Browse

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

ID PMID Title PublicationDate abstract
15937633 Reproducibility of bone mineral density measurements using dual X-ray absorptiometry in da 2005 Dec Bone mineral density (BMD) measurements are frequently performed repeatedly for each patient. Subsequent BMD measurements allow reproducibility to be assessed. Previous studies have suggested that reproducibility may be influenced by age and clinical status. The purpose of the study was to examine the reproducibility of BMD by dual energy X-ray absorptiometry (DXA) and to investigate the practical value of different measures of reproducibility in three distinct groups of subjects: healthy young volunteers, postmenopausal women and patients with chronic rheumatic diseases. Two hundred twenty-two subjects underwent two subsequent BMD measurements of the spine and hip. There were 60 young healthy subjects, 102 postmenopausal women and 60 patients with chronic rheumatic diseases (33 rheumatoid arthritis, 10 ankylosing spondylitis and 10 other systemic diseases). Forty-five patients (75%) among the third group were receiving corticosteroids. Reproducibility was expressed as the smallest detectable difference (SDD), coefficient of variation (CV), least significant change (LSC) and intraclass correlation coefficient (ICC). Sources of variation were investigated by linear regression analysis. The median interval between measurements was 0 days (range 0-7). The mean difference (SD) between the measurements (g/cm2) was -0.0001 (+/-0.003) and -0.0004 (+/-0.002) at L1-L4 and the total hip, respectively. At L1-L4 and the total hip, SDD (g/cm2) was +/-0.04 and +/-0.02, CV (%) was 2.02 and 1.29, and LSC (%) 5.60 and 3.56, respectively. The ICC at the spine and hip was 0.99 and 0.99, respectively. Only a minimal difference existed between the groups. Reproducibility in the three groups studied was good. In a repeated DXA scan, a BMD change, the least significant change (LSC) or the SDD should be regarded as significant. Use of the SDD is preferable to use of the CV and LSC because of its independence from BMD and its expression in absolute units. Expressed as SDD, a BMD change of at least +/-0.04 g/cm2 at L1-L4 and +/-0.02 g/cm2 at the total hip should be considered significant. This reproducibility seems independent from age and clinical status and improved in the hips by measuring the dual femur.
15993395 Development of immunoassays for serum tartrate-resistant acid phosphatase isoform 5a. 2005 Sep BACKGROUND: Serum tartrate-resistant acid phosphatase (TRACP) consists of 2 structurally related isoforms, TRACP 5a and 5b. TRACP 5b is from bone-resorbing osteoclasts. TRACP 5a may be a macrophage product of inflammation. We used a novel antibody to TRACP 5a to standardize immunoassays for serum TRACP 5a activity and protein. METHODS: Biotinylated anti-TRACP antibodies were used to immobilize serum TRACP isoforms. TRACP activity was measured using 4-nitrophenyl phosphate as substrate. TRACP 5a protein was measured with an independent peroxidase-conjugated anti-TRACP antibody. Immunoassays were standardized for linearity of serum dose response, sensitivity and precision. Reference ranges for TRACP 5a were established from serum of 50 healthy males and 50 healthy age-matched females. Serum TRACP 5a activity and protein were determined in 29 cases of rheumatoid arthritis. RESULTS: Serum matrix interference in both TRACP 5a assays required dilution to 10% serum to approach linearity. Intra-assay and inter-assay CV% were <10%. Mean serum TRACP 5a activity and protein were significantly higher in healthy men than women. There was a slight, but significant age related increase in both serum TRACP 5a and 5b among females, but not males, from age 20 to 70 years. TRACP 5a activity was positively correlated to TRACP 5a protein in healthy sera. Neither TRACP 5a activity nor protein was correlated strongly to TRACP-5b activity. TRACP 5a protein was significantly increased in 8/29 RA sera, whereas TRACP 5a and 5b activities were not. TRACP 5a activity and protein were not significantly correlated in RA sera. CONCLUSIONS: Although TRACP 5a and 5b are related biosynthetically, their circulating levels in healthy humans were independent, suggesting differential regulation of expression. In chronic diseases, increased TRACP 5a may represent pathological processes of inflammation unrelated to bone metabolism.
16720219 Direct determination of single nucleotide polymorphism haplotype of NFKBIL1 promoter polym 2006 Apr We previously revealed that one of the human leukocyte antigen-linked susceptibility genes for Takayasu's arteritis (TA) was mapped between TNFA and MICB loci and that -63T allele of NFKBIL1, which is between TNFA and MICB loci, was associated with rheumatoid arthritis (RA) in the Japanese population. We have developed a novel typing method based on reference strand-mediated conformation analysis for the upstream sequence of the NFKBIL1 gene, where -422 (T)8/(T)9, -325 C/G, -263 A/G, and -63 T/A polymorphisms were found. Upon the analysis of the patients with TA (n = 84), those with RA (n = 120), and healthy control subjects (n = 217), five common haplotypes named IKBLp*01 through IKBLp*05 were found in the Japanese population. The frequency of IKBLp*03 was significantly increased in the patient with TA (57.1% vs 35.0%, giving an odds ratio of 2.47). In addition, the frequency of IKBLp*01, but not that of other -63T-bearing alleles, was increased in the patients with RA (73.3% vs 58.1%, giving an odds ratio of 1.99), suggesting that the susceptibility to RA was conferred not by -63T alone but by combination of single nucleotide polymorphisms in the NFKBIL1 promoter. A higher promoter activity associated with IKBLp*03 and a lower activity associated with IKBLp*01 may contribute to the susceptibility to TA and RA, respectively.
16607625 The v-MFG test: investigating maternal, offspring and maternal-fetal genetic incompatibili 2006 May The MFG test is a family-based association test that detects genetic effects contributing to disease in offspring, including offspring allelic effects, maternal allelic effects and MFG incompatibility effects. Like many other family-based association tests, it assumes that the offspring survival and the offspring-parent genotypes are conditionally independent provided the offspring is affected. However, when the putative disease-increasing locus can affect another competing phenotype, for example, offspring viability, the conditional independence assumption fails and these tests could lead to incorrect conclusions regarding the role of the gene in disease. We propose the v-MFG test to adjust for the genetic effects on one phenotype, e.g., viability, when testing the effects of that locus on another phenotype, e.g., disease. Using genotype data from nuclear families containing parents and at least one affected offspring, the v-MFG test models the distribution of family genotypes conditional on offspring phenotypes. It simultaneously estimates genetic effects on two phenotypes, viability and disease. Simulations show that the v-MFG test produces accurate genetic effect estimates on disease as well as on viability under several different scenarios. It generates accurate type-I error rates and provides adequate power with moderate sample sizes to detect genetic effects on disease risk when viability is reduced. We demonstrate the v-MFG test with HLA-DRB1 data from study participants with rheumatoid arthritis (RA) and their parents, we show that the v-MFG test successfully detects an MFG incompatibility effect on RA while simultaneously adjusting for a possible viability loss.
16602610 Fatal pulmonary Mycobacterium abscessus infection in a patient using etanercept. 2006 Jan A case of fatal pulmonary Mycobacterium abscessus infection in a 56-year-old man is reported. The patient had a longstanding history of seropositive, nodular rheumatoid arthritis with severe joint manifestations that had been treated with a regimen of prednisone, leflunomide, and etanercept. He presented to our facility with complaint of productive cough, persistent fevers, pleuritic chest discomfort, and dyspnea at rest. The patient was admitted to hospital, placed in isolation, a left-sided chest tube was inserted (left pneumothorax identified), and sputum acid-fast bacteria stains and cultures were obtained. Fluorochrome stains demonstrated numerous acid-fast bacteria, and M. abscessus was recovered from the culture media. He was treated with a regimen of amikacin, cefoxitin, and clarithromycin. He initially responded well, and was discharged home with this regimen. He remained afebrile with decreased cough and sputum production until 15 days after discharge when he was again admitted to hospital, with acute onset dyspnea and right-sided chest discomfort (right pneumothorax identified). He ultimately expired, due to overwhelming pulmonary infection, 20 days after readmission to hospital. Autopsy revealed acid fast bacilli in the setting of numerous, bilateral, necrotic, granulomatous, cavitary pulmonary lesions. Based on its mechanism of action, we propose an association between the use of etanercept, a tumor necrosis factor alpha (TNF-alpha) inhibitor, and this case of fatal pulmonary mycobacterial infection. We recommend that physicians exercise cautious clinical judgment when initiating etanercept therapy in persons with underlying lung disease, especially in communities in which mycobacterial organisms are highly prevalent. We also advise physicians to maintain a high level of vigilance for late onset granulomatous infection in persons using etanercept.
16874796 Antirheumatic drug use and the risk of acute myocardial infarction. 2006 Aug 15 OBJECTIVE: To assess the risk of acute myocardial infarction (AMI) associated with the use of disease-modifying antirheumatic drugs (DMARDs) and other medications commonly used in rheumatoid arthritis (RA). METHODS: We conducted a nested case-control analysis within a cohort of subjects with RA, observed between 1999 and 2003, identified from the PharMetrics claims database. For each first AMI hospitalization identified during followup, 10 controls matched on sex, age, and time of study entry were randomly selected from the cohort. Conditional logistic regression was used to estimate the rate ratio (RR) of AMI associated with the current use of anti-RA therapy, as measured from dispensed prescriptions, after adjustment for AMI risk factors. RESULTS: The cohort included 107,908 subjects (average age 54 years at cohort entry). During followup, 558 AMI cases occurred (3.4 per 1,000 per year). AMI rate was significantly decreased with the current use of any DMARD (adjusted RR 0.80, 95% confidence interval [95% CI] 0.65-0.98). This effect was consistent across all DMARDs, including methotrexate (RR 0.81, 95% CI 0.60-1.08), leflunomide (RR 0.28, 95% CI 0.12-0.65), and other traditional DMARDs (RR 0.67, 95% CI 0.46-0.97), but not biologic agents (RR 1.30, 95% CI 0.92-1.83). AMI rate increased with the use of glucocorticoids (RR 1.32, 95% CI 1.02-1.72) but not with nonselective nonsteroidal antiinflammatory drugs (RR 1.05, 95% CI 0.81-1.36) or cyclooxygenase 2 (COX-2) inhibitors (RR 1.11, 95% CI 0.87-1.43). CONCLUSION: DMARD use is associated with a reduction in AMI risk in patients with RA. No risk increase was found with the COX-2 inhibitors in this population.
16782032 Human 6-sulfo LacNAc-expressing dendritic cells are principal producers of early interleuk 2006 Jun Early and high-level production of IL-12 is crucial for effective immune responses against pathogens. Up until now, the cells providing this initial IL-12 have remained elusive. Here we show that a subset of human blood dendritic cells (DC) is the principal and primary source of IL-12p70 when blood leukocytes are stimulated with the TLR4-ligand LPS or with CD40-ligand. These so-called slanDC are characterized by the 6-sulfo LacNAc modification of PSGL-1, which is identified by the mAb M-DC8. The IL-12 response of slanDC requires a few hours of in vitro maturation, which is completely blocked in the presence of erythrocytes. This inhibition of maturation depends on the expression of CD47 on erythrocytes and of its ligand SIRPalpha on DC. While strictly controlled in the blood by erythrocytes, the high IL-12- and TNF-alpha-producing capacity of slanDC in tissues may be critical in fighting off pathogens; if uncontrolled, it may lead to adverse inflammatory reactions.
15634819 Impaction grafting in revision total elbow arthroplasty. 2005 Jan BACKGROUND: Revision total elbow arthroplasty is often undertaken in patients who have severe osteolysis of both the distal part of the humerus and the proximal part of the ulna. To deal with such bone loss, we have adopted the practice of impaction grafting, which has become a well-established technique in the proximal part of the femur. METHODS: We retrospectively reviewed the results of twelve patients who had undergone revision total elbow arthroplasty with impaction grafting between 1993 and 1997. There were eight women and four men with a mean age of fifty-seven years. All patients were followed for at least two years (range, twenty-five to 113 months), with an average duration of follow-up of seventy-two months. Seven of the patients had an initial diagnosis of rheumatoid arthritis, and five had posttraumatic arthritis. Impaction grafting was undertaken during the initial revision in three of the patients, whereas the remaining nine patients had undergone at least one prior revision without impaction grafting. Four patients had impaction grafting on the ulnar side alone, six had it on the humeral side alone, and two underwent impaction grafting of both the humerus and the ulna. Six allograft struts were placed to span structural defects in five patients. RESULTS: At the time of the latest follow-up, eight of the elbow prostheses were intact after the index impaction grafting procedure. Two elbows had been revised because of loosening, and another had been revised because of a fracture of the ulnar component. A fourth patient had undergone a resection arthroplasty because of infection. The eight remaining patients demonstrated marked radiographic improvement in bone quality in the region of the impaction graft without clinical symptoms of loosening. At the time of the last follow-up, after an additional revision in three elbows, there were five excellent, four good, and three fair results. CONCLUSIONS: Impaction grafting is a reliable technique for treating osteolysis in patients undergoing revision total elbow arthroplasty; however, complications can occur, and a high percentage of patients need additional surgery.
16906369 The clinical application of etanercept in Chinese patients with rheumatic diseases. 2006 Over a 2-year period, to evaluate the efficacy and safety of biologic agents, etanercept (25 mg twice per week, s.c.) was used to treat 57 rheumatoid arthritis (RA) patients, 9 ankylosing spondylitis (AS) patients, 6 psoriatic arthritis (PSA) patients, and 4 juvenile rheumatoid arthritis (JRA) patients. In addition to inflammatory arthritis, I have used this tumor necrosis factor (TNF) blocker in other rheumatic diseases including idiopathic thrombocytopenic purpura (ITP), Behçet's disease with intractable oral ulcer, fibromyalgia syndrome, and systemic lupus erythematosis with intractable pleural effusion and acute lumbar disc herniation. For RA, after 6 months of etanercept treatment, all the parameters including number of swollen joints, number of tender joints, disease activity score, erythrocyte sedimentation rate, C-reactive protein, and global health status were rapidly improved (P < 0.001 or P < 0.0001). The anticyclic citrullinated peptide (anti-CCP) antibody and rheumatoid factor also significantly declined. For spondyloarthropathy, it also gave a similar effect as to RA. Both Bath Ankylosing Spondylitis Disease Activity Index and Bath Ankylosing Spondylitis Functional Index also improved. One of the two cases with Behçet's disease with intractable oral ulcer had a long-term remission after etanercept. The other Behçet's disease patient with oral ulcer and another with ITP obtained a good response temporarily. The short-term use of etanercept (<3 months) did not bring a significant effect for cases of fibromyalgia syndrome, pleural effusion, and lumbar disc herniation. In conclusion, a dramatic and rapid clinical response in different kinds of arthritis patients can be achieved by etanercept. Moreover, the TNF-alpha inhibitor also can treat other severe rheumatic-related symptoms. In general, except for a few cases with infection and two cases with malignancy, etanercept was safe in our arthritis patients. We need to study a larger number of patients in order to better understand the efficacy and safety of etanercept.
17013442 [Ultrasonographic assessment of the response to Etanercept treatment in patients with rheu 2006 Jul OBJECTIVES: To evaluate, using musculoskeletal ultrasound (MSUS), the effects of Etanercept therapy in patients with rheumatoid arthritis (RA) over 3 months of treatment. METHODS: Eighteen consecutive patients, 3 male and 15 female, affected by RA (ACR criteria) who were non-responders or partial responders to DMARDs therapy were commenced on Etanercept treatment. MSUS was performed bilaterally in the 2nd and 5th metacarpophalangeal, 3rd interphalangeal, wrist and knee joints, using a Philips/HP Image Point HX machine with a 7,5 MHz linear probe for knee joints and a 14 MHz probe for the hands and wrists. In addition, power Doppler was used with the following settings: PRF 700-1000Hz, gain 60-65 dB, low filter. For all the changes a semi-quantitative score (0-3) was used to indicate the presence of a localised inflammatory process (synovitis, tenosynovitis). An overall score was then calculated based on the sum of the single scores in order to obtain a comprehensive score indicative of the global pathological change. RESULTS: The overall score significantly (p<10-5) reduced between T0 (8,5) and T3 (5). Even the most part of the local joint scores significantly reduced. CONCLUSIONS: A positive response to treatment with Etanercept was demonstrated by MSUS examination of several joints. The results of our study are supportive of those presented in other reports where MSUS was used to monitor disease activity. We were able however to demonstrate this in a wider range of anatomical targets than in previous studies. MSUS is a useful tool in the monitoring of biologic therapy in RA.
17121678 Impact of concomitant DMARD therapy on adherence to treatment with etanercept and inflixim 2006 The objective of this work is to compare the adherence to therapy of patients receiving etanercept and infliximab during first tumour necrosis factor (TNF)-blocking treatment course in rheumatoid arthritis. Special emphasis is placed on potential predictors for treatment termination and the impact of concomitant methotrexate (MTX) or other disease-modifying antirheumatic drugs (DMARDs). Patients (n = 1,161) with active rheumatoid arthritis, not responding to at least two DMARDs including MTX starting etanercept or infliximab therapy for the first time, were included in a structured clinical follow-up protocol. Information on diagnosis, disease duration, previous and ongoing DMARDs, treatment start and termination, as well as cause of withdrawal was prospectively collected during the period of March 1999 through December 2004. Patients were divided into six groups according to TNF-blocking drugs and concomitant DMARDs. Five-year level (one-year) of adherence to therapy was 36% (69%) for patients receiving infliximab in combination with MTX compared with 65% (89%) for patients treated with etanercept and MTX (p < 0.001). Cox regression models showed that the risk for premature treatment termination of patients treated with infliximab was threefold higher than for etanercept (p < 0.001). Also, the regression analysis showed that patients receiving concomitant MTX had better treatment continuation than patients treated solely with TNF blockers (p < 0.001). Moreover, patients receiving concomitant MTX had superior drug survival than patients receiving other concomitant DMARDs (p < 0.010). The superior effect of MTX was associated primarily with fewer treatment terminations because of adverse events. In addition, the study identifies low C-reactive protein level, high age, elevated health assessment questionnaire score, and higher previous number of DMARDs as predictors of premature treatment termination. In summary, treatment with etanercept has higher adherence to therapy than treatment with infliximab. Concomitant MTX is associated with improved treatment continuation of biologics when compared with both TNF blockers as monotherapy and TNF blockers combined with other DMARDs.
17318328 Diets and circadian rhythms: challenges from biology for medicine. 2006 Autoimmune diseases such as rheumatoid arthritis and gastrointestinal disorders such as stomach ulcers are often treated with drugs. NSAIDs, a common treatment in rheumatoid arthritis, may cause stomach ulcers which call for additional medications, notably antacids in the sense of drugs that suppress acid secretion by the stomach. Infection with Helicobacter pylori also plays a role in the ulcers. The infection is typically treated with antibiotics added to antacids. Considering NSAIDs and antacids, we suspect that overmedication is common to the extent that particular diets are a better option. Current research and current treatments with these drugs are also problematic since circadian rhythms are mostly disregarded. All the processes involved in the disorders treated show marked variations in the course of the day. Hence experiments conforming to the guidelines of evidence-based medicine, and treatments in line with them, have outcomes strongly depending on the time factor. This calls for reforms in medicine with fresh inputs from biology.
16899386 Direct, quantitative clinical assessment of hand function: usefulness and reproducibility. 2007 May Methods of assessing functional impairment in arthritic hands include pain assessments and disability scoring scales which are subjective, variable over time and fail to take account of the patients' need to adapt to deformities. The aim of this study was to evaluate measures of functional strength and joint motion in the assessment of the rheumatoid (RA) and osteoarthritic (OA) hand. Ten control subjects, ten RA and ten OA patients were recruited for the study. All underwent pain and disability scoring and functional assessment of the hand using measures of pinch/grip strength and range of joint motion (ROM). Functional assessments including ROM analyses at interphalangeal (IP), metacarpophalangeal (MCP) and wrist joints along with pinch/grip strength clearly discriminated between patient groups (RA vs. OA MCP ROM P<0.0001), pain and disability scales were unable to. In the RA there were demonstrable relationships between ROM measurements and disability (R2=0.31) as well as disease duration (R2=0.37). Intra-patient measures of strength were robust whereas inter-patient comparisons showed variability. In conclusion, pinch/grip strength and ROM are clinically reproducible assessments that may more accurately reflect functional impairment associated with arthritis.
16670823 Bilateral spontaneous pneumothorax in a patient with pulmonary rheumatoid nodules, seconda 2007 Jul This case report describes a 50-year-old woman with rheumatoid arthritis (RA) in whom nodular opacities were found on chest X-ray. She developed a bilateral spontaneous pneumothorax treated with surgical pleurodesis. Cultures remained negative. Histological examination of specimens confirmed the clinical diagnosis of rheumatoid granulomata. Therefore, corticosteroid therapy was started, after which the nodules decreased slightly in size and inflammatory parameters normalized. Three months later, she presented with respiratory insufficiency based on pulmonary fungus infection. Differential diagnosis between rheumatoid nodules and granulomas caused by Aspergillus is difficult in RA patients with pulmonary nodular lesions; in this case, both complications appeared subsequently.
16507131 Identification of blood biomarkers of rheumatoid arthritis by transcript profiling of peri 2006 Rheumatoid arthritis (RA) is a chronic debilitating autoimmune disease that results in joint destruction and subsequent loss of function. To better understand its pathogenesis and to facilitate the search for novel RA therapeutics, we profiled the rat model of collagen-induced arthritis (CIA) to discover and characterize blood biomarkers for RA. Peripheral blood mononuclear cells (PBMCs) were purified using a Ficoll gradient at various time points after type II collagen immunization for RNA preparation. Total RNA was processed for a microarray analysis using Affymetrix GeneChip technology. Statistical comparison analyses identified differentially expressed genes that distinguished CIA from control rats. Clustering analyses indicated that gene expression patterns correlated with laboratory indices of disease progression. A set of 28 probe sets showed significant differences in expression between blood from arthritic rats and that from controls at the earliest time after induction, and the difference persisted for the entire time course. Gene Ontology comparison of the present study with previous published murine microarray studies showed conserved Biological Processes during disease induction between the local joint and PBMC responses. Genes known to be involved in autoimmune response and arthritis, such as those encoding Galectin-3, Versican, and Socs3, were identified and validated by quantitative TaqMan RT-PCR analysis using independent blood samples. Finally, immunoblot analysis confirmed that Galectin-3 was secreted over time in plasma as well as in supernatant of cultured tissue synoviocytes of the arthritic rats, which is consistent with disease progression. Our data indicate that gene expression in PBMCs from the CIA model can be utilized to identify candidate blood biomarkers for RA.
16856901 Evaluation of t-PA, PAI-2, IL-1beta and PGE(2) in gingival crevicular fluid of rheumatoid 2006 Sep AIMS: This study was undertaken to compare periodontal conditions, gingival crevicular fluid (GCF) levels of tissue-type plasminogen activator (t-PA), its inhibitor plasminogen activator inhibitor-2 (PAI-2), interleukin-1beta (IL-1beta), prostaglandin E(2) (PGE(2)) in rheumatoid arthritis (RA) patients and control groups. METHODS: Twenty-three RA patients, 17 systemically healthy patients with periodontal disease (PD), and 17 systemically and periodontally healthy subjects were recruited. GCF samples were obtained from two single-rooted teeth. Full-mouth clinical periodontal measurements were recorded at six sites/tooth. GCF samples were analysed using relevant ELISA kits. Data were tested statistically by appropriate tests. RESULTS: Total amounts of t-PA, PAI-2 and PGE(2) in GCF samples of the healthy control group were significantly lower than the other groups (p<0.05). The RA group exhibited a higher total amount of t-PA in GCF samples than the PD group (p<0.05). PAI-2, IL-1beta and PGE(2) total amounts were similar in RA and PD groups (p>0.05). CONCLUSION: The coexistence of RA and periodontitis does not seem to affect clinical periodontal findings or systemic markers of RA. Similar inflammatory mediator levels in RA and PD groups, despite the long-term usage of corticosteroids, non-steroidal anti-inflammatory drugs, suggest that RA patients may have a propensity to overproduce these inflammatory mediators.
16951473 [Fracture risk assessment tool]. 2006 Sep World Health Organization (WHO) has proposed the use of 10-year absolute risk for fracture (calculated based on incidence and life span) using clinical risk factors as new intervention thresholds. Eight risk factors to be included in the fracture assessment risk tool are age, bone mineral density or body mass index (BMI) when bone density is not available, steroid use, parental history of femoral neck fracture, history of osteoporotic fracture, smoking, excessive alcohol consumption, and rheumatoid arthritis. WHO has proposed that a treatment-intervention threshold be established in accordance with the medical situation in each country.
17012439 Dose escalation of the anti-TNF-alpha agents in patients with rheumatoid arthritis. A syst 2007 Mar OBJECTIVE: To estimate the proportion of rheumatoid arthritis (RA) patients on anti-tumour necrosis factor (anti-TNF) who require dose escalation. METHODS: Systematic review of the scientific literature. Infliximab, etanercept and adalimumab studies in RA were considered. Primary outcome was the proportion of patients requiring dose escalation. American College Rheumatology (ACR) and Disease activity score (DAS) responses post-escalation were assessed when available. RESULTS: From 1801 references, 16 studies with 8510 patients were included. Of all the infliximab patients, 53.7% underwent dose escalation. Fourty-four per cent of the infliximab patients experienced dose increase and 8.3%, frequency increase. The ACR20 response to dose escalation ranged from 27 to 36% and DAS28 improved from 5.2 to 4.5 in one study and from 4.1 to 3.7 in another. Of the etanercept patients, 17.5% experienced a dose increase but changes on the mean dose were not statistically significant. CONCLUSIONS: Dose escalation is common in patients treated with infliximab, and less frequent with etanercept. In a proportion of patients, the dose escalation seems effective. The design and evidence level of the available studies limit the strength of the conclusions.
16633924 The role of c-Src kinase in the regulation of osteoclast function. 2006 The targeted disruption of c-Src impairs osteoclast bone resorbing activity, causing osteopetrosis. Although it has been reported that restoring only the c-Src adaptor function at least partly rescues the skeletal phenotypes, the importance of c-Src kinase activity remains controversial. We here highlight the contributions of the Src adaptor and kinase activities in cytoskeletal organization and osteoclast function using adenovirus vectors containing various mutants of Src or Pyk2. In addition, we describe the importance of c-Src in mitochondria, where it phosphorylates cytochrome c oxidase (Cox). Src-induced Cox activity is also required for bone resorbing activity of osteoclasts that require high levels of ATP. Thus, c-Src kinase activity not only on the plasma membrane but also within mitochondria is essential for the regulation of osteoclastic bone resorption.
16024218 The distribution of the endogenous retroviruses HERV-K113 and HERV-K115 in health and dise 2005 Sep The human endogenous retroviruses HERV-K113 and HERV-K115 are full-length proviruses but unusual in being found in only a proportion of the population. Here, we study the geographic distribution of these HERVs and their prevalence in autoimmune disease. The frequency of HERV-K113 and HERV-K115 in 174 individuals from Africa was 21.8 and 34.1%, respectively, compared to 4.16 and 1% in 96 people in the United Kingdom (p < 0.001). Prevalence in Yemen (n = 56) was 8 and 7.14% and in Papua New Guinea (n = 54) 0% for both. In the United Kingdom, HERV-K113 was found in 15.6% of 96 Sjögren's syndrome patients (p < 0.01) and 11.9% of 109 multiple sclerosis patients (p < 0.05). No increase in prevalence in either disease was seen with HERV-K115. These data suggest that both viruses are recently integrated and/or under positive evolutionary selection pressure. HERV-K113 may be a genetic risk factor for some types of autoimmunity.