Increased IL-1 receptor antagonist (IL-1ra) production and decreased IL-1 beta/IL-1ra ratio in mononuclear cells from rheumatoid arthritis patients

Leukocyte-Reduced Platelet-Rich Plasma Normalizes Matrix Metabolism in Torn Human Rotator Cuff Tendons

BACKGROUND

The optimal platelet-rich plasma (PRP) for treatment of supraspinatus tendinopathy has not been determined.

PURPOSE

To evaluate the effect of low- versus high-leukocyte concentrated PRP products on catabolic and anabolic mediators of matrix metabolism in diseased rotator cuff tendons.

STUDY DESIGN

Controlled laboratory study.

METHODS

Diseased supraspinatus tendons were treated with PRP made by use of 2 commercial systems: Arthrex Autologous Conditioned Plasma Double Syringe System (L(lo) PRP) and Biomet GPS III Mini Platelet Concentrate System (L(hi) PRP). Tendon explants were placed in 6-well plates and cultured in L(lo) PRP, L(hi) PRP, or control media (Dulbecco's Modified Eagle Medium + 10% fetal bovine serum) for 96 hours. Tendons were processed for hematoxylin-eosin histologic results and were scored with the modified Bonar scale. Group 1 tendons were defined as moderate tendinopathy (Bonar score <3); group 2 tendons were assessed as severely affected (Bonar score = 3). Transforming growth factor β-1 (TGFβ-1), interleukin-1β (IL-1β), interleukin-1 receptor antagonist (IL-1Ra), interleukin-6 (IL-6), interleukin-8 (IL-8), and matrix metalloproteinase-9 (MMP-9) concentrations in PRP media were measured by use of enzyme-linked immunosorbent assay after 96 hours of culture with diseased tendon. Tendon messenger RNA expression of collagen type I (COL1A1), collagen type III (COL3A1), cartilage oligomeric matrix protein (COMP), MMP-9, MMP-13, and IL-1β was measured with real-time quantitative polymerase chain reaction.

RESULTS

Leukocytes and platelets were significantly more concentrated in L(hi) PRP compared with L(lo) PRP. Increased IL-1β was present in L(hi) PRP after culture with group 1 tendons. IL-6 was increased in L(hi) PRP after culture with group 2 tendons. Both TGFβ-1 and MMP-9 were increased in L(hi) PRP after culture with either tendon group. In L(lo) PRP cultures, IL-1Ra:IL-1β in PRP used as media and COL1A1:COL3A1 gene expression were increased for group 1 tendon cultures. Gene expression of MMP-9 and IL-1β was increased in group 2 tendons cultured in L(lo) PRP. There was no significant difference in the expression of MMP-13 or COMP in either group of tendons cultured in L(lo) PRP or L(hi) PRP.

CONCLUSION

L(lo) PRP promotes normal collagen matrix synthesis and decreases cytokines associated with matrix degradation and inflammation to a greater extent than does L(hi) PRP in moderately degenerative tendons. In severely degenerative tendons, neither PRP preparation enhanced matrix synthesis.

CLINICAL RELEVANCE

L(lo) PRP may promote healing in moderately degenerative rotator cuff tendons.

Ex vivo interleukin 1 receptor antagonist production on lipopolysaccharide stimulation is associated with rheumatoid arthritis and with joint damage

OBJECTIVES

(1) To assess innate ex vivo production of interleukin 1beta (IL1beta) and interleukin 1 receptor antagonist (IL1Ra) in patients with recent-onset rheumatoid arthritis (RA) as compared with healthy controls; (2) to assess the association of ex vivo IL1beta and IL1Ra production with progression of joint damage in RA; (3) to determine whether differences in ex vivo IL1beta production are explained by distribution of the IL1beta single nucleotide polymorphism C-511T.

METHODS

Levels of IL1beta and IL1Ra (measured by ELISA after whole-blood stimulation with lipopolysaccharide) and distribution of IL1beta C-511T were compared in 76 patients with recent-onset RA who had received no disease-modifying antirheumatic drugs (DMARDs), and 63 healthy controls. ORs for RA based on ex vivo IL1beta and IL1Ra production were calculated. Association of ex vivo IL1beta and IL1Ra production with progression of joint damage (Sharp-van der Heijde score over 2 years) was determined by linear regression with correction for baseline characteristics.

RESULTS

Patients with recent-onset RA showed lower ex vivo IL1beta and higher ex vivo IL1Ra production than healthy controls (p<0.001), with ORs for RA of 2.4 (95% CI 1.2 to 4.9) for low IL1beta-producers and 7.6 (95% CI 3.2 to 18.0) for high IL1Ra-producers. High ex vivo IL1Ra production was associated with progression of joint damage (p = 0.01). The IL1beta C-511T genotype distribution was not significantly different between patients and controls.

CONCLUSIONS

Patients with recent-onset RA had decreased ex vivo IL1beta production and increased ex vivo IL1Ra production compared with controls. Ex vivo IL1Ra production is an independent predictor of progression of joint damage in recent-onset RA.

Different activation patterns of proinflammatory cytokines in melancholic and non-melancholic major depression are associated with HPA axis activity

BACKGROUND

Recent studies showed an activation of the cytokine system and the HPA axis in major depression, although with inconsistent results. While the non-melancholic subtype displayed a proinflammatory cytokine pattern, the melancholic subtype showed signs of impaired cytokine production. In order to understand the potential pathogenic significance of these systems further, the interplay between the cytokine system and the HPA axis in depressive subtypes as well as potential changes of these systems during the course of disease were investigated.

METHODS

N=37 initially unmedicated patients with acute major depression were sub-classified (melancholic vs. non-melancholic) and compared with N=37 matched healthy controls. Upon admission and after complete clinical remission, basal plasma ACTH and serum cortisol levels as well as cytokine productions (IL-1beta, IL-1 receptor antagonist (IL-1RA)) upon mitogen stimulation (PHA) were measured in a whole blood assay.

RESULTS

ACTH and cortisol concentrations were significantly elevated on admission in the melancholic but not the non-melancholic subgroup. Non-melancholic patients produced significantly more IL-1beta and IL-1RA upon admission than controls or melancholic patients. The IL-1 RA/IL-1beta ratio was significantly lower in the non-melancholic compared to the melancholic subgroup and increased significantly upon remission.

LIMITATIONS

Patient treatment was not standardized. No Dex/CRH test was performed.

CONCLUSIONS

Melancholic patients demonstrated an activation of the HPA axis in acute stage with partial normalization upon remission but no signs of inflammation. Non-melancholic patients showed signs of inflammation in acute depression with normalization upon remission while the function of the HPA axis was normal.

Differential contribution of IL-1Ra isoforms to allele-specific IL-1Ra mRNA accumulation

The interleukin-1 (IL-1) receptor antagonist (IL-1Ra) gene produces two isoforms of IL-1Ra, intracellular (icIL-1Ra) and secreted (sIL-1Ra). Distinct promoter regions control synthesis of each isoform. Five alleles of this gene, defined by sIL-1Ra intron 2 polymorphism, have been described. Although differences in IL-1Ra protein production have been demonstrated in various tissues and cells obtained from individuals carrying allele 1 vs. allele 2, the underlying mechanisms of this discrepancy remain poorly understood. We hypothesize that one mechanism contributing to differences in protein levels may be allele-specific accumulation of icIL-1Ra or sIL-1Ra mRNA. Quantification of allele-specific differences in mRNA accumulation in colonic biopsies and peripheral blood mononuclear cells (PBMC) of heterozygous individuals shows that the amount of allele 1-specific icIL-1Ra mRNA averaged four times higher relative to allele 2. In transfection assays, gene expression directed by the allele 1-specific icIL-1Ra promoter fragment was found to be greater than that directed by the allele 2 promoter, suggesting that icIL-1Ra promoter activity contributes to the disparity in the allele-specific icIL-1Ra mRNA accumulation. Our data show that differences in the transcriptional regulation of icIL-1Ra alleles 1 and 2 may be involved in the production of icIL-1Ra protein. Disregulated icIL-1Ra production may play a role in chronic inflammatory diseases where the balance between IL-1 and IL-1Ra has been implicated as a key pathogenic mechanism.

IL-1 beta, IL-1 receptor antagonist and soluble type II IL-1 receptor in synovial fluid of patients with temporomandibular disorders

Among the members of the interleukin-1 (IL-1) family, IL-1 beta, which is a major agonist, has been detected in synovial fluid (SF) of the temporomandibular joint (TMJ) of patients with temporomandibular joint disorders (TMD). However, there is little knowledge regarding suppressive molecules, such as IL-1 receptor antagonist (IL-1ra) and the soluble form of type II IL-1 receptor (sIL-1RII), in TMD patients. The aim of this study was to investigate the levels of IL-1 beta, IL-1ra and sIL-1RII in the TMJ SF of patients with TMD and their relationship. Fifty-two SF samples from TMD patients and nine samples from asymptomatic volunteers were examined. Detected levels of IL-1 beta and sIL-1RII were significantly higher in the TMD group compared with the volunteer group. There was no significant difference in IL-1ra levels between the TMD and volunteer groups. The IL-1 beta/IL-1ra ratio in the TMD group, however, was higher than that in the volunteer group. In the TMD group, positive correlations were found between IL-1 beta and IL-1ra, IL-1ra and sIL-1RII, and IL-1 beta and sIL-1RII. In addition to increased IL-1 beta, development of TMD may also lead to decreased IL-1ra and increased sIL-1RII in response to increasing IL-1.

Interleukin-1-induced glenohumeral synovitis and shoulder pain in rotator cuff diseases

Synovitis of the subacromial bursa has been identified as a main source of shoulder pain in rotator cuff diseases. Little interest, however, has been paid into the synovitis of glenohumeral joint. The mRNA expression levels of interleukin-1beta (IL-1beta) and interleukin-1 receptor antagonists produced in the synovitis reflect the magnitude of inflammation. The present study was undertaken to determine the relationship between mRNA expression levels of IL-1beta and its receptor antagonists (secreted interleukin-1 receptor antagonist (IL-1ra) and intracellular IL-1ra) in the synovium of the glenohumeral joint and shoulder pain in rotator cuff diseases, analyzing the synovial specimens by reverse transcriptase polymerase chain reaction. Thirty-five patients with rotator cuff diseases were candidates. Based on the presence of cuff perforation, they were divided into two categories: 16 with non-perforating tears and 19 with perforating tears. The degree of shoulder pain was evaluated by use of a visual analogue scale. The pain degree of non-perforating tears was significantly greater than that of perforating tears (P < 0.01). In contrast, the expression levels of the cytokine-mRNAs were constitutively greater in perforating tears than in non-perforating tears (P < 0.01, respectively). The expression levels of the cytokine-mRNAs were inversely correlated with the degree of pain (IL-1beta: r = 0.930; secreted IL-1ra: r = 0.861; intracellular IL-1ra: r = 0.932, P < 0.001 respectively). These results suggest that the expression levels of the cytokine-mRNAs in the synovium of the glenohumeral joint contribute less to the generation of shoulder pain in rotator cuff diseases.

Autoantibodies against interleukin 1alpha in rheumatoid arthritis: association with long term radiographic outcome

OBJECTIVES

To investigate the possible association of interleukin 1alpha autoantibodies (IL1alpha aAb) with the long term course of joint erosion in patients with rheumatoid arthritis (RA).

METHODS

Serum samples from 176 patients with RA included in a prospective study over 30 years were analysed for IL1alpha aAb by binding to human [(125)I]IL1alpha. Erosions of 19 diarthrodial joints were radiographically scored by the Larsen method.

RESULTS

The relative risk (RR) of early IL1alpha aAb positive patients developing at least 30% of maximum radiographic joint destruction was significantly lower than for IL1alpha aAb negative patients, RR=0.29 (p=0.04). In rheumatoid factor positive patients RR was only 0.18 (p=0.02). Patients who seroconverted more than two years after the onset of RA showed the most aggressive development of joint erosion, with a relative risk of at least 40% of maximum radiographic joint destruction of 2.56 (p=0.048)

CONCLUSIONS

The progression of radiographic joint destruction in patients with RA is associated with, and perhaps modified by, circulating IL1alpha aAb, suggesting that IL1alpha or IL1alpha aAb, or both, have a role in the erosive processes. IL1alpha aAb appear to be of prognostic significance in RA.

Cytokine balance in the lungs of patients with acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) involves an intense inflammatory response in the lungs, with accumulation of both pro- and antiinflammatory cytokines in bronchoalveolar lavage fluid (BALF). Our goal was to determine how the balance between pro- and antiinflammatory mediators in the lungs changes before and after the onset of ARDS. We identified 23 patients at risk for ARDS and 46 with established ARDS and performed serial bronchoalveolar lavage (BAL). We used immunoassays to measure tumor necrosis factor alpha (TNF-alpha) and soluble TNF-alpha receptors I and II; interleukin 1 beta (IL-1 beta), IL-1 beta receptor antagonist, and soluble IL-1 receptor II; IL-6 and soluble IL-6 receptor; and IL-10. We used sensitive bioassays to measure net TNF-alpha, IL-1 beta, and IL-6 activity. Although individual cytokines increased before and after onset of ARDS, greater increases occurred in cognate receptors and/or antagonists, so that molar ratios of agonists/antagonists declined dramatically at the onset of ARDS. The molar ratios remained low for 7 d or longer, limiting the activity of soluble IL-1 beta and TNF-alpha in the lungs at the onset of ARDS. This significant antiinflammatory response early in ARDS may provide a key mechanism for limiting the net inflammatory response in the lungs.

Interleukin-1-induced subacromial synovitis and shoulder pain in rotator cuff diseases

OBJECTIVE

To determine the relationship between the expression of interleukin-1beta (IL-1beta) and IL-1 receptor antagonists (IL-1ra) in the subacromial bursa and shoulder pain in rotator cuff diseases.

METHODS

Synovial specimens were analysed using various methods including reverse transcriptase-polymerase chain reaction (RT-PCR), immunohistochemistry and in situ RT-PCR. Thirty-nine patients with rotator cuff diseases were candidates. The degree of their shoulder pain was evaluated using a visual analogue scale.

RESULTS

The mRNA expression levels of the cytokines were significantly correlated with the degree of pain [IL-1beta: r=0.782; secreted IL-1ra (sIL-1ra): r=0.756; intracellular IL-1ra (icIL-1ra): r=0.806, P<0.001, respectively]. The combined results of immunohistochemistry and in situ RT-PCR analysis indicated that both synovial lining and sublining cells produce IL-1beta, while synovial lining cells predominantly produce icIL-1ra and sublining cells secrete sIL-1ra.

CONCLUSIONS

The differential regulation of the two forms of IL-1ra mRNAs may play an important role in shoulder pain in rotator cuff diseases, regulating IL-1-induced subacromial synovitis.

Progress in the use of biochemical and biological markers for evaluation of rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic systemic inflammatory autoimmune disorder which is predominant in females. The exact etiology remains undefined. Recently, a large number of biochemical and biologic markers, which are useful in the diagnosis, prognosis, and monitoring therapy of RA, have been reported. The new markers include genetic markers, filaggrin, citrulline containing peptides, A2/RA33, cytokines, joint and collagen breakdown products, and bone turnover markers. No laboratory tests in and of themselves are diagnostic of RA. The new markers have been employed in monitoring RA patients during treatment and following the course of the disease. With the development of innovative therapies for RA, many of the biochemical and biologic markers will be useful.

Production of interleukin (IL)-1beta, IL-1 receptor antagonist and IL-10 by blood mononuclear cells in chronic arthritis

Joint erosion is a prevalent feature of rheumatoid arthritis (RA) but not of many other chronic inflammatory arthritides (non-RA). Joint destruction is mediated by cytokines, primarily interleukin (IL)-1 and tumour necrosis factor. Less erosive activity in patients with non-RA compared to RA might be related to factors that inhibit production and/or function of IL-1. Release of IL-1beta, and the two antagonists, IL-1 receptor antagonist (IL-1ra) and IL-10 from blood mononuclear cells were therefore quantitated by ELISA in 22 patients with RA, 11 with non-RA and 15 healthy age-matched controls. Release of IL-1beta was comparable between the three groups but only detectable in cultures stimulated with lipopolysaccharide; it decreased in patients treated with prednisolone: 3.8 ng/10(6)monocytes (median) vs 11.7 (P=0.045). Release of IL-1ra was in all but IgG-stimulated cultures comparable between groups. The ratio of IL-1ra/IL-1beta was elevated in LPS-stimulated cells from RA patients only: 2.0 versus 1.3 (P=0.02). In contrast, IgG-induced IL-1ra release was significantly elevated only in non-RA patients: 95 ng/10(6)monocytes vs 40 (P=0.014), and the levels correlated positively to those of blood CRP (P=0.02). Though stimulated release of IL-10 was similar between the three groups, the levels were lower in non-erosive than erosive arthritis patients, and controls (P=0. 05). In conclusion, increased IgG-stimulated IL-1ra release and elevated IL-1ra/IL-1beta ratio may protect against actions of IL-1 in vivo, and decreased release of IL-10 might be related to features of non-erosive arthritis.

IL-1 inhibitors: novel agents in the treatment of rheumatoid arthritis

IL-1 is a pleiotropic cytokine shown to play a major role in synovitis and in the mechanisms that lead to the progressive joint destruction of rheumatoid arthritis (RA). IL-1 receptor antagonist (IL-1Ra), a member of the IL-1 family, binds IL-1 receptors but does not induce a cellular response. IL-1Ra competitively inhibits the binding of IL-1 to its cell surface receptors and thus acts as an endogenous anti-inflammatory mediator. In different experimental animal models of arthritis systemic administration of IL-1Ra, or local delivery into the joints by gene therapy attenuated the severity of the inflammatory response and reduced articular destruction. In addition, treatment of RA patients with IL-1Ra led to an improvement in different clinical and biological parameters and to a reduction in the radiological signs of joint erosions. Recently, interesting results were obtained using IL-1Ra in combination with methotrexate, a well-known antirheumatic drug, or in combination with other strategies designed to block the effects of tumour necrosis factor (TNF)-alpha. Encouraging results also have been reported in both in vitro and in vivo experimental models of arthritis by using other strategies designed to block the effects of IL-1.

Determination of interleukin-1 receptor antagonist, interleukin-10, and transforming growth factor-beta1 in synovial fluid aspirates of patients with temporomandibular disorders

PURPOSE

This study was undertaken to examine the presence of interleukin-1 receptor antagonist (IL-1ra), IL-10, and transforming growth factor-beta1 (TGF-beta1) in the synovial fluid (SF) lavage specimens of patients with temporomandibular disorders (TMDs).

PATIENTS AND METHODS

Synovial fluid lavage specimens were obtained from 14 temporomandibular joints (TMJs) of 12 patients with TMJ internal derangement (ID) and 17 TMJs of 15 patients with TMJ osteoarthritis (OA). Seven synovial fluid lavage samples of TMJs of four asymptomatic donors served as normal controls. The concentrations of IL-1ra, IL-10, and TGF-beta1 were detected with sensitive and specific sandwich enzyme-linked immunosorbent assay (sandwich-ELISA).

RESULTS

IL-1ra, IL-10, and TGF-beta1 in all the normal controls were undetectable. IL-1ra concentrations were 175.78 +/- 52.43 pg/mL in the patients with TMJ ID and 187.85 +/- 59.51 pg/mL in those with TMJ OA. IL-10 was undetectable in all the TMJ ID and OA samples. The concentration of TGF-beta1 in TMJ ID patients (47.93 +/- 88.25 pg/mL) was significantly less than in patients with TMJ OA (143.61 +/- 108.00 pg/mL) (P < .01).

CONCLUSION

The results suggest that deficiencies of IL-1ra, IL-10, and TGF-beta1 probably play an important role in the cause and pathogenesis of TMJ ID and OA.

Treatment of rheumatoid arthritis with IL-1 inhibitors

Extensive evidence from both in vivo and in vitro experiments indicate that IL-1, a prototypic proinflammatory cytokine, is involved in the mechanisms that lead to progressive joint destruction in RA. IL-1Ra, a member of the IL-1 family, binds IL-1 receptors but does not induce any cellular responses. IL-1Ra competitively inhibits the binding of IL-1 to its cell surface receptors and thus, acts as an endogenous antiinflammatory mediator. However, the results of several studies suggest that a relatively deficient production in IL-1Ra as compared to that of IL-1 in RA synovium may predispose to the perpetuation of chronic inflammation. Systemic administration of IL-1Ra, or local delivery into the joint by gene therapy, in different experimental animal models of arthritis attenuated the severity of the inflammatory response and reduced articular destruction. In addition, treatment of rheumatoid patients with IL-1Ra led to an improvement in different clinical and biological parameters and to a reduction in the radiological signs of joint erosions. Encouraging results also have been reported in both in vitro and in vivo experimental animal models of arthritis through using other strategies designed to block the effects of IL-1 at the level of production, prevent the binding of IL-1 to its cell surface receptors, or interfere with the effects of IL-1 at the post-receptor level.

Interleukin-1 receptor antagonist: role in biology

The interleukin-1 receptor antagonist (IL-1Ra) is a member of the IL-1 family that binds to IL-1 receptors but does not induce any intracellular response. Two structural variants of IL-1Ra have previously been described: a 17-kDa form that is secreted from monocytes, macrophages, neutrophils, and other cells (sIL-1Ra) and an 18-kDa form that remains in the cytoplasm of keratinocytes and other epithelial cells, monocytes, and fibroblasts (icIL-1Ra). An additional 16-kDa intracellular isoform of IL-1Ra has recently been described in neutrophils, monocytes, and hepatic cells. Both of the major isoforms of IL-1Ra are transcribed from the same gene through the use of alternative first exons. The two promoters regulating transcription of the secreted and intracellular forms have been cloned, and some of the functional cis-acting DNA regions have been characterized. The production of IL-1Ra is stimulated by many substances including adherent IgG, other cytokines, and bacterial or viral components. The tissue distribution of IL-1Ra in mice indicates that sIL-1Ra is found predominantly in peripheral blood cells, lungs, spleen, and liver, while icIL-1Ra is found in large amounts in skin. Studies in transgenic and knockout mice indicate that IL-1Ra is important in host defense against endotoxin-induced injury. IL-1Ra is produced by hepatic cells with the characteristics of an acute phase protein. Endogenous IL-1Ra is produced in numerous experimental animal models of disease as well as in human autoimmune and chronic inflammatory diseases. The use of neutralizing anti-IL-1Ra antibodies has demonstrated that endogenous IL-1Ra is an important natural antiinflammatory protein in arthritis, colitis, and granulomatous pulmonary disease. Treatment of human diseases with recombinant human IL-1Ra showed an absence of benefit in sepsis syndrome. However, patients with rheumatoid arthritis treated with IL-1Ra for six months exhibited improvements in clinical parameters and in radiographic evidence of joint damage.

Effects of antirheumatic agents on cytokines

A review of the literature concerning the effects of traditional antirheumatic drugs on cytokines and the cytokine and anticytokine approaches already used in the therapy of rheumatoid arthritis (RA) is presented. Many antirheumatic drugs are capable of cytokine modulation in vitro. Corticosteroids inhibit the transcription of a broad spectrum of genes including those encoding monocyte, T cell-derived cytokines and several hemopoietic growth factors, whereas drugs such as cyclosporin A and D-penicillamine interfere with T cell activation more specifically by suppressing interleukin 2 (IL-2) production. The in vivo effects of drug therapy on cytokines in RA patients are less well established. Gold compounds reduce circulating IL-6 levels and the expression of monocyte-derived cytokines, such as IL-1, tumor necrosis factor (TNF), and IL-6, in the rheumatoid synovium. Decreases in circulating IL-6, soluble IL-2 (sIL-2R), and TNF receptors and in synovial fluid IL-1 levels have been reported with methotrexate. Reductions in circulating IL-6 and sIL-2R concentrations have also been observed with cyclosporin and corticosteroids, whereas azathioprine reduces IL-6 but not sIL-2R. Studies on sulfasalazine are conflicting and the in vivo effects of D-penicillamine and antimalarials have not been studied yet. Interferon gamma therapy is not effective in RA but may prove a useful antifibrotic for systemic sclerosis. Colony stimulating factors improve the granulocytopenia associated with Felty's syndrome or drug toxicities but can induce arthritis flares and should be reserved to treat infectious complications. Promising results are being obtained with selective antagonism of TNF and IL-1 in RA, and combinations of anticytokine strategies with traditional antirheumatic drugs have been already envisaged. These should preferably be based in a broader knowledge of the effects of antirheumatic agents on the cytokine network.