Browse

Search for: rheumatoid arthritis    methotrexate    autoimmune disease    biomarker    gene expression    GWAS    HLA genes    non-HLA genes   

ID PMID Title PublicationDate abstract
21278072 Rituximab infusion-related adverse event rates are lower in patients with systemic lupus e 2011 Jun OBJECTIVES: Rituximab (RTX) is a therapeutic option for patients with SLE or RA. We conducted a prospective, longitudinal, observational study to compare rates of RTX-related adverse events (AEs) in these two patient groups. METHODS: RTX was used in 23 patients with SLE that was refractory to conventional therapy and in 31 patients with RA that had been unsuccessfully treated with TNF-α inhibitors. Infusion-related and infectious AE rates were calculated for each group. RESULTS: Seven (22.5%) RA patients experienced an infusion-related reaction. These AEs involved 7/91 (7.7%) infusions administered in the RA group. None of the 102 infusions administered to SLE patients was associated with infusion-related AEs (P = 0.038 vs RA group). The mean daily glucocorticoid dose administered during the week preceding RTX treatment in the SLE group was higher than that for the RA group [0.25 (0.2) vs 0.18 (0.14) mg/kg, P = not significant] and significantly higher than that received by the subgroup of the seven RA patients who experienced infusion-related AEs [0.10 (0.02) mg/kg; P = 0.0017]. Infectious AE rates were also lower (but not significantly so) in the SLE group (8.7 vs 12.9% in RA). CONCLUSIONS: Repeated cycles of RTX in combination with different immunosuppressants is a safe therapeutic option for SLE and RA patients. The lower incidence of infusion-related AEs in the SLE patients might reflect the higher dosage glucocorticoid therapy they received during the week before RTX infusion.
21690185 Safety of anti-tumour necrosis factor agents in patients with chronic hepatitis C infectio 2011 Sep OBJECTIVES: To identify all of the patients affected by chronic hepatitis C infection treated with TNF-α blockers (adalimumab, certolizumab pegol, etanercept, golimumab and infliximab) in order to evaluate the safety profile. METHODS: A systematic review of the literature from January 1990 to October 2010. RESULTS: In total, 37 publications with data on 153 patients who were treated with anti-TNF-α agents in the setting of HCV infection were found. The mean anti-TNF-α treatment duration was 11.9 months. Ninety-one patients had RA, 22 had psoriasis, 6 had Crohn's disease and 14 patients had other chronic inflammatory diseases. To date, etanercept is the biological agent that has been most extensively used in the patients with HCV infection, with only one definitely confirmed case of HCV hepatitis worsening and five suspected cases (elevation of transaminases not associated with an increase in the HCV viral load and vice versa) in 110 treated patients. Treatment with this agent resulted in stable levels of liver transaminases and a stable viral load in 74 patients, with an improvement in HCV chronic liver disease in combination with IFN-ribavirin therapy in 29 patients. CONCLUSIONS: The safety profile of anti-TNF-α agents in the setting of HCV infection seems to be acceptable, even if differences in the hepatotoxic profile are apparent between different agents. In the absence of long-term and large, controlled clinical trials a definitive statement on the safety of anti-TNF-α therapies in the setting of chronic HCV infection cannot be made.
22379953 Changes in utilization and costs for patients with rheumatoid arthritis, 1997 to 2006. 2012 Apr BACKGROUND: Rheumatoid arthritis (RA) is a chronic autoimmune disease that often results in joint pain, inflammation and bone erosions. Perhaps the most notable change in RA treatment during the last decade is the advent of biologics, and, in particular, anti-tumour necrosis factor agents. Given these advances, it is useful to assess how healthcare and work-loss costs of patients with RA have changed. OBJECTIVE: Our objective was to assess changes in healthcare utilization and costs from 1997 to 2006 for patients diagnosed with RA. METHODS: Two cohorts (1997 and 2006) of patients with RA and matched controls were identified from two administrative claims databases along with subsamples of employed patients and matched controls. The analysis focused on the more homogeneous employee subsample. We compared annual excess co-morbidity rates, resource utilization and healthcare and work-loss costs per patient between the 1997 (n = 279) and 2006 cohorts (n = 837) with difference-in-differences methodology. Results with p < 0.05 were considered statistically significant. RESULTS: In the employee subsample, there were no statistically significant differences in the excess prevalence of non-RA co-morbidities or Charlson Co-morbidity Index results, except for cardiovascular disease, which decreased by 11.1%. Excess number of ED visits and days hospitalized decreased by 1.1 visits/patient and 0.9 days/patient, respectively, while rheumatologist visits increased by 0.9 visits/patient. Excess per-patient direct costs were unchanged. However, drug costs increased by $US633/patient, but medical costs decreased by $US618/patient (not significant) [year 2006 values]. CONCLUSION: For employed patients with RA, there were significant reductions in per-patient excess hospital days, as well as ED visits, and no changes in excess total direct costs over time. New treatments introduced during the study period may be associated with cost savings that offset changes in employee utilization of drug and medical services. In addition, the reductions in excess ED visits and hospital days suggest improvements in patient quality of life.
22661088 TLR5, a novel and unidentified inflammatory mediator in rheumatoid arthritis that correlat 2012 Jul 1 The innate immune system plays an important role in rheumatoid arthritis (RA) pathogenesis. Previous studies support the role of TLR2 and 4 in RA and experimental arthritis models; however, the regulation and pathogenic effect of TLR5 is undefined in RA. In this study, we show that TLR5 is elevated in RA and osteoarthritis ST lining and sublining macrophages and endothelial cells compared with normal individuals. Furthermore, expression of TLR5 is elevated in RA synovial fluid macrophages and RA peripheral blood monocytes compared with RA and normal peripheral blood in vitro-differentiated macrophages. We also found that TLR5 on RA monocytes is an important modulator of TNF-α in RA synovial fluid and that TLR5 expression on these cells strongly correlates with RA disease activity and TNF-α levels. Interestingly, TNF-α has a feedback regulation with TLR5 expression in RA monocytes, whereas expression of this receptor is regulated by IL-17 and IL-8 in RA macrophages and fibroblasts. We show that RA monocytes and macrophages are more responsive to TLR5 ligation compared with fibroblasts despite the proinflammatory response being mediated through the same signaling pathways in macrophages and fibroblasts. In conclusion, we document the potential role of TLR5 ligation in modulating transcription of TNF-α from RA synovial fluid and the strong correlation of TLR5 and TNF-α with each other and with disease activity score in RA monocytes. Our results suggest that expression of TLR5 may be a predictor for RA disease progression and that targeting TLR5 may suppress RA.
21071479 Ultrasound Doppler measurements predict success of treatment with anti-TNF-α drug in 2011 Mar OBJECTIVE: To investigate the predictive ability of core outcomes applied in RA trials, including ultrasound (US) Doppler (USD) measurements differentiating patients who remain on anti-TNF-α therapy following 1 year. METHODS: Patients with RA in anti-TNF-α therapy were followed 1 year after therapy initiation. All patients had wrist involvement. At baseline, 2 weeks, 26 weeks and 1 year a USD examination, clinical examination including tender and swollen joint count, visual analogue scale (VAS) global and HAQ, biochemical measures and 28-joint DAS (DAS28) were collected for all patients. The amount of USD signal in the synovium was quantified by measuring the percentage of colour pixels-the colour fraction (CF). Predictive validity for patients who remain on anti-TNF-α therapy after 1 year was assessed for both USD measurements and other disease measures. Baseline values of disease measures of patients who remained on treatment after 1 year was compared with those who stopped therapy. RESULTS: The study cohort consisted of 109 patients. In this study, the baseline CF was the only measure predicting which patients would stay on the initial anti-TNF-α therapy for 1 year, evaluated using the square-root of CF (P = 0.024). The other disease markers could not significantly differentiate between the two groups of patients, with P-values of 0.86 and 0.98 for tender and swollen joint count, respectively, 0.86 for CRP, 0.24 for VAS, 0.10 for HAQ and 0.38 for DAS28. CONCLUSION: There is now evidence to support that baseline USD, in contrast to clinical measures, can predict which patients will remain on anti-TNF-α 1 year after initiating therapy.
21607292 Restoring the balance of the autonomic nervous system as an innovative approach to the tre 2011 Sep The immunomodulatory effect of the autonomic nervous system has raised considerable interest over the last decades. Studying the influence on the immune system and the role in inflammation of the sympathetic as well as the parasympathetic nervous system not only will increase our understanding of the mechanism of disease, but also could lead to the identification of potential new therapeutic targets for chronic immune-mediated inflammatory diseases, such as rheumatoid arthritis (RA). An imbalanced autonomic nervous system, with a reduced parasympathetic and increased sympathetic tone, has been a consistent finding in RA patients. Studies in animal models of arthritis have shown that influencing the sympathetic (via α- and β-adrenergic receptors) and the parasympathetic (via the nicotinic acetylcholine receptor α7nAChR or by electrically stimulating the vagus nerve) nervous system can have a beneficial effect on inflammation markers and arthritis. The immunosuppressive effect of the parasympathetic nervous system appears less ambiguous than the immunomodulatory effect of the sympathetic nervous system, where activation can lead to increased or decreased inflammation depending on timing, doses and kind of adrenergic agent used. In this review we will discuss the current knowledge of the role of both the sympathetic (SNS) and parasympathetic nervous system (PNS) in inflammation with a special focus on the role in RA. In addition, potential antirheumatic strategies that could be developed by targeting these autonomic pathways are discussed.
22729670 Evaluation of content on EQ-5D as compared to disease-specific utility measures. 2013 May PURPOSE: The goal of this study was to appraise the extent of unique content on disease-specific preference-based measures (DSPMs) when contrasted with the EQ-5D using published studies and to inform whether EQ-5D could be inadequate as a utility measure in its content coverage for a given disease-specific application. METHODS: A structured search of published literature was performed using PubMed and EMBASE/Medline database from Jan 1, 1990 to Mar 31, 2011. Articles were eligible for inclusion if algorithms were developed to convert components from disease-specific measures into utility scores. RESULTS: Of 1,029 articles identified, 50 studies satisfied the inclusion criteria. The most frequent conditions where DSPMs were developed included cancer (12 studies), coronary artery disease (4 studies), osteoarthritis, rheumatoid arthritis (3 studies of each), obesity, and stroke (2 studies of each). Most studies involved mapping items or scores from disease-specific non-preference-based measures onto a preference-based measure of health such as the EQ-5D. A substantial number of DSPMs appeared to include unique content not covered by EQ-5D dimensions. CONCLUSIONS: Several conditions were identified as potential areas where the richness of the EQ-5D descriptive system could be enhanced. It is yet unclear whether added dimension(s) would contribute unique explained variance to a utility score. Given the resources required to rigorously develop a utility measure, the need for such measures should be carefully vetted.
21794776 [Anti-transglutaminase, antigladin and ultra purified anti-gladin antibodies in patients w 2011 Jan Celiac disease (CD) is an enteric disease caused by dietary gluten in individuals with genetic predisposition. One of the clinical manifestations of CD is the peripheral arthritis that may simulate RA. OBJECTIVE: To determine the frequency of anti-gliadin (aGL), anti-tissue transglutaminase (aTGT) and ultra purified anti-gliadin (AGLU) antibodies in patients with RA. METHODS: Cross-sectional study. We included consecutive patients diagnosed as RA (ACR). Demographic and clinical data was registered by direct interview and serum levels of aGL, aTGT y aGLU were determined using ELISA. RESULTS: Eighty-five RA patients were included; 87% were women. Mean age was 44±12 years, mean disease duration 12 ±9 years. aGL IgG antibodies were positive in 16 patients, IgA aGL antibodies in 29 patients, aGLU in 14 patients and only one patient had aTGT. CONCLUSIONS: It is possible that CD may be the correct diagnosis in a patient with polyarthritis, even if the patient meets the ACR criteria for RA. In other words, CD should be considered among the differential diagnoses in a patient with poly-arthritis.
22353730 Regulation of inflammatory arthritis by the upstream kinase mitogen activated protein kina 2012 Feb 21 INTRODUCTION: The c-Jun N-terminal kinase (JNK) is a key regulator of matrix metalloproteinase (MMP) and cytokine production in rheumatoid arthritis (RA) and JNK deficiency markedly protects mice in animal models of arthritis. Cytokine-induced JNK activation is strictly dependent on the mitogen-activated protein kinase kinase 7 (MKK7) in fibroblast-like synoviocytes (FLS). Therefore, we evaluated whether targeting MKK7 using anti-sense oligonucleotides (ASO) would decrease JNK activation and severity in K/BxN serum transfer arthritis. METHODS: Three 2'-O-methoxyethyl chimeric ASOs for MKK7 and control ASO were injected intravenously in normal C57BL/6 mice. PBS, control ASO or MKK7 ASO was injected from Day -8 to Day 10 in the passive K/BxN model. Ankle histology was evaluated using a semi-quantitative scoring system. Expression of MKK7 and JNK pathways was evaluated by quantitative PCR and Western blot analysis. RESULTS: MKK7 ASO decreased MKK7 mRNA and protein levels in ankles by about 40% in normal mice within three days. There was no effect of control ASO on MKK7 expression and MKK7 ASO did not affect MKK3, MKK4 or MKK6. Mice injected with MKK7 ASO had significantly less severe arthritis compared with control ASO (P < 0.01). Histologic evidence of synovial inflammation, bone erosion and cartilage damage was reduced in MKK7 ASO-treated mice (P < 0.01). MKK7 deficiency decreased phospho-JNK and phospho-c-Jun in ankle extracts (P < 0.05), but not phospho-MKK4. Interleukin-1beta (IL-1β), MMP3 and MMP13 gene expression in ankle joints were decreased by MKK7 ASO (P < 0.01). CONCLUSIONS: MKK7 plays a critical regulatory role in the JNK pathway in a murine model of arthritis. Targeting MKK7 rather than JNK could provide site and event specificity when treating synovitis.
22685579 CD6 and syntaxin binding protein 6 variants and response to tumor necrosis factor alpha in 2012 BACKGROUND: TNFα inhibitor therapy has greatly improved the treatment of patients with rheumatoid arthritis, however at least 30% do not respond. We aimed to investigate insertions and deletions (INDELS) associated with response to TNFα inhibitors in patients with rheumatoid arthritis (RA). METHODOLOGY AND PRINCIPAL FINDINGS: In the DANBIO Registry we identified 237 TNFα inhibitor naïve patients with RA (81% women; median age 56 years; disease duration 6 years) who initiated treatment with infliximab (n=160), adalimumab (n=56) or etanercept (n=21) between 1999 and 2008 according to national treatment guidelines. Clinical response was assessed at week 26 using EULAR response criteria. Based on literature, we selected 213 INDELS potentially related to RA and treatment response using the GeneVa® (Compugen) in silico database of 350,000 genetic variations in the human genome. Genomic segments were amplified by polymerase chain reaction (PCR), and genotyped by Sanger sequencing or fragment analysis. We tested the association between genotypes and EULAR good response versus no response, and EULAR good response versus moderate/no response using Fisher's exact test. At baseline the median DAS28 was 5.1. At week 26, 68 (29%) patients were EULAR good responders, while 81 (34%) and 88 (37%) patients were moderate and non-responders, respectively. A 19 base pair insertion within the CD6 gene was associated with EULAR good response vs. no response (OR=4.43, 95% CI: 1.99-10.09, p=7.211×10(-5)) and with EULAR good response vs. moderate/no response (OR=4.54, 95% CI: 2.29-8.99, p=3.336×10(-6)). A microsatellite within the syntaxin binding protein 6 (STXBP6) was associated with EULAR good response vs. no response (OR=4.01, 95% CI: 1.92-8.49, p=5.067×10(-5)). CONCLUSION: Genetic variations within CD6 and STXBP6 may influence response to TNFα inhibitors in patients with RA.
23261300 Rare, low-frequency, and common variants in the protein-coding sequence of biological cand 2013 Jan 10 The extent to which variants in the protein-coding sequence of genes contribute to risk of rheumatoid arthritis (RA) is unknown. In this study, we addressed this issue by deep exon sequencing and large-scale genotyping of 25 biological candidate genes located within RA risk loci discovered by genome-wide association studies (GWASs). First, we assessed the contribution of rare coding variants in the 25 genes to the risk of RA in a pooled sequencing study of 500 RA cases and 650 controls of European ancestry. We observed an accumulation of rare nonsynonymous variants exclusive to RA cases in IL2RA and IL2RB (burden test: p = 0.007 and p = 0.018, respectively). Next, we assessed the aggregate contribution of low-frequency and common coding variants to the risk of RA by dense genotyping of the 25 gene loci in 10,609 RA cases and 35,605 controls. We observed a strong enrichment of coding variants with a nominal signal of association with RA (p < 0.05) after adjusting for the best signal of association at the loci (p(enrichment) = 6.4 × 10(-4)). For one locus containing CD2, we found that a missense variant, rs699738 (c.798C>A [p.His266Gln]), and a noncoding variant, rs624988, reside on distinct haplotypes and independently contribute to the risk of RA (p = 4.6 × 10(-6)). Overall, our results indicate that variants (distributed across the allele-frequency spectrum) within the protein-coding portion of a subset of biological candidate genes identified by GWASs contribute to the risk of RA. Further, we have demonstrated that very large sample sizes will be required for comprehensively identifying the independent alleles contributing to the missing heritability of RA.
21963744 Leukoencephalopathy induced by low-dose methotrexate in a patient with rheumatoid arthriti 2011 We report a patient with rheumatoid arthritis (RA) who developed leukoencephalopathy while being treated with low-dose methotrexate (MTX). She suddenly developed loss of recent memory and left homonymous hemianopsia ascribable to the bilateral but right-predominant occipitotemporal lesions. Intravenous administration of dexamethasone and cessation of MTX quickly relieved her clinical symptoms. Low-dose MTX-induced leukoencephalopathy is a rare complication in RA, but is important with regard to the possibility of serious neurological sequellae.
21833894 [Stem cell treatment of autoimmune disease]. 2011 Aug Over 1,500 patients world wide have received a hematopoietic stem cell transplant (HSCT) as treatment for a severe autoimmune disease. Most of these have been autologous and mostly have occurred in the past 15 years. Over 1,000 of these have been registered in the European Group for Bone Marrow Transplantation (EBMT) and European League Against Rheumatism (EULAR) combined data base. A recent retrospective analysis of 900 patients (1) showed that the majority had multiple sclerosis (n = 345) followed by systemic sclerosis (n = 175), systemic lupus erythematosus (n = 85), rheumatoid arthritis (n = 89), juvenile idiopathic arthritis (n = 65) and idiopathic cytopenic purpura (n = 37). An overall 85 % 5-year-survival and 43 % progression-free survival was seen, with 100-day-transplant-related-mortality (TRM) ranging between 1 % (rheumatoid arthritis) and 11 % (systemic lupus erythematosus and juvenile idiopathic arthritis). Around 30 % of patients in all disease subgroups had a complete response, often durable despite full immune reconstitution. In many, e. g. systemic sclerosis, morphological improvement such as reduction of skin collagen and normalisation of microvasculature was documented, beyond any predicted known effects of intense immunosuppression alone. The high TRM was in part related to conditioning intensity, comorbidity and age, and the final risk/benefit assessment will be made after the results of the three randomised propective clinical trials are known. [nl]Recently, multipotent mesenchymal stromal cells have been tested in various autoimmune diseases, exploiting their immune modulating properties and apparent low acute toxicity. Despite encouraging small phase I/II studies, no positive data from randomised, prospective studies are as yet available in the peer reviewed literature.
23212592 Clinical characteristics and risk factors for Pneumocystis jirovecii pneumonia in patients 2013 Nov OBJECTIVES: To investigate the clinical characteristics and risk factors of Pneumocystis jirovecii pneumonia (PCP) in rheumatoid arthritis (RA) patients treated with adalimumab. METHODS: We conducted a multicenter, retrospective, case-control study to compare RA patients treated with adalimumab with and without PCP. Data from 17 RA patients who were diagnosed with PCP and from 89 RA patients who did not develop PCP during adalimumab treatment were collected. RESULTS: For the PCP patients, the median age was 68 years old, with a median RA disease duration of eight years. The median length of time from the first adalimumab injection to the development of PCP was 12 weeks. At the onset of PCP, the median dosages of prednisolone and methotrexate were 5.0 mg/day and 8.0 mg/week, respectively. The patients with PCP were significantly older (p < 0.05) and had more structural changes (p < 0.05) than the patients without PCP. Computed tomography of the chest revealed ground-glass opacity without interlobular septal boundaries in the majority of the patients with PCP. Three PCP patients died. CONCLUSIONS: PCP may occur early in the course of adalimumab therapy in patients with RA. Careful monitoring, early diagnosis, and proper management are mandatory to secure a good prognosis for these patients.
23099285 Safety profile of biological intravenous therapy in a rheumatoid arthritis patients cohort 2013 Mar INTRODUCTION: The Biologics used in the management of rheumatoid arthritis (RA) in recent years, have comprehensively permitted to understand its security, as shown in registries such as BIOBADASER. The present manuscript represents an observational cohort study to describe the safety perinfusional profile of those intravenous treatments. OBJECTIVES: To confirm the safety profile of biological therapies in routine clinical practice, after the administration of intravenous drugs and 24 hours post-administration. MATERIAL AND METHODS: We evaluated a cross-sectional cohort of 114 patients with RA (according to the American College of Rheumatology ACR criteria), attending within one month in 2009 the nursing clinics of day care hospital of 12 Catalonian hospitals. All patients were treated with intravenous biological agents. We recorded the age, sex, current and previous drug treatments, we also collected data about previous vaccination and premedication received and any adverse event occurring at the time of drug administration or within 24 hours. If an adverse event occurred, was categorized by MedDRAv11.0 International Dictionary, and categorized in terms of intensity (mild, moderate, severe), relationship to drug administration according to Karch and Lasagna algorithm (unrelated, unlikely, possible, probable, definite) and the further measures taken. RESULTS: 111 patients met the inclusion criteria, with a mean age of 56.06 years (SD: 12.12), 90 of them women (81.1%) and mean time since diagnosis of the disease of 11.97 years (SD: 7.95). 24 patients (21.6%) had a history of allergy. 12 adverse events were observed in 7 patients, 9 of which at the time of administration and 3 in 24 hours after. There were no serious adverse events and only one of the adverse events (AEs) was rated as moderate (urticaria). The remaining AA were mild.
21719043 Evaluation of liver fibrosis by transient elastography in methotrexate treated patients. 2011 Nov 26 BACKGROUND AND AIMS: Methotrexate (MTX) safety is questioned by the risk of inducing liver fibrosis (LF). As transient elastography (FibroScan®) is an effective non-invasive technique to evaluate LF, our aims were to assess LF in MTX-treated patients, to evaluate LF regarding treatment duration and cumulative dose, and to determine differences depending on the underlying disease. PATIENTS AND METHODS: Prospective study including patients with rheumatoid arthritis, inflammatory bowel disease, and psoriasis treated with MTX. Hepatic stiffness was determined by FibroScan®. The LF cut-off values were established using METAVIR score. RESULTS: Of 53 patients, 22 were men (41.5%), mean age was 55 (15) years, 17 (32%) had rheumatoid arthritis, 18 (34%) inflammatory bowel disease, and 18 (34%) psoriasis. Mean MTX cumulative dose was 1,805 (1,560) mg, and mean treatment duration was 178 weeks. Mean hepatic stiffness was 6.19 (2.43) KPa. In 49 patients (92.5%), absence/mild LF was found (F ≤ 2), and 4 patients (7.5%) had advanced LF (F ≥ 3). Treatment duration or cumulative doses of MTX were not associated with LF. CONCLUSIONS: Regarding LF development, MTX therapy is safe. FibroScan® is useful for monitoring LF in MTX-treated patients.
22280353 Kruppel-like factor 2 (KLF2) regulates monocyte differentiation and functions in mBSA and 2012 Feb Kruppel-like factor 2 (KLF2) plays an important role in the regulation of a variety of immune cells, including monocytes. We have previously shown that KLF2 inhibits proinflammatory activation of monocytes. However, the role of KLF2 in arthritis is yet to be investigated. In the current study, we show that recruitment of significantly greater numbers of inflammatory subset of CD11b(+)F4/80(+)Ly6C+ monocytes to the inflammatory sites in KLF2 hemizygous mice compared to the wild type littermate controls. In parallel, inflammatory mediators, MCP-1, Cox-2 and PAI-1 were significantly up-regulated in bone marrow-derived monocytes isolated from KLF2 hemizygous mice, in comparison to wild-type controls. Methylated-BSA and IL-1β-induced arthritis was more severe in KLF2 hemizygous mice as compared to the littermate wild type controls. Consistent with this observation, monocytes isolated from KLF2 hemizygous mice showed an increased number of cells matured and differentiated towards osteoclastic lineage, potentially contributing to the severity of cartilage and bone damage in induced arthritic mice. The severity of arthritis was associated with the higher expression of proteins such as HSP60, HSP90 and MMP13 and attenuated levels of pPTEN, p21, p38 and HSP25/27 molecules in bone marrow cells of arthritic KLF2 hemizygous mice compared to littermate wild type controls. The data provide new insights and evidences of KLF2-mediated transcriptional regulation of arthritis via modulation of monocyte differentiation and function.
22536334 A genome-wide homozygosity association study identifies runs of homozygosity associated wi 2012 Rheumatoid arthritis (RA) is a chronic inflammatory disorder with a polygenic mode of inheritance. This study examined the hypothesis that runs of homozygosity (ROHs) play a recessive-acting role in the underlying RA genetic mechanism and identified RA-associated ROHs. Ours is the first genome-wide homozygosity association study for RA and characterized the ROH patterns associated with RA in the genomes of 2,000 RA patients and 3,000 normal controls of the Wellcome Trust Case Control Consortium. Genome scans consistently pinpointed two regions within the human major histocompatibility complex region containing RA-associated ROHs. The first region is from 32,451,664 bp to 32,846,093 bp (-log10(p)>22.6591). RA-susceptibility genes, such as HLA-DRB1, are contained in this region. The second region ranges from 32,933,485 bp to 33,585,118 bp (-log10(p)>8.3644) and contains other HLA-DPA1 and HLA-DPB1 genes. These two regions are physically close but are located in different blocks of linkage disequilibrium, and ∼40% of the RA patients' genomes carry these ROHs in the two regions. By analyzing homozygote intensities, an ROH that is anchored by the single nucleotide polymorphism rs2027852 and flanked by HLA-DRB6 and HLA-DRB1 was found associated with increased risk for RA. The presence of this risky ROH provides a 62% accuracy to predict RA disease status. An independent genomic dataset from 868 RA patients and 1,194 control subjects of the North American Rheumatoid Arthritis Consortium successfully validated the results obtained using the Wellcome Trust Case Control Consortium data. In conclusion, this genome-wide homozygosity association study provides an alternative to allelic association mapping for the identification of recessive variants responsible for RA. The identified RA-associated ROHs uncover recessive components and missing heritability associated with RA and other autoimmune diseases.
22720388 A technique for motion capture of the finger using functional joint centres and the effect 2012 May A method of kinematic analysis of the fingers using stereo-photogrammetry, referred to as the phalanx transformation technique, has been proposed. Functional methods were used to define the joint axes and subsequently each finger segments' anatomical coordinate system. Thirteen subjects were tested and the accuracy of the technique assessed. The average error across the three joints of the finger was found to be 0.6 mm, which translates to a 2.2% error in predicted joint reaction force when using a biomechanical model. The subjects were required to have sufficient movement in their joints to define the joint axes functionally. Some subjects of clinical interest can have a significantly reduced mobility owing to injury or pathology, therefore, the effect of calibration range of motion on accuracy was analysed. It was found that, for a range of motion typical of a subject with rheumatoid arthritis, the errors in predicted joint reaction force were < 7%. The accuracy of this technique compared favourably with others previously proposed and, considering the other errors inherent in modelling, those found in this study were deemed to be acceptable.
21068383 A bifunctional role for group IIA secreted phospholipase A2 in human rheumatoid fibroblast 2011 Jan 28 Human group IIA-secreted phospholipase A(2) (sPLA(2)-IIA) is an important regulator of cytokine-mediated inflammatory responses in both in vitro and in vivo models of rheumatoid arthritis (RA). However, treatment of RA patients with sPLA(2)-IIA inhibitors shows only transient benefit. Using an activity-impaired sPLA(2)-IIA mutant protein (H48Q), we show that up-regulation of TNF-dependent PGE(2) production and cyclooxygenase-2 (COX-2) induction by exogenous sPLA(2)-IIA in RA fibroblast-like synoviocytes (FLSs) is independent of its enzyme function. Selective cytosolic phospholipase A(2)-α (cPLA(2)-α) inhibitors abrogate TNF/sPLA(2)-IIA-mediated PGE(2) production without affecting COX-2 levels, indicating arachidonic acid (AA) flux to COX-2 occurs exclusively through TNF-mediated activation of cPLA(2)-α. Nonetheless, exogenous sPLA(2)-IIA, but not H48Q, stimulates both AA mobilization from FLSs and microparticle-derived AA release that is not used for COX-2-dependent PGE(2) production. sPLA(2)-IIA-mediated AA production is inhibited by pharmacological blockade of sPLA(2)-IIA but not cPLA(2)-α. Exogenous H48Q alone, like sPLA(2)-IIA, increases COX-2 protein levels without inducing PGE(2) production. Unlike TNF, sPLA(2)-IIA alone does not rapidly mobilize NF-κB or activate phosphorylation of p38 MAPK, two key regulators of COX-2 protein expression, but does activate the ERK1/2 pathway. Thus, sPLA(2)-IIA regulates AA flux through the cPLA(2)-α/COX-2 pathway in RA FLSs by up-regulating steady state levels of these biosynthetic enzymes through an indirect mechanism, rather than direct provision of substrate to the pathway. Inhibitors that have been optimized for their potency in enzyme activity inhibition alone may not adequately block the activity-independent function of sPLA(2)-IIA.