Phagocytosis and intracellular killing of Staphylococcus aureus by polymorphonuclear cells from synovial fluid of patients with rheumatoid arthritis

Simultaneous bilateral septic arthritis of the knee after intraarticular steroid injection: A clinical report

Osteoarthritis of knee is one of the common problems in elderly population. Intraarticular corticosteroid injection is a conservative management modality in osteoarthritis of knee. Septic arthritis is an infective complication of intraarticular corticosteroid injection. Septic arthritis in rheumatoid arthritis patients have worse prognosis because of delay in diagnosis. A higher rate of infectious complications following intraarticular injection is expected in immunocompromised and rheumatoid patients. We would like to report an extremely rare case of simultaneous bilateral knee septic arthritis after bilateral knee intraarticular steroid injection in a rheumatoid arthritis patient. Patient was treated successfully with multiple bilateral knee arthroscopic washouts and long-term intravenous antibiotics. This case report emphasizes the increased risk of infection in rheumatoid arthritis patients and a risk benefit assessment on individual basis before carrying out intraarticular steroid injection. Patient should be aware of this increased risk of infection.

Septic arthritis in patients with rheumatoid arthritis

There is an increasing number of rheumatoid patients who get septic arthritis. Chronic use of steroids is one of the important predisposing factors. The clinical picture of septic arthritis is different in immunocompromised patients like patients with rheumatoid arthritis. The diagnosis and management are discussed in this review article.

Fcgamma receptors in autoimmune diseases

Fcgamma-receptors (Fcgamma-R) recognise the Fc portion of IgG and thus form a link between humoral and cellular immunity. These receptors are expressed by a variety of immune cells, and they function in the binding of immune complexes or IgG-opsonised particles, such as microbial pathogens. The are three major types of Fcgamma-R, namely Fcgamma-RI (CD64), Fcgamma-RII (CD32) and Fcgamma-RIII (CD16), and these differ in their ability to bind IgG and complexes. There are many isoforms of these receptors and a number of recently identified polymorphisms in their structure. This review describes the structure and function of these Fcgamma-Rs, and highlights how gene deficiencies and polymorphisms may contribute to the pathology of human diseases.

Infections in systemic lupus erythematosus and rheumatoid arthritis

Patients with systemic lupus erythematosus have a higher infection rate than the general population. It is estimated that at least 50% of them will suffer a severe infectious episode during the course of the disease. Improvements in the control of the disease are discussed in this article.

A risk-benefit assessment of slow-acting antirheumatic drugs in rheumatoid arthritis

There is no ideal slow-acting antirheumatic drug. Therapy of rheumatoid arthritis (RA) is currently being modified, with strong recommendations to abandon the traditional pyramidal approach. The call is for a more aggressive, earlier approach to suppress inflammation. Combination therapy rather than the use of a single agent is advocated by some. Improved methods for assessing disease activity as well as measurement of outcome have been developed. Markers of poor prognosis have helped to define patients for earlier treatment. Comparison of toxicity among such a diverse group of drugs is probably best achieved with a toxicity index measuring the number of episodes expressed in terms of patient-years of exposure. Toxicity remains the commonest reason for discontinuing an agent, while remission beyond 36 months on therapy is uncommon, except with methotrexate. The profile of toxicity is clearly defined for individual agents, but combination therapy may reveal an entirely different set of toxic manifestations. There is an urgent need to develop a set of risk factors to predict toxicity in an individual patient. Juvenile chronic arthritis behaves differently from adult RA. Drug toxicity profiles are similar, but less common. Outcome is more difficult to measure, with the major impact of disease and therapy being on growth retardation.

Stimulation of reactive oxidant production in neutrophils by soluble and insoluble immune complexes occurs via different receptors/signal transduction systems

Cell-free synovial fluid from patients with rheumatoid arthritis contains soluble and insoluble IgG-containing immune complexes which activate reactive oxidant production in human neutrophils. In this report we have measured the effects of inhibitors of signal transduction pathways on neutrophil activation by these complexes and also following activation by synthetic soluble and insoluble immune complexes made from human serum albumin (HSA) and anti-(HSA) antibodies. In all aspects studied, the soluble rheumatoid complexes and the soluble synthetic complexes were indistinguishable in the ways in which they activated neutrophils. Activation of reactive oxidant production in response to these soluble complexes was completely inhibited by pertussis toxin (indicating G-protein coupling of receptor occupancy), completely insensitive to staurosporine (indicating that oxidant production did not require protein kinase C activity), only marginally (< 30%) inhibited by butanol (indicating that dependence upon activity of phospholipase D was minimal), and completely inhibited by chloracysine, an inhibitor of phospholipase A2. In contrast, activation of reactive oxidant production in response to the insoluble rheumatoid or insoluble synthetic immune complexes was largely pertussis toxin insensitive, inhibited by > 50% by staurosporine, inhibited by > 50% by butanol, and completely inhibited by chloracysine. These results show that the receptor-mediated signal transduction systems activated by the soluble and insoluble immune complexes are different. Because the soluble complexes activate a transient burst of reactive oxidant secretion from primed neutrophils, the mechanisms regulating either the release or the intracellular production of oxidants within rheumatoid joints are distinct and hence may be pharmacologically modified independently of each other.

Cytokine expression by inflammatory neutrophils

Bloodstream neutrophils do not express mRNA for interleukin-1 beta (IL-1 beta), but transcripts for this cytokine are rapidly induced following exposure to recombinant granulocyte-macrophage colony-stimulating factor (rGM-CSF) in vitro. Levels of IL-1 beta mRNA reach maximal values 1 h after exposure to rGM-CSF and then decline to near basal levels by 4 h. Similarly, rGM-CSF treatment of blood neutrophils in vitro induced increases in levels of mRNA for IL-6 and tumour necrosis factor-alpha (TNF-alpha). RNA extracted from neutrophils isolated from the synovial fluid of patients with rheumatoid arthritis expressed low, but significant levels of IL-1 beta mRNA that were between 0.5 and 3% of the levels that could be maximally induced by rGM-CSF treatment of blood neutrophils. However, transcripts for TNF-alpha and IL-6 were not detected in these synovial fluid neutrophils. mRNA for transforming growth factor-beta (TGF-beta) was constitutively expressed in blood and synovial fluid neutrophils and transcripts for this cytokine were not altered by rGM-CSF exposure. Because of the transient nature of IL-1 beta expression by activated neutrophils, we propose that the low levels of expression of mRNA for this cytokine in the synovial fluid neutrophils represents expression by a small, perhaps newly-recruited and activated, sub-population of cells. IL-1 beta expression by this sub-population may thus contribute to the pathogenesis of rheumatoid disease.

Activation of neutrophils by soluble and insoluble immunoglobulin aggregates from synovial fluid of patients with rheumatoid arthritis

OBJECTIVES

Previous work has shown that synovial fluid isolated from patients with active rheumatoid arthritis contains soluble (not sedimented by centrifugation at 11,600 g for two minutes) and insoluble (sedimented by centrifugation at 11,600 g for two minutes) immunoglobulin aggregates that are capable of activating reactive oxidant production by bloodstream neutrophils. The purpose of this study was to determine which of these types of immunoglobulin aggregates activated the secretion of reactive oxygen metabolites and granule enzymes from neutrophils.

METHODS

Cell free synovial fluid (from patients with rheumatoid arthritis) was added to neutrophils isolated from blood of healthy controls that had been incubated in the presence and absence of granulocyte-macrophage colony stimulating factor (GM-CSF). Reactive oxidant production was measured by luminol chemiluminescence (which detects both intracellular and extracellular oxidant production) and by cytochrome c reduction (which measures superoxide secretion).

RESULTS

The soluble aggregates only activated neutrophils that were previously primed, and activated a rapid and transient burst of reactive oxidant secretion. On the other hand, the insoluble aggregates activated primed and unprimed neutrophils with similar efficacy and most of the oxidants generated (especially in unprimed cells) were intracellular. The soluble aggregates, but not the insoluble aggregates, also activated the secretion of myeloperoxidase from neutrophils that had either been pretreated with cytochalasin B or primed with GM-CSF.

CONCLUSION

It is thus proposed that these soluble immunoglobulin aggregates are responsible for activation of the release of tissue damaging granule enzymes and reactive oxidants from primed neutrophils within the rheumatoid joint.

Activation of neutrophil reactive-oxidant production by synovial fluid from patients with inflammatory joint disease. Soluble and insoluble immunoglobulin aggregates activate different pathways in primed and unprimed cells

Cell-free synovial fluid from patients with rheumatoid arthritis stimulated the NADPH oxidase activity in human neutrophils, which reached a peak 15-20 min after addition. Insoluble immunoglobulin aggregates isolated from these fluids activated a similar pattern of oxidase activity. However, when synovial fluid was added to neutrophil suspensions which had been previously exposed to granulocyte-macrophage colony-stimulating factor, the stimulated oxidase activity was biphasic, in that an additional transient activity was observed which reached a peak within 5 min of addition. The additional neutrophil-stimulating activity could not be sedimented by centrifugation at 330,000 g-min, and only activated oxidase activity in neutrophils which had previously been primed. The neutrophil-stimulating activity in this soluble fraction was removed by Protein A affinity chromatography, and activity was recovered in eluates from this column. Thus activity in this soluble fraction from synovial fluid is attributed to the presence of soluble immunoglobulin aggregates. Whereas oxidase activity stimulated by the isoluble immunoglobulin aggregates was inhibited by staurosporine (and hence largely dependent on the activity of protein kinase C), the activity stimulated by the soluble immunoglobulin aggregates was staurosporine-insensitive. The soluble immunoglobulin aggregates were present at significantly higher levels in synovial fluids from patients with rheumatoid arthritis compared with those from other joint arthropathies. Thus rheumatoid synovial fluids possess heterogeneous immunoglobulin aggregates which activate neutrophils via distinct molecular pathways. As neutrophils within rheumatoid joints are primed, the soluble immunoglobulin aggregates are likely to be of importance in disease pathology.

Activation of the neutrophil myeloperoxidase-H2O2 system by synovial fluid isolated from patients with rheumatoid arthritis

Synovial fluid isolated from 16 patients with rheumatoid arthritis activated luminol dependent chemiluminescence in bloodstream neutrophils, and the maximal activity stimulated varied over a 50-fold range. In contrast, these same fluids only activated a much lower range (two- to threefold) of maximal rates of lucigenin dependent chemiluminescence and cytochrome c reduction, two assays which only measure oxidant secretion which is independent of myeloperoxidase. Over 95% of the luminol dependent chemiluminescence activated by all samples was inhibited by azide (indicating its dependence upon myeloperoxidase), but anti-(myeloperoxidase) IgG (which specifically inhibits only the extracellular activity of this enzyme) only inhibited the response stimulated by some samples: those fluids which activated the highest luminol dependent chemiluminescence also stimulated the greatest activity of an extracellular myeloperoxidase-H2O2 system. A clear correlation was shown to exist between the activity of myeloperoxidase already present in the fluids (after its secretion from neutrophils in situ within the rheumatoid joint) and the ability of the fluid to activate luminol dependent chemiluminescence. It is concluded, therefore, that all synovial fluid samples tested possess almost equivalent levels of a factor(s) which activated O2-/H2O2 secretion and that the variations in the measured activity of the extracellular myeloperoxidase-H2O2 system are dependent upon the level of degranulation which had occurred within the joint.

Neutrophils isolated from the synovial fluid of patients with rheumatoid arthritis: priming and activation in vivo

The oxidative metabolism of neutrophils isolated from the bloodstream and synovial fluid of 16 patients with rheumatoid arthritis was compared by measuring the ability of neutrophils to generate luminol dependent chemiluminescence and to secrete O2-. Measurements of receptor mediated--that is, N-formyl-methionyl-leucyl-phenylalanine stimulated--activation or receptor and second message independent--that is phorbol myristate acetate stimulated--activation showed that synovial fluid neutrophils had biochemical characteristics to suggest that they had been either up-regulated (primed) or down-regulated (activated) in vivo. These conclusions were confirmed by comparison of these responses with the changes in oxidative metabolism observed during in vitro priming and activation of control neutrophils: synovial fluid neutrophils possessed lower levels of myeloperoxidase than paired bloodstream cells, and unlike bloodstream cells could not be primed in vitro. These data thus suggest that synovial fluid neutrophils have been exposed to both priming and activating agents within rheumatoid joints.

Pyarthrosis in patients with rheumatoid arthritis: a report of 13 cases and a review of the literature from the past 40 years

PURPOSE

The purpose of this study is to report 13 cases and review the literature for pyarthrosis occurring in the setting of rheumatoid arthritis (RA). Special emphasis is placed on evaluating both the changing, as well as the constant, features of this complication and on assessing diagnostic and therapeutic aspects that have a bearing upon outcome.

PATIENTS AND METHODS

A retrospective review of records from our institution revealed 13 cases of pyarthrosis in patients with RA over the past 14 years. Information obtained included patient demographics, RA history, concomitant illnesses and medications, length of symptoms prior to the diagnosis of pyarthrosis, peri-articular manifestations, probable source of infection, joint(s) involved, relevant laboratory data, and information on treatment and outcome based on initial surgical therapy versus closed needle drainage. In addition, 213 cases from 45 citations were reviewed for similar information.

RESULTS

Our series was notable for a high percentage of associated serious medical illnesses and peri-articular manifestations of the pyarthrosis (i.e., sinus tract formation, concomitant septic bursitis, or infected synovial cyst). The erythrocyte sedimentation rate was a useful monitor of adequate therapy and was often a signal of recurrent infection. In all patients, the skin was the major source of infection. The mortality from pyarthrosis has declined over the past 40 years but is still unacceptably high, especially in patients with polyarticular involvement. Preliminary observations suggest that an initial surgical approach to joint drainage may be preferable to closed needle drainage in order to improve joint outcome in patients with RA and pyarthrosis.

CONCLUSION

Pyarthrosis occurring in patients with RA continues to produce unacceptable morbidity and mortality despite 40 years' experience. Earlier recognition (which may include peri-articular features) and perhaps an aggressive surgical approach to drainage may improve the prognosis.

Synovial fluid neutrophils of patients with rheumatoid arthritis have membrane antigen changes that reflect activation

The level of expression of surface antigens was studied on neutrophils from paired samples of blood and synovial fluid of patients with rheumatoid arthritis (RA). By measuring the immunofluorescence of labelled monoclonal antibodies it was shown that on joint neutrophils there was an increase in expression of complement receptor 3 (CR3) and granulocyte functional antigens 1 and 2 compared with blood neutrophils, whereas the expression of GpIIb-IIIa was reduced. The pattern of expression was the same as that seen with in vitro activation and strongly suggest that activation is occurring within the joint.