Recognition of a mycobacteria-specific epitope in the 65-kD heat-shock protein by synovial fluid-derived T cell clones.

Adjuvant arthritis in rats is induced by a T cell clone specific for amino acids 180-188 of the mycobacterial 65-kD heat-shock protein, and synovial T cell responses to this same Ag have been noted in human arthritis. We have isolated 65-kD Ag-specific T cell clones from synovial fluid mononuclear cells of a patient with acute arthritis, which, unlike the corresponding PBMC, showed a marked proliferative response to the 65-kD Ag. Using synthetic peptides corresponding to the whole sequence of the 65-kD Ag, all the clones were shown to recognize an epitope present in the first NH2-terminal peptide (amino acids 1-15), with no response to the adjacent peptide (amino acids 6-22) or to any other peptide. The complete dominance of this epitope in the response to the 65-kD Ag was shown by documenting responses to the peptide in PBMC obtained after recovery from the arthritis. This epitope, like that recognized by the rat arthritogenic T cell clone, is in a portion of the 65-kD sequence that is not conserved between bacteria and eukaryotes, so that in this case, joint inflammation could not be attributed to bacteria-induced T cell clones cross-reacting with the self 65-kD Ag.

Intracellular calcium signalling patterns reflect the differentiation status of human T cells.

Stimulation of T lymphocytes results in the calcium-dependent activation and repression of a large number of genes. However, the functional response made by different T cell subsets is heterogeneous, as their differentiation results in alterations in their sensitivity to activation and in the secretion of cytokines. Here we have investigated the patterns of calcium responses in CD4 and CD8 T cell subsets to help explain their different responses to activation. CD4(+) CD45RA(+) T cells isolated freshly from human blood gave a sustained calcium signal after stimulation, but this was smaller than elicited in CD4(+) CD45RO(+) cells. On in vitro differentiation of CD4(+) CD45RA(+) cells to CD45RO(+), the level of the cytoplasmic calcium response rose initially, but then declined steadily during further rounds of differentiation. The proportion producing an oscillatory calcium response or not responding was increased and differentiation was accompanied by a shift in the calcium between intracellular pools. CD8(+) T cells gave a smaller calcium response than paired CD4(+) T cells and showed a difference in the numbers of cells giving a transient, rather than sustained, calcium signal. The increase in oscillating cells in the CD4(+) CD45RO(+) population may reflect the heterogeneity of this population, particularly in terms of cytokine production. The changing patterns of calcium responses in T cells as they differentiate may explain variation in the cellular response to activation at different stages in their lifespan and emphasize the importance of the both the quantity and the quality of the calcium signal in determining the outcome of T cell activation.

Self-perpetuating mechanisms of immunoglobulin G aggregation in rheumatoid inflammation.

When human IgG is exposed to free radical generating systems such as ultraviolet irradiation, peroxidizing lipids, or activated human neutrophils, characteristic auto-fluorescent monomeric and polymeric IgG is formed (excitation [Ex], 360 nm, emission [Em], 454 nm). 1 h ultraviolet irradiation of IgG results in the following reductions in constituent amino acids; cysteine (37.0%), tryptophan (17.0%), tyrosine (10.5%), and lysine (3.6%). The fluorescent IgG complexes, when produced in vitro, can stimulate the release of superoxide from normal human neutrophils. In the presence of excess unaltered IgG, further fluorescent damage to IgG occurs. Measurement and isolation of fluorescent monomeric and polymeric IgG by high performance liquid chromatography, from in vitro systems and from fresh rheumatoid sera and synovial fluid, indicates that identical complexes are present in vivo; all these fluorescent complexes share the property of enhancing free radical production from neutrophils. The results described in this study support the hypothesis that fluorescent monomeric and aggregated IgG may be formed in vivo by oxygen-centered free radicals derived from neutrophils, and that in rheumatoid inflammation this reaction may be self-perpetuating within the inflamed joint.

Inhibition of T cell apoptosis in the rheumatoid synovium.

Synovial T cells in rheumatoid arthritis are highly differentiated and express a phenotype suggesting susceptibility to apoptosis (CD45RB dull, CD45RO bright, Bcl-2 low, Bax high, Fas high). However, no evidence of T cell apoptosis was found in synovial fluid from any of 28 patients studied. In contrast, synovial fluid from 10 patients with crystal arthritis showed substantial levels of T cell apoptosis. The failre of apoptosis was not an intrinsic property of rheumatoid synovial T cells, as they showed rapid spontaneous apoptosis on removal from the joint. Synovial T cells from rheumatoid arthritis and gout patients could be rescued from spontaneous apoptosis in vitro either by IL-2R gamma chain signaling cytokines (which upregulate Bcl-2 and Bcl-XL) or by interaction with synovial fibroblasts (which upregulates Bcl-xL but not Bcl-2). The phenotype of rheumatoid synovial T cells ex vivo (Bcl-2 low, Bcl-xL high) suggested a fibroblast-mediated mechanism in vivo. This was confirmed by in vitro culture of synovial T cells with fibroblasts which maintained the Bcl-xL high Bcl-2 low phenotype. Synovial T cells from gout patients were Bcl-2 low Bcl-xL low and showed clear evidence of apoptosis in vivo. Inhibition experiments suggested that an integrin-ligand interaction incorporating the Arg-Gly-Asp motif is involved in fibroblast-mediated synovial T cell survival. We propose that environmental blockade of cell death resulting from interaction with stromal cells is a major factor in the persistent T cell infiltration of chronically inflamed rheumatoid synovium.

Suppression of inflammation in primary systemic vasculitis restores vascular endothelial function: lessons for atherosclerotic disease?

BACKGROUND: Chronic inflammatory rheumatic disorders are associated with excess cardiovascular mortality. This may result from arteriosclerosis following inflammatory damage to the vessel wall by vasculitis. Our hypothesis that vasculitis results in arteriosclerosis by causing vascular endothelial dysfunction was tested in patients with primary systemic necrotizing vasculitis (SNV). METHODS AND RESULTS: Endothelial function was assessed in cross-sectional and longitudinal studies of patients with primary SNV by measuring flow-mediated, endothelium-dependent brachial artery vasodilatation. These patients exhibited marked endothelial dysfunction compared with controls. Remission induction in patients with active primary SNV restored endothelial function. CONCLUSIONS: Endothelial function is significantly impaired in adults with primary SNV, supporting the hypothesis that premature arteriosclerosis in chronic inflammatory rheumatic disorders results from endothelial dysfunction secondary to vasculitis. Normalization of endothelial function after the treatment of primary SNV suggests that early suppression of disease activity in chronic inflammatory rheumatic disorders may reduce long-term vascular damage. The role of inflammation in atheroma formation is increasingly appreciated; this work raises questions regarding the potential for anti-inflammatory therapy in atherosclerosis itself.

The kinetics of interaction between lymphocytes and magnetic polymer particles.

Magnetic polymer-coated particles linked to antibodies are considered to be an efficient rosetting matrix for immunoselection. We have shown that a 20:1 bead:target cell ratio and a 90 min incubation period are the optimal conditions for specific binding of monoclonal antibody-labelled cells to goat anti-mouse IgG-coated beads. Higher ratios or longer incubation periods resulted in considerable non-specific binding. Characterisation of the optimal conditions for specific depletion of lymphocyte subpopulations showed that (a) a range of bead:target cell ratios and incubation periods can be used, with resulting high efficiency and specificity; (b) multiple monoclonal antibodies can be used simultaneously for the depletion of diverse lymphocyte subpopulations; (c) non-specific bead-to-cell binding does not affect the specificity and efficiency of magnetic depletion; (d) specific binding of one bead only was adequate for effective magnetic separation. These findings define the most economical, specific and efficient conditions of use of beads for negative immunoselection but preclude the use of beads as an analytical rosetting medium.

Quantitative flow cytometry for the analysis of T cell receptor Vbeta chain expression.

Detailed characterisation of the T cell receptor (TCR) repertoire expressed by peripheral blood lymphocytes has been used to study specific T cell responses in disease conditions. The methods have mostly involved molecular biology analysis of transcribed gene products isolated from T cell subsets or individual clones. Extensive characterisation of the TCR Vbeta chain repertoire by flow cytometry is now possible due to the recently increased availability of specific monoclonal antibodies. However, there are major logistical problems inherent in this analysis relating to the number of cells required to obtain accurate results and the vast amounts of data generated. To reduce these factors to a practical level, we have performed a detailed study to define the limits of precision of cell subset analysis by flow cytometry. Maximal achievable precision was obtained by analysing 10(4) lymphocytes; no significant improvement was obtained by analysing greater numbers of cells up to 10(5) cells, even for cell subsets present at frequencies as low as 0.5%. Careful application of these precision profiles will also permit more effective use of clinical research samples for flow cytometry when the availability of cells is limited.

The use of cytocentrifuge preparations for the demonstration of T cell surface antigens.

Cytocentrifuged cell preparations have been evaluated as substrates for the demonstration by immunofluorescence of T cell surface antigens. Results obtained by a 2-stage method with fluorescent conjugate specific for the isotype of the first stage monoclonal antibody, and by a 3-stage procedure employing an intermediate antiserum to mouse IgG as amplifying agent, showed good correlation with those obtained by a standard technique performed on cells in suspension. These methods have the advantages of requiring fewer cells and less antibody and the cytocentrifuge preparations may be stored for batch assay.

Nonsteroidal anti-inflammatory drugs and immunologic function. Overview of the European experience.

A large number of nonsteroidal anti-inflammatory drugs are available in Europe. There appears to be little difference in overall clinical effectiveness of these drugs, despite individual patient variation, suggesting a common mode of action. Occasionally, a nonsteroidal anti-inflammatory drug will show some evidence of a more impressive anti-rheumatic effect, perhaps related to a more prolonged or different mode of action. The evidence for an immunologic effect of nonsteroidal anti-inflammatory drugs is largely derived from in vitro studies. In patients with rheumatoid arthritis treated with piroxicam, there are no overall changes in lymphocyte numbers or T4/T8 ratios, but numbers of activated cells expressing la decrease and rheumatoid factor titers may also fall. It is suggested that this is not a direct immunosuppressive effect, but one that is related to local inhibition of polymorphonuclear leukocyte-derived free radical production within the joint, which may lower the antigenic load of IgG altered by free radicals, with subsequent diminished immune stimulation.

Intravenous cyclophosphamide plus methylprednisolone in treatment of systemic rheumatoid vasculitis.

Systemic vasculitis in rheumatoid arthritis shows similarities to polyarteritis nodosa and may require equally aggressive therapy. Forty-five patients with systemic rheumatoid vasculitis were studied during treatment with either cyclophosphamide plus methylprednisolone given by intermittent bolus intravenous injection (21 patients) or a variety of other more conventional drug regimens (24 patients). In this open study, the intravenous treatment group had more severe initial disease, a higher incidence of neuropathy, and more frequent evidence of necrotizing arteritis on biopsy than the other treatment group. Despite this, intravenous cyclophosphamide plus methylprednisolone resulted in more frequent healing of vasculitic lesions including leg ulcers and neuropathy, a lower incidence of relapse, fewer serious complications, and a lower mortality than did other treatments. Toxic effects were similar in both study groups. Intravenous cyclophosphamide plus methylprednisolone is a useful early treatment for systemic rheumatoid vasculitis.

Accelerated atherogenesis in autoimmune rheumatic diseases.

The observation that systemic inflammatory rheumatic diseases such as rheumatoid arthritis (RA) are associated with a significantly increased rate of cardiovascular disease, which often occurs at a younger age than in the normal population, is particularly important given the increasing interest in the role of inflammation in atherogenesis in the general population. This review examines the accumulating evidence for accelerated atherogenesis of RA and updates the hypothesis that vasculitis plays a major role in this. Endothelial dysfunction (ECD), widely regarded as initial lesion in atherogenesis, has been shown to occur commonly in primary vasculitis. This ECD is a diffuse event, demonstrable in more than one vascular bed. It is not simply due to scarring in the vessel wall, related to the focal inflammation of the underlying vasculitis, since it may be reversed by suppression of the immune inflammation. However, the mechanisms for this ECD differ from that of the primary vasculitis. Preliminary evidence suggests that inflammatory mediators such as CRP, TNF, or sphingolipids may be involved. The diffuse ECD of vasculitis may have important consequences for both the progression of the primary disease and for cardiovascular events. A model for the role of vasculitis-induced ECD in the accelerated atherogenesis of rheumatic diseases is presented. These concepts are discussed together with the messages they suggest for 'idiopathic' atherosclerosis in the general population.

The role of endothelial cell dysfunction in the cardiovascular mortality of RA.

Rheumatoid patients present clinically with chronic inflammatory immune arthritis but die of the same cardiovascular (CVS) disease as the normal population. Recent studies emphasize the increased frequency and earlier development of CVS involvement in RA. The mechanisms of this accelerated atherosclerosis are the subject of active research. The hypothesis that rheumatoid vasculitis is a major factor has been pursued through studies in primary systemic vasculitis. These reveal diffuse endothelial dysfunction occurring across a spectrum of vasculitis and involving more than one vascular bed. This may relate to cytokines such as TNF alpha that are both prominent in rheumatoid inflammation and important in the upregulation of endothelium in innate immune responses. Endothelial injury or dysfunction is widely accepted as the initial factor in atheroma. Its occurrence in vasculitis leads us to propose a model for RA where this dysfunction is the essential first step on which other factors, ranging from adverse lipid profiles to specific T-cell subsets, may build accelerated atherogenesis related to the rheumatoid inflammation.

Side effect profile of 200 patients with inflammatory arthritides treated with sulphasalazine.

The side effect profile of sulphasalazine was documented in 200 patients with inflammatory joint disease treated with the drug for at least 1 year. Fifty-eight percent of patients developed one or more adverse reactions and in 21.5% the drug was withdrawn. A further 28% continued taking the drug at a reduced dose. Five percent of the side effects were judged to be potentially serious. In all patients the reactions subsided on either discontinuation of the drug or reduction of the dose. Gastrointestinal (33%) and central nervous system reactions (19%) were the most common, but all were relatively minor. Neutropenia (2%), thrombocytopenia (1%) and pan-hypogammaglobulinaemia (1%) were potentially the most serious effects. The side effect profile of sulphasalazine in inflammatory joint disease appeared to be similar to that in inflammatory bowel disease, but reactions were more frequent in inflammatory joint disease. Enteric-coated sulphasalazine is a useful addition to the small number of slow acting antirheumatic drugs, and in view of its established efficacy, its level of toxicity was found to be 'acceptable' as long as patients were carefully monitored and regular blood tests were carried out.

Vasculitis associated with connective tissue disorders.

This article focuses on the important association of vasculitis with the connective tissue diseases. The immunopathologic mechanisms in these secondary vasculitides, with complement and immune-complex involvement, differ from those involved in primary systemic necrotizing vasculitis even though histologically the lesions may appear identical. Any size of vessel may be involved, so biopsy evidence of small vessel disease does not exclude arterial lesions elsewhere. The clinical manifestations are equally wide ranging and vary from one connective tissue disease to another. Treatment of vasculitis is generally with immunosuppressive agents but is dependent on the degree and severity of the vasculitis. There is an important need to make a distinction between vasculopathy, where there is no evidence of underlying inflammation, and true vasculitis because the former requires anticlotting therapy rather than immunosuppression.

Rectal biopsy in the diagnosis of systemic vasculitis.

Vasculitis has been seen in rectal biopsies from 22 patients over a six year period. The most common finding was a necrotising vasculitis of small arteries, indistinguishable from that seen in polyarteritis nodosa (PAN). Sub-acute, chronic ("burnt out") and leucocytoclastic changes were also seen. Sixteen patients had vasculitis complicating rheumatoid arthritis (RA), 3 PAN and 3 overlap syndromes. Patients with RA and rectal vasculitis had a higher mortality, and a greater incidence of neuropathy than those with negative biopsies. An adequate biopsy is positive in 40% of patients with clinical vasculitis and RA but was only positive in one of a control series of 46 RA patients with no clinical vasculitis. Rectal biopsy in experienced hands is a safe, and repeatable procedure. It is useful as a "blind" biopsy site in the diagnosis of systemic vasculitis, especially that complicating RA. It can also be used for serial studies of the evolution of vasculitis. Serial sections of the entire biopsy may be required to reveal the vasculitis which is often focal in nature.

Clinical value of ELISA assays for IgM and IgG rheumatoid factors.

The clinical value of enzyme linked immunosorbent assays (ELISA) assays for IgM and IgG rheumatoid factors was assessed in a series of studies using rabbit IgG as antigen. The tests were reproducible with intra-assay coefficients of variation of 6% and could be simply and rapidly performed. Normal ranges were established using 106 sera from healthy controls. In a cross sectional study of 208 rheumatoid patients these assays were compared with the Rose-Waaler and laser nephelometric assessments of rheumatoid factor. In some patients there were discrepancies between rheumatoid factor positivity determined by one method or another. IgM ELISA and Rose-Waaler titres showed a significant correlation (r = +0.58; p less than 0.001), but there was a low correlation between IgM and IgG ELISA (r = +0.27; p less than 0.001). There was no evidence to show that the measurement of IgM or IgG rheumatoid factor gave significantly more clinical information than traditional tests such as the Rose-Waaler or latex agglutination tests.

Rheumatoid lymphadenopathy: a morphological and immunohistochemical study.

Sixteen lymph nodes from 14 patients with rheumatoid arthritis were examined immunohistochemically and morphometrically and compared with 10 control nodes showing follicular hyperplasia from patients without rheumatoid disease. Frozen material was available from nine patients and all controls. The nodes from patients with rheumatoid arthritis seemed to share characteristic features. The most striking of these was follicular hyperplasia in which the germinal centres, in spite of being quite large, showed relatively sparse proliferative activity. The nodes often showed infiltration of germinal centres by CD8 positive T lymphocytes and contained fewer IL2R positive cells in the paracortex than controls. These and other features may have some correlation with disease activity. Lymphadenopathy in rheumatoid arthritis may not just be a manifestation of joint inflammation but an active component of this multisystem disease and may reflect a widespread immunological abnormality.

Birmingham Vasculitis Activity Score (BVAS) in systemic necrotizing vasculitis.

The continuing morbidity of patients with vasculitis, despite the improved prognosis with aggressive therapy, underlines the need for accurate disease assessment. We have devised a clinical index of disease activity, and evaluated its use in several forms of necrotizing vasculitis. The weighted score is based on symptoms and signs in nine separate organ systems. Disease features are only scored if they are attributable to active vasculitis. The Birmingham Vasculitis Activity Score (BVAS) was compared with two other published vasculitis activity scores, with the physician's global assessment (PGA), with outcome, and with serological markers of disease activity. In a cross-sectional study of 213 consecutive patients with different forms of vasculitis, all 107 vasculitis patients who were judged completely well on clinical assessment had a BVAS score of 0. Twenty-two patients with active vasculitis prior to treatment had a median score of 7.5 (range 4-30) and 69 with active disease on treatment had a median score of 10 (1-29). Of the 12 who died, median score immediately prior to death was 20.5 (9-30). In a serial prospective study, 30 cases had documented episodes of active disease. During periods of disease activity, the median BVAS values were significantly higher than in remission (15 [range 3-32] vs. 0 [0-2], p < 0.001); the same was true for CRP values (80 [9-361] vs. 13.5 [5-68], p < 0.001). This was not true for erythrocyte sedimentation rate (ESR), haemoglobin (Hb) or von Willebrand factor (VWF).(ABSTRACT TRUNCATED AT 250 WORDS)

Damage occurs early in systemic vasculitis and is an index of outcome.

Because death after acute systemic vasculitis is now uncommon, alternative measures of outcome are required. A significant component of patient morbidity is disease-related damage, which can be quantified by the Vasculitis Damage Index (64 items in 11 organ-based systems). We investigated serially the time-course of damage in 120 patients with systemic vasculitis, to determine the earliest indicators of outcome. High damage scores at 2 years after presentation were characteristic of fatal disease (OR 8.1-12.4). Significant damage occurred within 6 months of presentation, and was a feature of fatal disease. More damage occurred after presentation than after relapse. Lung and multi-system damage were early indicators of poor outcome in severe non-fatal disease. Damage occurs early in systemic vasculitis, and is an indicator of poor outcome. This novel observation, together with evidence of persistent subclinical disease activity and the high frequency of relapse, suggests a need for new treatment strategies. Analogy with the management of acute leukaemia suggests a strategy of early diagnosis and intensive induction of remission, with early escalation of treatment for resistant disease.