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The destruction of cartilage is an important characteristic of rheumatoid arthritis (RA). Immune complexes (IC) are usually found in high amounts in RA synovial fluids (SF) and in the superficial layers of RA cartilage. The objective of this study was to investigate if IC have a direct influence on proliferation, survival and production of nitric oxide (NO) of cytokine-activated chondrocytes. Primary bovine chondrocytes were incubated with cytokines (huIL-1alpha, bovIFN-gamma, huTNF-alpha) and IC containing precipitates of peripheral blood (PB) and/or synovial fluid (SF) of 14 RA patients, 5 osteoarthritis (OA) patients and 10 healthy age and sex-matched controls. After 48 h, chondrocyte viability, proliferation, apoptosis, NO production and oxygen radical levels were measured. Staining with May-Grünwald-Giemsa after incubation with IC of RA PB and SF, showed apoptotic chondrocytes with condensation of the nuclei. The proliferation rates of cytokine-activated chondrocytes, incubated with sera and SF IC of RA patients were significantly decreased compared to chondrocytes, incubated with sera and SF IC of OA patients and compared to sera of controls. Quantitative evaluation of apoptotic cells by annexin-V/propidium iodide and TUNEL assays revealed a significant increase after incubation with sera and SF IC of RA patients, compared to control sera and OAs sera and SF. In all TUNEL positive samples, active-caspase-3-positive cells were found. There was a significant increase of chondrocyte NO production, after incubation with SF IC of RA patients, compared to OA SF. These results support the hypothesis that IC, present in serum and SF of RA patients, have a profound influence on chondrocyte growth, NO production and apoptosis, contributing to cartilage destruction in RA.

Objective: To investigate whether anti-TNF therapy could have an effect on dendritic cells (DCs) and regulatory T cells in rheumatoid arthritis (RA) patients., Methods: A four-colour flow cytometric technique was used to measure CD4+CD25+ T cells i.e. CD4+CD25high+ (regulatory T cells) and CD4+CD25low+ (activated T cells)), DCs as well as the in vitro, intracellular, lipopolysaccharide-stimulated cytokine production of DCs., Results: Clinical and laboratory parameters of disease activity decreased after anti-TNF treatment. Before anti-TNF therapy, RA patients demonstrated a decreased count of Th2-promoting lymphoid DCs as compared to controls and after anti-TNF therapy this decrease was sustained. Intracellular cytokine production was only found in the myeloid DCs population and there was a higher production of TNF-alpha and IL1-b as compared to healthy controls. Treatment did not alter this cytokine production. Before anti-TNF therapy, the percentage CD4+CD25+ T cells was significantly elevated in RA patients than in healthy controls., Conclusion: These results demonstrate anti-TNF to be a potent anti-inflammatory drug, as mirrored by the decrease in clinical and biological parameters as well as the decrease in activated CD4+ T cells. However, in this study no demonstrable effect on DCs and regulatory T cells was found.

Introduction: It has been shown that T lymphocytes and monocytes/macrophages, producing pro-inflammatory cytokines, play a pivotal role in the pathophysiology of rheumatoid arthritis (RA). In recent placebo-controlled double-blind randomized studies, chimeric (human/mouse) tumour necrosis factor-alpha (TNFalpha) antibodies (cA2) proved to be very effective in improving clinical disease activity and reducing inflammatory parameters in RA., Objective: To investigate whether anti-TNFalpha therapy influences the in vitro intracellular cytokine production in peripheral blood monocytes and T lymphocytes of RA patients after one single (24 h) and multiple intravenous infusions (6 months)., Methods: An intracellular flow cytometric technique was applied to measure interleukin 1beta (IL-1beta), IL-6, TNFalpha, IL-10 and IL-12 in monocytes and IL-2, IL-4 and interferon-gamma in T lymphocytes of 15 patients, before, after 24 h and after 6 months of therapy with monoclonal chimeric anti-TNFalpha antibodies (3 mg/kg, bimonthly i.v.). All patients were on stable therapy with methotrexate (15-20 mg/week i.m.). Cytokine content in monocytes was measured directly after blood sampling (basal levels), after 8 h of culture (spontaneous production) and after 8 h of stimulation with lipopolysaccharides (LPS-stimulated production)., Results: Basal levels and production (after 8 h) of IL-1beta, IL-6 and TNFalpha were significantly decreased 24 h after the first administration of anti-TNFalpha (for IL-1beta P < 0.01; for IL-6 P < 0.01; for TNF P < 0.003) and after 6 months of therapy (for IL-1beta P < 0.02; for IL-6 P < 0.03; for TNFalpha P < 0.001). For IL-12, basal levels were significantly decreased 24 h and 6 months after the start of therapy with anti-TNFalpha antibodies (P=0.0001; P=0.003, respectively). In contrast, IL-10 production increased significantly after 24 h and after 6 months (P=0.02; P=0.01). The T(H2)/T(H1) cytokine ratio in CD4+ T cells was significantly increased after 24 h and after 6 months of anti-TNFalpha therapy (P=0.003; P=0.0007)., Conclusion: Anti-TNFalpha therapy might down-regulate the monocytic capacity to produce pro-inflammatory cytokines and induces a shift to a more pronounced anti-inflammatory T(H2) cytokine production.

Objective: Rheumatoid arthritis (RA) is a chronic inflammatory disease with predominance of type I cytokine [interleukin 2 (IL-2), interferon-gamma (IFN-gamma)] production. In this prospective study, we evaluated the influence of longterm therapy with methotrexate (MTX) in combination with low dose corticosteroids on the type 1/type 2 cytokine balance in RA., Methods: Peripheral blood mononuclear cells were isolated from 10 controls and 20 patients with RA before therapy and after 12 mo of therapy with MTX in combination with low dose corticosteroids. Using flow cytometry, the intracellular production of IL-2, IFN-gamma, and IL-4 was measured in CD4+ and CD8+ T lymphocytes., Results: Compared with healthy controls, patients with RA before therapy showed an increased percentage of IL-2 positive CD4+ and CD8+ T cells (p = 0.002, p = 0.01, respectively). An increased percentage of IFN-gamma positive CD8+ T cells was found (p = 0.0006) compared with the control group. After 12 months of therapy, a significantly decreased percentage of IL-2 positive CD4+ T cells and IFN-gamma positive CD4+ and CD8+ T lymphocytes was observed (p = 0.0003, p = 0.0007, p = 0.001). The percentage of IL-4/IFN-gamma positive CD4+ and CD8+ T cells was significantly higher after 12 months of therapy (p = 0.01, p = 0.02). There was a positive correlation between the percentage of IFN-gamma positive CD4+ T cells and disease activity variables (Ritchie Index and number of swollen joints) in RA patients before therapy (r = 0.6, p = 0.04 and r = 0.4, p = 0.05)., Conclusion: Longterm therapy with MTX in combination with low dose corticosteroids for RA influenced the predominance of type 1 cytokines toward normalization of the cytokine balance in both CD4+ and CD8+ T lymphocytes.

Objectives: The aim of this work was to evaluate in a randomised double-blind prospective study the effect of pamidronate on intracellular monocytic cytokine profiles (IL-1, IL-6, TNF-alpha) and bone density in rheumatoid arthritis patients., Methods: Twenty rheumatoid arthritis patients were treated for one year with methotrexate and a low dose of prednisolone. Double blind randomisation was performed for either i.v. pamidronate (at 3-month intervals) or placebo. The effect of pamidronate was evaluated on intracellular cytokine profiles (IL-1, IL-6, TNF-alpha), disease activity and bone mass measurements. The human monocytic cell line THP-1 was used to evaluate in vitro apoptosis by pamidronate., Results: Spontaneous production of interleukin-1 beta by patient blood monocytes was lower in the pamidronate group and was associated with an increase in bone density of the spine after 12 months of therapy. In vitro a dose-related increase in pamidronate induced apoptosis was found in THP-1 cells., Conclusions: This prospective double-blind randomised study demonstrated that pamidronate therapy resulted in an increase of bone density despite treatment with steroids. This rise is associated with a suppression of interleukin-1 beta production in monocytes of patients treated with pamidronate. Our in vitro experiments suggest that this anti-inflammatory effect could be due to an increase in the apoptosis of monocytic cells.

Experimental data suggest that pro-inflammatory cytokines such as interleukin 1beta (IL-1beta), interleukin 6 (IL-6) and tumour necrosis factor alpha (TNF-alpha) are important in the pathogenesis of osteoporosis in rheumatoid arthritis. Therefore we compared the production of these cytokines by monocytes in 10 rheumatoid arthritis patients and 10 controls. Cytokine levels in rheumatoid arthritis patients were related to disease activity parameters, bone mineral density (BMD) corrected for age and sex (Z scores) and osteocalcin as a laboratory parameter of bone remodelling. Cytokines were determined by a flow cytometrical technique. There was a tendency for higher IL-1beta levels in patients compared with controls. A positive correlation between erythrocyte sedimentation rate and spontaneous production of monocytic cytokines was found. Z scores of the lumbar spine showed a negative correlation with spontaneous production of IL-1beta and IL-6. Plasma osteocalcin levels were positively correlated with spontaneous production of IL-1beta, IL-6 and TNF-alpha. In conclusion, the correlation of the levels of these cytokines with parameters of bone metabolism and osteoporosis suggest that especially IL-1beta and IL-6 are associated with more pronounced osteoporosis in active rheumatoid arthritis., (Copyright 1999 Academic Press.)

A 72-year-old rheumatoid arthritis patient is described presenting with acute dyspnoea and peripheral oedema. A pericardial effusion with signs of tamponade was diagnosed. Examination of the pericardial fluid revealed the presence of cholesterol crystals and IgE-containing immune complexes. The significance of these findings in the differential diagnosis of pericardial disease is discussed.

IgE-containing circulating immune complexes (IgE-CIC) were determined with a 2.5% PEG-precipitation assay in 98 patients with classical or definite rheumatoid arthritis (RA). Of the 45 IgE-CIC positive sera, only 4 had elevated total serum IgE. IgE-CIC positive patients had more active disease than patients without IgE-CIC, as determined by their more swollen joints and higher Ritchie indices (p less than 0.04 and 0.02, respectively). Apart from IgE, other immunoglobulin isotypes, rheumatoid factor (RF) of the IgG-, IgA- and IgM-classes, C3 and antinuclear antibodies could be demonstrated in the IgE-containing PEG-precipitates. IgE-RF could not be demonstrated in serum or in IgE-CIC. Anti-IgE of the IgM-class (IgMaIgE) were frequently found (28/45 patients) in the IgE-positive PEG-precipitates. All 14 patients positive for IgGaIgE in the IgE-CIC were also positive for IgMaIgE in the CIC. As in the serum, there was a good correlation in the CIC between the level of IgGaIgE and the level of IgMaIgE (r = 0.64). The correlation between the respective levels of IgGaIgE and IgMaIgE in serum and in CIC was high (r = 0.93 and 0.79, respectively). On the other hand, only 1 patient was positive for IgAaIgE in the IgE-CIC. We conclude that IgE and aIgE of the IgM- and IgG-classes are frequently present in the immune complex form in RA and that they are correlated with the clinical activity of arthritis.