Deep penetration of antibodies into the articular cartilage of patients with rheumatoid arthritis

This study was conducted to determine the presence of immunoglobulin G (IgG) and albumin in deep layers of articular cartilage from patients with rheumatoid arthritis or osteoarthritis and from normal organ donors. Cartilage plugs were cut into 20-m slices with a microtome and ten consecutive slices were pooled, dividing the specimen into 200 m sections starting from the articular surface. Each pool was extracted overnight thrice with neutral buffer, thrice with 6 M guanidine hydrochloride, and then degraded with bacterial collagenase. IgG and albumin were quantified in each extract. From the surface and deep layers significantly more IgG and albumin were extracted from rheumatoid than from normal specimens, both with neutral buffer and with guanidine. In neutral buffer extracts the molar ratios of IgG to albumin were comparable from normal and rheumatoid specimens, with a molar excess of albumin. In contrast, the molar ratios of IgG to albumin in guanidine extracts from rheumatoid cartilages were significantly higher than in normal cartilages, and the IgG was in molar excess of albumin only in rheumatoid extracts. These results show for the first time that IgG has penetrated deep into the cartilage in rheumatoid arthritis and may contribute to the degradation of cartilage by inflammation.     

Immunoglobulin G and serum albumin isolated from the articular cartilage of patients with rheumatoid arthritis or osteoarthritis contain covalent heteropolymers with proteoglycans

Summary The present study was undertaken to identify the cartilage matrix molecules that are bound with intermolecular disulfide bonds to IgG and serum albumin molecules recovered from the articular cartilage of patients with rheumatoid arthritis (RA) or osteoarthritis (OA). The cartilage specimens were extracted sequentially with three changes of neutral buffer, three changes of 6 M guanidine hydrochloride and then partiallydegraded with bacterial collagenase. The extracted IgG and albumin, along with matrix molecules bound to these proteins, were isolated with affinity chromatography using antibodies to IgG or human serum albumin conjugated to agarose beads. The isolated materials were characterized with sodium dodecyl sulfate polyacrylamide gel electrophoresis and transfer blotting, using specific antibodies to IgG, albumin, and proteoglycans. In the isolated materials, heteropolymers with IgG or albumin wer identified. These polymers contained keratan sulfate and less frequently chondroitin-4-sulfate and chondroitin-6-sulfate. These findings identified the keratan sulfate rich proteoglycans, prevalent at the surface of joint cartilage, as the most common cartilage matrix molecules that are covalently bound to IgG or to serum albumin by disulfide bonds in the articular cartilage of patients with RA or OA.     

Expression of CD44 in articular cartilage is associated with disease severity in knee osteoarthritis

Abstract

Objectives To investigate CD44 levels in articular cartilage of knee osteoarthritis (OA) and the relationship between CD44 and severity of the disease.

Methods All 50 cartilage tissues included normal and OA cartilage, and were ascribed to the following four groups on the basis of modified Mankin score: normal, mild lesions, moderate lesions and severe lesions. CD44 levels in articular cartilage were assessed by immunohistochemical methods.

Results CD44 levels were detected in all four groups. The difference in average gray value of CD44 expression showed statistical significance when compared between each group (P < 0.05). In addition, CD44 expression in each group correlated with disease severity, according to the modified Mankin score (ρ = ?0.848, P < 0.01).

Conclusions CD44 in articular cartilage is associated with progressive knee OA joint damage.     

Degradation in vivo of articular cartilage in rheumatoid arthritis and juvenile chronic arthritis by cathepsin G and elastase from polymorphonuclear leukocytes

Summary Peroxidase-anti-peroxidase (PAP) staining and specific antibodies against cathepsin G and elastase from polymorphonuclear leukocytes (PMN) were applied to pannus-free and microscopically intact superficial articular cartilage. Restricted local deposits containing cathepsin G and elastase were found in three of ten patients with seropositive rheumatoid arthritis (RA), in one of three patients with seronegative RA and in one patient with juvenile chronic arthritis (JCA). Similarly, localized deposits of IgG and C3 were found in the patients with seropositive RA and JCA, but not in the patient with seronegative RA. Adjacent sections exhibited esterase activity in and around the PMN. In proteinase-positive areas from patients with seropositive RA the inhibitors ₁-proteinase inhibitor (₁-PI) and ₂-macroglobulin (₂-MG) were present in two of three and one of three patients, respectively. In JCA only ₁-proteinase inhibitor was present, and in seronegative RA no inhibitors were found. No staining of articular cartilage was observed in a patient with psoriatic arthritis. One of three cases with osteoarthritis exhibited patchy superficial staining for IgG only. In articular cartilage covered by pannus, in three patients with seropositive RA, in one with seronegative RA and in the patient with JCA a few regions with variably dense PMN infiltrates were observed. Cathepsin G, elastase and esterase activity were found in and around the PMN. In one of the three patients with seropositive RA the adjacent cartilage-pannus junction exhibited distinct staining for cathepsin G and elastase, but not for IgG/C3 and proteinase inhibitors. The findings suggest that cathepsin G and elastase from PMN are involved in the breakdown of rheumatoid articular cartilage in the presence, as well as in the absence, of entrapped immune-complex-like material, and that proteinase inhibitors are often lacking in such regions.This paper is dedicated to Prof. Dr. A. Böni and Prof. Dr. H. Mathies for their 75th and 70th birthdays     

Assessment of long-term articular damage and function in rheumatoid arthritis patients

Aim of the work

This study aimed to assess long-term articular damage and function in rheumatoid arthritis (RA) patients in relation to the type of treatment. Early disease modifying anti-rheumatic drug (DMARD) therapy has not been evaluated in this study.

Atlanto-odontoid osteoarthritis in rheumatoid arthritis: dynamic CT findings

We analyzed the CT appearances of degenerative change in the atlanto-odontoid joint (AOJ) in patients with rheumatoid arthritis (RA) and evaluated the effect of these changes on atlanto-axial joint (AAJ) rotation by dynamic CT. This revealed that 9 patients (24%) treated with methotrexate had degenerative features in the AOJ. The ratio of AAJ rotation to the total rotation of the cervical spine was significantly higher in normal subjects (54±3%) than in patients (38±12%). The degree of AAJ rotation was significantly lower in the patient group with degenerative features in the AOJ (20.9±8.4°) than in patients without degenerative features (28.5±7.4°). RA patients with a history of longstanding disease and treatment with antirheumatic drugs may develop AO OA. Although secondary OA was described as healing phenomena in the joints of RA patients, it can limit rotation in the AAJ and cause suboccipital neck pain. A regular check-up of the AAJ and AOJ by means of dynamic CT in all RA patients is proposed to avoid possible antirheumatic drug complications.Abbreviations AAJ Atlanto-axial joint - AOJ Atlanto-odontoid joint - MTX Methotrexate - OA Osteoarthritis - RA Rheumatoid arthritis     

Comparison of chondroitin sulphate composition of femoral head articular cartilage from patients with femoral neck fractures and osteoarthritis and controls

The glycosaminoglycan (GAG) and uronic acid (UA) composition of human hip articular cartilage from patients with femoral neck fractures [assumed osteoporosis (OP); n=12], from patients with osteoarthritis (OA; n=12) and from normal controls (n=9) was determined. Full depth tissue samples from the control and OP groups were analysed from the superior, inferior, anterior and posterior regions, while the OA tissue was from cystic (tissue growing on top of cystic bone lesions) and osteophytic regions, from normal and fibrillated resident cartilage and from regions immediately adjacent to eburnated bone. The total sulphated GAG and UA content was reduced in the inferior region of control cartilage compared to the other regions and the values of all regions of the assumed OP group. Cystic regions and OA cartilage adjacent to the bone also showed lower GAG and UA levels than the other regions. The ratios of chondroitin 6-sulphate (C6S) to chondroitin 4-sulphate (C4S) indicated a similar pattern in the different regions of controls and the patient group with femoral neck fractures (OP group). The cystic and osteophytic cartilage of the OA group exhibited lower C6S/C4S ratios than any other region. The levels of dermatan sulphate (DS) in the cartilage of all regions of the OP and control groups were very similar and low, while the tissues of the OA group contained significantly higher amounts, particularly the cartilage from osteophytes. The previously presumed compositional similarity between normal aged and osteoporotic articular hip cartilage was essentially confirmed in a comparative analysis. Significant changes in GAG and UA composition of OA cartilage from distinct regions was also recorded.     

Serum cartilage oligomeric matrix protein (COMP) in rheumatoid arthritis and knee osteoarthritis

The cartilage oligometrix matrix protein (COMP) is a noncollagenous protein, a glycoprotein, the function of which is to bind to type II collagen fibres and stabilise the collagen fibre network in the articular cartilage. In the serum of the normal population the COMP level is 5 g/ml. An increased level of COMP in the synovial fluid was described in the early stage of rheumatoid arthritis (RA), whereas in advanced stages of RA, the level of COMP decreased. In this study we assessed the serum COMP level in patients with RA and knee osteoarthritis (OA) and found a correlation between the serum COMP level and other markers as well as bone mass density (BMD) changes, activity of disease, disease duration and the age of the patients. The blood was collected from 30 RA patients and 30 OA patients who constituted the control group. The serum COMP level was determined using an inhibition enzyme-linked immunosorbent assay (ELISA). The average value of the serum COMP level in RA patients was 10.4±3.6 U/l. There was a correlation between the serum COMP level and the age of RA patients (p<0.005) and disease activity score (DAS) value (p<0.01). According to correlation coefficients, the serum COMP level was independent of stage of disease, number of painful and swollen joints, duration of morning stiffness, disease duration and titre of the Waaler–Rose test. The influence of rheumatoid nodule presence on the serum COMP level was shown (p<0.05). In RA patients with erythrocyte sedimentation rate (ESR) values below 20 mm/h compared with patients with ESR values over 60 mm/h, the serum COMP level was observed to be significantly lower (p<0.05). The average value of COMP in OA patients was 10.4±2.7 U/l. No correlation was found between the serum COMP level and patients age and disease duration. There was a correlation between the serum COMP level and Western Ontario and McMaster Universities (WOMAC) index pain scale for the lower limbs (p<0.005) and T-score value of densitometry examinations (p<0.036) in OA patients. No statistical differences were found between the average serum COMP level in RA and OA patients.     

Elastase from polymorphonuclear leukocyte in articular cartilage and synovial fluids of patients with rheumatoid arthritis

Summary Objective was to study the significance and the mechanism of action of elastase from polymorphonuclear leukocyte (PMN elastase) in patients with rheumatoid arthritis (RA). The experiments conducted consisted of two phases. Firstly, articular cartilage and synovia from 8 patients with RA undergoing total knee replacement were obtained, and the gelatinolytic enzyme activity was extracted with 2M guanidine hydrochloride. The gelatinolytic activity of each tissue was measured to confirm that the activity was due to PMN elastase by using an antihuman leukocyte elastase antibody. Secondly, the levels of PMN elastase-1 proteinase inhibitor complex (EIC) in the blood and synovial fluid of 170 patients with RA were measured by immunoassay. The results were as follows: 1. Gelatinolitic activity was shown to be mainly due to PMN elastase, and found to be highest in cartilage and synovia in RA joints. 2. The EIC levels in plasma of RA patients were significantly higher than those in gout and osteoarthritis (OA), and the EIC levels increased according to the stage of articular cartilage destruction. Moreover, the EIC levels in synovial fluid of RA patients were higher compared to those of OA patients. The activity of PMN elastase was elevated in destructive joints of RA. With the progression of articular cartilage destruction, EIC levels in plasma of RA patients increased as well. We suggest that PMN elastase may play a significant role in RA disease.     

Immunohistochemical detection of factor XIIIa and factor XIIIs in synovial membranes of patients with rheumatoid arthritis or osteoarthritis

In spite of differences in etiology, RA and OA lead to astonishingly similar synovitic alterations. Fibroblastic transformation of the synovial membrane and an increase in monocytes constitute a rare but highly characteristic feature of RA. Monocytes synthesize factor (F) XIII, implying that FXIII (a and s) in synovial tissue might help to differentiate between RA and OA. Biopsies were obtained at open surgery from 98 unselected patients with the clinical diagnosis of RA (n=54) or OA (n=44). In a three-stage (ABC) immunoperoxidase technique, polyclonal antisera against factor XIIIa and factor XIIIs were investigated. Compared to OA sections, RA synovium showed more FXIIIa-positve cells - monocytes, fibrocytes, fibroblasts and synovial lining cells. In the subsynovial layer, band-like structure of FXIIIa-stained cells was observed in 27.8% of the RA patients, but in only one OA specimen. Higher proportions of FXIIIa-positive monocytes, macrophages, histiocytes and fibroblasts, as well as positive Langhans' giant cells and vascular wall regions (except endothelial cells), were observed in RA. OA specimens revealed more intense FXIIIa labeling of these cells with a lower percentage of stained cells. Overall, labeling with FXIIIs antibody resulted in less intense staining. In conclusion, distinction between synovitis caused by RA and synovitis due to OA is possible, as the former show higher numbers of FXIIIa-positive cells, including monocytes, fibroblasts, fibrocytes and synovial lining cells. Furthermore, RA tissue is stained less intensely than OA tissue. There is evidence for continuous excretion of FXIII in the synovial membrane by the above-mentioned cell systems.     

Health‐related quality of life in women with symptomatic hand osteoarthritis: A comparison with rheumatoid arthritis patients,healthy controls,and normative data

Objective

Data on the burden of disease and impact on health‐related quality of life (HRQOL) in hand osteoarthritis (OA) are limited. The goal of this study was to compare HRQOL in patients with hand OA with HRQOL in patients with rheumatoid arthritis (RA), healthy controls, and normative data from the general population.

Methods

A total of 190 women with hand OA were compared with 194 women with RA and 144 healthy women of the same age. Health status was measured using the Short Form 36 (SF‐36), Short Form 6D (SF‐6D), modified Health Assessment Questionnaire (M‐HAQ), pain and fatigue visual analog scales, and grip strength. Scores were compared by analysis of variance and a multivariate analysis of covariance, adjusting for age, number of comorbidities, and years of education. Gaps between patients and population subjects were assessed by calculating S scores on all dimensions of the SF‐36.

Results

Hand OA and RA patients had worse scores on all assessed dimensions of subjective health compared with healthy controls. RA patients showed poorest general health (SF‐36), poorest physical function (M‐HAQ, SF‐36 physical, grip strength), and highest level of fatigue compared with hand OA patients. Hand OA patients reported poorer mental health. Mean utility scores (SF‐6D) in hand OA and RA were 0.64 and 0.63, respectively, with a mean difference compared with healthy controls of 0.13 in hand OA and 0.14 in RA patients. S scores confirmed a marked disparity between individuals with a rheumatic diagnosis (hand OA, RA) and population subjects.

Conclusion

This study illustrates that patients with hand OA experience a broad impact on HRQOL compared with healthy controls. Fatigue and physical function are worse in RA than hand OA.     

Distribution of lysozyme in synovial tissue of patients with osteoarthritis and rheumatoid arthritis demonstrated by different enzyme histochemical methods

Summary Lysozyme-producing cells were analysed by enzyme histochemistry in paraffin sections of synovial tissue of 60 patients with rheumatoid arthritis (RA) and 20 patients with osteoarthritis (OA). For lysozyme detection three enzym histochemical systems — peroxydase-antiperoxydase, alkaline phosphatase and biotin-avidin — were used in parallel experiments. Lysozyme was found to be produced by polymorphonuclear cells, mononuclear phagocytes and part of synovial lining cells. All types of lysozyme-producing cells were increased in RA compared with OA. Subgrouping of RA synovitis according to histomorphological criteria allowed the demonstration of an inverse relationship between the number of lysozyme-producing cells and the grade of proliferation of fibroblasts, called mesenchymoid transformation by Fassbender [19]. The different methods of lysozyme detection differed in specificity and sensitivity. The immunoenzymatic staining of lysozyme allows specific and quantitative evaluation of phagocyting cells in RA and OA.     

Intercellular network in articular cartilage of pigs with experimentally induced arthritis

Summary Porcine articular cartilage from cases of experimentally induced Erysipelas arthritis was examined with different histological techniques and by electron microscopy. A small percentage of specimens of osteoarthritic cartilage revealed an interlacunar network in the extracellular matrix. These matrix-streaks showed characteristic features of densely packed fibrillar elements and collagenous fibrils, as narrow bands connecting adjacent chondrocytes. In a given cartilage site the network had a constant pattern. It is hypothesized that the network formation is correlated with altered joint metabolism and represents regressive changes in cartilage matrix as a result of external mechanical forces. Using a variety of methods, the possibility of the network being an artifact of histological processing could virtually be ruled out. As there are so far only few and contradictory reports on the interlacunar network of articular cartilage, its precise biological significance remains to be established.     

Serum and synovial fluid histidine: a comparison in rheumatoid arthritis and osteoarthritis

Summary The serum and synovial fluid (SF) histidine, sulphydryl, and protein concentrations were compared in simultaneous samples from 84 patients with rheumatoid arthritis (RA) and a control group comprising 29 patients with osteoarthritis (OA). The SF levels of histidine were higher than the serum levels in the RA patients but significantly lower than corresponding results in patients with OA (P<0.001). The latter had levels of serum and SF histidine which were equivalent and within the normal range. Greater quantities of protein were found in the SF of the patients with RA compared with the OA group. The serum and SF sulphydryl concentrations expressed as mol/g protein were low but in equilibrium in patients with RA. However the SF sulphydryl (mol/g protein) was depressed relative to serum levels in patients with OA.     

A comparison of patients with late-stage rheumatoid arthritis and osteoarthritis of the shoulder using self-assessed shoulder function and health status

Objective . To compare the function and health status of individuals with advanced rheumatoid arthritis (RA) and osteoarthritis (OA) of the shoulder using standardized patient self-assessment tools. Methods . A group of patients with late-stage arthritic involvement of the shoulder was evaluated at the time of initial presentation using 2 questionnaires, one focusing on shoulder function and the other on overall health status. Results . There was substantial variability in the shoulder function and health status within each diagnostic group; however, both groups demonstrated significant deficits in their Simple Shoulder Test responses and in many of their Health Status Questionnaire-Short Form 36 scores. While the patients with RA tended to have somewhat greater impairment of shoulder function, many of the differences were not statistically significant. By contrast, most health status parameters were significantly more impaired in the patients with RA. Conclusions . Among patients with late-stage shoulder arthritis, the overall health status of those with RA is significantly worse than those with OA. Differences in health status may be important in selecting the optimal management for individual patients with latestage shoulder arthritis. Self-assessment questionnaires are effective in characterizing these differences.     

Synthesis of abnormal articular cartilage proteoglycans in rapidly destructive arthropathy (osteoarthritis)

Summary Articular cartilage fragments were obtained from four femoral heads and one femoral condyle, resected in five patients undergoing prosthetic surgery for rapidly destructive arthropathy (RDA) and from one normal femoral head and one normal femoral condyle resected at autopsy. The cartilage fragements were labelled in vitro with ³⁵SO₄ and newly-synthesized proteoglycans, (³⁵S-PGs) were then extracted with 4 M guanidinium hydrochloride (GuHCl) and analyzed. In three cases a much greater and in one case a significantly increased proportion of small ³⁵S-PGs enriched in dermatan sulfate (DS) was demonstrated in diseased tissues in comparison with control samples. These DS ³⁵S-PGs were completely unable to interact with hyaluronan (HA) and had longer glycosamino-glycan (GAG) side chains than large ³⁵S-PGs. Also, large ³⁵S-PGs extracted from diseased tissue interacted poorly under associative conditions with exogenous HA when this was added to the crude extract. However, they interacted much better following the addition of exogenous HA to the purified high density proteoglycans. This suggests the presence of an inhibitor of PG-HA interaction in the crude extract which is lost during PG purification. The synthesis of an abnormally large proportion of small PGs by articular chondrocytes and impaired aggregation of large PGs may account for the accelerated destruction of articular cartilage in this condition.     

Reliability of the rheumatoid arthritis articular damage score in Tunisian patients

The clinical rheumatoid arthritis articular damage (RAAD) score is easy to perform and showed good intraobserver reliability. It correlates well with the Larsen score and disease duration and can be recommended for rheumatoid arthritis patients follow-up in developing countries.     

Assessment of both articular synovitis and tenosynovitis by ultrasound is useful for evaluations of hand dysfunction in early rheumatoid arthritis patients

Objectives: We investigated the association between hand dysfunction and ultrasound (US)-detected articular synovitis and tenosynovitis in patients with rheumatoid arthritis (RA).

Methods: Thirty RA patients were examined. In both hands of all subjects, articular synovitis and tenosynovitis were assessed by US at 22 joints and 12 tendons. Each joint and tendon was scored by gray-scale (GS) and power Doppler (PD) on a scale from 0 to 3. The sums of the GS or PD scores were used as the articular synovitis score and the tenosynovitis score. The sum of the articular synovitis and tenosynovitis scores was used as the combined US score. Hand dysfunction was evaluated by a grip-Health Assessment Questionnaire (HAQ) and visual analog scale of morning stiffness (MS-VAS). We used Spearman’s correlation coefficient to determine the relationships among the US scores, the two hand dysfunction indices, and the DAS28-ESR.

Results: The articular synovitis scores were significantly correlated with grip-HAQ (GS: r_s?=?0.47, p?=?0.009, PD: r_s?=?0.48, p?=?0.006), but not with MS-VAS. The tenosynovitis scores were correlated with MS-VAS (GS: r_s?=?0.38, p?=?0.039, PD: r_s?=?0.36, p?=?0.053), but not with grip-HAQ. Both grip-HAQ (GS: r_s?=?0.53, p?=?0.002, PD: r_s?=?0.55, p?=?0.001) and the MS-VAS (GS: r_s?=?0.39, p?=?0.031, PD: r_s?=?0.47, p?=?0.008) were correlated with the combined US scores.

Conclusions: The US scores combined with articular synovitis and tenosynovitis scores well reflect the severity of hand dysfunction in early-stage RA patients.     

The role of cartilage canals in the pathogenesis of experimentally induced polyarthritis

Summary Porcine articular cartilage from cases of experimentally induced Erysipelas polyarthritis, a comparative model of rheumatoid arthritis (RA) in man, was examined with different histological and immunohistochemical techniques. The preexisting canals in articular cartilage played a crucial role during the flooding and deposition of arthritogenic microorganisms deep into the cartilage matrix. Subsequently this vascularized tissue mediated the same inflammatory reactions in hyaline cartilage of young animals as seen in other connective tissues. However, these stereotypical responses to injury were modulated by the unique composition and structure of articular cartilage.