Tumor necrosis factor-alpha blockade in the treatment of rheumatoid arthritis

The use of TNF alpha antagonists in RA has been extremely instructive. They have taught us that selective targeting of a pathogenic element can provide substantial clinical benefit. They have reinforced the concept of TNF alpha as a pivotal cytokine in the pathogenesis of RA. Pharmacodynamic studies of TNF alpha antagonists have further clarified the pathogenic processes involved in the disease. TNF alpha antagonists have set a new therapeutic standard for RA. Indeed, they are one of the most important advances in the history of the treatment of the disorder. If clinical efficacy is sustained and the safety profile remains benign over the long term, TNF alpha antagonists may replace MTX as the gold standard and become the agent of choice for combination therapy in RA. Further studies are needed to clarify their ultimate position in the therapeutic algorithm.     

Tumor necrosis factor-alpha gene polymorphism in severe and mild-moderate rheumatoid arthritis

OBJECTIVE: To examine whether severe rheumatoid arthritis (RA) carries a -238 or +489 tumor necrosis factor-alpha (TNF-alpha) genotype different from mild-moderate RA. METHODS: We investigated 163 patients (66 with severe disease) and 67 healthy blood donor controls. Genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism. RESULTS: Patients with severe RA (all active disease despite disease modifying antirheumatic drug combination therapy) disclosed the -238 GG genotype in 100% of cases versus 92.8% of the mild-moderates and 92.5% of controls (OR 11.7, Cl 0.6-216, p = 0.03). The +489 AA genotype was seen less often in patients than in controls (OR 4.2. CI 0.97-18.4, p = 0.045), and the contribution to this trend appeared predominant in the anti-TNF treated subgroup. CONCLUSION: The -238 AG genotype was absent in severe RA; in contrast, patients with mild-moderate RA disclosed the same frequency as controls. Thus -238 GG homozygosity is associated with severe RA. The +489 AA genotype might instead protect against worse outcome in RA.     

Novel pathways that regulate tumor necrosis factor-alpha production in rheumatoid arthritis

Clinical intervention studies have clearly shown the benefit in suppressing tumor necrosis factor-alpha (TNF-alpha) rheumatoid arthritis (RA). In consequence, considerable interest has arisen in those pathways that in turn regulate TNF-alpha production, because they may offer further possible therapeutic targets. Several candidate pathways are currently being investigated. They include T cell/macrophage interactions mediated primarily through cell-cell membrane contact; novel cytokine activities; microbial-derived products, in particular bacterial deoxyribonucleic acid sequences; autoreactive T cells, and immunoglobulins. At the subcellular level, there is further interest in targeting signaling and mRNA processing and cytokine cleavage pathways required for optimal TNF-alpha production. The key recent observations in these areas, particularly in the extracellular compartment, are reviewed.     

Anti-tumor necrosis factor-alpha response in rheumatoid arthritis is associated with an increase in serum soluble CD30

OBJECTIVE: Patients with rheumatoid arthritis (RA) display high serum concentrations of soluble CD30 (sCD30), which correlate with counter-regulatory activity of CD30+ T cells in the inflamed joint. To verify the contribution of this T cell subset to disease remission, sCD30 levels were analyzed longitudinally in patients with active RA following infliximab therapy. METHODS: Infliximab plus methotrexate were started in 39 patients with active RA, while 20 patients with inactive disease, controlled by stable doses of methotrexate, acted as controls. Serial evaluations of sCD30 concentrations and disease activity indexes were performed throughout 38 weeks. RESULTS: sCD30 levels were higher in patients than in healthy controls. Rapid infliximab-induced decrease in disease activity was associated with an overall increase of sCD30 levels. In contrast, levels remained stable in controls. An inverse correlation between sCD30 levels and Disease Activity Score 28 was observed from the 22nd week of infliximab treatment. Analysis of sCD30 levels according to American College of Rheumatology response showed, after an initial general enhancement of sCD30 concentrations, a persistent increase of sCD30 in responders, but not in nonresponders. CONCLUSION: sCD30 serum levels are enhanced by tumor necrosis factor-a (TNF-a) blockade in patients with active RA and inversely correlated with disease activity, but only after some weeks of treatment. Of interest, a sustained increase of sCD30 is present only in subjects with evidence of persistent clinical response to anti-TNF-alpha. As sCD30 serum levels mirror antiinflammatory activity of joint T cells, the present data may suggest a role of synovial counter-regulatory CD30+ T cells in the induction of infliximab-mediated remission in RA.     

Current tumor necrosis factor-alpha inhibitor use is associated with a higher probability of remissions in patients with rheumatoid arthritis

OBJECTIVE: To determine if current tumor necrosis factor-alpha (TNF-alpha) inhibitor use is associated with a higher probability of remission than non-use in patients with rheumatoid arthritis (RA). METHODS: Clinical and demographic data were collected from 322 patients with RA during regularly scheduled clinic visits. Current and past medications were recorded. Disease activity status (remission or not) was determined using American College of Rheumatology preliminary criteria for clinical remission of RA. A logistic regression analysis was used to calculate crude and adjusted odds ratios (OR) for remission for current TNF-alpha inhibitor users versus non-users. Multivariate analysis included age, gender, race, disease duration, use of nonsteroidal antiinflammatory drugs (NSAID), prednisone dosage, and numbers of previously used disease modifying antirheumatic drugs (DMARD). RESULTS: Of the 111 patients enrolled in the study who were users of TNF-alpha inhibitors, 25.2% were found to be in clinical remission. Of the 211 patients who were non-users, 14.7% were in clinical remission. The unadjusted OR for remission in TNF-alpha inhibitor users was 1.96 (95% confidence interval, CI: 1.10 to 3.48). The adjusted OR was 2.74 (95% CI: 1.40 to 5.34). CONCLUSION: Cross-sectional observations from an outpatient arthritis clinic found a significantly higher remission rate in patients with RA taking a TNF-alpha inhibitor compared to non-users.     

Tumor necrosis factor-alpha -1031 T/C polymorphism is associated with smaller and more proatherogenic low density lipoprotein particles in patients with rheumatoid arthritis

OBJECTIVE: To study, in patients with rheumatoid arthritis (RA), the association between the tumor necrosis factor (TNF)-alpha -1031 T/C polymorphism and quantitative and qualitative low density lipoprotein (LDL) characteristics.METHODS: From a sample of 100 patients with RA and 100 controls, we used the strategy of "recruit by genotype" to select 30 patients with RA: 15 carriers of the rare allele (C) and 15 homozygous for the more frequent allele (T). These were matched with 30 controls. Plasma lipoprotein profile including size distribution of lipoproteins was determined using nuclear magnetic resonance spectrometry. LDL susceptibility to oxidation was assessed by diene formation. The LDL affinity for extracellular matrix was determined using electrophoretic mobility shift assay. Genotyping was performed by SnapShot. RESULTS: Compared to TT patients with RA, carriers of the C allele had (1) LDL particles significantly smaller [20.74 (0.68) nm vs 21.18 (0.52), p < 0.02]; (2) LDL particles with a greater affinity for the proteoglycans (i.e., with a lower Kd) [197.26 (123.98) nmol/l vs 259.26 (139.31), p = 0.05]; and (3) LDL particles with significantly greater susceptibility to oxidation [shorter lag phase: 47 (20.01) min vs 74 (41.8), p < 0.03, and higher maximal rate of diene production: 3.1 (0.5) mol/min vs 2.6 (0.95), p < 0.05]. None of these differences was observed in the control group. CONCLUSION: In patients with RA, genetic variability in the TNF-alpha gene is associated with smaller LDL particles that have a greater affinity for extracellular matrix and higher susceptibility to oxidation. Because these characteristics are associated with a greater risk of atherosclerosis, identification of such predisposition in patients with RA could help in implementing early preventive intervention measures against cardiovascular disease.     

Tumor necrosis factor-alpha and Interleukin-10 gene promoter polymorphisms in Turkish rheumatoid arthritis patients

Tumor necrosis factor and interleukin 10 have been implicated in the pathogenesis of rheumatoid arthritis (RA). Certain single-nucleotide polymorphisms (SNPs) within the promoter region of the IL-10 and TNF genes have been associated with altered levels of circulating IL10 and TNF. We aimed to explore the association of IL-10 and TNF-alpha polymorphisms in Turkish RA patients. We analyzed the association of TNF-alpha (-308G/A, -238G/A, -376G/A) and IL10 (-1082G/A, -819C/T, -592C/A) polymorphisms in 98 Turkish patients with rheumatoid arthritis and 122 healthy subjects using ARMS-PCR. The correlation of these findings with RF positivity and erosive disease in RA patients was also sought. A significant association was found between having RA and -1082 G allele (p = 0.008; OR = 1.44, 95% CI 1.11-1.86). There was no association between RA and -819C/T polymorphism. Significant differences were observed in IL10 GCC and ACC haplotypes distribution between RA and control subjects (p = 0.006; OR = 1.46, 95% CI 1.13-1.89 and p = 0.011; OR = 1.43, 95% CI 1.09-1.88, respectively). No statistically significant association was found between TNF-alpha 308G/A, -238G/A, -376G/A polymorphisms and RA. No significant association was found between RF positivity and erosive disease and TNF-alpha, IL10 gene polymorphisms. In addition, when combined genotypes were analyzed, no significant difference was found between RA patients and healthy controls. Our findings suggest that IL-10 1082 G/A polymorphism or GCC, ACC haplotypes may be associated with RA in Turkish patients.     

Tumor necrosis factor-alpha (TNF-alpha) converting enzyme contributes to production of TNF-alpha in synovial tissues from patients with rheumatoid arthritis

OBJECTIVE: Expression and function of tumor necrosis factor-alpha (TNF-alpha) converting enzyme (TACE) in synovia of patients with rheumatoid arthritis (RA) were examined to investigate posttranslational regulation of TNF-alpha production by TACE in RA. METHODS: Expression of TACE protein was evaluated by immunohistochemistry. Cytokines and soluble cytokine receptors were measured by ELISA. TACE mRNA was detected by RT-PCR. The enzymatic activity of TACE was measured using TACE-specific fluorogenic substrate. RESULTS: Expression of TACE at protein level in synovial tissue (ST) of patients with RA was significantly stronger than that of patients with osteoarthritis (OA). In RA, TACE was mainly expressed in CD68+ macrophage-like synovial cells. ST from 9 of 9 RA and 3 of 8 OA patients expressed TACE mRNA. RA ST cells possessed significantly higher TACE-like enzymatic activity than OA ST. A synthetic TACE inhibitor significantly reduced the release of TNF-alpha and p75 TNF receptor from RA ST cells. CONCLUSION: TACE is an important regulator of the secretion of TNF-alpha from synovia of patients with RA.     

Tumor necrosis factor-alpha receptor II polymorphism in patients from southern Europe with mild-moderate and severe rheumatoid arthritis

OBJECTIVE: To define the frequency of the exon 6 tumor necrosis factor-alpha (TNF-alpha) receptor II (TNFRII) gene polymorphism in severe and mild-moderate rheumatoid arthritis (RA) and its possible influence on anti-TNF-alpha treatment responsiveness. METHODS: Two cohorts of patients with RA, the first (n = 97) defined as methotrexate responders (MTX-R) with mild-moderate synovitis, and the second (n = 78) defined as nonresponders to combination therapy and receiving anti-TNF-alpha treatment because of their severe and aggressive disease (TNF-T), were studied retrospectively and compared to age, sex, and ethnically matched controls (n = 84). In the prospective study, 66 patients with severe RA were followed over the first 6 months of anti-TNF-alpha therapy and their response was examined according to genotype. RESULTS: We observed a trend towards an increased frequency of the GG genotype in patients with severe RA (6.4%) in comparison with patients with mild-moderate disease (3.1%) and controls (1.2%). When looking at the response to anti-TNF-alpha therapy, we observed that after 12 weeks of treatment, 37.8% of the TT versus 10.7% of the TG/GG patients passed from high to medium-low disease activity (p = 0.03). CONCLUSION: In our cohorts of patients selected by response to the conventional therapy and by disease severity, our preliminary study results showed a trend towards a higher prevalence of the GG genotype for the exon 6 TNFRII polymorphism in the less responsive patients with more aggressive disease. We also found a lower degree of response to anti-TNF-alpha treatments in patients carrying the G allele.     

Tumor necrosis factor-alpha gene promoter polymorphism is not associated with smoking-related COPD in Thailand

OBJECTIVE: Susceptibility to COPD is, in part, genetically determined. Tumour necrosis factor (TNF)-alpha gene promoter polymorphisms have been investigated in different populations with inconsistent results. This study aimed to determine the genetic predisposition in Thai smoking-related COPD patients. METHODOLOGY: The polymorphism at position -308 of the TNF-alpha gene promoter was examined in 57 patients with smoking-related COPD, 67 smoker control subjects, and 116 control anonymous blood donors. Genomic DNA from peripheral blood lymphocytes was used for genotypic analysis by polymerase chain reaction with sequence specific primers. RESULTS: TNF-alpha-308*2 allele frequency was not significantly different between the population control subjects and the smoking-related COPD patients (4.7% vs. 7.9%, P= 0.14). This allele frequency was also not significantly different between smokers with and without COPD (7.9% vs. 7.5%, P= 0.46). CONCLUSIONS: Although it has been speculated that TNF-alpha might have a causal relationship with COPD, a role for the TNF-alpha gene promoter polymorphism in disease development in Thailand was not demonstrated.     

Tumor necrosis factor-alpha inhibitor associated ulcerative colitis

BACKGROUND: Flares or onset of inflammatory bowel disease in association with immunosuppression has been reported in the literature. METHODS: We studied 4 cases of patients with rheumatic disease who developed or had a flare of ulcerative colitis either after initiation of or while taking a tumor necrosis factor-alpha inhibitor. RESULTS: We identified 4 patients, three male and one female. Two of the male patients had a seronegative spondyloarthropathy and one had rheumatoid arthritis. The female patient had amyopathic dermatomyositis. Two of the 4 patients had ulcerative colitis prior to tumor necrosis factor-alpha treatment. Both of these patients had quiescent ulcerative colitis that flared after they began taking etanercept. Two patients developed de novo ulcerative colitis while taking a tumor necrosis factor-alpha inhibitor. CONCLUSIONS: The data presented in these 4 cases supports a temporal relationship between initiating a tumor necrosis factor-alpha inhibitor and onset or flare of ulcerative colitis. These observations raise the possibility that tumor necrosis factor-alpha inhibitor therapy, which has been used as treatment for inflammatory bowel disease, may rarely be a factor in the development of disease.     

Protein biomarker analysis by mass spectrometry in patients with rheumatoid arthritis receiving anti-tumor necrosis factor-alpha antibody therapy

OBJECTIVE: To investigate the mechanism of action of anti-tumor necrosis factor-alpha (TNF-alpha) antibody in patients with rheumatoid arthritis (RA), we analyzed serum or plasma proteins by mass spectrometry system. METHODS: Ten RA patients who received treatment with anti-TNF-alpha antibody were studied. Samples obtained before and after therapy were analyzed by a two-dimensional liquid chromatography tandem mass spectrometry (2D LC-MS/MS) system after pretreatment by a recently developed method to remove high molecular weight proteins. RESULTS: Using this system, certain proteins were identified after treatment with anti-TNF-alpha antibody, including proteins related to the TNF-alpha-mediated pathway for nuclear factor kappa B (NF-kappaB) activation and/or to the metabolism (including regeneration) of articular cartilage. CONCLUSION: Our mass spectrometry system appears to be useful for proteomic analysis. The efficacy of anti-TNF-alpha antibody therapy for RA may be related to various consequence of the inhibition of TNF-alpha activity.     

GITRL is associated with increased autoantibody production in patients with rheumatoid arthritis

The study aimed to determine the serum level of glucocorticoid-induced tumor necrosis factor receptor family-related protein ligand (GITRL) in patients with rheumatoid arthritis (RA) and investigate its clinical significance. GITRL levels were measured by enzyme-linked immunosorbent assay (ELISA) in 88 RA patients, 20 osteoarthritis (OA) patients, and 20 healthy controls (HCs). Anti-cyclic citrullinated peptide (anti-CCP) antibodies and rheumatoid factor immunoglobulin G (RF-IgG) were also tested by ELISA. RF-IgM, anti-keratin antibody (AKA), and anti-perinuclear factor (APF) antibodies and the erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and immunoglobulins were measured by standard laboratory techniques. The disease activity was evaluated by the 28-joint count Disease Activity Score (DAS28). GITRL concentrations were significantly elevated in both serum and synovial fluid (SF) of RA patients. GITRL levels in RA sera were significantly higher than those in matched SFs. Positive correlations were found between serum GITRL levels and inflammation parameters or autoantibody production. GITRL levels are significantly elevated in RA serum and SF and are positively correlated with autoantibody production in RA, suggesting a role of GITRL in the development of RA.     

Anti-tumor necrosis factor-alpha blockade improves insulin resistance in patients with rheumatoid arthritis

OBJECTIVE: Systemic inflammation, insulin resistance, and endothelial dysfunction have been implicated in the development of cardiovascular disease in rheumatoid arthritis (RA). Since insulin resistance can promote endothelial dysfunction and anti-TNF-alpha blockade yield a rapid improvement of endothelial function, we have sought to assess whether TNF-alpha blockade may also result in a reduction of insulin serum levels and improvement of insulin resistance in RA patients who require this therapy because of severe and refractory disease. METHODS: We recruited patients with RA seen over a period of 1 month at Hospital Xeral-Calde, Lugo, Spain, that were on treatment with anti-TNF-alpha monoclonal antibody-infliximab. Patients with diabetes mellitus or plasma glucose > 110 mg/dl were excluded. Fasting blood samples were taken for determination of plasma glucose and serum insulin levels immediately prior to and after infliximab infusion. RESULTS: Twenty-seven RA patients (21 women; mean age: 57.1 years; mean DAS28: 4.43) fulfilled the inclusion criteria. Dramatic reduction in the serum insulin levels and insulin/glucose index was observed following infliximab infusion. Also, a significant improvement of insulin resistance and insulin sensitivity was found. CONCLUSION: Our study confirms a rapid beneficial effect of infliximab on insulin resistance and insulin sensitivity in RA patients treated periodically with this drug. It may support the long-term use of drugs that act blocking TNF-alpha function to reduce the mechanisms implicated in the development of atherosclerosis in patients with RA.     

Tumor necrosis factor-alpha haplotype is strongly associated with bone mineral density in patients with Crohn's disease

BACKGROUND AND AIM: There is limited consensus on the major variables that determine bone integrity and bone loss in patients with Crohn's disease. Twin and family studies in the general population indicate that up to 85% of variance in bone mineral density is inherited. The aim was to determine the prevalence of bone loss and both molecular and clinical risk factors for bone loss in a large Crohn's disease population. METHODS: This was a cross-sectional study of 304 patients with Crohn's disease attending the Inflammatory Bowel Disease unit at Royal Brisbane and Women's Hospital, Queensland. The results of bone density testing were ascertained directly and by a mailed questionnaire. Bone mineral density data were combined with clinical information and correlated with single nucleotide polymorphisms within the tumor necrosis factor-alpha (TNF-alpha), interleukin-10, and NOD2/CARD15 genes. RESULTS: Of 304 Crohn's disease patients, 101 had undergone previous bone density testing. Forty-five patients (45%) had been diagnosed with osteopenia and 18 (18%) were osteoporotic. After multivariate analysis, both the TNF-alpha GT haplotype and the -857 CC genotype showed strong associations with bone mineral density overall (P = 0.003 and P = 0.002, respectively). Body mass index (P = 0.01) and previous bowel resection in female patients (P = 0.03) were predictive of a higher spine bone density, while body mass index (P = 0.003) and the effect of years since first bowel resection (P = 0.02) remained independent predictors of proximal femur bone mineral density. There were no other significant associations observed. CONCLUSIONS: This study has identified a novel protective association between a TNF-alpha haplotype and bone mineral density in Crohn's disease. It confirms the important influence of body mass index and intestinal resection on bone loss in this population.