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The purpose of this study was to investigate the feasibility of adipose-derived stem cells (ADSCs) as the seed cells of cartilage tissue engineering. ADSCs were isolated from adipose tissue that was harvested under sterile conditions from the inguen fold of porcines and cultured in vitro. Acellular cartilage extracellular matrix (ACECM) scaffolds of pigs were then constructed. Moreover, inflammatory cells, as well as cellular and humoral immune responses, were detected using hematoxylin and eosin staining staining, immunohistochemical staining, and western blot analysis. The results showed that the cartilage complex constructed by ADSCs and ACECM through tissue engineering successfully repaired the cartilage defect of the pig knee joint. The in vivo repair experiment showed no significant difference between chondrocytes, ADSCs, and induced ADSCs, indicating that ADSCs do not require in vitro induction and have the potential for chondrogenic differentiation in the environment around the knee joint. In addition, pig-derived acellular cartilage scaffolds possess no obvious immune inflammatory response when used in xenotransplantation. ADSCs may serve as viable seed cells for cartilage tissue engineering., (© 2020 Wiley Periodicals LLC.)

Background and Objective: Rheumatoid arthritis (RA) is a predominant inflammatory autoimmune disorder. The incidence and prevalence of RA is increasing with considerable morbidity and mortality worldwide. The pathophysiology of RA has become clearer due to many significant research outputs during the last two decades. Many inflammatory cytokines involved in RA pathophysiology and the presence of autoantibodies are being used as potential biomarkers via the use of effective diagnostic techniques for the early diagnosis of RA. Currently, several disease-modifying anti-rheumatic drugs are being prescribed targeting RA pathophysiology, which have shown significant contributions in improving the disease outcomes., Discussion: Even though innovations in treatment strategies and monitoring are helping the patients to achieve early and sustained clinical and radiographic remission, the high cost of drugs and limited health care budgets are restricting the easy access of RA treatment. Both direct and indirect high cost of treatment are creating economic burden for the patients and affecting their quality of life., Conclusion: The aim of this review is to describe the updated concept of RA pathophysiology and highlight current diagnostic tools used for the early detection as well as prognosis - targeting several biomarkers of RA. Additionally, we explored the updated treatment options with side effects besides discussing the global economic burden., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)

Recent progress in treatment and imaging enables us to aim the clinical remission in rheumatoid arthritis. In terms of achieving deep remission (structural remission) and predicting prognosis, useful serological biomarkers are now expected. Recently, some of the serological biomarkers, such as RANKL (receptor activator of NF-κB ligand) and TRACP (tartrate-resistant acid phopshatate)-5b, are used to assess the activity of rheumatoid arthritis. The levels of these biomarkers well reflect bone erosion but are less affected by age or physiological variation.

Rheumatoid arthritis (RA) is characterized by chronic synovitis and RANKL-dependent osteoclastogenesis leading to bone damage, which causes severe physical disability. Focal and systemic bone and cartilage destruction including secondary osteoporosis contributes to the morbidity associated with RA. The biologics targeting TNF and IL-6 has revolutionized the treatment of RA, producing significant improvements in clinical and structural outcomes. Furthermore, an anti-RANKL antibody denosumab possesses a potential to inhibit joint destruction as well as systemic osteoporosis. Targeting RANKL therapy will most likely enlarge the possibilities of osteoporosis treatment and improve the prognosis in RA patients.

Semaphorins family consists of more than 20 proteins, categorized into 8 subclasses. Semaphorins play critical roles in neural development, immune response, and bone metabolism. Rheumatoid arthritis (RA) is a disease which shows abnormality in immunity and bone homeostasis. Therefore, semaphorins are suggested to be relevant to RA. Here, we described the role of semaphorins in bone metabolism and the association with semaphorins and RA which are found by basic and translational research.

CTLA4-Ig is a regulator of co-stimulation and inhibits the activation of T cells through interfering with the interaction of CD80/86 on antigen-presenting cells with CD28. Recently CTLA4-Ig has shown additional effect beyond T cell inhibition, such as direct inhibition of differentiation of osteoclast, enhancement of osteogenesis. These effects may contribute to prevention of bone destruction in rheumatoid arthritis.

The term "chondropenia" indicates the early stage of degenerative cartilage disease, and it has been identified by carefully monitoring early-stage osteoarthritis (OA). Not only is it the loss of articular cartilage volume, but it is also a rearrangement of biomechanical, ultrastructural, biochemical and molecular properties typical of healthy cartilage tissue. Diagnosing OA at an early stage or an advanced stage is valuable in terms of clinical and therapeutic outcome. In fact degenerative phenomena are supported by a complex biochemical cascade which unbalances the extracellular matrix homeostasis, closely regulated by chondrocytes. In the first stage an intense inflammatory reaction is triggered: pro-catabolic cytokines such as IL-1β and TNF-α triggering matrix metalloproteases and aggrecanase (ADAMT-4 and 5), responsible for the early loss of ultrastructural components, such as type II collagen and aggrecan. In addition nitric oxide and reactive oxygen species modulate the physiopathology of the condral matrix inducing apoptosis of chondrocytes through a mitochondria-dependent pathway. In addition, "Lonely Death": chondrocytes, are confined within a dense, avascular extracellular matrix capsule, and can trigger a genetically induced apoptosis and necrosis. The degenerative process starts from a central point and then spreads in a centrifugal manner in depth and in adjacent areas, eventually covering the whole joint; chondropenia represents a journey from the first clinically detectable time-point until it can be characterized as frank osteoarthritis. Currently, there are no instruments sensitive enough which allow a timely diagnosis of chondropenia. Innovative magnetic resonance imaging techniques, such as T2 mapping, can be effective and a sensitive diagnostic instrument for quantifying cartilage volume and proteoglycan content. However, avant-garde biophysical techniques, such as mechanical indenters, ultrasound and biochemical markers (uCTX-II), are rational and scientific tools applicable to the clinical and therapeutic management of early degenerative cartilage disease. The objective of this review on chondropenia is to present a state of the art and innovative concepts.

Rheumatoid arthritis(RA)is an autoimmune diseases characterized by inflammation and destruction of bone and cartilage. Bone destruction in RA is triggered by abnormal activation of immune system and osteoclasts induced by RANKL. Advances in osteoimmunology clarified that immune-factors such as inflammatory cytokines and antibodies promote not only inflammation but also bone destruction in RA. Importantly, a newly identified Th17 subset induces osteoclastogenesis potently by upregulating RANKL on synovial fibroblasts, indicating a synergy between T-synovial fibroblast plays a primary role in the inflammatory bone destruction. Recently, novel bone-regulating factors are identified and can be attractive therapeutic targets for destruct ion of bone and cartilage in RA.

Sometime ago, there was little choice for the treatment of rheumatoid arthritis(RA)that was regarded as an untreateble disease but supportive analgesics and mild disease modified drugs. The advent of biological agents with abundant clinical researches regarding remarkable efficacy has cased dramatically the paradigm shift in the treatment of RA. The strategy for medical care to RA has now entered a new era in that treatment target should be clarified and shared between patient and rheumatologist aiming the prevention of structural damage and the maintain of long-term quality of life(QOL)by tight-control. In this review, we summarize the "treat to target"(T2T)strategies for RA and its impact to manage for bone and cartilage destructions.

Joint bleeding after (sports) trauma, after major joint surgery, or as seen in hemophilia in general leads to arthropathy. Joint degeneration is considered to result from the direct effects of blood components on cartilage and indirectly from synovial inflammation. Blood-provided proinflammatory cytokines trigger chondrocytes and induce the production of cartilage-degrading proteases. In the presence of erythrocyte-derived iron, cytokines stimulate radical formation in the vicinity of chondrocytes inducing apoptosis. To unravel the role of interleukin (IL) 1β and tumor necrosis factor (TNF) α in the pathogenesis of this blood-induced cartilage damage, the effect of antagonizing these cytokines was examined in human in vitro cultures. Addition of recombinant human IL-1β monoclonal antibody or IL-1 receptor antagonist resulted in a dose- and time-dependent protection of cartilage from blood-induced damage. In higher concentrations, almost complete normalization of cartilage matrix proteoglycan turnover was achieved. This was accompanied by a reduction in IL-1β and IL-6 production in whole blood cultures, whereas TNFα production remained unaffected. Interestingly, addition of a TNFα monoclonal antibody, although demonstrated to inhibit the direct (transient) effects of TNFα on cartilage, exhibited no effect on blood-induced (prolonged) cartilage damage. It is demonstrated that IL-1β is crucial in the development of blood-induced joint damage, whereas TNFα is not. This hierarchical position of IL-1β in blood-induced joint damage warrants studies on targeting IL-1β to potentially prevent joint degeneration after a joint bleed., (© 2015 by The American Society of Hematology.)

Introduction: Although it is well known that BMP-2 and BMP-7 play significant roles in cartilage metabolism, data about intra-articular expression and localization of these proteins and their receptors in humans are rare., Methods: Biopsies of synovia and debrided cartilage were taken in patients undergoing autologous chondrocyte implantation. Expression of BMP-2, BMP-7, and their receptors BMPR-1A, BMPR-1B and BMPR-2 were semiquantitatively evaluated by immunohistological staining., Results: BMP-7 was equally highly expressed in all cartilage and synovial biopsies. Increased levels of BMPR-1A, but not of BMPR-1B, and BMPR-2, were found in all synovial and 47% of all cartilage samples (P = 0.002). BMP-2 was positively scored in 47% of all cartilage and 40% of all synovial specimens. Defect size, KOSS, Henderson or Kellgren-Lawrence score did not statistically significant correlate with the expression of the analyzed proteins or Mankin and Pritzker scores. Duration of symptoms and localization of lesions were associated with KOSS (P < 0.02), but there was no influence of these parameters on protein expression., Conclusions: BMP-2, BMP-7, and BMPR-1A were expressed in cartilage and synovia of knees with focal cartilage lesions. Although defect localization and duration of symptoms decisively influence KOSS, there was no associated alteration of protein expression observed.

Background: The anti-human Fas/APO-1/CD95 (Fas) mouse/human chimeric monoclonal IgM antibody ARG098 (ARG098) targets the human Fas molecule. The cytotoxic effects of ARG098 on cells isolated from RA patients, on normal cells in vitro, and on RA synovial tissue and cartilage in vivo using implanted rheumatoid tissues in an SCID mouse model (SCID-HuRAg) were investigated to examine the potential of ARG098 as a therapy for RA., Methods: ARG098 binding to each cell was analyzed by cytometry. The effects of ARG098 on several cells were assessed by a cell viability assay in vitro. Effects on the RA synovium, lymphocytes, and cartilage were assessed in vivo using the SCID-HuRAg mouse model., Results: ARG098 bound to cell surface Fas molecules, and induced apoptosis in Fas-expressing RA synoviocytes and infiltrating lymphocytes in the RA synovium in a dose-dependent manner. However, ARG098 did not affect the cell viability of peripheral blood mononuclear cells of RA patients or normal chondrocytes. ARG098 also induced apoptosis in RA synoviocytes and infiltrating lymphocytes in the RA synovium in vivo. The destruction of cartilage due to synovial invasion was inhibited by ARG098 injection in the modified SCID-HuRAg mouse model., Conclusions: ARG098 treatment suppressed RA synovial hyperplasia through the induction of apoptosis and prevented cartilage destruction in vivo. These results suggest that ARG098 might become a new therapy for RA.

Background: The alpha7 subunit of nicotinic acetylcholine receptors (alpha7nAChR) can negatively regulate the synthesis and release of proinflammatory cytokines by macrophages and fibroblast-like synoviocytes in vitro. In addition, stimulation of the alpha7nAChR can reduce the severity of arthritis in murine collagen-induced arthritis (CIA)., Objective: To provide more insight into the role of the alpha7nAChR in the pathogenesis of arthritis by investigating the effect of the absence of alpha7nAChR in CIA in alpha7-deficient (alpha7nAChR(-/-)) compared with wild-type (WT) mice., Methods: CIA was induced in alpha7nAChR(-/-) and WT littermate mice at day 0 by immunisation with chicken collagen type II (cCII) followed by a booster injection with cCII on day 20. Mice were killed on day 44 or day 63 and arthritis activity as well as radiological and histological damage were scored. The effects on the immune response were evaluated by measurement of antigen-specific antibodies and cytokines, and evaluation of the effects on antigen-specific stimulated spleen cells., Results: In alpha7nAChR(-/-) mice a significant increase in the incidence and severity of arthritis as well as increased synovial inflammation and joint destruction were seen. Exacerbation of CIA was associated with elevated systemic proinflammatory cytokines and enhanced T-helper cell 1 (Th1)-cytokine and tumour necrosis factor alpha production by spleen cells. Moreover, a specific decrease in the collagen-specific 'Th1-associated' IgG2a response was seen, whereas IgG1 titres were unaffected., Conclusions: The results presented here indicate that immune cell function in a model of rheumatoid arthritis is regulated by the cholinergic system and, at least in part, mediated by the alpha7nAChR.

Introduction: In inflammatory joint disease, such as osteoarthritis (OA), there is an increased level of proinflammatory cytokines, such as interleukin (IL)-1β. These cytokines stimulate the production of matrix metalloproteinases (MMPs), which leads to the degradation of the cartilage extracellular matrix and the loss of key structural components such as sulphated glycosaminoglycan (sGAG) and collagen II. The aim of this study was to examine the therapeutic potential of n-3 polyunsaturated fatty acids (PUFAs) in an in vitro model of cartilage inflammation., Methods: Two specific n-3 compounds were tested, namely, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), each at 0.1, 1 and 10 μM. Full thickness bovine cartilage explants, 5 mm in diameter, were cultured for 5 days with or without IL-1β and in the presence or absence of each n-3 compound. The media were replaced every 24 hours and assayed for sGAG content using the 1,9-dimethylmethylene blue (DMB) method. Chondrocyte viability was determined at the end of the culture period using fluorescence microscopy to visualise cells labelled with calcein AM and ethidium homodimer., Results: Treatment with IL-1β (10 ng.ml⁻¹) produced a large increase in sGAG release compared to untreated controls, but with no effect on cell viability, which was maintained above 80% for all treatments. In the absence of IL-1β, both n-3 compounds induced a mild catabolic response with increased loss of sGAG, particularly at 10 μM. By contrast, in the presence of IL-1β, both EPA and DHA at 0.1 and 1 μM significantly reduced IL-1β-mediated sGAG loss. The efficacy of the EPA treatment was maintained at approximately 75% throughout the 5-day period. However, at the same concentrations, the efficacy of DHA, although initially greater, reduced to approximately half that of EPA after 5 days. For both EPA and DHA, the highest dose of 10 μM was less effective., Conclusions: The results support the hypothesis that n-3 compounds are anti-inflammatory through competitive inhibition of the arachidonic acid oxidation pathway. The efficacy of these compounds is likely to be even greater at more physiological levels of IL-1β. Thus we suggest that n-3 PUFAs, particularly EPA, have exciting therapeutic potential for preventing cartilage degradation associated with chronic inflammatory joint disease.

Purpose of Review: To report on the expanding clinical and immunological spectrum associated with ribonuclease mitochondrial RNA-processing mutations and to review the cellular and molecular mechanisms involved in the pathophysiology of cartilage-hair hypoplasia (CHH) and related disorders in humans., Recent Findings: Different types of mutations are associated with skeletal or extraskeletal manifestations of CHH, respectively. In particular, severe immunodeficiency is mostly associated with mutations that alter cyclin B2 mRNA cleavage and thus are likely to reflect disturbances in cell cycle control. The first cases of ribonuclease mitochondrial RNA-processing mutations with severe immunodeficiency, but no skeletal abnormalities, have been identified., Summary: Abnormalities of ribosome biogenesis have been shown to cause distinct bone marrow failure syndromes, including CHH. However, the specific role of ribosomal and extraribosomal defects in the pathophysiology of the various phenotypic features of CHH remains undefined. Development of suitable animal models is needed to address this important issue.

Background: Cartilage hair hypoplasia is an autosomal recessive type of metaphyseal chondrodysplasia, caused by mutations in the ribonuclease mitochondrial RNA processing (RMRP) gene. Typical features of cartilage hair hypoplasia include short stature, a predisposition to malignancy, and a variable degree of impairment of cellular immunity., Objective: We sought to describe the heterogeneity of clinical and immunologic phenotype in 12 consecutive patients with RMRP mutations who were referred to 2 different institutions for immunologic evaluation., Methods: We have retrospectively analyzed the clinical and laboratory features in 12 patients with molecular defects in the RMRP gene. T-cell repertoire was investigated by quantitating Vbeta families' expression and analyzing their diversity. T-cell receptor excision circle analysis was used to study thymic output., Results: All 12 patients had significant immune abnormalities, leading to severe immune deficiency in 9. CD8 lymphocytopenia was identified as a novel phenotype associated with RMRP mutations. Significant, even intrafamilial, phenotypic heterogeneity was observed. In 3 cases, severe immunodeficiency was the only phenotypic manifestation associated with RMRP mutations, a novel finding. Mutations leading to significant immune defects were most often located in the promoter, and the first case of a compound heterozygote for 2 such mutations is reported., Conclusion: This report broadens the spectrum of phenotypes associated with RMRP mutations and suggests that mutations in this gene should be considered when evaluating patients with combined immune deficiency, regardless of the presence of other manifestations.

Cartilage is unable to repair itself. The actual treatments for cartilage lesions primarily cover up symptoms only and this had led to develop alternative means to restore degenerated cartilage, above all by using cell therapy. The therapeutic approaches initially focused on the implantation of autologous chondrocytes, but this technique proved unsatisfactory. The discovery that several adult human tissues contain mesenchymal stem cells (MSCs) capable of differentiating into chondrocytes raised the possibility of using MSCs to repair cartilages. In the present study we investigated whether mesenchymal stem cells from adipose tissue (hADAS) are able to differentiate into cartilage cells. We isolated cells from lipoaspirates, characterized them detecting specific surface markers by FACS analysis and immunofluorescence. We differentiate hADAS towards condrogenic line in a culture media supplemented with some specific factors and in a specific condition called pellet culture. The isolation of hADAS cells is reproducible and characterized by an high reproductivity, non dependent from the donor age. The expression of surface markers suits with the literature data. The cells differentiated towards chondrogenic line in pellet culture show a different morphology from the undifferentiated cells. The potential application of MSC therapy provides new hope for the development of innovative treatments for the repair of cartilage lesions and disorders.

Objective: Synovial inflammation in rheumatoid arthritis (RA) leads to pannus tissue invasion and destruction of cartilage/bone matrix by proteinases. Our intention was to analyze some of the key matrix metalloproteinases (MMPs) in pannus tissue overlying evolving cartilage erosions in RA., Methods: Frozen tissue samples of pannus and synovium from advanced RA and synovium from osteoarthritic patients were used for immunohistochemical, western blotting and quantitative reverse transcriptase polymerase chain reaction (RT-PCR) analysis of MMP-1, -3, -13 and -14. Synovial fibroblast cultures, stimulated with tumour necrosis factor alpha (TNF-alpha) and interleukin-1 beta (IL-1beta), were analyzed with enzyme-linked immunosorbent assays (ELISA) and quantitative RT-PCR., Results: MMP-3 was highly expressed in pannus tissue compared with significantly lower expression levels of MMP-1, -13 and -14. In fibroblast cultures IL-1beta was a potent stimulus for MMP-3, whereas TNF-alpha was more potent for MMP-1., Conclusion: This is the first study to demonstrate quantitatively in real time that MMP-3 mRNA expression is clearly higher in advanced RA pannus tissue compared to parallel RA or osteoarthritic synovium. MMP-3 mRNA levels were also clearly overexpressed in RA pannus compared to MMP-1, -13 and -14. Advanced RA has previously been found to overexpress IL-1beta. The high expression of MMP-3 in pannus and IL-1beta, mediated stimulation of MMP-3 suggest that MMP-3 plays a significant role in the progression of erosions through the proteoglycan-rich cartilage matrix.

Objective: To examine the capacity of T cell interleukin-17A (IL-17A; referred to hereinafter as IL-17) to induce cartilage damage during experimental arthritis in the absence of IL-1., Methods: Local IL-17 gene transfer was performed in the knee joint of IL-1-deficient mice and wild-type controls during streptococcal cell wall (SCW)-induced arthritis. Knee joints were isolated at various time points for histologic analysis of cartilage proteoglycan (PG) depletion. Expression of messenger RNA for inducible nitric oxide synthase, matrix metalloproteinases (MMPs) 3, 9, and 13, and ADAMTS-4 was determined by quantitative polymerase chain reaction analysis. VDIPEN staining was analyzed to study MMP-mediated cartilage damage. In addition, systemic anti-IL-1alpha/beta antibody treatment was performed in mice immunized with type II collagen and injected locally with an adenoviral vector expressing IL-17 or with control adenovirus. Knee joints were isolated and analyzed for cartilage PG depletion, chondrocyte death, and cartilage surface erosion., Results: During SCW-induced arthritis, local T cell IL-17 gene transfer turned this acute, macrophage-driven joint inflammation into a severe, chronic arthritis accompanied by aggravated cartilage damage. Of high interest, the IL-1 dependency of cartilage PG depletion was fully abrogated when IL-17 was locally overexpressed in the joint. Moreover, local IL-17 gene transfer increased MMP expression without the need for IL-1, although IL-1 remained essential for part of the cartilage VDIPEN expression. Furthermore, when IL-17 was overexpressed in the knee joints of mice with collagen-induced arthritis, anti-IL-1 treatment did not reduce the degree of chondrocyte death or cartilage surface erosion., Conclusion: These data show the capacity of IL-17 to replace the catabolic function of IL-1 in cartilage damage during experimental arthritis.

The early phase of cartilage degeneration was immunohistochemically examined in order to clarify the importance of autoimmune reaction against type II collagen in MRL/Mp- lpr/lpr (MRL/ l) mouse in an experimental model of rheumatoid arthritis (RA). Anti-type II collagen antibodies were detectable in 3-week-old mice and preceded the appearance of rheumatoid factors. Furthermore, mesenchymal cells and tartrate-resistant acid phosphatase-positive cells began to accumulate remarkably in the periphysis, a fibrochondro-osseous area in the bone marrow vicinity. The numbers of these cells increased with mice age, together with serum levels of anti-type II collagen antibodies. Immunostaining of the periphysis revealed expression of type II collagen, IgG, C3, Mac-3, MHC class II antigen Ia, and cathepsin-L. Osteoclast-like cells and macrophage infiltration into the lesion area were confirmed by transmission electron microscopy. The results indicate that cartilage degeneration in MRL/ l mouse may originate in the periphysis and progress via a pathway independent of synovial invasion.

Progressive degradation of articular cartilage is a central feature of arthritis and a major determinant of long term joint dysfunction. There are no treatments able to halt the progression of cartilage destruction presently available, and monitoring the benefit of potential therapies is hampered by our inability to measure the "health" of articular cartilage. Serial radiographic assessment of joint space narrowing, the current gold standard, requires measurements over a prolonged time (1-5 years) and is prone to technical difficulties. Other strategies for evaluating cartilage degradation are needed to enable both short and long term monitoring of disease progression and response to therapy. One avenue that holds promise is the use of biomarkers that accurately reflect the degradative state of the articular cartilage. Antibodies that recognise terminal amino acid sequences generated by proteolysis at specific sites in the core protein of both aggrecan and type II collagen (neoepitope antibodies) have become available in recent years. These antibodies have been invaluable for identifying the proteinases responsible for cartilage breakdown both in vitro and in vivo. The presence of neoepitope sequences generated by specific metalloenzyme cleavage of aggrecan and type II collagen correlates well with the progression of cartilage degeneration, both in vitro and in mouse models of arthritis. Preliminary results with quantitative assays of type II collagen neoepitopes suggest that they may be useful markers of joint disease in humans. Long term studies correlating neoepitope concentration with clinical and radiographic disease are now required to validate the utility of neoepitopes as surrogate markers of cartilage degeneration and joint disease.

Nitric oxide (NO) is thought to mediate most effects of interleukin-1 (IL-1) on cartilage. In vitro evidence includes the decreased synthesis of extracellular matrix components, the abnormal cell renewal, the decreased production of IL-1 receptor antagonist, the induction of apoptosis and the enhanced sensitivity of chondrocytes to oxidative stress. Studies in NOS2(-/-) mice or administration of NO synthase inhibitors in animal models of joint disorders have confirmed its potent pathophysiological role in cartilage. Using L-NMMA (1 mM), as a NO synthase inhibitor, and CuDips (10 microM), as a SOD mimetic, we provide evidence that the inhibitory potency of IL-1beta on proteoglycan synthesis and its stimulating effect on COX-2 activity depend both on NO and O2-* production. Peroxynitrite formation is further demonstrated by the occurrence of 3-nitrotyrosines in chondrocytes stimulated in vitro with 2.5 ng/ml IL-1 and in femoral condyles of rats injected locally with 1 microg IL-1. Preliminary data suggest that such contribution of reactive oxygen species is not shared in common by IL-17, another NO-producing cytokine. We conclude that superoxide is a key modulator of NO-mediated effects in chondrocyte stimulated with IL-1 and that a combined therapy with NO synthase inhibitors and antioxidants may be promising for a full cartilage protection.

Objective: Cartilage-hair hypoplasia (CHH), a metaphyseal chondrodysplasia, is usually associated with impaired cellular immunity. This study evaluates humoral immunity in patients with CHH., Methods: The concentrations of immunoglobulins G, A, and M (IgG, IgA, and IgM) and IgG subclasses were studied in 20 patients. Data for 5 additional patients with recurrent infections were retrospectively reviewed., Results: Seven of the prospectively evaluated patients (35%) had defective humoral immunity. Three patients had IgA deficiency. Four patients had IgG2 deficiency, accompanied by IgA deficiency, IgG4 deficiency, or both in 3 patients. IgG4 was low in most patients. Increased infections were usually associated with supranormal IgG and IgG1 and subnormal IgA, IgG2, or IgG4 concentrations. One retrospectively reviewed patient had severe hypogammaglobulinemia, and 3 had multiple IgG subclass deficiencies., Conclusions: Humoral immunity is impaired in CHH and contributes to the increased susceptibility to infections.

A type II collagen autoimmune response results in arthritis, auricular chondritis and tympanosclerosis in humans and animals. The purpose of this study is to further define the molecular and pathogenic events involved in these lesions in rodents. Type II collagen fragment CB11-specific monoclonal antibodies induced lesions in joints, ear lobes and tympanic membranes. In immunized mice, the thickness of tympanic membranes increased to two- to fourfold normal size. Electron micrography showed that the arrangement of collagen fibers is irregular in both radial and auricular layers, containing fibroblasts, a homogeneous material resembling low-density cholesterol crystals and cell infiltration. The mice with auricular chondritis had lymphocytes expressing V beta-8 T cell receptor (TCR) in arthritic joints and lymphocytes expressing V beta-6 TCR in ear lobe lesions. A monoclonal antibody specific to the TCR V beta-8 subfamily suppressed the onset of arthritis. Sequence analyses of the V beta structure of TCR involved in the lesions confirm the immunohistologic study.

The study was undertaken to determine whether immunologic mechanisms could account for hip stiffness and chondrolysis in Perthes' disease. Histologic and electron microscopic evidence of perivascular collections of plasma cells and lymphocytes in synovial tissue and the demonstration of elevated levels of circulating immunoglobulins in children with Perthes' disease suggest that immunologic processes are involved. Chondrolysis was observed only in children who were > 10 years old, with a totally avascular epiphysis in the stage of fragmentation. Because the serum immunoglobulin levels were not dependent on age, extent of epiphyseal avascularity, and the degree of hip stiffness, monitoring of these levels is unlikely to be of help in predicting chondrolysis.

An immune response directed against type II collagen (CII) has been reported in several autoimmune diseases including the animal models of collagen-induced arthritis (CIA) and collagen-induced autoimmune ear disease (CIAED). In this communication, we have found that T cells from type II collagen-immunized DBA/1-lac could transfer auricular chondritis to naive mice. The T cells from type II collagen-immunized H-2r and H-2q mice recognize different epitopes from the CB11 peptide of CII. The CII-specific T cells from H-2q background mice recognize peptide residues p121-147 (P1) but do not respond to residues p211-247 (P2). The T cells of H-2r mice immunized with CII respond better to P2 rather than P1. By altering certain amino acids within these epitopes, the response of CII-specific TCR to antigen has been increased or abolished. Our results suggest that the lysine residues at positions 129, 141, and 147 in P1, the arginine residue at position 227, and glutamic acid at position 230 in P2 might play an important role in the trimolecular interaction. Ten clonally distinct T cell hybridomas specific for CII have been established from H-2r B10.RIII mice and the beta chains of their TCR have been analyzed. Three subfamilies, V beta 1, V beta 6, and V beta 8, were utilized with dominant expression of V beta 8 (60%). This is quite similar to the pattern found in type II collagen-induced arthritis in H-2q mice. This preferential use of V beta 8 in CIAED implies that an immunotherapy may make it possible to control this autoimmune disease, even in a MHC-diverse situation.

The clinical relevance of antibodies against components of cartilage in the reconstructive surgery has not yet been clarified. In our study four groups of patients with successful and unsuccessful autologous cartilage transplantation in rhinosurgery, patients with ear perichondritis and patients with tracheal stenosis after long-term intubation were investigated for the presence of a humoral immune reactivity to cartilage. The control groups consisted of healthy persons and patients with RA. The antibodies against cartilage matrix and chondrocytes were determined using indirect immunofluorescence methods. Patients with unsuccessful cartilage transplantation showed increased antibodies against autologous cartilage (until 1:100) compared to the patients with successful cartilage transplantation. Furthermore, patients suffering from ear perichondritis and tracheal stenosis showed also increased antibodies against cartilage. These data suggest that a humoral immune reactivity against autologous cartilage--independent of an infection--can be one cause for the destruction of cartilaginous tissue.

Objectives: Rheumatoid arthritis (RA) is a disease which predominantly affects women. Interestingly, low serum androgen levels and clinical improvement with androgen replacement have been reported in male patients. The aetiopathogenic role of sex hormones in arthritis and their potential long term effects on joint destruction and disability remains unclear, however. This study was designed to investigate the potential influence of sex hormones on inflammation induced cartilage degradation in male rodents., Methods: An in vivo model of cotton wrapped cartilage implants was used to assess the effects of androgen, oestradiol, and progesterone on inflammation induced cartilage degradation, and in vitro techniques were used to investigate the direct actions on cartilage metabolism and cytokine production in male animals., Results: Orchidectomy resulted in accelerated cartilage damage which was reversed by replacement of physiological levels of androgens. Granulomatous tissue from castrated male rodents produced higher amounts of interleukin 1. Sex hormones reduced spontaneous proteoglycan loss in vitro but did not interfere with the effects of interleukin 1 on cultured cartilage., Conclusions: Androgens appear to protect cartilage from inflammation induced breakdown in male animals. These results support a pathogenic role for hypoandrogenism in rheumatoid arthritis and suggest that long term androgen replacement may help prevent joint damage and disability.

An animal model was used to evaluate the role of pin penetration into the hip joint as the cause of chondrolysis. The gross and microscopic studies, as well as the biochemical studies, showed changes indicating cartilage destruction. These changes were more severe when the pins remained in the joint. Immunologic studies showed some type of immunological interaction. The immunologic response may be initiated by release of cartilage byproducts. The initial insult of the slip may cause release of cartilage byproducts from the exposed growth plate within the joint, and is compounded by penetration of the pin in the hip joint.

A murine monoclonal antibody (E10) was made against cultured cartilage cells. The E10 antibody binding is localized to the surface of cultured cartilage cells in suspension and is present in the cytoplasm in paraffin embedded sections. There is no reactivity with cartilage matrix, or with the matrix of cartilaginous tumors. Reactivity is removed by treatment with trypsin and hyaluronidase, but not by treatment with heparinase, neuraminidase, and chondroitinase. Regeneration of E10 antigen after trypsinization takes 48 hours in chondrocytes in tissue culture. SDS-polyacrylamide gel electrophoresis of an E10 immune precipitate of cultured chondrocytes results in two peaks: one at a very high molecular weight and a small fragment at approximately 250 kd. Specificity has been demonstrated by cytofluorometry, immunofluorescence, and immunohistochemistry, in both frozen and paraffin-embedded tissues. Positive reactivity was seen in cultured cartilage cells, chondrocytes in fetal and adult cartilage, chondrosarcomas, and chordomas. Minimal reactivity was found in a chondromyxoid liposarcoma. Acinar cells of salivary and sweat glands and mast cells in various tissues and tumors were also positive. There was no reactivity with other tissues and tumors, including myxoid and mucinous tumors and epithelial tissues.

Epiphyseal cartilage grown in vitro was transplanted using fibrin clot into a cartilage defect produced on the femoral articular surface of the knee joints in white New Zealand rabbits 5-6 months of age. The transplantation was successful for two weeks in 64% and for 3-24 weeks in 26%. Almost dead transplanted tissues were replaced by fibrous tissues to preserve the joint function. Immunological studies such as counting of inflammatory cells in the joint fluid, evaluation of the anti-allo antibody titer by passive hemagglutination inhibition, immunofluorescence studies, and assay of cytolytic reaction by 51Cr labelled allogenic target cells suggested that the transplanted cartilage began to degenerate from two or three weeks after the transplantation partially due to humoral immunity but more importantly on account of cellular immunity.

Investigations were performed to determine the potential of an immunologically-mediated basis underlying development of severe bilateral knee chondrolysis arising over a 2-yr period in a 29-yr-old man. Humoral and cell-mediated immune responses to autologous and homologous articular cartilage proteoglycan and collagen rich fractions were identified in sequential studies. Employing gradient derived peripheral blood mononuclear cells there was demonstration of spontaneous, T cell mitogen augmented and autologous cartilage antigen-induced release of factors capable of degrading articular cartilage proteoglycans and inhibiting chondrocyte glycosaminoglycan synthesis. Evidence has thus been provided incriminating immunologic events, likely functioning in a perpetuant manner, in the pathogenesis of this chondrolytic process.

Three patients with systemic lupus erythematosus (SLE) and relapsing auricular and nasal chondritis are described. Chondritis in SLE is a rare event (less than 1% of our patients), was accompanied by clinical and laboratory evidence of SLE activity and resembled relapsing polychondritis in clinical presentation and pathology. Clinical involvement was limited, cartilage collapse did not occur and response to steroid therapy was prompt. Cartilage inflammation in two ear biopsies was relatively mild, with deposits of IgG and C3 in the chondrofibral junction and adjacent skin vessels. Immune complexes (cryoglobulins) were present in the serum. We postulate an immune complex pathogenesis of this rare manifestation of SLE.

We report a case of cartilage-hair hypoplasia in a girl. The patient had short stature with short limbs and scalloped long bone metaphyses, sparse, poorly-pigmented hair, and increased susceptibility to infections. Several features of this case deserve attention: neutropenia, probably due to an autoimmune mechanism, was an initial manifestation; the immune deficiency (defective B and T cell immunity, autoimmune manifestations) was severe, and cytomegalovirus infection possibly aggravated the immune deficiency and hormone abnormalities. Whereas this patient's short stature is becoming more marked, prophylaxis of infections and administration of immune globulins have effectively prevented complications for the last two years.

Patients previously described with cartilage-hair hypoplasia, a distinctive form of short-limbed dwarfism, have been found to have deficient cell-mediated immunity with intact antibody-mediated immunity. The patient with cartilage-hair hypoplasia described in the present report is unusual in that she had both deficient antibody-mediated immunity and deficient cell-mediated immunity. In addition, she developed severe, vaccine-related paralytic poliomyelitis. This complication suggests that live viral vaccines should not be administered to children with short-limbed dwarfism until the form of short-limbed dwarfism is established and immunologic evaluation is performed when indicated.

The encapsulation of intact rat femoral head cartilage or discs of bovine nasal cartilage with cotton-gauze before implantation in the subcutaneous tissues of mice, results in an accelerated loss of cartilage proteoglycan. Loss of proteoglycan from bovine nasal cartilage occurred later than rat femoral head cartilage, but eventually brought about complete dissolution of the cartilage. Freeze-thaw killing of bovine nasal cartilage did not alter the amount of proteoglycan lost. Destruction of both femoral and nasal cartilage was related to the mass of cotton implanted and to the growth of connective tissue within the implanted cotton. Mice previously implanted with femoral head cartilage were able to show enhanced degradation to new implants; this was even greater if the original implants were encapsulated with cotton. Presoaking of cotton-cartilage implants with the non-specific irritant, carrageenan inhibited the breakdown of cartilage. Autoradiographs of 35sulphate pulsed femoral cartilage following implantation with cotton showed reduced incorporation of radiolabel by chondrocytes.

Associations were sought between ELA A1-A10 and W11 antigens and the presence of laryngeal hemiplegia, arytenoid chondritis, umbilical hernias and cryptorchidism in Thoroughbreds and/or Quarter Horses. No significant associations were detected between laryngeal hemiplegia and any ELA antigen in Thoroughbreds. The association between arytenoid chondritis and A9 was significant with a relative risk (RR) of 15.6 and aetiologic fraction (EF) of 0.80 in Thoroughbreds. There were apparent associations based on RR between A4 and A5 in Quarter Horses with umbilical hernias (RR = 7.5 and 6.1 respectively); however, these were not statistically significant. No significant associations were detected with cryptorchidism in Quarter Horses when the control population included both sexes. When only unaffected males were used as the control group, there was an apparent increase in relative risk with A6 (from RR = 1.7 to 4.3); however this was not statistically significant. Cryptorchidism in Thoroughbreds showed an increased relative risk with A5 regardless of whether the control population included males and females (RR = 4.1) or only males (RR = 4.7) but the increases were not statistically significant.

Several benign and malignant tumors of bone and cartilage were examined by means of type-specific collagen antibodies in connection with indirect immunofluorescence technique in order to determine wether there is a positive correlation between cell morphology and gene expression as refered to the synthesis of tissue- or cell-specific collagen. In general benign bone and cartilage tumors show the collagen type corresponding to the original maternal tissue. In malignant osteogenic tumors a strong positive correlation was found between morphologic differentiation of osteosarcoma cells and tissue specific collagen synthesarcomas. Unrelated to the grade of differentiation and the type of malignant tumor, collagen type III could be demonstrated in all tumors investigated, occurring rather from vascular stroma than from the tumor cell itself.

A 29-year-old white woman had short limbs, hyperextendable joints, fine skin and body hair, anergy to common skin test antigens, subnormal lymphocyte response to phytohemagglutinin, and increased numbers of natural killer cells, characteristic of cartilage-hair hypoplasia, an autosomal, recessively inherited disorder found in America mainly among the old-order Amish. Her forearm skin was hyperextendable and numerous verrucae were present on the digits of her hands. A skin biopsy from hyperextendable skin showed ovoid, 10- to 20-micron bodies in the papillary dermis. Ultrastructurally, the bodies were interpreted as abnormal elastic fibers.

Two patients with rapidly progressive chondrolysis of the hip are reported. Immunofluorescent staining showed deposits of immunoglobulins and complement components in the synovium and the remaining femoral head cartilage. Seven patients with osteoarthritis of the hip and knee, or femoral neck fractures, were used as controls and all had a negative immunofluorescent staining reaction in the synovium. We suggest that an autoimmune reaction against articular cartilage antigens may play a role in the development of chondrolysis.

Individuals with cartilage-hair hypoplasia (CHH), an autosomal recessive form of short-limbed dwarfism, have markedly reduced lymphocyte proliferative responses and cutaneous delayed hypersensitivity reactions, but normal humoral immunity. In the present study we investigated the cellular basis of the immunodeficiency in CHH. Defective lymphocyte proliferation could be due to a) an imbalance of immunoregulatory lymphocyte subpopulations, b) defective accessory cell function, or c) an intrinsic cellular defect in lymphocytes from CHH individuals. The absolute numbers of B cells and immunoregulatory (OKT4+, OKT8+) T cells were markedly diminished, but the proportions of these populations were the same as in the normal controls. OKM1+ lymphocytes were increased in proportion, and OKM1+ macrophages had normal adherence, helper, and phagocytic properties. Co-culture experiments failed to reveal any evidence of suppression by CHH mononuclear cells. CHH lymphocytes could not be stimulated to proliferate normally with B and T cell activators, mitogenic monoclonal antibody (OKT3), allogeneic cells, or chemical activators (Ca++ ionophore A23187 and phorbol myristate acetate). Fibroblasts from three CHH individuals also proliferated at a significantly decreased rate, compared to two normal lines. These results demonstrate a selective loss of B and T lymphocytes in CHH, as well as an intrinsic proliferative defect in CHH lymphocytes distal to the initial events in the lymphocyte activation sequence. These findings in CHH fibroblasts and lymphocytes may reflect a generalized defect present in multiple cell types in CHH.

Cartilage is a focal point of attack by cellular and molecular elements of the inflammatory response which occurs in arthritic diseases. Neutrophils damage articular cartilage by degrading matrix components and inhibiting their synthesis. The aim of this study was to elucidate mechanisms of this damage. Human neutrophils were isolated from blood by centrifuging through Ficoll-Hypaque and granule extract prepared from them. Articular cartilage from adult humans and cattle was maintained in organ culture. Cartilage degradation (release of 35S-labelled proteoglycan) or synthesis (incorporation of 35S into proteoglycan) was determined after various treatments. Human neutrophils and neutrophil granule extract degraded proteoglycan and inhibited proteoglycan synthesis. The specific leucocyte elastase inhibitor N-methoxysuccinyl-(ala)2-pro-val-chloromethylketone (MAAPVCMK) partially reversed these effects. H2O2, a product of the neutrophil respiratory burst, when added directly at 10(-6)mol/L, or generated by glucose oxidase (GO)/glucose inhibited proteoglycan synthesis but had no effect on degradation. Hypochlorous acid (OHCl), a product of the myeloperoxidase (MPO)/H2O2/Cl system at 50 mumol/L degraded proteoglycan and inhibited its synthesis. OHCl produced by granule extract (as a source of MPO) + GO-generated H2O2 + Cl- degraded proteoglycan. The results indicate that neutrophil-mediated proteoglycan degradation and inhibition of synthesis is largely attributable to elastase and secondarily to OHCl, whereas H2O2 impairs synthesis without affecting degradation of proteoglycan.

A spontaneous apparently unique auricular chondritis in the pinna of fawn-hooded rats is described. The chondritis was bilateral, with adult onset, and resulted in a marked thickening of the auricular cartilage. Microscopically, islands of proliferative cartilage were present, and at the margins between the normal cartilage and the thickened abnormal cartilage a marked cellular inflammatory response was present. The condition was familial in rats of the fawn-hooded strain and appeared to be unrelated to the platelet storage pool deficiency in this strain of rats. Biochemically no increased synthesis of pinna cartilage was detected. No histopathologic lesions were detected in other cartilaginous tissues of affected rats. The lesions in the pinna bore a striking resemblance to those induced in rats by immunization with Type II collagen. The spontaneous condition described herein may, therefore, represent a unique model of relapsing polychondritis of human beings, a disease with auricular chondritis associated with antibodies to Type II collagen.