower in two of the juvenile sets (SEA syndrome and Atypical spondyloarthritis), respectively 44.2% and 51.2%, as opposed to the other criteria (>85%; p<0.01 by Mc Nemar test). Specificity and positive predictive value (PPV) was the highest for the SEA syndrome criteria (98.5%, vs. 95.0%) followed by the ERA (95.6 % vs. 92.1 %) and the Garmisch criteria (94.2% vs. 91.3%). The positive likelihood ratio (LR+) was >10 in SEA (30.5), ERA (18.7) and Garmisch (16.8). The negative likelihood ratio (LR-) was <0.1 only in the Garmisch criteria (0.02). CONCLUSION: Sensitivity, specificity, PPV, LR+ and LR- for the Garmisch-Partenkirchen criteria suggest that they classify almost the same population as defined by LOPA. The SEA syndrome criteria, which were not designed to be classification criteria, being very specific, cannot be used in this patient population to classify a sufficient number of patients. The sensitivity and specificity for the ESSG criteria being similar in these children as in adults suggest they have similar characteristics. The Garmisch-Partenkirchen criteria and/or LOPA definition are major candidates for future research in identifying spondyloarthritis in juvenile patients.

Cyclodextrin polysulphate protects articular cartilage in experimental lapine knee osteoarthritis.

OBJECTIVE: To evaluate the in vivo chondroprotective effect of cyclodextrin polysulphate (CDPS) in a rabbit model of experimental osteoarthritis (OA). DESIGN: Experimental OA was induced in rabbits by anterior cruciate ligament transection (ACLT). Forty-eight hours post-surgery, the rabbits were randomised into three treatment groups (n=15 in each group) and a sham-operated control group. The rabbits were either injected subcutaneously with saline, 0.25 mg/kg CDPS or 1 mg/kg CDPS once a week for a period of 12 weeks, and their weight was monitored as a parameter for their general status. The animals were then sacrificed for macroscopic and histological assessment of the knee joints. RESULTS: At the lowest dose, CDPS treatment was unable to induce a significant improvement of cartilage degradation vs the saline control in the experimentally induced knee OA. However, subcutaneous injections of 1 mg/kg CDPS induced a marked inhibition (P<0.05) of osteophyte formation. Additionally, a significant reduction of cartilage degradation revealed an overall chondroprotective effect of CDPS at a concentration of 1 mg/kg. No significant effects on weight gain were noted. CONCLUSIONS: Systemic administration of CDPS is able to protect cartilage in vivo and can therefore be considered as a chondroprotective agent with structure modifying capacities.

Chemical agents and enzymes used for the extraction of gut lymphocytes influence flow cytometric detection of T cell surface markers.

Chemical agents (DTT, EDTA) and enzymes (collagenase, DNAse) are often used for the generation of a single cell suspension from tissue samples. In this study, flow cytometry was used to examine the effect of chemical agents and enzymes on the expression of cell membrane markers of T lymphocytes from tonsils and peripheral blood. Expression of CD4, CD8, CD25, CD38, L-selectin, CD44, alphaEbeta7 and alpha4beta7 were studied. Incubation of lymphocytes with DTT and EDTA resulted in a decrease of CD38, alphaEbeta7 and alpha4beta7 expression. Incubation with collagenase A and DNAse resulted in a decrease of CD25, L-selectin, alphaEbeta7 and alpha4beta7. The results of this study indicate that a careful interpretation is necessary for phenotypic descriptions of lymphocyte populations obtained by enzymatic isolation techniques.

Focal up-regulation of E-cadherin-catenin complex in inflamed bowel mucosa but reduced expression in ulcer-associated cell lineage.

The E-cadherin-catenin complex is important for the maintenance of epithelial architecture. We studied its expression in Crohn disease, ulcerative colitis, acute ileitis, and controls. Immunohistochemical stainings for E-cadherin, alpha-catenin, beta-catenin and gamma-catenin were performed. E-cadherin messenger RNA (mRNA) was detected using riboprobes. In active inflammation, there was up-regulation of the complex. In particular, epithelium adjacent to ulcers showed increased expression of protein and mRNA, but in ulcer-associated cell lineage, the intensity of staining was weak to negative. In focal inflammation, up-regulation was found in affected areas. Reparative epithelium growing over denuded areas showed weaker expression. Since structural or functional perturbation in any of the molecules of the E-cadherin-catenin complex results in loss of intercellular adhesion, the preexistent epithelium may benefit from up-regulation to try to maintain its normal architecture under inflammatory conditions. Reduced expression in reparative epithelium and ulcer-associated cell lineage could facilitate the motility of these cells.

Intra-articular injection pentosanpolysulphate results in increased hyaluronan molecular weight in joint fluid.

The influence of an oversulphated glycosaminoglycan, pentosanpolysulphate, on hyaluronan metabolism of the synovial lining cell was studied in vivo in human volunteers. Significant increases in the mean degree of polymerisation of the hyaluronan chains were observed after a series of four to six intra-articular injections of this glycosaminoglycan. No increases in hyaluronan synthesis rates were observed. Repeated administration of the drug did not cause any inflammation or bleeding in the joint cavity.

Goldsalts, levamisole and D-penicillamine as first choice slow-acting antirheumatic drugs in rheumatoid arthritis--a long-term follow-up study.

In the present study, 345 rheumatoid arthritis patients were treated using goldsalts, D-Penicillamine or levamisole as the slow-acting antirheumatic drug of first choice. Goldsalts were given to 182 patients, levamisole to 139 and D-Penicillamine to 24. At the time of the present evaluation, 83 patients were still on goldsalts (44.6%), 63 on levamisole (45.2%) and 11 on D-Penicillamine (45.9%). Adverse reactions required interruption of treatment in 64 patients on goldsalts (35.2%), in 44 on levamisole (31.7%) and in 5 on D-Penicillamine (20.8%). Inefficacy was responsible for withdrawal of 33 patients receiving goldsalts (18.1%), 30 receiving levamisole (21.6%) and 8 receiving D-Penicillamine (33.3%). The duration of treatment was 4.6 years for goldsalts, 3.6 years for levamisole and 3.6 years for D-Penicillamine. In the present analysis none of the compounds was found to have a definite advantage over the others. The rather favourable treatment continuation rates in this study can be attributed to the fact that the slow-acting antirheumatic drugs were given at an early stage of the disease, preferably before the occurrence of radiological lesions.

Reparative response of human articular cartilage in tissue culture. Comparison between a normal and an osteoarthritic knee of the same donor.

Some evidence is presented that the metabolism of visually intact cartilage taken from a knee with focal osteoarthritic lesions, may already be affected. Proteoglycan metabolism of articular cartilage from the macroscopically unaffected right knee and the osteoarthritic left knee of the same donor was assayed in long-term tissue culture. A good reparative response was found in the right knee with an increase in the relative amount of radiolabelled proteoglycan and proteoglycan aggregates, and in the total amount of labelled proteoglycan per mg dry tissue. No significant differences were found when the anteromedial, anterolateral and posterolateral areas were compared. Visually intact samples taken from the left knee, with a deep osteoarthritic cartilage erosion on the medial condyle, showed no accumulation of radiolabel into proteoglycan and proteoglycan aggregates for the enzymatically pretreated samples. This was interpreted as a repair failure.

The influence of hydrocortisone on aggrecan metabolism in human articular chondrocyte cultures: comparison of two different matrices.

OBJECTIVE: Numerous reports of negative effects as well as protective effects of glucocorticoids on articular cartilage convinced us to study the influence of hydrocortisone on aggrecan synthesis of isolated phenotypically stable human articular chondrocytes cultured in two different matrices. METHODS: Macroscopically normal human articular cartilage was obtained from femoral condyles within 24 hours postmortem. Chondrocytes were isolated and cultured in gelled agarose or in alginate. After 14 days in culture, hydrocortisone was added for 5 days at concentrations ranging from 0.005 microgram to 1 mg/ml for the agarose cultures and from 0.005 microgram to 1 microgram/ml for the alginate culture system. Aggrecan synthesis was measured by the incorporation of 35Sulphate, and the proportion of neosynthesized aggrecan that bound to hyaluronan to form aggrecan aggregates was analyzed by gel chromatography. RESULTS: At concentrations from 0.005 to 1 microgram/ml, hydrocortisone was found to produce a similar dose-dependent stimulation of aggrecan synthesis in both matrices. The synthesis of aggrecans remained at the same level for concentrations of 1 microgram/ml up to 100 micrograms/ml of hydrocortisone. When supraphysiological concentrations of hydrocortisone were added the aggrecan synthesis rate plateau declined. Simultaneously with the increase in aggrecan synthesis, the proportion of low-molecular weight 35S-proteoglycans decreased in favour of 35S-aggrecan aggregates and monomers in the agarose system. The chondrocytes cultured in alginate showed this increase of aggrecan aggregates and monomeric aggrecans in both the cell-associated and the inter-territorial matrix. CONCLUSION: Hydrocortisone is a stimulator of aggrecan synthesis by normal human articular chondrocytes cultured in vitro. The two culture systems (agarose and alginate) tested in this experiment showed a comparable aggrecan synthesis rate, increasing under the influence of hydrocortisone at concentrations up to 1 microgram/ml. The proportions of 35Sulphate incorporated in aggrecan aggregates and monomeric aggrecan were also higher under the influence of hydrocortisone.

Broadening of the T cell receptor spectrum among rheumatoid arthritis synovial cell-lines in relation to disease duration.

OBJECTIVE: The aim of the study was to evaluate the T cell receptor (TCR) family usage in T cell-lines from subcutaneous nodules and synovium from patients with rheumatoid arthritis (RA), with specific reference to the duration of symptoms. In vitro adherence characteristics of nodular T cells was studied as well. METHODS: Monoclonal antibodies were used to determine the distribution of TCR families in T cell-lines from synovium of patients with early and long-standing RA, from rheumatoid nodules and control tissues. An in vitro binding assay with T cell-lines from 2 rheumatoid nodules was performed. RESULTS: In early RA synovium, a restricted TCR family usage was observed in 5 out of 8 patients, contrary to long-standing disease, peripheral blood, ileum and colon. In RA nodules, a similar degree of restriction was noted. Moreover, the same TCR family was overexpressed by T cell-lines from different nodules derived from the same patient. T cell-lines from rheumatoid nodules demonstrated a preferential in vitro adherence to rheumatoid synovium and rheumatoid nodules, while no binding was observed on skin or tonsil. CONCLUSION: The TCR spectrum among RA synovial cell-lines broadens in relation to the disease duration. The overexpression of the same TCR family in different rheumatoid nodules from the same patients, and the in vitro adherence of T cell-lines from rheumatoid nodules may be indicative for recirculation between the different disease manifestations in RA.