Macrophage subpopulations in rheumatoid synovium: reduced CD163 expression in CD4+ T lymphocyte-rich microenvironments.

OBJECTIVE: The cell surface glycoprotein CD163 is a member of the cysteine-rich scavenger receptor family, highly specific for leukocytes of the mononuclear phagocyte lineage. In vitro, it is induced by glucocorticoids, interleukin-6 (IL-6), and IL-10 and down-regulated by interferon-gamma (IFNgamma), indicating that it has a role in antiinflammatory or other immunomodulatory pathways. We assessed CD163 expression in microenvironments within rheumatoid arthritis (RA) synovium to clarify the relationships among CD4+ T lymphocytes, IFNgamma, and macrophage function in RA. METHODS: Double immunofluorescence and serial immunoenzymatic studies were performed on normal, osteoarthritic, and RA synovium and tonsil with antibodies to CD163, CD45, CD68, CD14, CD3, CD4, CD8, CD19, and IFNgamma. RESULTS: CD163 was observed on all CD14+ cells in synovium and tonsil with the exception of cells within larger T lymphocyte clusters in synovium and within tonsillar follicles. All brightly CD14+ cells in or around vessel walls (interpreted as immigrant monocytes) were CD163+. CD163 labeled fewer cells than did CD68 in synovial intima, but all CD45+ intimal cells were CD163+. CD4+,IFNgamma+ T lymphocytes in RA synovium were chiefly localized within clusters containing CD68+, CD163- cells. CONCLUSION: Within RA synovium, CD163 has major advantages as a macrophage marker and does not appear to be restricted to "mature" macrophages. CD163 discriminates between synovial macrophages and synovial intimal fibroblasts, which also stain positively for CD68 in diseased tissue.

Differential distribution of Fc gamma RIIIa in normal human tissues and co-localization with DAF and fibrillin-1: implications for immunological microenvironments.

Fc gamma RIIIa is a cytokine-inducible IgG Fc receptor implicated in the activation of macrophages by immune complexes. Differential expression of Fc gamma RIIIa by macrophages in different tissues may therefore modulate local immune responsiveness. Fc gamma RIIIa expression in normal human tissues was assessed semiquantitatively using microdensitometry. Synovial intimal, serosal, alveolar, salivary gland and placental macrophages, Kupffer cells, and macrophages in mechanically stressed dermis expressed high levels of Fc gamma RIIIa. Less consistent expression was seen in skeletal muscle and lymphoid organs. No significant expression was observed in brain, thyroid, spine, intestine, myocardium, prostate, uterus, flexor forearm dermis, uterus, or kidney. Staining for Fc gamma RIII was also observed on extracellular matrix, and co-localized with both complement decay-accelerating factor and fibrillin-1. It is proposed that differential levels of both cellular and extracellular Fc gamma RIIIa, by modulating the response to immune complexes, may contribute to relative tissue susceptibility to infection and autoimmune disease.

Quantitative assessment of the rheumatoid synovial microvascular bed by gadolinium-DTPA enhanced magnetic resonance imaging.

OBJECTIVE: To examine the relation between rate of synovial membrane enhancement, intra-articular pressure (IAP), and histologically determined synovial vascularity in rheumatoid arthritis, using gadolinium-DTPA enhanced magnetic resonance imaging (MRI). METHODS: Dynamic gadolinium-DTPA enhanced MRI was performed in 31 patients with knee synovitis (10 patients IAP study, 21 patients vascular morphometry study). Rate of synovial membrane enhancement was quantified by line profile analysis using the image processing package ANALYZE. IAP was measured using an intra-compartmental pressure monitor system. Multiple synovial biopsy specimens were obtained by a blind biopsy technique. Blood vessels were identified immunohistochemically using the endothelial cell marker QBend30 and quantified (blood vessel numerical density and fractional area). RESULTS: Median blood vessel numerical density and fractional area were 77.5/mm2 (IQR; 69.3-110.7) and 5.6% (IQR; 3.4-8.5) respectively. The rate of synovial membrane enhancement (median 2.74 signal intensity units/s, IQR 2.0-3.8) correlated with both blood vessel numerical density (r = 0.46, p < 0.05) and blood vessel fractional area (r = 0.55, p < 0.02). IAP did not influence the rate of enhancement. CONCLUSIONS: Gadolinium-DTPA enhanced MRI may prove to be a valuable technique for evaluating drugs that influence angiogenesis.

Primary care. Toil and trouble.

Establishing PCGs will represent a huge change even in areas with well-developed primary care. The inclusion of nurses in PCGs is likely to prove problematic. The new groups will need to achieve high-profile early successes in order to maintain credibility. There is little evidence that fewer managers will be required.

Restricted expression of Fc gammaRIII (CD16) in synovium and dermis: implications for tissue targeting in rheumatoid arthritis (RA).

Interactions between immune complexes and immunoglobulin Fc receptors may contribute to inflammation in RA. Previous studies suggested that Fc gammaRIII (CD16) may be preferentially expressed in diseased synovial intima. The distribution of immunoreactive Fc gammaRIII was examined in normal fetal limb tissues, and both normal and selected abnormal samples of adult synovium and skin. In fetal limbs at 10-14 weeks gestation Fc gammaRIII was restricted to synovial intima. In normal adult synovium Fc gammaRIII was restricted to intimal cells. In inflamed synovia differential expression of Fc gammaRIII in the intima was less consistent. In both fetal and adult synovium Fc gammaRIII was largely restricted to cells expressing CD45 (leucocyte common antigen). Staining for Fc gammaRIII was, however, occasionally associated with CD45 intimal cells in fetal synovium. In both fetal and adult tissues cell membrane Fc gammaRIII was frequently closely associated with complement decay-accelerating factor (DAF), which is present on intimal fibroblasts and extracellular matrix. Fc gammaRIII expression was minimal in normal forearm dermis, but widespread on CD45+ cells in skin exposed to mechanical stress. In skin containing rheumatoid nodules, Fc-gammaRIII was preferentially expressed on palisading macrophages. These observations indicate that expression of Fc gammaRIII on macrophages may be involved in the susceptibility of connective tissues to immune complex-induced damage in RA. Colocalization of Fc gammaRIII and DAF in synovium may indicate an unrecognized functional interrelationship.

Evaluating the antioxidant potential of new treatments for inflammatory bowel disease using a rat model of colitis.

BACKGROUND: Reactive oxygen species may mediate tissue injury in inflammatory bowel disease. Aminosalicylates have antioxidant activity and the antioxidants, superoxide dismutase and allopurinol, are of reported benefit in inflammatory bowel disease. AIM: To develop a convenient technique for testing the antioxidant potential of standard and novel therapeutic agents for use in inflammatory bowel disease. METHODS: Amplified chemiluminescence was used to measure reactive oxygen species production by colonic biopsy specimens from rats with acetic acid induced colitis and to assess the in vitro effect of conventional antioxidants, standard therapies and proposed novel therapies for inflammatory bowel disease. RESULTS: The model was validated by demonstrating that the profile of effects on chemiluminescence of acetic acid induced colitis biopsy specimens given by conventional antioxidants (sodium azide, catalase, copper-zinc superoxide dismutase, dimethyl sulphoxide, N-acetylcysteine and ascorbate) and standard therapies (5-aminosalicylate and hydrocortisone) resembled that previously reported using biopsy specimens from ulcerative colitis. Human recombinant manganese superoxide dismutase did not alter chemiluminescence. Two novel compounds, LY231617 (10 mM) and amflutizole (20 mM), reduced chemiluminescence by 98% (n = 5, p = 0.009) and 88% (n = 5, p = 0.03), respectively. CONCLUSIONS: The similarity of the chemiluminescence responses of colonic biopsy specimens from acetic acid induced colitis and ulcerative colitis to a range of conventional antioxidants and standard treatments suggests that this model is a useful method for testing the antioxidant potential of new therapies for inflammatory bowel disease. The antioxidant actions of dimethyl sulphoxide, ascorbate, and the novel compounds, amflutizole and LY231617 in this model suggest that these agents merit further assessment in the treatment of inflammatory bowel disease.

Activation of the transcription factor nuclear factor-kappaB in human inflamed synovial tissue.

OBJECTIVE: The transcription factor nuclear factor kappaB (NF-kappaB) has been implicated in the inflammatory response and is known to be activated by a process involving reactive oxygen intermediates. The purpose of the present study was to demonstrate the presence and distribution of activated NF-kappaB in synovium samples from patients with rheumatoid arthritis (RA) and osteoarthritis (OA) and from autopsy subjects with no known history of arthritis. METHODS: Immunohistochemical staining was performed using both polyclonal and monoclonal "activity-specific" antibodies to the Rel-A (p65) subunit of NF-kappaB (anti-Rel-A nuclear location sequences). Histologic features of inflammation were also scored. RESULTS: Both antibodies demonstrated positive staining of synovial tissue, with a cellular distribution that was nuclear. The staining was associated with specific cell types within the tissue, in particular, type A synoviocytes and vascular endothelium. Notably, lymphoid aggregates were unstained. Using the monoclonal antibody, a further study was carried out to investigate the distribution of staining in tissues from patients with different disease activities and clinical diagnoses, as well as in normal control tissue obtained at autopsy. Patients with acute RA more commonly showed vessel staining (P = 0.05) and, conversely, showed less frequent staining of the synovial lining (P < 0.005) compared with OA patients. Synovial tissue from controls exhibited either no staining or only weak staining in the synovial lining. CONCLUSION: The activation of NF-kappaB in vascular endothelium and type A synovial lining cells is a feature of synovial tissue from both RA and OA patients. The distribution of this staining appears to be related to the clinical diagnosis.

Quantification of rheumatoid synovitis by magnetic resonance imaging.

OBJECTIVE: To develop a method for quantifying acute synovial inflammation in rheumatoid arthritis (RA), utilizing magnetic resonance imaging (MRI). METHODS: Gadolinium-diethylenetriamine pentaacetic acid-enhanced MRI was performed in 21 patients with knee synovitis. Changes in synovial membrane signal intensity were identified and quantified by line profile analysis. Multiple synovial biopsies were obtained by a blind biopsy technique, and standard clinical and laboratory measurements of disease activity were recorded. RESULTS: The rate of synovial membrane enhancement correlated with histologic features of acute inflammation (r = 0.63, P < 0.01), but not with clinical or laboratory assessments. CONCLUSION: Dynamic MRI is a valuable technique for assessing acute synovial inflammation in RA.

Developing outcome measures for ambulatory care--an application to asthma and diabetes.

Increasing emphasis is now being placed on the assessment of patient outcomes, both in evaluating medical interventions and in quality assurance initiatives. Clinicians, purchasers, managers and researchers need outcome measures that are valid, reliable and responsive. This paper describes the theory and practice underlying the development of outcome measures for two chronic conditions, asthma and diabetes, for application in ambulatory settings. Existing generic and condition-specific health status and health-related quality-of-life measures were administered to almost 1300 patients. The psychometric properties of these measures were examined to identify those that were of adequate validity and reliability in these population groups. Step-wise regression procedures were then used to identify a core set of scales that best predicted patients' general health perceptions, which could be used in measuring general health outcomes for each of these groups. These core sets consist of up to 40 items, spanning physical function, energy and vitality, emotional well-being and condition-specific aspects of health such as symptom control. Further analysis is being carried out to assess the responsiveness to change of these core item sets.

Development of a symptom based outcome measure for asthma.

Measuring symptom specific health outcome is complex, but the methodologies now exist to develop measures with the appropriate properties. As one element of a major programme to develop multidomain health outcome measures for chronic disease, a symptom based measure for asthma care has been developed for use in general practice and outpatient departments. This article outlines the development process, which used a framework recently described in the theoretical literature to show the constraints that scientific criteria place on the development of outcome measures and the means of overcoming such limiting factors. Although substantial effort is required to undertake a rigorous process of development, useful tools are the result. Two five item, symptom based outcome measures for adult asthma are described.