Barbara Lisowska

Comparison of rheumatoid articular adipose and synovial tissue reactivity to proinflammatory stimuli: contribution to adipocytokine network

Objectives (1) To compare spontaneous and stimuli-induced adipocytokine secretion by articular adipose tissue (AAT) and synovial membrane (SM) explants obtained from patients with rheumatoid arthritis (RA). (2) To investigate the biological activity of AAT and SM released factors. Methods Tissues were obtained from patients undergoing joint replacement surgery. Tissue explants were treated with proinflammatory cytokines relevant to RA pathogenesis (interleukin 1β (IL-1β), tumour necrosis factor (TNF), interferon γ, IL-15, IL-17, IL-23). Selected adipocytokine (TNF, IL-6, IL-8, IL-1β, IL-1Ra, adiponectin, leptin) concentrations were measured in culture supernatants using ELISA. The biological activity of tissue-conditioned media was evaluated by measuring production of selected factors (IL-6, IL-8, Dickkopf-1, osteoprotegerin) by fibroblast-like synoviocytes (FLS). Results Spontaneous cytokine release from AAT was ≤12% of that produced by SM, while leptin was secreted in similar amounts. AAT was highly reactive to proinflammatory cytokines (IL-1β>TNF). AAT treated with IL-1β released four times more leptin, similar amounts of IL-6 and IL-8 and about 20% of TNF, as compared with SM. Upon activation, the IL-1 receptor antagonist (IL-1Ra)/IL-1β ratio was higher in AAT than in SM cultures. Irrespective of activation status, SM produced twice as much adiponectin as AAT. Conditioned media from AAT and SM cultures similarly upregulated IL-6, IL-8, Dickkopf-1 and osteoprotegerin production by rheumatoid FLS. Conclusion Rheumatoid AAT is highly reactive tissue which upon stimulation secretes considerable amounts of proinflammatory (IL-6, IL-8, TNF) and anti-inflammatory (IL-1Ra) cytokines and classical adipokines. This tissue releases biologically active factors that intensify pathogenic activities of rheumatoid FLS. Thus, AAT should be considered an important contributor to the pathological processes taking place in the RA joint.

Anaesthesiological problems in patients with rheumatoid arthritis undergoing orthopaedic surgeries

The article presents anaesthesiological problems in patients with rheumatoid arthritis (RA) scheduled for orthopaedic surgeries. Organ changes due to RA and related treatment were taken into account. The anaesthetic techniques used for patients with RA underwent orthopaedic procedures were presented.

Anesthesiology and the cytokine network.

The immune response is a highly specific reaction carried out by means of specialized cells that belong to the immune system. There are two types of immune response mechanisms aimed towards pathogens: non-specific, innate reactions, and specific, acquired reactions. Acquired immunity, characterized by its specificity, is comprised of lymphocytes, including both T cell and B cell populations. The role of B lymphocytes is not limited to the humoral response, though the cellular immune response is carried out mainly by various T lymphocyte subpopulations. The reactions of the humoral and cellular responses complement and stimulate one another mutually - cytokines are their common linking element. The attachment of cytokines to their specific receptors activates a sequence of signals - either intracellular or between the cells of various systems. This organization of respective connections and reactions, including the functional relations between cells of the immune response, in its complexity, is best described as a cytokine network. The response of the immune system to surgical trauma can be looked at from both a local and a general perspective. Not only surgical trauma caused by tissue damage, however, influences the functioning of the immune system, but also the drugs and techniques used during anesthesia. Our article is a presentation of the effects of medications used in anesthesia with respect to their influence on the cytokine network.

THU0077 Multimeric Adiponectin Isoforms in Rheumatoid Arthritis: Local and Systemic Effects

Background Multimeric adiponectin isoforms of high-, middle-, and low-molecular weight (HMW, MMW and LMW) exist in body fluids. Their implication in rheumatoid arthritis (RA) pathogenesis is suggested but not fully confirmed. Objectives (1) To evaluate adiponectin isoform concentrations in sera and synovial fluids (SF) of RA patients. (2) To search for relationship between adiponectin isoform levels and clinical data. (2) To investigate the effect of adiponectin isoforms on rheumatoid fibroblast-like synoviocytes (FLS) function. Methods The concentrations of HMW, MMW, LMW isoforms and total adiponectin (T) were measured in sera (n=44) and SF (n=12) of patients with established RA, using ELISA (ALPCO Diagnostic). Body composition was measured by dual-energy X-ray absorptiometry (DXA); total (tFM) and visceral (vFM) fat mass were assessed. Rheumatoid FLS were treated for 18 hrs with human HMW, LMW or LMW+MMW isoforms, applied at 0.1-10 ng/ml. Untreated and cytokine-treated (1 ng/ml of IL-1ß or 10 ng/ml of TNF) cells were used as negative and positive controls, respectively. The concentrations of proinflammatory cytokines (IL-6, IL-8) and connective tissue degrading enzyme, matrix metalloproteinase-3 (MMP-3), were measured in cell culture supernatants by specific ELISA. The Wilcoxon signed-rank test was applied to evaluate the effect of stimuli and to compare adiponectin concentrations in sera and SF. The correlation was assessed using a Spearman test. Results All adiponectin isoform concentrations were higher in sera than in SF, but in SF the LMW/T and LMW+MMW/T ratios were significantly higher than in sera of the same patients. There was a correlation between tFM/vFM and serum ratios of HMW/T (inverse correlation) and LMW+MMW/T (positive correlation). Moreover, serum HMW/T and LMW+MMW/T ratios showed inverse and positive correlation, respectively, with atherogenic index (AI = total cholesterol/high density lipoprotein-cholesterol, HDL-C). In addition, serum MMW concentrations correlated inversely with disease activity score (DAS28) and ESR (erythrocyte sedimentation rate), a marker of systemic inflammation. In vitro, both HMW and mixture of LMW+MMW significantly up-regulated IL-6, IL-8 and MMP-3 production by FLS, while pure LMW had no effect. Conclusions In RA patients circulating adiponectin isoform pool is dependent on body FM; obesity/overweight favours low HMW and high LMW+MMW levels. Circulating HMW and LMW+MMW have opposite systemic effects, i.e. anti-atherogenic and proatherogenic, respectively, which is consistent with observations of others. However, the role of adiponectin isoforms in joint inflammation and destructions is more complex. HMW and MMW (more likely than LMW), isoforms may support these pathological processes. Nevertheless, serum high MMW level is associated with less active/inflammatory disease. Thus, we report that HMW and MMW may have some protective, i.e. antiatherogenic (HMW) or anti-inflammatory (MMW) systemic action, but their local effect is disadvantageous (proinflammatory, prodestructive). Acknowledgements Sponsored by grant No NN402 369938 from the National Science Centre. Disclosure of Interest None Declared

SAT0047 The origin and biological activities of classical adipokines in rheumatoid joint

Background Classical adipokines, leptin and adiponectin, are thought to originate principally from white adipose tissue. Although both of them have been suggested to participate in pathogenesis of rheumatoid arthritis (RA), their role is still controversial [1]. Data concerning leptin contribution are inconsistent. Adiponectin was reported to exert mostly proinflammatory and prodestructive effects, but little is known about biological activities of its low (LMW) and high molecular (HMW) complexes. We have recently reported that not only rheumatoid synovial membrane (SM), but also articular adipose tissue (AAT) releases biologically active factors, including leptin and adiponectin [2]. However, it is not known whether periarticular subcutaneous adipose tissue (ScAT) shows similar secretory activity. Objectives (1) To compare the production of leptin and adiponectin by rheumatoid ScAT, AAT, and SM explants. (2) To investigate the effects of leptin and adiponectin on rheumatoid fibroblast-like synoviocytes (FLS) function. Methods Tissue specimens were obtained from the knee joints of 60 patients with established rheumatoid arthritis (RA) who were undergoing total joint replacement surgery. Tissue explants (100 mg/ml/well) were cultured in medium (DMEM) alone or treated for 18 h with recombinant human cytokines relevant to RA pathogenesis: IL-1β, TNF, interferon γ or IL-15, applied at 1, 10 or 40 ng/ml concentrations, respectively. After the treatment leptin and adiponectin concentrations were measured in tissue explants culture supernatants by ELISA. Moreover, RA FLS isolated from SM specimens were stimulated for 18 h with recombinant human leptin, HMW or LMW adiponectin (0.1-10 ng/ml), then the culture supernatants were collected and concentrations of proinflammatory cytokines (IL-6, IL-8) and connective tissue degrading enzyme, matrix metalloproteinase-3 (MMP-3), were measured using specific ELISA. Results Spontaneous leptin secretion by AAT, ScAT and SM explants was similar (

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Enoxaparine treatment enhanced angiogenic activity of mouse and human serum

200 pg/100 mg), while SM secreted twice as much adiponectin as AAT and ScAT (mean ± SEM equal 7966±1016, 4649±340 and 4962±585 pg/100 mg, respectively). The release of both adipokines from SM did not change upon stimulation, while all applied stimuli raised their secretion from AAT and ScAT. In these conditions AAT and ScAT produced twice as much leptin but still less adiponectin than SM. Exogenously added adipokines exerted little (leptin), moderate (HMW adiponectin) or strong (LMW adiponectin) stimulatory effects on IL-6, IL-8 and MMP-3 secretion by RA FLS. Interestingly, the effect of LMW adiponectin (10 ng/ml) was comparable to that exerted by TNF. Conclusions Joint-associated adipose tissues (AAT and ScAT) are highly reactive to proinflammatory cytokines and upon stimulation their contribution to local adipokine pool is substantial. In RA joints adiponectin, especially of LMW, may contribute to synovitis and tissue destruction owing to potent up-regulation of IL-6, IL-8 and MMP-3 secretion by FLS. Acknowledgements This work was sponsored by grant No N N402 369938 from the Polish Ministry of Science and Higher Education. References Neumann E et al., Arthritis Rheum., 2011, 63:1159-69. Kontny E et al., Ann Rheum Dis., 2012, 71:262-267. Disclosure of Interest None Declared