ABSTRACT
Consultants regularly need to decide whether a trainee can be entrusted to perform a clinical activity independently. 'Entrustable professional activities' (EPA) provide a framework for justifying and better utilising supervisor entrustment decisions for trainee feedback and assessment in the workplace. Since being proposed by Olle ten Cate in 2005, EPA are emerging as an integral part of many international medical curricula, and are being considered by the Royal Australasian College of Physicians in the current review of physician training. EPA are defined as tasks or responsibilities that can be entrusted to a trainee once sufficient competence is reached to allow for unsupervised practice. An example might be to entrust a trainee to 'Initiate and co-ordinate care of the palliative patient' with only off-site or indirect supervision. Rather than attempting to measure directly each of the many separate competencies required to undertake such a complex task, EPA direct the trainee and supervisor's attention to the trainee's performance in a limited number of selected, representative, important day-to-day activities. EPA-based assessment is gaining momentum, amongst significant concerns regarding feasibility of implementation. While the optimal process for designing and implementing EPA remains to be determined, it is an assessment strategy where the over-arching goal of optimal patient care remains in clear sight. This review explores the central role of trust in medical training, the case for EPA and potential barriers to implementing EPA-based assessment.
Subject(s)
Clinical Competence/standards , Education, Medical/standards , Physicians , Trust , Work Performance/education , Education, Medical/methods , HumansABSTRACT
AIM: To review systematically the management of acute gout during hospitalization. METHODS: Case-file review of all episodes of acute gout occurring in a large tertiary hospital over a 20-month period. RESULTS: Of 134 acute gout episodes identified, the large majority (118) occurred in patients not admitted under the rheumatology unit. Baseline anti-gout medications were frequently ceased on admission and in 9% of episodes, no pharmacotherapy was prescribed. Delays in initiation of treatment occurred in up to 29% of patients. Acute management included anti-inflammatory monotherapy, or combinations of colchicine, non-steroidal anti-inflammatory drugs (NSAIDs) and corticosteroids. Of patients prescribed colchicine, 26% received >1.5 mg/day and a strong correlation was found between colchicine dose and the occurrence of diarrhoea. NSAIDs were prescribed in 29% of patients with pre-existing renal impairment. Overall, 25% of patients received inappropriate pharmacological management. In patients not under the direct care of the rheumatology unit, in-hospital rheumatology consultation was sought by the treating unit in 34% of episodes. Consultation was sought more frequently in patients with multiple joint involvement, but there were no other obvious differences in baseline clinical characteristics between cases with or without rheumatology involvement. In cases with rheumatology involvement, patients were investigated more frequently, they received more pharmacotherapeutic intervention, in particular combination anti-inflammatory therapy, and they achieved better symptomatic relief and long-term follow up. CONCLUSION: Acute gout episodes in hospital are variably investigated and treated with frequent suboptimal management. We recommend establishment of a hospital-wide protocol to support decision-making regarding investigations, treatment and follow up.
Subject(s)
Clinical Protocols , Gout/diagnosis , Gout/therapy , Health Services Needs and Demand/trends , Hospitalization/trends , Acute Disease , Adolescent , Adult , Aged , Aged, 80 and over , Clinical Protocols/standards , Disease Management , Female , Follow-Up Studies , Gout Suppressants/therapeutic use , Health Services Needs and Demand/standards , Humans , Male , Middle Aged , Young AdultABSTRACT
INTRODUCTION: This study aimed to determine outcomes of percutaneous vertebroplasty for osteoporotic vertebral compression fractures (VCFs). METHODS: Prospective assessment of short-term (Subject(s)
Fractures, Compression/surgery
, Osteoporosis/complications
, Spinal Fractures/surgery
, Vertebroplasty/methods
, Aged
, Aged, 80 and over
, Back Pain/diagnosis
, Back Pain/etiology
, Back Pain/surgery
, Disability Evaluation
, Female
, Follow-Up Studies
, Fractures, Compression/etiology
, Humans
, Male
, Middle Aged
, Pain Measurement/methods
, Pain Measurement/statistics & numerical data
, Prospective Studies
, Radiology, Interventional/methods
, Spinal Fractures/etiology
, Spine/surgery
, Treatment Outcome
ABSTRACT
OBJECTIVES: To compare the expression of leucocyte immunoglobulin-like receptors (LILRs) also known as ILTs and LIRs in rheumatoid arthritis (RA) synovial membrane before and after treatment with disease-modifying anti-rheumatic drugs (DMARDs) and investigate regulation of LILR-expression and function in vitro. METHODS: A study was performed on serial synovial biopsies obtained from 10 RA patients before and after treatment with DMARDs. Expression of the activating LILRA2 (ILT1 or LIR-7) and inhibitory LILRB2 (ILT4 or LIR-2) and LILRB3 (ILT5 or LIR-3) was evaluated by immunohistochemical staining, and quantified by a validated scoring system. Peripheral blood mononuclear cells and in vitro derived macrophages were used to determine effects of DMARDs on expression and function of LILRs. RESULTS: Abundant expression of LILRB2, B3 and A2 was found in synovial tissue of all patients before treatment. Number of inflammatory cells expressing both inhibitory and activating LILRs dramatically decreased in patients who responded to treatment, but remained high in those who did not. However, treatment of macrophages with DMARDs in vitro did not down-regulate LILR expression. On the other hand, reduction in LILR expression in RA synovia was associated with decreased inflammatory infiltrates in those who responded to treatment. Cross-linking of LILRA2 on macrophages caused substantial production of tumour necrosis factor (TNF-alpha) in a dose- and time-dependent manner that was strongly inhibited by dexamethasone. CONCLUSIONS: We show that expression of LILRs in RA synovium was significantly reduced only in patients who responded to treatment. However, clinical responses may not be due to direct effects of DMARDs on LILR expression but due to partial inhibition of LIRA2-mediated TNF-alpha production by steroids leading to suppression of inflammation.
Subject(s)
Antirheumatic Agents/therapeutic use , Arthritis, Rheumatoid/immunology , Down-Regulation/drug effects , Membrane Glycoproteins/metabolism , Receptors, Immunologic/metabolism , Synovial Membrane/immunology , Aged , Aged, 80 and over , Antirheumatic Agents/pharmacology , Arthritis, Rheumatoid/drug therapy , Cells, Cultured , Cohort Studies , Dose-Response Relationship, Drug , Female , Humans , Macrophage Activation , Macrophages/drug effects , Macrophages/metabolism , Male , Middle Aged , Receptors, Fc/metabolism , Severity of Illness IndexABSTRACT
OBJECTIVES: Elevated plasma C-reactive protein (CRP) levels predict coronary events, but it is unclear whether CRP plays a role in thrombosis associated with these events. We investigated tissue factor (TF) induction by CRP on peripheral blood mononuclear cells (PBMC) from patients with coronary disease. PATIENTS AND METHODS: PBMC from 35 patients with stable angina (SA) in study 1, 10 male patients with SA, 10 with unstable angina (UA) and 10 matched controls in study 2, and 25 patients with inflammatory disorders (ID) and 24 normal controls in study 3 were stimulated with CRP, interferon-gamma (IFN) or lipopolysaccharide (LPS), or their combination. PBMC from additional normal donors were also stimulated with CRP in adherent and non-adherent conditions, and TF activity, antigen and mRNA expression detected. RESULTS: CRP (5-25 microg mL(-1)) dose dependently induced more TF on PBMC from SA patients than 42 contemporary controls (P = 0.001, study 1). Compared with controls, patients with SA or UA had higher basal, and much higher CRP- or CRP/LPS-induced monocyte TF activity although serum CRP levels were similar (study 2). IFN induced monocyte TF activity in patients with angina, but not in controls. Basal or CRP-induced TF levels did not differ between controls and ID, even though ID patients had much higher serum CRP levels (study 3). CRP-induced monocyte TF activity correlated with serum CRP levels in controls (P = 0.005) and ID (P = 0.007) in study 3, but not in patients with angina (P =0.84) in study 2. CRP induced more TF activity, protein and mRNA under adherent than non-adherent conditions implying that it may mainly target macrophages in lymphocyte-rich lesions. CONCLUSIONS: Our results indicate that monocytes from patients with angina are preactivated and express TF but CRP is unlikely to be a major priming factor in vivo. IFN and CRP further increase TF levels that may contribute to the hypercoagulable state in coronary disease.
Subject(s)
C-Reactive Protein/pharmacology , Coronary Artery Disease/blood , Thrombophilia/chemically induced , Adult , Aged , Angina Pectoris/blood , Case-Control Studies , Cells, Cultured , Dose-Response Relationship, Drug , Female , Gene Expression Regulation/drug effects , Humans , Interferon-gamma/pharmacology , Leukocytes, Mononuclear/drug effects , Leukocytes, Mononuclear/pathology , Lipopolysaccharides/pharmacology , Male , Middle Aged , Thromboplastin/geneticsABSTRACT
Rheumatoid arthritis (RA) affects approximately 1% of the population and is a chronic inflammatory joint disease resulting in joint destruction, increased morbidity and mortality. Although the aetiology of this disease is unknown, the pivotal role played by cytokines and degradative enzymes in mediating inflammation and joint destruction, particularly early in the disease process, has been the focus of recent literature and will be the focus of this review. Up until recently, studies on early RA were limited as there was an inherent delay in patients reaching the rheumatologist's care and initial diagnostic confusion may have compounded these problems. In particular, the observation that early intervention improves outcome, has driven the study of early RA. It is difficult to define early RA but most studies have defined this as disease duration of less than 12 months from symptom onset. Clearly, it is important to study the synovial membrane in early disease, in particular to try and answer the important questions: (1) What are the earliest changes to occur in the RA synovium? (2) Can we distinguish RA on the basis of synovial membrane pathology? (3) Can synovial immunopathology predict outcome? (4) What is the role of arthroscopic biopsy in early RA?
Subject(s)
Arthritis, Rheumatoid/physiopathology , Inflammation Mediators/physiology , Synovial Membrane/physiopathology , Arthritis, Rheumatoid/diagnosis , Arthritis, Rheumatoid/metabolism , Arthritis, Rheumatoid/pathology , Arthroscopy , Biopsy , Cell Adhesion Molecules , Chemokines/metabolism , Chemokines/physiology , Cytokines/metabolism , Cytokines/physiology , Humans , Synovial Membrane/metabolism , Synovial Membrane/pathologyABSTRACT
OBJECTIVE: To compare macrophage infiltration and expression of chemokines and matrix metalloproteinases (MMPs) in synovial tissue between patients with early and long-standing rheumatoid arthritis (RA). METHODS: Knee synovial biopsies were taken from 22 patients with early (<1 yr) and 22 patients with long-standing (>5 yr) RA and immunostained with antibodies specific for CD68; macrophage inflammatory protein (MIP)-1alpha and monocyte chemoattractant protein (MCP)-1; MMP-1 and -3 and the tissue inhibitors of metalloproteinases (TIMP)-l and -2. Immunostaining was quantified using a colour video image analysis system. RESULTS: CD68+ macrophage infiltration and the expression of MIP-1alpha, MCP-1, MMP-1, MMP-3, TIMP-1, and TIMP-2 were observed in synovial tissue of patients with early RA. In long-standing RA, there was a further increase in CD68+ macrophage infiltration and MIP-1alpha expression in the synovial lining layer. CD68 expression correlated with MIP-1alpha (R=0.39, P=0.01), but not with MCP-1 expression. CONCLUSION: Macrophage accumulation, and the expression of chemokines and MMPs in synovial tissue occur in early RA. Targeting chemokines which play a role in the migration of macrophages into the joints may be of therapeutic benefit in RA patients.
Subject(s)
Arthritis, Rheumatoid/metabolism , Chemokines/metabolism , Matrix Metalloproteinases/metabolism , Aged , Antigens, CD/metabolism , Antigens, Differentiation, Myelomonocytic/metabolism , Arthritis, Rheumatoid/pathology , Arthritis, Rheumatoid/physiopathology , Female , Humans , Image Processing, Computer-Assisted , Immunoenzyme Techniques , Joints/pathology , Joints/physiopathology , Knee Joint/metabolism , Knee Joint/pathology , Macrophages/metabolism , Macrophages/pathology , Male , Severity of Illness Index , Synovial Membrane/metabolism , Synovial Membrane/pathology , Tissue Inhibitor of Metalloproteinase-1/metabolism , Tissue Inhibitor of Metalloproteinase-2/metabolismABSTRACT
OBJECTIVE: Rheumatoid synovitis is characterized by a mast cell response in which tryptase containing mast cells (MCT) associate with T lymphocyte infiltration, and tryptase and chymase containing mast cells (MCTC) correlate more closely with tissue damage or repair events. We investigated expression of the alphaEbeta7 integrin and its ligand E-cadherin in rheumatoid and normal synovium and compared this expression to synovial mast cell responses. METHODS: Immunohistochemical analysis was used to determine the expression of alphaEbeta7 and E-cadherin in rheumatoid (n = 17) and normal (n = 6) synovium. The density of MCT and MCTC mast cell subsets was compared to the density of alphaEbeta7 positive mast cells. RESULTS: The mean density of alphaEbeta7 positive cells in rheumatoid synovia was 25.2 cells/mm2 (range 0.3-102.9), of which 26.7% (range 0-68.6%) were mast cells. A mean of 11.9% (range 0-30.4%) of rheumatoid synovial mast cells expressed alphaEbeta7 compared to 0% in normal synovium (p < 0.0001). There was a strong correlation between the density of alphaEbeta7 positive cells and the total mast cell density in rheumatoid synovium (r2= 0.74). alphaEbeta7 positive mast cell density correlated significantly with the MCT subset density (r2 = 0.5, p = 0.014), but not with the MCTC subset density. E-cadherin expression was increased in rheumatoid compared with normal synovium, but did not colocalize or correlate with alphaEbeta7 expression. CONCLUSION: These results indicate a role for alphaEbeta7 in the mast cell response that occurs in rheumatoid synovitis, in particular the MCT mast cell subset expansion associated with inflammatory events and interactions with infiltrating lymphocytes.
Subject(s)
Arthritis, Rheumatoid/metabolism , Integrins/biosynthesis , Mast Cells/metabolism , Synovial Membrane/metabolism , Arthritis, Rheumatoid/pathology , Cadherins/metabolism , Humans , Immunohistochemistry , Integrins/immunology , Synovial Membrane/pathologyABSTRACT
BACKGROUND: Asthma is an acute-on-chronic inflammatory disease of the airways characterized by recruitment of eosinophils into the epithelial layer, chronic inflammation in the lamina propria, as well as variable accumulation of mast cells in the airway wall. The role of local production of allergen-specific immunoglobulins in triggering mast cell-mediated asthmatic inflammation is unknown. METHODS: We used a chronic inhalational exposure model of asthma in ovalbumin-sensitized BALB/c mice to examine the phenotype of immunoglobulin-secreting cells and mast cells in the airway wall. In parallel, we assayed ovalbumin-specific IgG and total IgE in the plasma of these animals. RESULTS: In sensitized mice exposed to aerosolized ovalbumin for 6 weeks, aggregates of chronic inflammatory cells consisted of a majority of plasmacytoid cells, including numerous IgG-synthesizing cells, which were significantly increased in sensitized animals compared to controls. IgA-synthesizing cells were also present, but were not increased in the sensitized exposed mice. Immunoglobulins in the cytoplasm of the plasma cells were demonstrated to be antigen-specific. No IgM-or IgE-synthesizing cells were observed, although levels of total IgE in the plasma were significantly increased. There was no recruitment of mast cells of either the mucosal or the connective tissue phenotype into the lamina propria or the epithelium. CONCLUSION: In this experimental model of chronic asthma, the pattern of inflammation in the airway wall is consistent with development of a local IgG-mediated humoral immune response. However, there is no evidence of local production of IgE or recruitment of mast cells.
Subject(s)
Asthma/immunology , Immunoglobulin G/biosynthesis , Trachea/immunology , Animals , Antibody-Producing Cells/physiology , Disease Models, Animal , Female , Immunoglobulins/blood , Mast Cells/physiology , Mice , Mice, Inbred BALB CABSTRACT
Antiphospholipid (aPL) syndrome (APS) is characterized by thromboembolic events, thrombocytopenia, or recurrent miscarriage associated with aPL Abs with specificity for beta2-glycoprotein-I (beta2GPI). We recently reported that at least 44% of patients with the APS possess circulating type 1 (Th1) CD4+ T cells that proliferate and secrete IFN-gamma when stimulated with beta2GPI in vitro. In this study, we show that stimulation of PBMCs from 20 APS patients with beta2GPI induced substantial monocyte tissue factor (TF) (80 +/- 11 TF stimulation index (TF-SI)), whereas no induction was observed using PBMCs from 13 patients with aPL Abs without APS (6 +/- 1 TF-SI) or 7 normal and 7 autoimmune controls (5 +/- 1 and 3 +/- 1 TF-SI, respectively) (p < 0.0001). TF induction on monocytes by beta2GPI was dose dependent and required CD4+ T lymphocytes and class II MHC molecules. Because monocyte TF induction by beta2GPI was observed in all patients with APS, but not in any patient with aPL Abs without APS, this response is a potentially useful predictor for APS in patients with aPL Abs, as well as providing mechanistic insight into thrombosis and fetal loss in these patients.
Subject(s)
Antibodies, Antiphospholipid/blood , Fetal Death/immunology , Glycoproteins/immunology , Lymphocyte Activation , Monocytes/immunology , T-Lymphocyte Subsets/immunology , Thromboplastin/biosynthesis , Thrombosis/immunology , Anticoagulants/immunology , Blood Coagulation Tests , CD4-Positive T-Lymphocytes/immunology , CD4-Positive T-Lymphocytes/metabolism , Dose-Response Relationship, Immunologic , Epitopes, T-Lymphocyte/blood , Epitopes, T-Lymphocyte/immunology , Female , Fetal Death/blood , Humans , Male , Monocytes/metabolism , T-Lymphocyte Subsets/metabolism , Thromboplastin/physiology , Thrombosis/blood , beta 2-Glycoprotein IABSTRACT
That mast cells participate in inflammatory reactions is beyond argument. A major question posed by mast cell biologists is whether specific functions in inflammation are subserved by different subsets of the mast cell population. We have investigated the two major subsets of human mast cells (MC(T) and MC(TC)), in the chronic inflammatory processes associated with rheumatoid arthritis (RA). Whereas normal synovium contains mainly MC(TC) mast cells, the MC(T) subset is selectively expanded in early RA, in numbers that correlate with synoviocyte hyperplasia and T-lymphocyte infiltration. In contrast, in RA of long duration, MC(TC) mast cells predominate in numbers that correlate with clinical indices of rapidity of disease progression. We suggest that MC(T) mast cells participate in active inflammatory events, whereas MC(TC) mast cells may be more relevant in repair or damage to connective tissues.
Subject(s)
Inflammation , Mast Cells/classification , Mast Cells/physiology , Arthritis, Rheumatoid/immunology , Arthritis, Rheumatoid/pathology , Humans , Inflammation/immunology , Inflammation/pathology , Mast Cells/immunology , Synovial Membrane/immunology , Synovial Membrane/pathologyABSTRACT
Patients with antiphospholipid syndrome (APS) suffer recurrent thromboses, thrombocytopenia, and/or fetal loss in association with Abs that can be detected in phospholipid-dependent assays. Despite the name, the Igs associated with APS are predominantly directed against epitopes on phospholipid-binding plasma proteins, such as beta 2-glycoprotein-1 (beta 2GP1) and prothrombin. The aim of this study was to examine the cellular immune response to beta 2GP1 in patients with APS. Using a serum-free stimulation assay, PBMCs from 8 of 18 patients with APS proliferated to purified beta 2GP1 or to the beta 2GP1 present in serum, whereas no stimulation was observed by PBMCs from healthy individuals, patients with other autoimmune diseases, or anticardiolipin Ab-positive patients without histories of thromboses or fetal loss. The immune response was Ag-specific, requiring class II molecules, CD4+ T cells, and APCs, and was associated with a selective expansion of CD4+ but not CD8+ T cells. The proliferating T cells produced IFN-gamma but not IL-4, indicating a bias toward a type 1 immune response. Chronic low grade stimulation of autoreactive beta 2GP1-specific, IFN-gamma-producing Th1 CD4+ T cells may contribute to the high risk of thromboses and pregnancy failure in patients with APS.
Subject(s)
Antiphospholipid Syndrome/immunology , Glycoproteins/immunology , Adult , Antibodies, Antiphospholipid/blood , Anticoagulants/blood , Anticoagulants/immunology , Antigen-Presenting Cells/immunology , Antiphospholipid Syndrome/blood , CD4-Positive T-Lymphocytes/immunology , Epitopes, T-Lymphocyte/immunology , Glycoproteins/blood , Glycoproteins/isolation & purification , Humans , Immunity, Cellular , Interferon-gamma/biosynthesis , Interferon-gamma/blood , Interleukin-4/biosynthesis , Interleukin-4/blood , Leukocytes, Mononuclear/immunology , Leukocytes, Mononuclear/metabolism , Lymphocyte Activation , Middle Aged , Phospholipids/blood , Phospholipids/immunology , beta 2-Glycoprotein ISubject(s)
IgG Deficiency/complications , Monoclonal Gammopathy of Undetermined Significance/complications , Sepsis/etiology , Aged , Arthritis, Infectious/etiology , Cellulitis/etiology , Fever/etiology , Humans , IgG Deficiency/therapy , Immunization, Passive , Male , Monoclonal Gammopathy of Undetermined Significance/therapy , Shoulder Pain/etiologyABSTRACT
The clinically relevant antiphospholipid antibodies (APA) include anticardiolipin antibodies and lupus anticoagulant. Most autoimmune APA require the presence of a cofactor for phospholipid binding, and the growing list of candidate cofactors has prompted redefinition of APA to 'antiphospholipid protein antibodies'. Current evidence favours beta2-glycoprotein I (beta2GPI) and prothrombin as the primary antigens for anticardiolipin antibodies and lupus anticoagulant respectively. Patients with APA show a predisposition for venous and arterial thromboembolism, recurrent fetal loss, thrombocytopenia and a number of neurological syndromes and miscellaneous conditions. The association between APA and thrombosis has been well documented, but a definite mechanism remains to be clarified. Proposed mechanisms have included disruption of endothelial regulatory processes, impairment of fibrinolysis, augmented platelet activation and/or adhesion, inhibition of antithrombin activity and negation of the anticoagulant effects of beta2GPI and annexin V. In this review we describe recent insights into the role of beta2GPI as a natural anticoagulant, the procoagulant effects of APA on the Protein C system, the interactions between APA and prothrombin resulting in augmentation of thrombin generation, and cellular expression of Tissue Factor in patients with APA. Cellular immunity to beta2GPI is also discussed. Elucidation of these pathophysiological mechanisms may shed further light on the association between APA and thrombosis.
Subject(s)
Antibodies, Antiphospholipid/blood , Thrombosis/immunology , Animals , Antibodies, Antiphospholipid/adverse effects , Antibodies, Antiphospholipid/physiology , Anticoagulants/blood , Anticoagulants/pharmacology , Female , Glycoproteins/blood , Glycoproteins/pharmacology , Humans , Lupus Coagulation Inhibitor/adverse effects , Lupus Coagulation Inhibitor/blood , Lupus Coagulation Inhibitor/immunology , Male , Pregnancy , Prothrombin/metabolism , Prothrombin/pharmacology , Thrombosis/blood , Thrombosis/etiology , beta 2-Glycoprotein IABSTRACT
By virtue of their target cell specificity, chemokines have the potential to selectively recruit leukocyte subpopulations into sites of inflammation. Their role in regulation of T lymphocyte traffic into lymph nodes during the development of an immune response has not previously been explored. The sensitization phase of contact hypersensitivity induced by the hapten, dinitrofluorobenzene (DNFB) in the mouse was used as a model of T lymphocyte trafficking in response to antigenic stimulation. Rapid accumulation of CD8+ and CD4+ T cells in the draining lymph nodes was closely associated with strongly enhanced expression of macrophage inflammatory protein (MIP)-1 alpha and MIP-1 beta mRNAs and proteins. Mast cells accumulating in the nodes during DNFB sensitization were the predominant source of MIP-1 beta, whereas MIP-1 alpha was expressed by multiple cell types. Neutralization of these chemokines profoundly inhibited T lymphocyte trafficking into lymph nodes and altered the outcome of a subsequent challenge to DNFB. Thus, beta-chemokines regulate T lymphocyte emigration from the circulation into lymph nodes during an immune response and contribute significantly to the immunologic outcome.
Subject(s)
Cell Movement/immunology , Lymph Nodes/immunology , Macrophage Inflammatory Proteins/physiology , T-Lymphocyte Subsets/physiology , Animals , CD4-Positive T-Lymphocytes/immunology , CD4-Positive T-Lymphocytes/pathology , CD4-Positive T-Lymphocytes/physiology , CD8-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/pathology , CD8-Positive T-Lymphocytes/physiology , Chemokine CCL4 , Dermatitis, Contact/immunology , Dinitrofluorobenzene/administration & dosage , Dinitrofluorobenzene/immunology , Female , Histiocytosis, Sinus/immunology , Histiocytosis, Sinus/pathology , Hyperplasia , Hypersensitivity, Delayed/immunology , Hypersensitivity, Delayed/prevention & control , Immune Sera/administration & dosage , Inguinal Canal , Injections, Intraperitoneal , Lymph Nodes/metabolism , Lymph Nodes/pathology , Lymphocyte Count/drug effects , Macrophage Inflammatory Proteins/biosynthesis , Macrophage Inflammatory Proteins/immunology , Male , Mast Cells/metabolism , Mice , Mice, Inbred C3H , Organ Size/immunology , T-Lymphocyte Subsets/pathologyABSTRACT
OBJECTIVES: To determine the synovial mast cell response in early rheumatoid arthritis (RA) during clinical improvement, and to examine for relations with clinical and histological parameters of disease activity. METHODS: Twenty two synovial samples were obtained from six patients with RA using needle arthroscopy. The mean disease duration at baseline was eight months, and two to three further samples were obtained over a mean follow up period of 15 months during which treatment initiated clinical improvement occurred. Sections were immunostained to detect MCT and MCTC mast cells and correlations were sought between clinical and histological data. RESULTS: The overall mean synovial mast cell density was 40.3 cells/mm2, with regional densities of 60.6 and 34.2 mast cells/mm2 in the superficial and deeper synovial layers respectively. The MCT subset predominated, outnumbering MCTC by 3:1. There was a significant correlation between the histological inflammation index and the MCT density, (r = 0.4, p < 0.05) but not the MCTC subset. The regional distribution and predominant subset of mast cells varied in individual patient's synovia over time, with a trend towards restriction of the mast cell response to the superficial synovium during clinical improvement. CONCLUSIONS: The mast cell response in early RA is characterised by substantial expansion of predominantly MCT mast cells that correlates with histological indices of inflammation. During clinical improvement, this expansion tended to become more superficial. Taken together with previous studies of long duration RA, which implicate MCTC cells in synovial damage and disease progression, these results suggest that MCT and MCTC mast cells may possess distinct functions in the spectrum of inflammatory events occurring during RA.
Subject(s)
Arthritis, Rheumatoid/drug therapy , Arthritis, Rheumatoid/immunology , Mast Cells/immunology , Synovial Membrane/immunology , Cell Count , Chymases , Follow-Up Studies , Humans , Immunity, Cellular , Inflammation Mediators/analysis , Mast Cells/enzymology , Serine Endopeptidases/analysis , TryptasesABSTRACT
OBJECTIVE: Thrombospondin 1 (TSP1) is a potent active site inhibitor of leukocyte elastase and cathepsin G. This effect is markedly dependent on the disulfide-bond conformation of TSP1, with one isoform, TSP1(0.1), being the most potent. The aims of this study were to examine the expression of different disulfide-bonded isoforms of TSP1 in inflammatory environments in which elastase and cathepsin G are present in variable amounts, and to determine the relationship between these proteinases and their potential inhibitor. METHODS: Immunohistochemical staining and histomorphometric analysis were used to examine adjacent sections of synovial tissue from patients with rheumatoid arthritis (RA), osteoarthritis (OA), and meniscal trauma (MT), for expression of TSP1 and the TSP1(0.1) isoform, elastase, cathepsin G, and chymase. RESULTS: TSP1 localized to vessels and cells within the synovium. TSP1 expression was highly up-regulated in RA (mean density 98 cells and vessels/mm2, compared with 13/mm2 in OA and 17/mm2 in MT). The TSP1(0.1) isoform was found virtually exclusively in RA, with 44% of vascular TSP1 staining being due to the TSP1(0.1) isoform in RA, as compared with 7% in OA (P = 0.0047). Elastase- and cathepsin G-positive cells were abundant in RA, with mean densities of 106 cells/mm2 and 103 cells/mm2, respectively, compared with 2 cells/mm2 and 11 cells/mm2 in OA. There was a wide range of both TSP1 and proteinase expression within the RA group, but samples containing large numbers of elastase- and cathepsin G-positive cells also showed high expression of TSP1, especially TSP1(0.1). A strong correlation was found between elastase or cathepsin G densities and TSP1(0.1) expression in blood vessels (r = 0.86 and r = 0.76 respectively, P < 0.01). CONCLUSION: TSP1(0.1), with the most potent inhibitory activity in vitro, is specifically up-regulated in RA, and this up-regulation is in proportion to the numbers of surrounding leukocytes containing elastase and cathepsin G. One role of TSP1 may be to act as a matrix-based regulator of leukocyte-derived serine proteinases in vivo.