Epidemiology of rheumatoid arthritis

Therapeutic delivery systems for rheumatoid arthritis based on hydrogel carriers

Rheumatoid arthritis (RA) is an autoimmune disease suffered by millions of people worldwide. It can significantly affect the patient's quality of life by damaging not only the joints but also organs such as the lungs and the heart. RA is normally treated using nonsteroidal anti-inflammatory drugs (NSAIDs), glucocorticoids, disease-modifying antirheumatic drugs (DMARDs), and biologics. These active agents often cause side effects and offer low efficacy due to their lack of specificity and limited retention time. In an attempt to improve RA treatments, hydrogel-based systems have been proposed as drug delivery carriers. Due to their exceptional adaptability and biocompatibility, hydrogels have the potential of enhancing the delivery of RA therapy through different administration routes in an efficient and effective manner. In this review, we explore the application of hydrogel systems as potential carriers in RA treatment. Additionally, we discuss recent work in the field and highlight the required hydrogel properties, depending on the administration route. The outstanding potential of hydrogel systems as carriers for RA was demonstrated; however, there is extensive research yet to be done to improve available treatments for RA.

Mechanism-driven strategies for prevention of rheumatoid arthritis

In seropositive rheumatoid arthritis (RA), the onset of clinically apparent inflammatory arthritis (IA) is typically preceded by a prolonged period of autoimmunity manifest by the presence of circulating autoantibodies that can include antibodies to citrullinated protein antigens (ACPA) and rheumatoid factor (RF). This period prior to clinical IA can be designated preclinical RA in those individuals who have progressed to a clinical diagnosis of RA, and an 'at-risk' status in those who have not developed IA but exhibit predictive biomarkers of future clinical RA. With the goal of developing RA prevention strategies, studies have characterized immune phenotypes of preclinical RA/at-risk states. From these studies, a model has emerged wherein mucosal inflammation and dysbiosis may lead first to local autoantibody production that should normally be transient, but instead is followed by systemic spread of the autoimmunity as manifest by serum autoantibody elevations, and ultimately drives the development of clinically identified joint inflammation. This model can be envisioned as the progression of disease development through serial 'checkpoints' that in principle should constrain or resolve autoimmunity; however, instead the checkpoints 'fail' and clinical RA develops. Herein we review the immune processes that are likely to be present at each step and the potential therapeutic strategies that could be envisioned to delay, diminish, halt or even reverse the progression to clinical RA. Notably, these prevention strategies could utilize existing therapies approved for clinical RA, therapies approved for other diseases that target relevant pathways in the preclinical/at-risk state, or approaches that target novel pathways.

Characterization of Rheumatoid Arthritis Risk-Associated SNPs and Identification of Novel Therapeutic Sites Using an In-Silico Approach

Simple Summary

Rheumatoid arthritis (RA) is a complex disease resulting from multiple genetic and environmental pathogenic factors. The genetic factors include single-nucleotide polymorphisms (SNPs), which have been reported to be associated with RA, but their specific role in the pathogenesis of RA remains unexplained. This study explains the potential role of RA risk-associated SNPs in its pathogenesis in order to provide a basis for understanding the genetic complexity of RA. Several roles of these SNPs are described in this study, and may also aid in the design of a therapeutic strategy for RA. Furthermore, novel potential therapeutic sites have also been researched, resulting in the identification of three novel therapeutic targets. The therapeutic strategies for the treatment of RA include inflammatory pathway-targeting drugs, which alleviate inflammation in joints. There is always a need for novel therapeutic targets that can play a role in alleviating inflammation in autoimmune diseases including RA. Therefore, these novel therapeutic sites are very important, and further experimental studies are required.

Abstract

Single-nucleotide polymorphisms (SNPs) are reported to be associated with many diseases, including autoimmune diseases. In rheumatoid arthritis (RA), about 152 SNPs are reported to account for ~15% of its heritability. These SNPs may result in the alteration of gene expression and may also affect the stability of mRNA, resulting in diseased protein. Therefore, in order to predict the underlying mechanism of these SNPs and identify novel therapeutic sites for the treatment of RA, several bioinformatics tools were used. The damaging effect of 23 non-synonymous SNPs on proteins using different tools suggested four SNPs, including rs2476601 in PTPN22, rs5029941 and rs2230926 in TNFAIP3, and rs34536443 in TYK2, to be the most damaging. In total, 42 of 76 RA-associated intronic SNPs were predicted to create or abolish potential splice sites. Moreover, the analysis of 11 RA-associated UTR SNPs indicated that only one SNP, rs1128334, located in 3′UTR of ETS1, caused functional pattern changes in BRD-BOX. For the identification of novel therapeutics sites to treat RA, extensive gene–gene interaction network interactive pathways were established, with the identification of 13 potential target sites for the development of RA drugs, including three novel target genes. The anticipated effect of these findings on RA pathogenesis may be further validated in both in vivo and in vitro studies.

How to investigate: Pre-clinical rheumatoid arthritis

Multiple studies have shown that there is a pre-clinical period preceding the development of rheumatoid arthritis (RA). During this period, complex interactions between the environmental and genetic causes occur, and the expression "preclinical RA" has been proposed to define it. Early treatment intervention is associated with less joint damage and has an increased possibility of achieving remission. In this review, we provide an overview of the preclinical phases of RA, new immunological and imaging biomarkers, and the clinical features, and the management of individuals at-risk of developing RA.

Rheumatoid arthritis and the mucosal origins hypothesis: protection turns to destruction

Individuals at high risk of developing seropositive rheumatoid arthritis (RA) can be identified for translational research and disease prevention studies through the presence of highly informative and predictive patterns of RA-related autoantibodies, especially anti-citrullinated protein antibodies (ACPAs), in the serum. In serologically positive individuals without arthritis, designated ACPA positive at risk, the presence of mucosal inflammatory processes associated with the presence of local ACPA production has been demonstrated. In other at-risk populations, local RA-related autoantibody production is present even in the absence of serum autoantibodies. Additionally, a proportion of at-risk individuals exhibit local mucosal ACPA production in the lung, as well as radiographic small-airway disease, sputum hypercellularity and increased neutrophil extracellular trap formation. Other mucosal sites in at-risk individuals also exhibit autoantibody production, inflammation and/or evidence of dysbiosis. As the proportion of individuals who exhibit such localized inflammation-associated ACPA production is substantially higher than the likelihood of an individual developing future RA, this finding raises the hypothesis that mucosal ACPAs have biologically relevant protective roles. Identifying the mechanisms that drive both the generation and loss of externally focused mucosal ACPA production and promote systemic autoantibody expression and ultimately arthritis development should provide insights into new therapeutic approaches to prevent RA.

Nonhemorrhagic joint disorders and vitamin K antagonists: an under-recognized adverse drug reaction?

Isolated arthralgia, without hemorrhagic side effect, exists and is considered as a very rare adverse drug reaction according to vitamin K antagonists' (VKAs) summary of product characteristics. Up to now, there are no literature reports of isolated, nonhemorrhagic joint complications in patients receiving VKAs. Hence, the objective of this study was to describe cases of VKA-related nonhemorrhagic joint disorders (fluindione, warfarin, and acenocoumarol) reported in the French Pharmacovigilance Database (FPVD). Sixty-one reports (male : female ratio, 1.18; median [interquartile range (IQR)] age: 60 [49-72]) were found. Fluindione, warfarin, and acenocoumarol were respectively suspected in 42, 12, and 7 cases. Arthralgia was reported in 47 cases (77%), arthritis in nine cases (15%), capsulitis in three cases (5%), and bursitis in two cases (3%). Although the joint symptoms mainly concerned the lower limbs, all types of joints were affected. Arthralgia was associated with myalgia in 14 cases and with tendinitis in three cases. The median (IQR) time interval between VKA introduction and arthralgia onset was 26 (10-98) days (range: 1-6935). VKA was withdrawn in 44 cases, and a decrease in the intensity of joint symptoms was observed in 30 cases. In three cases, reintroduction of the same VKA led to the recurrence of symptoms. In view of the large prescription of this drug class worldwide, patients and clinicians (and especially primary care physicians and geriatricians) should be aware of this possible adverse drug reaction when confronted with joint disorders in patients of all ages taking VKAs.

Defining criteria for rheumatoid arthritis patient-derived disease activity score that correspond to Disease Activity Score 28 and Clinical Disease Activity Index based disease states and response criteria

OBJECTIVE

Two versions of a patient-based DAS (PDAS) 1 and 2 (with and without ESR) have been developed and validated in RA. The objective of this study was to define PDAS1- and PDAS2-based criteria for remission, low, moderate and high disease activity and responses to treatment.

METHOD

Using receiver operating characteristic curves, the optimal thresholds for PDAS1 and PDAS2 that correspond to validated assessor-based DAS (DAS28) and Clinical Disease Activity Index (CDAI) disease statuses were determined. Data from RA patients initiated on disease-modifying drugs were used to determine optimal thresholds for PDAS1 and PDAS2 that corresponded to EULAR good and moderate responses. Agreement with DAS28, CDAI and EULAR response criteria was assessed by Cohen's κ statistic.

RESULTS

Threshold for PDAS1 and PDAS2 demonstrated fair to moderate agreement with DAS28 [κ = 0.44 (95% CI: 0.40, 0.50) and 0.31 (95% CI: 0.25, 0.38)] and CDAI [κ = 0.27 (95% CI: 0.22, 0.33) and 0.42 (95% CI: 0.35, 0.49)] disease statuses, respectively, which was similar to agreement between DAS28 and CDAI [κ = 0.54 (95% CI: 0.46, 0.61)] within this group. Agreement of EULAR good and moderate response with PDAS1 and PDAS2 was κ = 0.46 (95% CI: 0.27, 0.64) and 0.38 (95% CI: 0.20, 0.56), respectively.

CONCLUSION

Thresholds for disease activity statuses and response to treatment for PDAS1 and PDAS2 have been established. They have comparable agreement to assessor-based criteria.

Targeting mechanisms at sites of complement activation for imaging and therapy

The complement system plays a key role in many acute injury states as well as chronic autoimmune and inflammatory diseases. Localized complement activation and alternative pathway-mediated amplification on diverse target surfaces promote local recruitment of pro-inflammatory cells and elaboration of other mediators. Despite a general understanding of the architecture of the system, though, many of the mechanisms that underlie site-specific complement activation and amplification in vivo are incompletely understood. In addition, there is no capability yet to measure the level of local tissue site-specific complement activation in patients without performing biopsies to detect products using immunohistochemical techniques. Herein is reviewed emerging evidence obtained through clinical research studies of human rheumatoid arthritis along with translational studies of its disease models which demonstrate that several parallel mechanisms are involved in site-specific amplification of activation of the complement system in vivo. Among these processes are de-regulation of the alternative pathway, effector pathway-catalyzed amplification of proximal complement activation, recognition of injury-associated ligands by components of the lectin pathway, and engagement of pathogenic natural antibodies that recognize a limited set of injury-associated neoepitopes. Studies suggest that each of these inter-related processes can play key roles in amplification of complement-dependent injury on self-tissues in vivo. These findings, in addition to development of an imaging strategy described herein designed to quantitatively measure local complement C3 fixation, have relevance to therapeutic and diagnostic strategies targeting the complement system.

Introduction of a metabolic joint asymmetry score derived from conventional bone scintigraphy. A new tool to differentiate psoriatic from rheumatoid arthritis

AIM

Clinical differentiation of psoriatic arthritis (PsA) and rheumatoid arthritis (rA) based on the pattern of joint involvement can be difficult; the frequent form of PsA with polyarthritis of the peripheral joints may sometime resemble rA. We investigated a metabolic joint asymmetry score (MJAS), reflecting the overall asymmetric joint involvement on conventional bone scintigraphy, for differentiating PsA from rA in patients presenting with peripheral polyarthritis.

PATIENTS, METHODS

106 patients (n = 61, PsA; n = 45, rA) with peripheral polyarthritis (≥ 5 joints) as well as 26 control subjects with no history of chronic joint disorders were analyzed. The intensity of articular 99mTc-MDP uptake in 40 peripheral joint pairs was scored regarding the bilateral difference of each joint based on a scale of 0-2 (no significant, moderate, and marked asymmetry, respectively). The patient's MJAS was defined as the sum of uptake difference scores of all joint pairs. The association of MJAS with the underlying condition (Psoriasis criteria, Revised Criteria of the ACR) was examined.

RESULTS

5280 peripheral joint pairs were investigated. There was no significant difference in the total number of involved joints in PsA 15.0 ± 8.2 versus rA 17.5 ± 8.8 patients (p = 0.132), but significantly less involvement in the control group (6.7 ± 5.0, p < 0.001). MJAS was markedly higher in PsA (17.0 ± 9.6) than in rA (4.8 ± 3.9, p < 0.001), and correlated with the total number of involved joints in PsA (r = 0.516, p < 0.001), but not in rA (r = 0.078, p = 0.380). The MJAS disparity between PsA and rA persisted after exclusion of the DIP joints (14.4 ± 7.7 vs. 4.4 ± 3.3; p<0.001).

CONCLUSIONS

The new reproducible semi-quantification method for the asymmetry of metabolic joint involvement permits differentiation of psoriatic from rheumatoid peripheral arthritis with MJAS being markedly higher in patients with PsA as compared to rA patients. The score may offer an effective complementary tool for characterizing patients with peripheral polyarthritis.

Insights from populations at risk for the future development of classified rheumatoid arthritis

Rheumatoid arthritis (RA) develops through a series of stages. In the seropositive subset of classified RA patients, a preclinical stage is present for years before the onset of clinically apparent disease. Relevant preclinical biomarkers include autoantibodies, alterations of lymphoid populations, elevated cytokines/chemokines, genetic/genomic factors, imaging studies, clinical findings, dietary and environmental biomarkers, cardiovascular disease risk assessment, microbiome analyses, and metabolomic changes. Identifying the population of asymptomatic subjects at sufficiently high risk for disease to be informative and representative of "preclinical patients" is a challenge. This article reviews the results of analyses that have been undertaken in these "at-risk" subjects.

Complement and its receptors: new insights into human disease

Although new activation and regulatory mechanisms are still being identified, the basic architecture of the complement system has been known for decades. Two major roles of complement are to control certain bacterial infections and to promote clearance of apoptotic cells. In addition, although inappropriate complement activation has long been proposed to cause tissue damage in human inflammatory and autoimmune diseases, whether this is indeed true has been uncertain. However, recent studies in humans, especially those using newly available biological therapeutics, have now clearly demonstrated the pathophysiologic importance of the complement system in several rare diseases. Beyond these conditions, recent genetic studies have strongly supported an injurious role for complement in a wide array of human inflammatory, degenerative, and autoimmune diseases. This review includes an overview of complement activation, regulatory, and effector mechanisms. It then focuses on new understandings gained from genetic studies, ex vivo analyses, therapeutic trials, and animal models as well as on new research opportunities.

Autoimmunity to citrullinated proteins and the initiation of rheumatoid arthritis

Clinical manifestations of rheumatoid arthritis (RA), the second most common human autoimmune disease, are primarily focused on the joints, causing disability and requiring life-long treatment to ameliorate signs and symptoms. The etiology of RA is unknown; however, important discoveries in two areas have been made which provide hope that the causal mechanisms can be identified. First, the most severe form of this disease is associated with the presence of humoral and cellular autoimmunity to citrullinated proteins and peptides. Second, in the natural history of RA, autoimmunity to citrullinated antigens appears years before the onset of clinically apparent disease. Herein is described a model in which to consider how these two features are linked during very early disease development.

Objective assessment of abnormal gait in patients with rheumatoid arthritis using a smartphone

A disturbance in gait pattern is a serious problem in patients with rheumatoid arthritis (RA). The aim of the present study was to examine the utility of the smartphone gait analysis application in patients with RA. The smartphone gait analysis application was used to assess 39 patients with RA (age 65.9 ± 10.0 years, disease duration 11.9 ± 9.4 years) and age-matched control individuals (mean age, 69.1 ± 5.8 years). For all RA patients, the following data were obtained: disease activity score (DAS) 28, modified health assessment questionnaire (mHAQ), and assessment of walking ability. Patients walked 20 m at their preferred speed, and trunk acceleration was measured using a Smartphone. After signal processing, we calculated the following gait parameters for each measurement terminal: peak frequency (PF), autocorrelation peak (AC), and coefficient of variance (CV) of the acceleration peak intervals. The gait parameters of RA and control groups were compared to examine the comparability of the 2 groups. Criterion-related validity was determined by evaluating the correlation between gait parameters and clinical parameters using Spearman's correlation coefficient. The RA group showed significantly lower scores for the walking speed, AC, and CV than the control group. There were no significant differences in PF. PF (gait cycle) was mildly associated with gait speed (P < 0.05). AC (gait balance) was moderately associated with the DAS, mHAQ, gait ability, and gait speed (P < 0.05). CV (gait variability) was moderately associated with the DAS, gait ability, and gait speed (P < 0.05). This is the first study to examine the use of a smartphone device for gait pattern measurement. The results suggest that some gait parameters recorded using the smartphone represent an acceptable assessment tool for gait in patients with RA.

Assessing physical activity in persons with rheumatoid arthritis using accelerometry

PURPOSE

To investigate empirically if the nonwear threshold and the "valid day" definition for accelerometer data from the general adult US population are appropriate for accelerometer data from persons with rheumatoid arthritis (RA).

METHODS

This study analyzed data from 107 persons with RA participating in the baseline (2006-2008) accelerometer assessment from two studies with common inclusion/exclusion criteria. We examined candidate nonwear thresholds ranging from 20 to 300 min of zero activity count. The effect of the selected nonwear threshold is examined in regard to 1) mean daily activity counts, 2) activity counts per wear hour, 3) mean daily minutes of moderate to vigorous physical activity (MVPA) according to count thresholds that occur in 10-min bouts, and 4) MVPA bout minutes per wear hour. The effect of ranging the definition of a valid day of accelerometer data from 8 h of wear time to 12 h on data retention was also examined.

RESULTS

In 737 d of accelerometer data analyzed, the average daily wear hours increased with length of nonwear threshold of allowed continuous zero activity count minutes. The mean number of nonzero activity count minutes increased with the chosen nonwear threshold until it stabilized at 478 min.d of activity, which corresponded to the 90-min nonwear threshold. Choosing this threshold and requiring at least 10 h of wear time to constitute a valid day were associated with 92.8% of days of collected data defined as "valid."

CONCLUSIONS

Data supported increasing the allowed nonwear threshold in this RA subpopulation from 60 to 90 min, while retaining the 10-h day as the measure of the "valid day."

Preclinical rheumatoid arthritis: identification, evaluation, and future directions for investigation

Rheumatoid arthritis (RA) likely develops in several phases, beginning with genetic risk, followed by asymptomatic autoimmunity, then finally, clinically apparent disease. Investigating the phases of disease that exist prior to the onset of symptoms (ie, the preclinical period of RA) will lead to understanding of the important relationships between genetic and environmental factors that may lead to disease, as well as allow for the development of predictive models for disease, and ultimately preventive strategies for RA.

MS analysis of rheumatoid arthritic synovial tissue identifies specific citrullination sites on fibrinogen

PURPOSE

Citrullination is a post-translational modification of arginine residues to citrulline catalyzed by peptidyl arginine deiminases. Induced expression of citrullinated proteins are frequently detected in various inflammatory states including arthritis; however, direct detection of citrullination in arthritic samples has not been successfully performed in the past.

EXPERIMENTAL DESIGN

Citrullination of human fibrinogen, a candidate autoantigen in arthritis, was studied. Accurate identification of citrullinated fibrinogen peptides from rheumatoid arthritis synovial tissue specimens was performed using accurate mass and retention time analysis.

RESULTS

A peptide with the sequence ESSSHHPGIAEFPSRGK corresponding to amino acids 559-575 of fibrinogen α-chain was identified to be citrullinated with an occupancy rate between 1.4 and 2.5%. Citrullination of the peptide KREEAPSLRPAPPPISGGGYRARPAK corresponding to amino acids 52-77 of the fibrinogen β-chain was identified with an occupancy rate of 1.2%.

CONCLUSIONS AND CLINICAL RELEVANCE

We report a proof of principle study for the identification of citrullinated proteins and within them, identification of citrullination sites and quantification of their occupancies in synovial tissue from rheumatoid arthritis patients using high-resolution MS. Detailed studies on which molecules are citrullinated in arthritis can provide information about their role in immune regulation and serve as novel biomarkers and potentially even as therapeutic targets.

Rheumatoid arthritis: the role of reactive oxygen species in disease development and therapeutic strategies

Autoimmune diseases such as rheumatoid arthritis (RA) are chronic diseases that cannot be prevented or cured If the pathologic basis of such disease would be known, it might be easier to develop new drugs interfering with critical pathway. Genetic analysis of animal models for autoimmune diseases can result in discovery of proteins and pathways that play key function in pathogenesis, which may provide rationales for new therapeutic strategies. Currently, only the MHC class II is clearly associated with human RA and animal models for RA. However, recent data from rats and mice with a polymorphism in Ncf1, a member of the NADPH oxidase complex, indicate a role for oxidative burst in protection from arthritis. Oxidative burst-activating substances can treat and prevent arthritis in rats, as efficiently as clinically applied drugs, suggesting a novel pathway to a therapeutic target in human RA. Here, the authors discuss the role of oxygen radicals in regulating the immune system and autoimmune disease. It is proposed that reactive oxygen species set the threshold for T cell activation and thereby regulate chronic autoimmune inflammatory diseases like RA. In the light of this new hypothesis, new possibilities for preventive and therapeutic treatment of chronic inflammatory diseases are discussed.

Psychosocial and reported inflammatory disease correlates of self-reported heart disease in women from South of Israel

BACKGROUND

Past and recent research suggests that psychological and biological factors may increase women's risk of coronary heart disease (CHD). This study examined the prevalence and correlates of self-reported heart disease among Jewish women from the Negev, a socio-economically and culturally unique region in south of Israel.

METHOD

A cross-sectional design was used. We interviewed over the phone 526 randomly-selected women (mean age: 44.3+/-14.2 years) about background variables (e.g., education), biomedical risk factors (e.g., body mass index or BMI), self-reported inflammatory diseases (rheumatoid arthritis or RA, urinary infections), psychosocial factors (depression, hopelessness, self-esteem, social-support) and self-rated health and heart disease.

RESULTS

Prior physician diagnosis of heart disease was reported by 8.2% of women. Age, economic difficulties, diabetes, hypertension, BMI, physical exercise, RA and urinary infections were significantly associated with reported heart disease. Of all psychosocial factors considered, hopelessness and self-esteem significantly distinguished heart disease cases from non-cases. In a multiple logistic regression, poor self-esteem, RA and hypertension were significant independent correlates of self-reported heart disease.

CONCLUSIONS

Pending replication with objective measures of heart disease and a prospective design, poor self-esteem and RA may prove to be new CHD risk factors in women.

Fine mapping of collagen-induced arthritis quantitative trait loci in an advanced intercross line

The generation of advanced intercross lines (AIL) is a powerful approach for high-resolution fine mapping of quantitative trait loci (QTLs), because they accumulate much more recombination events compared with conventional F2 intercross and N2 backcross. However, the application of this approach is severely hampered by the requirements of excessive resources to maintain such crosses, i.e., in terms of animal care, space, and time. Therefore, in this study, we produced an AIL to fine map collagen-induced arthritis (CIA) QTLs using comparatively limited resources. We used only 308 (DBA/1 x FVB/N)F11/12 AIL mice to refine QTLs controlling the severity and onset of arthritis as well as the Ab response and T cell subset in CIA, namely Cia2, Cia27, and Trmq3. These QTLs were originally identified in (DBA/1 x FVB/N)F2 progeny. The confidence intervals of the three QTLs were refined from 40, 43, and 48 Mb to 12, 4.1, and 12 Mb, respectively. The data were complemented by the use of another QTL fine-mapping approach, haplotype analysis, to further refine Cia2 into a 2-Mb genomic region. To aid in the search for candidate genes for the QTLs, genome-wide expression profiling was performed to identify strain-specific differentially expressed genes within the confidence intervals. Of the 1396 strain-specific differentially expressed genes, 3, 3, and 12 genes were within the support intervals of the Cia2, Cia27, and Trmq3, respectively. In addition, this study revealed that Cia27 and Trmq3 controlling anti-CII IgG2a Ab and CD4:CD8 T cell ratio, respectively, also regulated CIA clinical phenotypes.

Th2 immune deviation induced by pregnancy: the two faces of autoimmune rheumatic diseases

One of the most important immunological modifications during pregnancy is the Th1/Th2 shift, due to the progressive increase of progesterone and estrogens during pregnancy, which reach their peak-level in the third trimester of gestation. At high levels, estrogens seem mainly to suppress Th1 cytokines and stimulate Th2-mediated immunological responses as well as antibody production. For this reason Th1-mediated diseases, like rheumatoid arthritis (RA), tend to improve and Th2-mediated disease, like systemic lupus erythematosus (SLE), tend to worsen during pregnancy. SLE is the autoimmune rheumatic disease in which pregnancy most frequently occurs because it predominantly affects young females in their childbearing age. Other autoimmune rheumatic diseases, including RA, are less frequently observed during pregnancy due to their low female-to-male ratio and peak onset after the age of 40. This review is focused on the disease course, gestational outcome and management of patients with SLE and RA during pregnancy.

Sensitive immunoassays for the autoantibodies reacting against citrullinated carboxy-terminal telopeptides of type I and type II collagens in patients with rheumatoid arthritis

We developed sensitive assay methods for autoantibodies recognizing the citrullinated synthetic peptides derived from type I and type II collagens in patients with rheumatoid arthritis (RA). These peptides were tested with the chemiluminescence method (Nichols Advantage

Identification of new quantitative trait loci in mice with collagen-induced arthritis

OBJECTIVE

Collagen-induced arthritis (CIA) in the mouse is one of the most widely used autoimmune experimental models, with many features similar to rheumatoid arthritis. This study sought to identify potential genetic regulatory mechanisms of CIA in major histocompatibility complex-matched (H2-q) F(2) hybrid mice.

METHODS

We used 126 polymorphic markers to perform simple sequence-length polymorphism analysis on 290 F(2) hybrids of arthritis-susceptible (DBA/1J) and arthritis-resistant (FVB/N) inbred mouse strains. The major clinical traits (disease severity and onset) were assessed, and serum antibodies specific to type II collagen (CII) were determined by enzyme-linked immunosorbent assay in 270 F(2) mice. Lymph nodes from 94 F(2) mice were used to test the ratio of CD4 to CD8 by fluorescence-activated cell sorter analysis, and cell proliferation was determined by XTT test.

RESULTS

Two quantitative trait loci (QTLs) identified in previous studies were confirmed; these were severity-controlling Cia2 and onset-controlling Cia4 on chromosome 2. Moreover, we identified 5 new QTLs, 1 for CII-specific IgG2a antibodies on chromosome 5, 2 controlling the CII-specific IgG1 antibody response on chromosomes 10 and 13, 1 for the CD4:CD8 ratio on chromosome 2, and 1 for cell proliferation (measured by XTT test) on chromosome 16. Complement component C5 was identified as the probable main candidate gene for the QTLs Cia2 and Cia4. F(2) mice carrying a 2-basepair deletion of C5, the FVB/N allele, had low incidence and less severe disease as compared with those carrying the DBA/1J allele.

CONCLUSION

This genome scan provides additional evidence confirming the role of C5 as a probable candidate gene for Cia2 and Cia4 loci, and identifies new QTLs controlling new traits in autoimmune arthritis.

The genetic control of rheumatoid factor production in a rat model of rheumatoid arthritis

OBJECTIVE

To investigate the genetic regulation of rheumatoid factor (RF) in a rat model of rheumatoid arthritis, in order to gain understanding of the enigmatic role of RF in the disease.

METHODS

IgM-RF and IgG-RF, as well as total levels of immunoglobulins of different subclasses, were measured in sera from rats with pristane-induced arthritis (PIA). The major gene regions were identified by linkage analysis of genetically segregating crosses.

RESULTS

The production of RF was found to correlate with development of arthritis and to be higher in females than in males. Surprisingly, the relatively arthritis-resistant E3 strain had higher levels of RF than the arthritis-susceptible DA strain. In an (E3 x DA)F(2) cohort a major locus controlling the levels of IgM-RF in serum was identified on chromosome 11 (Rf1) and another on chromosome 16 (Rf3), and these were not related to arthritis susceptibility. However, the Rf2 locus on chromosome 4 controlled IgG-RF levels, IgG2a levels, and chronic arthritis in males (Pia5). Some previously defined arthritis loci (Pia4, Pia6, Pia7, and Pia8) were found to also control immunoglobulin levels in serum.

CONCLUSION

RFs are produced in the rat PIA model and correlate with development of arthritis. Gene regions controlling RF and serum immunoglobulin levels were identified, of which some cosegregated with arthritis. This suggests a new focus of study to elucidate the role of RF in the pathogenesis of arthritis.

Adverse Drug Events Involving COX-2 Inhibitors

OBJECTIVE

To describe the types and severity of adverse drug-related events (ADEs) observed in patients receiving cyclooxygenase-2 (COX-2) inhibitors and to increase the awareness of risk factors that predispose patients to ADEs associated with COX-2 inhibitors.

METHODS

A review of ADEs reported at the University of Pittsburgh Medical Center Presbyterian Hospital (UPMC-P) revealed significant events related to use of celecoxib or rofecoxib. A query of the internal ADE database was performed to identify ADEs involving COX-2 inhibitors from January 1999 to June 2002. A similar query was performed to identify ADEs involving nonselective nonsteroidal antiinflammatory drugs (NSAIDs) reported during this same time period. Utilization data were also collected.

RESULTS

Forty-eight ADEs involving 24 patients receiving COX-2 inhibitors were reported and validated via the UPMC-P ADE review process compared with 38 events in 33 patients receiving nonselective NSAIDs. The types of ADEs reported as related to COX-2 inhibitors were similar to those reported in association with nonselective NSAIDs. Forty-two percent of ADEs (n = 20) involving COX-2 inhibitors and 45% of events (n = 17) involving nonselective NSAIDs were classified as severe. All patients receiving COX-2 inhibitors and 91% of patients receiving nonselective NSAIDs exhibited risk factors that increased their risk to experience an ADE; all but 1 of these patients were receiving outpatient COX-2 inhibitor therapy.

CONCLUSIONS

The observed ADEs involving COX-2 inhibitors were similar to those associated with nonselective NSAIDs. Most events may have been preventable, highlighting the need for education regarding the appropriate use of COX-2 inhibitors.

Effects and mechanisms of glucosides of chaenomeles speciosa on collagen-induced arthritis in rats

Effects of glucosides of chaenomeles speciosa (GCS)-a Chinese traditional herbal medicine (CTM) on inflammatory and immune responses and its mechanisms in collagen-induced arthritis (CIA) rat were studied. Hind paw volumes of rats were measured by volume meter; lymphocyte proliferation, interleukin-1, interleukin-2, TNF-alpha level was determined by 3-(4,5-2 dimethylthiazal-2yl)2,5-diphenyltetrazoliumbromide (MTT) assay; cAMP level in synoviocytes was analyzed by competitive protein binding assay (CPBA). mRNA expression of G(i,), G(s), and TNF-alpha of synoviocytes in CIA rats was measured by RT-PCR and antibodies to collagen type II (CII) were determined by enzyme-linked immunosorbent assay (ELISA), respectively. There was a marked secondary inflammatory response in CIA model, which accompanied with the decrease of body weight and the weight of immune organs simultaneously. The administration of GCS (30, 60, 120 mg x kg(-1), ig x 7 days) inhibited the inflammatory response and restored body weight and the weight of immune organs of CIA rats. Lymphocyte proliferation and IL-2 production of CIA rats increases, together with IL-1 and TNF-alpha in peritoneal macrophages and synoviocytes. The administration of GCS (30, 60, 120 mg x kg(-1), ig x 7 days) reduced above changes significantly. GCS at the concentration of 0.5, 2.5, 12.5, 62.5, 125 mg x l(-1) increased cAMP level of synoviocytes, which decreased in CIA rats in vitro. At the same time, GCS inhibited mRNA expression of G(i,) and TNF-alpha of synoviocytes and increased mRNA expression of G(s) of synoviocytes in CIA rats. GCS had no effect on the concentration of antibodies to CII. GCS possesses anti-inflammatory and immunoregulatory actions and has a therapeutic effect on CIA rats due to G protein-AC-cAMP transmembrane signal transduction of synoviocytes, which play a crucial role in pathogenesis of this disease.

Balance assessment in patients with peripheral arthritis: applicability and reliability of some clinical assessments

BACKGROUND AND PURPOSE

Many individuals with peripheral arthritis blame decreased balance as a reason for limiting their physical activity. It is therefore important to assess and improve their balance. The purpose of the present study was to evaluate the applicability and the reliability of some clinical balance assessment methods for people with arthritis and various degrees of disability.

METHOD

To examine the applicability and reliability of balance tests, 65, 19 and 22 patients, respectively, with peripheral arthritis participated in sub-studies investigating the applicability, inter-rater reliability and test-retest stability of the following methods: walking on a soft surface, walking backwards, walking in a figure-of-eight, the balance sub-scale of the Index of Muscle Function (IMF), the Timed Up and Go (TUG) test and the Berg balance scale.

RESULTS

For patients with moderate disability walking in a figure-of-eight was found to be the most discriminative test, whereas ceiling effects were found for the Berg balance scale. Patients with severe disability were generally able to perform the TUG test and the Berg Balance Scale without ceiling effects. Inter-rater reliability was moderate to high and test-retest stability was satisfactory for all methods assessed.

CONCLUSIONS

Applicable and reliable assessment methods of clinical balance were identified for individuals with moderate and severe disability, whereas more discriminative tests need to be developed for those with limited disability.

Epidemiology and genetics of rheumatoid arthritis

The prevalence of rheumatoid arthritis (RA) is relatively constant in many populations, at 0.5-1.0%. However, a high prevalence of RA has been reported in the Pima Indians (5.3%) and in the Chippewa Indians (6.8%). In contrast, low occurrences have been reported in populations from China and Japan. These data support a genetic role in disease risk. Studies have so far shown that the familial recurrence risk in RA is small compared with other autoimmune diseases. The main genetic risk factor of RA is the HLA DRB1 alleles, and this has consistently been shown in many populations throughout the world. The strongest susceptibility factor so far has been the HLA DRB1*0404 allele. Tumour necrosis factor alleles have also been linked with RA. However, it is estimated that these genes can explain only 50% of the genetic effect. A number of other non-MHC genes have thus been investigated and linked with RA (e.g. corticotrophin releasing hormone, oestrogen synthase, IFN-gamma and other cytokines). Environmental factors have also been studied in relation to RA. Female sex hormones may play a protective role in RA; for example, the use of the oral contraceptive pill and pregnancy are both associated with a decreased risk. However, the postpartum period has been highlighted as a risk period for the development of RA. Furthermore, breastfeeding after a first pregnancy poses the greatest risk. Exposure to infection may act as a trigger for RA, and a number of agents have been implicated (e.g. Epstein-Barr virus, parvovirus and some bacteria such as Proteus and Mycoplasma). However, the epidemiological data so far are inconclusive. There has recently been renewed interest in the link between cigarette smoking and RA, and the data presented so far are consistent with and suggestive of an increased risk.

The epidemiology of rheumatoid arthritis

Studies of the descriptive epidemiology of RA indicate a population prevalence of 0.5% to 1% and a highly variable annual incidence (12-1200 per 100,000 population) depending on gender, race/ethnicity, and calendar year. Secular trends in RA incidence over time have been shown in several studies, supporting the hypothesis of a host-environment interaction. People with RA have a significantly increased risk of death compared with age- and sex-matched controls without RA from the same community. The determinants of this excess mortality remain unclear; however, reports suggest increased risk from gastrointestinal, respiratory, cardiovascular, infectious, and hematologic diseases among RA patients compared with controls. Despite extensive epidemiologic research, the etiology of RA is unknown. Several risk factors have been suggested as important in the development or progression of RA. These include genetics, infectious agents, oral contraceptives, smoking, and formal education. Epidemiologic research is an essential contributor to our understanding of RA.

Identification of Genes Controlling Collagen-Induced Arthritis in Mice: Striking Homology with Susceptibility Loci Previously Identified in the Rat

The susceptibility to collagen-induced arthritis in the highly susceptible DBA/1 mouse has earlier been shown to be partly controlled by the MHC class II gene Aq. To identify susceptibility loci outside of MHC, we have made crosses between DBA/1 and the less susceptible B10.Q strain, both expressing the MHC class II gene Aq. Analysis of 224 F2 intercross mice with 170 microsatellite markers in a genome-wide scan suggested 4 quantitative trait loci controlling arthritis susceptibility located on chromosomes 6, 7, 8, and 10. The locus on chromosome 6 (Cia6), which was associated with arthritis onset, yielded a logarithm of odds score of 4.7 in the F2 intercross experiment and was reproduced in serial backcross experiments. Surprisingly, the DBA/1 allele had a recessive effect leading to a delay in arthritis onset. The suggestive loci on chromosomes 7 and 10 were associated with arthritis severity rather than onset, and another suggestive locus on chromosome 8 was most closely associated with arthritis incidence. The loci on chromosomes 7, 8, and 10 all appeared to contain disease-promoting alleles derived from the DBA/1 strain. Interestingly, most of the identified loci were situated in chromosomal regions that are homologous to regions in the rat genome containing susceptibility genes for arthritis; the mouse Cia6 locus is homologous with the rat Cia3, Pia5, Pia2, and Aia3; the locus on chromosome 7 (Cia7) is homologous with the rat Cia2; and the locus on chromosome 10 (Cia8) is homologous with the rat Cia4.

Hormonal regulation of tumor necrosis factor-alpha, interleukin-12 and interleukin-10 production by activated macrophages. A disease-modifying mechanism in rheumatoid arthritis and systemic lupus erythematosus?

Rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) frequently develop and progress in settings in which sympathoadrenomedullary and gonadal hormone levels are changing, e.g., during pregnancy, postpartum period, menopause, estrogen administration. This paper addresses the view that adrenal and gonadal hormonal deficiency facilitates excessive macrophage production of TNF-alpha and IL-12 that characterizes RA, whereas excessive estrogen action is suggested to play an essential role in the production of IL-10 in patients with SLE. Disease activity in SLE, in contrast to RA, appears to be associated with high-level production of IL-10, relative to the proinflammatory cytokines, TNF-alpha and IL-12. Accumulating data suggest that novel therapeutic approaches may ultimately be developed from continued investigation of the role of the neuroendocrine factors in RA and SLE.

The epidemiology of rheumatoid arthritis in Rochester, Minnesota, 1955-1985

OBJECTIVE

To describe trends in the epidemiology of rheumatoid arthritis (RA) over a period of 30 years in a population-based cohort.

METHODS

An inception cohort of Rochester, Minnesota residents who were > or =35 years of age and had RA (as defined by the 1987 American College of Rheumatology criteria for RA) first diagnosed between January 1, 1955 and January 1, 1985 was assembled and followed up until January 1, 1995. Incidence rates were age- and sex-adjusted to the 1970 US white population. Prevalence of RA in this cohort was estimated on January 1, 1985. A birth-cohort analysis was performed by calculating and comparing incidence rates in each of 16 birth cohorts.

RESULTS

Of the 425 Rochester residents who fulfilled the inclusion criteria, there were 113 men (26.6%) and 312 women (73.4%), with a mean age at diagnosis of 60.2 years. The mean followup time was 15.1 years. The overall age- and sex-adjusted annual incidence of RA among Rochester, Minnesota residents > or =35 years of age (1955-1985) was 75.3 per 100,000 population (95% confidence interval 68.0-82.5). This incidence was approximately double in women compared with that in men and increased steadily with age, until age 85, after which the incidence of RA decreased. Secular trends in the incidence of RA over the entire study period were demonstrated. The overall prevalence of RA on January 1, 1985 was approximately 1%. The birth-cohort analysis showed peak incidence rates in the 1880-1895 birth cohorts.

CONCLUSION

The epidemiology of RA is dynamic. The findings in this study lend further support to the hypothesis of a host-environment interaction in the pathogenesis of RA.

The prevalence and severity of rheumatoid arthritis in Oslo. Results from a county register and a population survey

The objective was (1) to examine the prevalence of rheumatoid arthritis (RA) by a county patient register, (2) to cross-validate the register findings by a postal population survey, and (3) to estimate prevalences of disease subsets according to age, sex, and levels of physical disability. The study was performed within a county setting in the city of Oslo with 356,486 inhabitants between 20 and 79 years of age. Prevalence estimates were calculated from a county patient register comprising 1333 patients with RA and a population survey of 10,000 inhabitants. The overall prevalence of RA between 20 and 79 years was 0.437 (95% CI 0.413, 0.461) after adjusting for the incompleteness of the register by a factor of 1.17. Prevalences exceeding 1.0% was only found among females over 60 years. The prevalence of RA with MHAQ scores > or = 1.5 and > or = 2.0 (range 1-4) was 0.225 (95% CI 0.209, 0.243) and 0.099 (0.088, 0.111) respectively. We conclude that RA is less frequent in the city of Oslo than stated in most of the literature. The prevalence of RA with physical disability levels assumed to be associated with increased mortality is less than half of the overall prevalence of 0.4-0.5%.

Predictors of joint damage in rheumatoid arthritis

Rheumatoid arthritis (RA) is the dominant form of destructive chronic arthritis with the potential to cause substantial disability and permanent functional impairment. The final extent and progression rate with time, however, varies markedly. In order to study effects of intervention and to support early aggressive and atoxic therapy in selected cases, predictive disease markers are needed. Recent advances regarding joint tissue composition and pathophysiology have defined a number of biological marker candidates which need to be explored for possible prognostic information. Some markers are characteristic for RA, such as rheumatoid factors and certain autoantibodies, which although they are more prevalent among patients with aggressive disease are not sensitive as predictors in early disease. Genetic susceptibility markers have been claimed to be good predictors of persisting arthritis in early synovitis clinics, but their role as severity markers in established disease is limited. Unspecific markers of inflammation, notably ESR or CRP when persistently elevated, are useful to monitor disease course and newer markers need to document their superiority over these. Another group of markers are attractive because of enriched or exclusive occurrence in joint tissue, and altered metabolism in joint disease. Thus, collagen type III propeptides, hyaluronates, and neopterin originating in the synovium could be useful, and, in particular, hyaluronate levels indeed do provide some predictive information. Highly tissue-specific cartilage metabolites include aggrecan fragments, collagen II fragments, cartilage oligomeric matrix protein (COMP) and the extraarticular cartilage matrix protein (CMP). When used alone or in combination in early disease some information can be obtained which may in the future facilitate prognostication. Bone metabolism can be monitored and there are different markers for synthesis and resorption. Meanwhile, whilst the new markers are essential research tools, their routine clinical usefulness remains to be proven.