A prospective cohort study of 14-3-3η in ACPA and/or RF-positive patients with arthralgia

Deep immunophenotyping reveals circulating activated lymphocytes in individuals at risk for rheumatoid arthritis

Rheumatoid arthritis (RA) is a systemic autoimmune disease with currently no universally highly effective prevention strategies. Identifying pathogenic immune phenotypes in 'At-Risk' populations prior to clinical disease onset is crucial to establishing effective prevention strategies. Here, we applied mass cytometry to deeply characterize the immunophenotypes in blood from At-Risk individuals identified through the presence of serum antibodies to citrullinated protein antigens (ACPA) and/or first-degree relative (FDR) status (n=52), as compared to established RA (n=67), and healthy controls (n=48). We identified significant cell expansions in At-Risk individuals compared with controls, including CCR2+CD4+ T cells, T peripheral helper (Tph) cells, type 1 T helper cells, and CXCR5+CD8+ T cells. We also found that CD15+ classical monocytes were specifically expanded in ACPA-negative FDRs, and an activated PAX5 low naïve B cell population was expanded in ACPA-positive FDRs. Further, we developed an "RA immunophenotype score" classification method based on the degree of enrichment of cell states relevant to established RA patients. This score significantly distinguished At-Risk individuals from controls. In all, we systematically identified activated lymphocyte phenotypes in At-Risk individuals, along with immunophenotypic differences among both ACPA+ and ACPA-FDR At-Risk subpopulations. Our classification model provides a promising approach for understanding RA pathogenesis with the goal to further improve prevention strategies and identify novel therapeutic targets.

An Autoantigen Atlas From Human Lung HFL1 Cells Offers Clues to Neurological and Diverse Autoimmune Manifestations of COVID-19

COVID-19 is accompanied by a myriad of both transient and long-lasting autoimmune responses. Dermatan sulfate (DS), a glycosaminoglycan crucial for wound healing, has unique affinity for autoantigens (autoAgs) from apoptotic cells. DS-autoAg complexes are capable of stimulating autoreactive B cells and autoantibody production. We used DS-affinity proteomics to define the autoantigen-ome of lung fibroblasts and bioinformatics analyses to study the relationship between autoantigenic proteins and COVID-induced alterations. Using DS-affinity, we identified an autoantigen-ome of 408 proteins from human HFL1 cells, at least 231 of which are known autoAgs. Comparing with available COVID data, 352 proteins of the autoantigen-ome have thus far been found to be altered at protein or RNA levels in SARS-CoV-2 infection, 210 of which are known autoAgs. The COVID-altered proteins are significantly associated with RNA metabolism, translation, vesicles and vesicle transport, cell death, supramolecular fibrils, cytoskeleton, extracellular matrix, and interleukin signaling. They offer clues to neurological problems, fibrosis, smooth muscle dysfunction, and thrombosis. In particular, 150 altered proteins are related to the nervous system, including axon, myelin sheath, neuron projection, neuronal cell body, and olfactory bulb. An association with the melanosome is also identified. The findings from our study illustrate a connection between COVID infection and autoimmunity. The vast number of COVID-altered proteins with high intrinsic propensity to become autoAgs offers an explanation for the diverse autoimmune complications in COVID patients. The variety of autoAgs related to mRNA metabolism, translation, and vesicles suggests a need for long-term monitoring of autoimmunity in COVID. The COVID autoantigen atlas we are establishing provides a detailed molecular map for further investigation of autoimmune sequelae of the pandemic, such as “long COVID” syndrome.

14-3-3η protein is associated with disease activity and osteoporosis in patients with rheumatoid arthritis

Introduction

This study was designed to explore the potential association of serum 14-3-3η protein level with disease activity and bone mineral density (BMD) in Egyptian patients with rheumatoid arthritis (RA). Patients were recruited from the outpatient clinic at Mansoura University Hospital.

Material and methods

One hundred eighty-eight patients with RA and 192 matched controls were enrolled. The rheumatoid arthritis activity parameters were evaluated in RA patients. Bone mineral density was measured. Serum levels of 14-3-3η protein and IL-6 were estimated for all participants by enzyme-linked immunosorbent assays (ELISA).

Results

Rheumatoid arthritis patients had a significantly higher median serum 14-3-3η protein level compared to matched controls (p ≤ 0.05). Serum level of 14-3-3η protein was significantly correlated with DAS28-ESR (p ≤ 0.05) and serum IL-6 level (p ≤ 0.05). The rheumatoid arthritis-osteoporosis group had significantly higher serum 14-3-3η protein than the RA-osteopenia group and RA-control group. Similarly, the difference of the serum 14-3-3η protein between the RA-osteopenia group and the RA-control group was significant. In the linear regression analysis, the strongest factors that were associated with BMD in RA patients were the serum level of 14-3-3η protein (p ≤ 0.05), IL-6 (p ≤ 0.05) and DAS28-ESR (p ≤ 0.05).

Conclusions

Serum level of 14-3-3η protein was significantly elevated in RA patients compared to controls and is significantly correlated with parameters of activity disease. The RA-osteoporosis group had significantly higher serum 14-3-3η protein than the RA-osteopenia group and RA-control group. Serum 14-3-3η protein can be a promising biomarker to reflect RA activity and predict presence of osteoporosis in RA patients.

Oral health-related quality of life in patients with early rheumatoid arthritis is associated with periodontal inflammation and painful temporomandibular disorders: a cross-sectional study

OBJECTIVES

To evaluate oral health-related quality of life (OHRQoL) in early rheumatoid arthritis (ERA) patients and individuals at risk of rheumatoid arthritis (RA) compared to healthy controls, and to explore possible associated factors.

MATERIALS AND METHODS

Fifty ERA patients, 50 at-risk individuals, and 50 age and gender matched healthy controls were recruited. OHRQoL (Oral Health Impact Profile-14 (OHIP-14)); number of decayed, missing, and filled teeth (DMFT); denture use; periodontal inflamed surface area (PISA); xerostomia (xerostomia inventory (XI)); and possible TMD (-pain) diagnoses were recorded. The groups were compared on these variables. Subsequently, backward multiple regression analyses were performed for the ERA and at-risk groups, with OHRQoL as the dependent variable and gender, age, DMFT, denture use, PISA, XI, non-painful TMD, and TMD pain as independent variables.

RESULTS

At-risk individuals had higher XI scores (U = 789.5, z = -3.181, p = 0.001, r = -0.32) and higher prevalence of TMD pain (p = 0.046, OR = 4.57; 95% CI 0.92-22.73) than healthy controls and higher OHIP-14 scores than the ERA group (U = 894.5, z = -2.418, p = 0.016, r = -0.24), while no difference in OHIP-14 was found between the control group and both other groups. For ERA patients, OHRQoL was associated with PISA and TMD pain (R2 = 0.498, p < 0.001). For at-risk individuals, OHRQoL was associated with XI score (R2 = 0.410, p < 0.001).

CONCLUSIONS

Alertness of health professionals to TMD pain and periodontal inflammation in ERA patients and to xerostomia and TMD pain in at-risk individuals is recommended.

CLINICAL RELEVANCE

The results of this study address orofacial aspects that require attention of health professionals in the timeframe around RA onset.

TRIAL REGISTRATION

Dutch National Trial Register (NTR, NTR6362).

EULAR points to consider for conducting clinical trials and observational studies in individuals at risk of rheumatoid arthritis

BACKGROUND

Despite growing interest, there is no guidance or consensus on how to conduct clinical trials and observational studies in populations at risk of rheumatoid arthritis (RA).

METHODS

An European League Against Rheumatism (EULAR) task force formulated four research questions to be addressed by systematic literature review (SLR). The SLR results informed consensus statements. One overarching principle, 10 points to consider (PTC) and a research agenda were proposed. Task force members rated their level of agreement (1-10) for each PTC.

RESULTS

Epidemiological and demographic characteristics should be measured in all clinical trials and studies in at-risk individuals. Different at-risk populations, identified according to clinical presentation, were defined: asymptomatic, musculoskeletal symptoms without arthritis and early clinical arthritis. Study end-points should include the development of subclinical inflammation on imaging, clinical arthritis, RA and subsequent achievement of arthritis remission. Risk factors should be assessed at baseline and re-evaluated where appropriate; they include genetic markers and autoantibody profiling and additionally clinical symptoms and subclinical inflammation on imaging in those with symptoms and/or clinical arthritis. Trials should address the effect of the intervention on risk factors, as well as progression to clinical arthritis or RA. In patients with early clinical arthritis, pharmacological intervention has the potential to prevent RA development. Participants' knowledge of their RA risk may inform their decision to participate; information should be provided using an individually tailored approach.

CONCLUSION

These consensus statements provide data-driven guidance for rheumatologists, health professionals and investigators conducting clinical trials and observational studies in individuals at risk of RA.

A core set of risk factors in individuals at risk of rheumatoid arthritis: a systematic literature review informing the EULAR points to consider for conducting clinical trials and observational studies in individuals at risk of rheumatoid arthritis

BACKGROUND

There is significant interest in determining risk factors in individuals at risk of rheumatoid arthritis (RA). A core set of risk factors for clinical arthritis development has not been defined.

METHODS

A literature search and systematic literature review (SLR) was conducted to identify risk factors in individuals at risk of RA using Medline, Embase, PubMed and Central databases.

RESULTS

3854 articles were identified by the literature search. After screening of titles, 138 abstracts were reviewed and 96 articles finally included. Fifty-three articles included data on risk factors including autoantibodies, subclinical inflammation on imaging, clinical features, serum and cellular biomarkers and genetic markers. Risk factors were dependent on the at-risk population. There was good evidence for serum anticitrullinated protein antibodies (ACPA) levels, as risk factors for arthritis in all at-risk populations (n=13 articles). Subclinical inflammation on ultrasound (n=12) and MRI (n=6) was reported as a risk factor in multiple studies in at-risk individuals with musculoskeletal (MSK) symptoms and undifferentiated arthritis (UA). Clinical features were reported as a risk factor in at-risk individuals with MSK symptoms and UA (n=13). Other risk factors, including serum and cellular markers were less frequently reported.

CONCLUSIONS

Risk factors for arthritis development in RA are specific to the at-risk population. Serum ACPA confers risk in all populations; subclinical inflammation on imaging and clinical features confer risk in at-risk individuals with MSK symptoms. This SLR informed the EULAR taskforce for points to consider on conducting clinical trials and studies in individuals at risk of RA.

A Master Autoantigen-ome Links Alternative Splicing, Female Predilection, and COVID-19 to Autoimmune Diseases

Chronic and debilitating autoimmune sequelae pose a grave concern for the post-COVID-19 pandemic era. Based on our discovery that the glycosaminoglycan dermatan sulfate (DS) displays peculiar affinity to apoptotic cells and autoantigens (autoAgs) and that DS-autoAg complexes cooperatively stimulate autoreactive B1 cell responses, we compiled a database of 751 candidate autoAgs from six human cell types. At least 657 of these have been found to be affected by SARS-CoV-2 infection based on currently available multi-omic COVID data, and at least 400 are confirmed targets of autoantibodies in a wide array of autoimmune diseases and cancer. The autoantigen-ome is significantly associated with various processes in viral infections, such as translation, protein processing, and vesicle transport. Interestingly, the coding genes of autoAgs predominantly contain multiple exons with many possible alternative splicing variants, short transcripts, and short UTR lengths. These observations and the finding that numerous autoAgs involved in RNA-splicing showed altered expression in viral infections suggest that viruses exploit alternative splicing to reprogram host cell machinery to ensure viral replication and survival. While each cell type gives rise to a unique pool of autoAgs, 39 common autoAgs associated with cell stress and apoptosis were identified from all six cell types, with several being known markers of systemic autoimmune diseases. In particular, the common autoAg UBA1 that catalyzes the first step in ubiquitination is encoded by an X-chromosome escape gene. Given its essential function in apoptotic cell clearance and that X-inactivation escape tends to increase with aging, UBA1 dysfunction can therefore predispose aging women to autoimmune disorders. In summary, we propose a model of how viral infections lead to extensive molecular alterations and host cell death, autoimmune responses facilitated by autoAg-DS complexes, and ultimately autoimmune diseases. Overall, this master autoantigen-ome provides a molecular guide for investigating the myriad of autoimmune sequalae to COVID-19 and clues to the rare but reported adverse effects of the currently available COVID vaccines.

An Autoantigen Profile from Jurkat T-Lymphoblasts Provides a Molecular Guide for Investigating Autoimmune Sequelae of COVID-19

In order to understand autoimmune phenomena contributing to the pathophysiology of COVID-19 and post-COVID syndrome, we have been profiling autoantigens (autoAgs) from various cell types. Although cells share numerous autoAgs, each cell type gives rise to unique COVID-altered autoAg candidates, which may explain the wide range of symptoms experienced by patients with autoimmune sequelae of SARS-CoV-2 infection. Based on the unifying property of affinity between autoantigens (autoAgs) and the glycosaminoglycan dermatan sulfate (DS), this paper reports 140 candidate autoAgs identified from proteome extracts of human Jurkat T-cells, of which at least 105 (75%) are known targets of autoantibodies. Comparison with currently available multi-omic COVID-19 data shows that 125 (89%) of DS-affinity proteins are altered at protein and/or RNA levels in SARS-CoV-2-infected cells or patients, with at least 94 being known autoAgs in a wide spectrum of autoimmune diseases and cancer. Protein alterations by ubiquitination and phosphorylation in the viral infection are major contributors of autoAgs. The autoAg protein network is significantly associated with cellular response to stress, apoptosis, RNA metabolism, mRNA processing and translation, protein folding and processing, chromosome organization, cell cycle, and muscle contraction. The autoAgs include clusters of histones, CCT/TriC chaperonin, DNA replication licensing factors, proteasome and ribosome proteins, heat shock proteins, serine/arginine-rich splicing factors, 14-3-3 proteins, and cytoskeletal proteins. AutoAgs such as LCP1 and NACA that are altered in the T cells of COVID patients may provide insight into T-cell responses in the viral infection and merit further study. The autoantigen-ome from this study contributes to a comprehensive molecular map for investigating acute, subacute, and chronic autoimmune disorders caused by SARS-CoV-2.

α2-3 Sialic acid binding and uptake by human monocyte-derived dendritic cells alters metabolism and cytokine release and initiates tolerizing T cell programming

Dendritic cells (DCs) are key in the initiation of the adaptive T cell responses to tailor adequate immunity that corresponds to the type of pathogen encountered. Oppositely, DCs control the resolution phase of inflammation and are able to induce tolerance after receiving anti-inflammatory cytokines or upon encounter of self-associated molecular patterns, such as α2-3 linked sialic acid (α2-3sia).

Objective: We here investigated whether α2-3sia, that bind immune inhibitory Siglec receptors, would alter signaling and reprogramming of LPS-stimulated human monocyte-derived DCs (moDCs).

Methods and Results: Transcriptomic analysis of moDCs stimulated with α2-3sia-conjugated dendrimers revealed differentially expressed genes related to metabolic pathways, cytokines, and T cell differentiation. An increase in genes involved in ATPase regulator activity, oxidoreductase activity, and glycogen metabolic processes was detected. Metabolic extracellular flux analysis confirmed a more energetic moDC phenotype upon α2-3sia binding as evidenced by an increase in both glycolysis and mitochondrial oxidative phosphorylation. TH1 differentiation promoting genes IFNL and IL27, were significantly downregulated in the presence of α2-3sia. Functional assays confirmed that α2-3sia binding to moDCs induced phosphorylation of Siglec-9, reduced production of inflammatory cytokines IL-12 and IL-6, and increased IL-10. Surprisingly, α2-3sia-differentiated moDCs promoted FoxP3+CD25+/-CD127- regulatory T cell differentiation and decreased FoxP3-CD25-CD127- effector T cell proliferation.

Conclusions: In conclusion, we demonstrate that α2-3sia binding to moDCs, phosphorylates Siglec-9, alters metabolic pathways, cytokine signaling, and T cell differentiation processes in moDCs and promotes regulatory T cells. The sialic acid-Siglec axis on DCs is therefore, a novel target to induce tolerance and to explore for immunotherapeutic interventions aimed to restore inflammatory processes.

Biomarker Approach Towards Rheumatoid Arthritis Treatment

Rheumatoid arthritis is an auto-immune disorder, recognized by cartilage as well as bone destruction, which causes irreversible joint deformities, which further results in functional limitations in the patient. Genes like HLA-DRB1 and PTPN22 are likely implicated in the genetic predisposition of rheumatoid arthritis pathology. The first and foremost clinical manifestation in a person with rheumatoid arthritis is joint destruction followed by cartilage and bone destruction caused by cell-cell interactions. The cell-cell interactions are thought to be initialized through the contact of antigen-presenting cells (APC) with CD4+ cells, leading to the progression of the disease. APC includes a complex of class ІІ major histocompatibility complex molecules along with peptide antigens and binds to the receptors present on the surface of T-cells. Further, the activation of macrophages is followed by the release of various pro-inflammatory cytokines such as IL-1 and TNF-α, which lead to the secretion of enzymes that degrade proteoglycan and collagen, which in turn, increase tissue degradation. Biomarkers like IL-6, IL-12, IL-8 and IL-18, 14-3-3η, RANKL, IFN-γ, IFN-β and TGF-β have been designated as key biomarkers in disease development and progression. The study of these biomarkers is very important as they act as a molecular indicator of pathological processes that aggravate the disease.

The oral microbiome in early rheumatoid arthritis patients and individuals at risk differs from healthy controls

OBJECTIVE

It has been suggested that rheumatoid arthritis (RA) may originate at the oral mucosa. Our aim was to assess the oral microbiome and the periodontal condition in patients with early rheumatoid arthritis (ERA) and individuals at risk of RA.

METHODS

Three groups were recruited (50 participants each): (1) ERA patients (2010 ACR/EULAR criteria), (2) at-risk individuals (arthralgia and autoantibodies), and (3) healthy controls. A periodontal examination resulted in scores for bleeding on probing (BOP), pocket probing depth (PPD), and periodontal inflamed surface area (PISA). The microbial composition of subgingival dental plaque, saliva, and tongue coating was assessed using 16S rDNA amplicon sequencing, and compared between groups with permutational multivariate analyses of variance (PERMANOVA).

RESULTS

There was no difference between the groups on the periodontal variables (BOP p=0.70; PPD p=0.30; PISA p=0.56). PERMANOVA showed a difference between the groups in the microbial composition of saliva (F=2.08, p<0.001) and tongue coating (F=2.04, p=0.008), but not plaque (p=0.51). Post-hoc tests showed no difference between the ERA group and at-risk group (saliva F=1.12, p=0.28; tongue coating F=0.834, p=0.59). Discriminative zero-radius operational taxonomic units (zOTUs) were identified: in ERA patients and at-risk individuals, Prevotella in saliva and Veillonella in saliva and tongue coating were at higher relative abundance compared to healthy controls.

CONCLUSION

The results show similarities in the oral microbiome between ERA patients and at-risk individuals, both presenting with increased relative abundance of potentially pro-inflammatory species compared to healthy controls, suggesting a possible association between the oral microbiome and RA onset.

An autoantigen profile of human A549 lung cells reveals viral and host etiologic molecular attributes of autoimmunity in COVID-19

We aim to establish a comprehensive COVID-19 autoantigen atlas in order to understand autoimmune diseases caused by SARS-CoV-2 infection. Based on the unique affinity between dermatan sulfate and autoantigens, we identified 348 proteins from human lung A549 cells, of which 198 are known targets of autoantibodies. Comparison with current COVID data identified 291 proteins that are altered at protein or transcript level in SARS-CoV-2 infection, with 191 being known autoantigens. These known and putative autoantigens are significantly associated with viral replication and trafficking processes, including gene expression, ribonucleoprotein biogenesis, mRNA metabolism, translation, vesicle and vesicle-mediated transport, and apoptosis. They are also associated with cytoskeleton, platelet degranulation, IL-12 signaling, and smooth muscle contraction. Host proteins that interact with and that are perturbed by viral proteins are a major source of autoantigens. Orf3 induces the largest number of protein alterations, Orf9 affects the mitochondrial ribosome, and they and E, M, N, and Nsp proteins affect protein localization to membrane, immune responses, and apoptosis. Phosphorylation and ubiquitination alterations by viral infection define major molecular changes in autoantigen origination. This study provides a large list of autoantigens as well as new targets for future investigation, e.g., UBA1, UCHL1, USP7, CDK11A, PRKDC, PLD3, PSAT1, RAB1A, SLC2A1, platelet activating factor acetylhydrolase, and mitochondrial ribosomal proteins. This study illustrates how viral infection can modify host cellular proteins extensively, yield diverse autoantigens, and trigger a myriad of autoimmune sequelae. Our work provides a rich resource for studies into “long COVID” and related autoimmune sequelae.

An Autoantigen-ome from HS-Sultan B-Lymphoblasts Offers a Molecular Map for Investigating Autoimmune Sequelae of COVID-19

To understand how COVID-19 may induce autoimmune diseases, we have been compiling an atlas of COVID-autoantigens (autoAgs). Using dermatan sulfate (DS) affinity enrichment of autoantigenic proteins extracted from HS-Sultan lymphoblasts, we identified 362 DS-affinity proteins, of which at least 201 (56%) are confirmed autoAgs. Comparison with available multi-omic COVID data shows that 315 (87%) of the 362 proteins are affected in SARS-CoV-2 infection via altered expression, interaction with viral components, or modification by phosphorylation or ubiquitination, at least 186 (59%) of which are known autoAgs. These proteins are associated with gene expression, mRNA processing, mRNA splicing, translation, protein folding, vesicles, and chromosome organization. Numerous nuclear autoAgs were identified, including both classical ANAs and ENAs of systemic autoimmune diseases and unique autoAgs involved in the DNA replication fork, mitotic cell cycle, or telomerase maintenance. We also identified many uncommon autoAgs involved in nucleic acid and peptide biosynthesis and nucleocytoplasmic transport, such as aminoacyl-tRNA synthetases. In addition, this study found autoAgs that potentially interact with multiple SARS-CoV-2 Nsp and Orf components, including CCT/TriC chaperonin, insulin degrading enzyme, platelet-activating factor acetylhydrolase, and the ezrin-moesin-radixin family. Furthermore, B-cell-specific IgM-associated ER complex (including MBZ1, BiP, heat shock proteins, and protein disulfide-isomerases) is enriched by DS-affinity and up-regulated in B-cells of COVID-19 patients, and a similar IgH-associated ER complex was also identified in autoreactive pre-B1 cells in our previous study, which suggests a role of autoreactive B1 cells in COVID-19 that merits further investigation. In summary, this study demonstrates that virally infected cells are characterized by alterations of proteins with propensity to become autoAgs, thereby providing a possible explanation for infection-induced autoimmunity. The COVID autoantigen-ome provides a valuable molecular resource and map for investigation of COVID-related autoimmune sequelae and considerations for vaccine design.

The pre-clinical phase of rheumatoid arthritis: From risk factors to prevention of arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease considered as a multistep process spanning from the interaction of genetic (e.g., shared epitope or non-HLA loci), environmental and behavioral risk factors (e.g., smoking) leading to breaking immune tolerance and autoimmune processes such as the production of autoantibodies (e.g., antibodies against citrullinated proteins ACPA or rheumatoid factors, RF), development of the first symptoms without clinical arthritis, and, finally, the manifestation of arthritis. Despite the typical joint involvement in established RA, the pathogenesis of the disease likely begins far from joint structures: in the lungs or periodontium in association with citrullination, intestinal microbiome, or adipose tissue, which supports normal findings in synovial tissue in ACPA+ patients with arthralgia. The presence of ACPA is detectable even years before the first manifestation of RA. The pre-clinical phase of RA is the period preceding clinically apparent RA with ACPA contributing to the symptoms without subclinical inflammation. While the combination of ACPA and RF increases the risk of progression to RA by up to 10 times, increasing numbers of novel autoantibodies are to be investigated to contribute to the increased risk and pathogenesis of RA. With growing knowledge about the course of RA, new aspiration emerges to cure and even prevent RA, shifting the "window of opportunity" to the pre-clinical phases of RA. The clinical definition of individuals at risk of developing RA (clinically suspect arthralgia, CSA) makes it possible to unify these at-risk individuals' clinical characteristics for "preventive" treatment in ongoing clinical trials using mostly biological or conventional synthetic disease-modifying drugs. However, the combination of symptoms, laboratory, and imaging biomarkers may be the best approach to select the correct target at-risk population. The current review aims to explore different phases of RA and discuss the potential of (non)pharmacological intervention aiming to prevent RA.

An Autoantigen Profile of Human A549 Lung Cells Reveals Viral and Host Etiologic Molecular Attributes of Autoimmunity in COVID-19

We aim to establish a comprehensive COVID-19 autoantigen atlas in order to understand autoimmune diseases caused by SARS-CoV-2 infection. Based on the unique affinity between dermatan sulfate and autoantigens, we identified 348 proteins from human lung A549 cells, of which 198 are known targets of autoantibodies. Comparison with current COVID data identified 291 proteins that are altered at protein or transcript level in SARS-CoV-2 infection, with 191 being known autoantigens. These known and putative autoantigens are significantly associated with viral replication and trafficking processes, including gene expression, ribonucleoprotein biogenesis, mRNA metabolism, translation, vesicle and vesicle-mediated transport, and apoptosis. They are also associated with cytoskeleton, platelet degranulation, IL-12 signaling, and smooth muscle contraction. Host proteins that interact with and that are perturbed by viral proteins are a major source of autoantigens. Orf3 induces the largest number of protein alterations, Orf9 affects the mitochondrial ribosome, and they and E, M, N, and Nsp proteins affect protein localization to membrane, immune responses, and apoptosis. Phosphorylation and ubiquitination alterations by viral infection define major molecular changes in autoantigen origination. This study provides a large list of autoantigens as well as new targets for future investigation, e.g., UBA1, UCHL1, USP7, CDK11A, PRKDC, PLD3, PSAT1, RAB1A, SLC2A1, platelet activating factor acetylhydrolase, and mitochondrial ribosomal proteins. This study illustrates how viral infection can modify host cellular proteins extensively, yield diverse autoantigens, and trigger a myriad of autoimmune sequelae.

Prevalence and significance of serum 14-3-3η in juvenile idiopathic arthritis

BACKGROUND

Prompt diagnosis of juvenile idiopathic arthritis (JIA) is important to avoid long term complications. Elevated serum 14-3-3η levels improve the diagnostic sensitivity of rheumatoid factor (RF) and cyclic citrullinated peptide (CCP) antibody in adult rheumatoid arthritis (RA), and have been associated with more severe phenotype. We investigated the prevalence and clinical significance of serum 14-3-3η in different types of JIA.

METHODS

JIA patients (n = 151) followed by the Pediatric Rheumatology Core at Children's Hospital of Los Angeles were categorized into 5 groups: polyarticular JIA RF+ (PJIA RF+; n = 39), PJIA RF- (n = 39), psoriatic arthritis (PsA; n = 19), enthesitis-related arthritis (ERA; n = 18), and oligoarticular JIA (OJIA [control group]; n = 36). RF, CCP antibody, and 14-3-3η were measured for all patients. 14-3-3η serum levels > 0.2 ng/mL were considered positive. Disease activity was assessed by the Juvenile Arthritis Disease Activity Score-71 (JADAS-71).

RESULTS

Elevated 14-3-3η levels were detected in 34/151 (23%) patients, and across all groups tested. Most patients with 14-3-3η had titers ≥4 times above the cutoff value. The majority (22, 65%) of 14-3-3η-positive patients were also positive for RF or CCP antibodies, 16 (47%) were positive for all 3, and 12 (35%) were single-positive for 14-3-3η. The highest prevalence of 14-3-3η was in PJIA RF+ patients (49%), followed by OJIA (22%). Positivity for 14-3-3η was not significantly associated with disease activity or age at diagnosis.

CONCLUSION

Serum 14-3-3η can be detected in all forms of JIA tested but appears to be most common in PJIA RF+. 14-3-3η does not appear to correlate with disease activity in JIA.

An Autoantigen Atlas from Human Lung HFL1 Cells Offers Clues to Neurological and Diverse Autoimmune Manifestations of COVID-19

COVID-19 is accompanied by a myriad of both transient and long-lasting autoimmune responses. Dermatan sulfate (DS), a glycosaminoglycan crucial for wound healing, has unique affinity for autoantigens (autoAgs) from apoptotic cells. DS-autoAg complexes are capable of stimulating autoreactive B cells and autoantibody production. Using DS affinity, we identified an autoantigenome of 408 proteins from human fetal lung fibroblast HFL11 cells, at least 231 of which are known autoAgs. Comparing with available COVID data, 352 proteins of the autoantigenome have thus far been found to be altered at protein or RNA levels in SARS-Cov-2 infection, 210 of which are known autoAgs. The COVID-altered proteins are significantly associated with RNA metabolism, translation, vesicles and vesicle transport, cell death, supramolecular fibrils, cytoskeleton, extracellular matrix, and interleukin signaling. They offer clues to neurological problems, fibrosis, smooth muscle dysfunction, and thrombosis. In particular, 150 altered proteins are related to the nervous system, including axon, myelin sheath, neuron projection, neuronal cell body, and olfactory bulb. An association with the melanosome is also identified. The findings from our study illustrate a strong connection between viral infection and autoimmunity. The vast number of COVID-altered proteins with propensity to become autoAgs offers an explanation for the diverse autoimmune complications in COVID patients. The variety of autoAgs related to mRNA metabolism, translation, and vesicles raises concerns about potential adverse effects of mRNA vaccines. The COVID autoantigen atlas we are establishing provides a detailed molecular map for further investigation of autoimmune sequelae of the pandemic.

Temporomandibular disorders in patients with early rheumatoid arthritis and at-risk individuals in the Dutch population: a cross-sectional study

OBJECTIVE

To evaluate the prevalence of temporomandibular disorders (TMD) in patients with early rheumatoid arthritis (ERA) and individuals at-risk of RA.

METHODS

150 participants were recruited in three groups (50 per group): (1) patients with ERA (2010 EULAR criteria) (2) at-risk individuals and (3) healthy controls. All participants were tested for seropositivity of rheumatoid factor and anticitrullinated protein antibodies. A possible TMD diagnosis was determined according to the standardised and validated diagnostic criteria for TMD (DC/TMD) in five categories: myalgia, arthralgia, articular disc displacement, degenerative joint disease and headache attributed to TMD. Results were tested for the prevalence of TMD (all categories combined) and TMD pain (myalgia and/or arthralgia). To investigate a possible role for bruxism, a probable sleep and/or awake bruxism diagnosis was determined based on self-report and several clinical features.

RESULTS

The prevalence of any TMD diagnosis did not differ between the three groups. However, at-risk individuals more often had a TMD-pain diagnosis than healthy controls (p=0.046). No such difference was found between the ERA group and the control group. However, within the ERA group, seronegative patients had a TMD-pain diagnosis more often than seropositive patients (4/12 (33%) vs 3/38 (8%), p=0.048). Participants with a TMD-pain diagnosis were more often diagnosed with probable sleep bruxism than those without a TMD-pain diagnosis.

CONCLUSION

The prevalence of TMD pain is increased in individuals at-risk of RA and seronegative ERA patients, and is associated with bruxism signs and symptoms. These results suggest that health professionals should be alert to TMD pain in these groups.

Evaluation of serum14-3-3η protein and Sema3A levels in rheumatoid arthritis: diagnostic and prognostic value

Background

Serum14-3-3η protein plays an important role in the pathogenesis of rheumatoid arthritis (RA) as it is a joint-derived proinflammatory mediator. Semaphorin3A (Sema3A) plays an immune regulatory and bone remodeling role in many autoimmune diseases. Their role in rheumatoid arthritis needs to be evaluated for diagnostic and prognostic prospective values.

Results

The serum level of protein 14-3-3n was significantly higher in patients with RA than those in healthy controls. Serum 14-3-3η has a significant positive correlation with RF and ACPA, but not with either DAS28, ESR, or CRP. Serum 14-3-3η levels were significantly correlated with radiographically assessed joint damage. Serum Sema3A levels were decreased in rheumatoid arthritis patients compared to controls. There were also negative correlations with disease duration and activity score (DAS28), ESR, CRP, and RF.

Conclusion

The discriminative ability of 14-3-3η was comparable to RF and ACPA enhancing its diagnostic capacity. Sema 3A might serve as a predictive marker for radiographic severity and could have a potential therapeutic role in RA.

Serum 14-3-3η is a Marker that Complements Current Biomarkers for the Diagnosis of RA: Evidence from a Meta-analysis

OBJECTIVE

To systematically evaluate the diagnostic value of 14-3-3η protein for rheumatoid arthritis (RA).

METHOD

Searched PubMed, Web of Science, Embase and China Biology Medicine (CBM) databases comprehensively from inception to May 2020. The evaluation index were the pooled sensitivity, specificity, diagnosis odds ratio (DOR), positive likelihood ratio (PLR), negative likelihood ratio (NLR), as well as the area under the summary receiver operating characteristic (SROC) curves. Meta-Disc 1.4 and RevMan 5.3 were used to analyze all statistics. QUADAS-2 tool was applied to evaluate the quality of eligible studies. Subgroup analysis and meta-regression were used to explore the sources of heterogeneity.

RESULTS

Nine articles containing eleven records were eligible for this meta-analysis. The pooled sensitivity of 14-3-3η was 0.63 (95% CI: 0.60 to 0.66), the pooled specificity was 0.90 (95% CI: 0.88 to 0.91). The pooled PLR and NLR was 6.10 (95% CI: 4.67 to 7.96) and 0.40 (95% CI: 0.33 to 0.48), respectively. The pooled DOR was 15.90 (95% CI: 11.15 to 22.68), and the area under the curve (AUC) was 0.8696. Compared with a single indicator (rheumatoid factor or anti-citrullinated protein antibodies), adding 14-3-3η can bring incremental benefits to the diagnosis of RA. The results of subgroup analysis and meta-regression suggested that the two factors (ethnicity, early vs established RA) we analyzed might not be the source of heterogeneity (P value were 0.0979 and 0.4298, respectively) and there was no publication bias among these articles (P = .42).

CONCLUSION

Serum 14-3-3η protein is a supplementary biomarker in the diagnosis of RA.

Serum levels of 14-3-3η are associated with increased disease risk, activity and duration of rheumatoid arthritis in Chinese patients

The aim of the present study was to determine the association between serum 14-3-3η expression levels and disease risk, inflammation level and disease duration in Chinese patients with rheumatoid arthritis (RA). A total of 45 Chinese patients with RA, 45 patients with osteoarthritis (OA) and 44 age- and sex-matched (with the RA group) healthy control (HC) subjects were consecutively recruited for the present case-controlled study. In addition, the demographic and clinicopathological characteristics of the patients with RA were collected. Serum samples were obtained from patients with RA, patients with OA and the HCs, and the serum levels of 14-3-3η were determined by ELISA. Compared with that in the OA patients (P=0.006) and HCs (P<0.001), 14-3-3η expression was significantly increased in RA patients, and receiver operating characteristics (ROC) analysis indicated that it served as a potential predictive marker for the risk of RA. In patients with RA, serum levels of 14-3-3η were positively correlated with disease duration (P=0.003), erythrocyte sedimentation rate (P=0.006) and disease activity score in 28 joints (P=0.025). The proportion of rheumatoid factor (RF)-positive patients (P=0.023) and anti-citrullinated protein antibody (ACPA)-positive patients (P=0.002) with RA was increased (when 14-3-3η expression was increased) compared with RF-negative patients or ACPA-negative patients, respectively. Of note, 14-3-3η serum levels were able to distinguish patients with established RA (disease duration, >2 years) from patients with early RA (disease duration, ≤2 years) with an AUC of 0.759 (95% CI, 0.612-0.905), and the sensitivity and the specificity at the best cut-off point (14-3-3η=0.613 ng/ml) were 79.3 and 75.0%, respectively. Furthermore, 14-3-3η was able to differentiate between RF-positive RA patients and RF-negative patients or HCs. In conclusion, circulating 14-3-3η expression may serve as a novel biomarker for disease risk and activity of RA in Chinese patients.

Preclinical rheumatoid arthritis and rheumatoid arthritis prevention

PURPOSE OF REVIEW

This review is to provide an update on the current understanding of rheumatoid arthritis (RA) development related to disease development prior to the onset clinically apparent synovitis (i.e. Pre-RA), and opportunities for disease prevention.

RECENT FINDINGS

A growing number of studies have demonstrated that serum elevations of autoantibodies rheumatoid factor, antibodies to citrullinated protein/peptide antigens (ACPAs) and antibodies to other posttranslationally modified proteins (e.g. carbamylated proteins) are highly predictive of future development of inflammatory arthritis/RA during a period that can be termed Pre-RA. Other factors including genetic, environmental, symptoms and imaging findings can also enhance prediction. Moreover, several novel biomarkers and changes in autoantibodies (e.g. glycosylation of variable domains) have been identified in Pre-RA. There has also been growing evidence that initiation and propagation of RA-related autoimmunity during the Pre-RA phase may be related to mucosal processes. The discovery of Pre-RA has also underpinned the development of several clinical prevention trials in RA; specifically, the PRAIRI study demonstrated that a single dose of rituximab can delay the onset of clinically apparent IA in at-risk individuals. Additional studies are evaluating the ability of drugs including abatacept, hydroxychloroquine and methotrexate to prevent or delay future RA.

SUMMARY

The results from ongoing natural history and prevention trials in RA should further inform several critical issues in RA prevention including identification and enrolment of individuals at high-risk of imminent RA, the efficacy, safety and cost-effectiveness of prevention, and potentially the identification of new targets for prevention.

Serum 14-3-3η protein is associated with clinical and serologic features of Sjögren's syndrome in patients with systemic lupus erythematosus: a cross-sectional analysis

INTRODUCTION/OBJECTIVES

Systemic lupus erythematosus (SLE) and Sjögren's syndrome (SS) may coexist and carry a higher risk for future comorbidities. Although 14-3-3η protein is recently a known diagnostic marker in rheumatoid arthritis (RA), its role has not been investigated in SLE. The aim of this study was to compare serum 14-3-3η protein level in SLE and RA patients and to examine its association with clinical and laboratory features in SLE patients.

METHODS

Eighty-four SLE patients and 39 RA patients were included. Sociodemographic, SLE disease activity index (SLEDAI), and damage index were assessed for SLE patients. Data about secondary SS were collected. 14-3-3η was measured by ELISA; titres above 0.19 ng/ml were considered positive.

RESULTS

Serum 14-3-3η protein in SLE was significantly lower than in RA (0.37 ± 0.09 vs 1.5 ± 0.51; p < 0.001). 14-3-3η protein level was comparable between SLE patients with and without arthritis (0.29 ± 0.8 vs 0.15 ± 0.08 respectively; p = 0.20). Serum 14-3-3η protein level was higher in SLE with secondary SS features compared to those without (0.22 ± 0.10 IU/ml vs 0.11 ± 0.04 IU/ml; respectively, p < 0.001). There were no differences in 14-3-3η positivity for other lupus criteria or correlation of 14-3-3η titer with SLEDAI. 14-3-3η protein at 1.11 ng/mL yield a secondary SS diagnostic accuracy of 71%.

CONCLUSIONS

Serum 14-3-3η protein level is high in SLE-associated SS. The 14-3-3η protein level was able to distinguish patients with secondary SS among patients with SLE. Studying the role of 14-3-3η protein in Sjögren's syndrome would be considered in further larger scale studies to confirm the impact of any association. Key Points • Serum 14-3-3η protein level is significantly higher in systemic lupus patients with secondary Sjögren's syndrome (SS) in comparison to those without. • Serum 14-3-3η protein can be used as a useful marker to distinguish patients with secondary SS among patients with systemic lupus. • 14-3-3η protein level shows no difference between systemic lupus patients with and without arthritis.

Tumour necrosis factor alpha promotes secretion of 14-3-3η by inducing necroptosis in macrophages

Background

14-3-3η is an intracellular protein also detected in the serum and synovial fluid of patients with rheumatoid arthritis (RA). It is closely related to disease activity and anti-cyclic citrullinated peptide antibody levels. However, the main source of 14-3-3η and the mechanism of its release into the extracellular space remain unclear. Addressing these two points was the main goal of the current study.

Methods

The source of 14-3-3η was investigated by immunostaining RA synovial tissue. Fibroblast-like synoviocytes, CD4⁺ cells, and macrophages were selected as candidates among the various cell types in the synovial tissue. Phosphorylation of mixed-lineage kinase domain-like pseudokinase (MLKL) and cell death of macrophages were studied by phalloidin staining and electron microscopy after stimulation with an oxidative stress inducer (diamide) or tumour necrosis factor (TNF)-α. Extracellular 14-3-3η protein levels were examined by western blotting.

Results

Macrophages from the synovial tissue from RA, but not osteoarthritis, showed dense and widespread cytoplasmic staining for the 14-3-3η protein, co-localized with peptidylarginine deiminase 4. Swelling and membrane rupture of macrophages were induced by treatment with TNF-α, but not interleukin (IL) 6/soluble IL-6 receptor (sIL-6R). Increased MLKL phosphorylation followed by necroptosis was also induced in TNF-α-stimulated macrophages. Necrostatin-1, a necroptosis inhibitor, antagonized MLKL phosphorylation. High levels of 14-3-3η were detected in the culture supernatants of macrophages stimulated with diamide and TNF-α, but not IL-6/sIL-6R.

Conclusions

Macrophages that highly express 14-3-3η undergo TNF-α-induced necroptosis with damage to the cellular structure, resulting in the secretion of 14-3-3η into the extracellular space. The current study provides a novel mechanism for 14-3-3η level increase in the RA synovial fluid.

Serologic Diagnosis of Rheumatoid Arthritis

Accurate diagnosis of inflammatory arthritides remains a challenge because of substantial clinical overlap. To achieve a granular classification for informing clinical decisions, numerous potential serologic biomarkers have been identified. Rheumatologists have settled on rheumatoid factor and anti-citrullinated protein antibodies for the diagnosis of rheumatoid arthritis (RA) based on specificity and sensitivity and their ability to be integrated into clinical algorithms. These biomarkers should be interpreted in their specific clinical context. This article discusses the serologic basis for the diagnosis of RA, how these biomarkers have framed conceptualization of the pathogenesis of RA, and the inherent limitations in their use.

A repertoire of 124 potential autoantigens for autoimmune kidney diseases identified by dermatan sulfate affinity enrichment of kidney tissue proteins

Autoantigens are the molecular targets in autoimmune diseases. They are a cohort of seemingly unrelated self-molecules present in different parts of the body, yet they can trigger a similar chain of autoimmune responses such as autoantibody production. We previously reported that dermatan sulfate (DS) can bind self-molecules of dying cells to stimulate autoreactive CD5+ B cells to produce autoantibodies. The formation of autoantigen-DS complexes converts the normally non-antigenic self-molecules to none-self antigens, and thus DS-affinity represents a common underlying biochemical property for autoantigens. This study sought to apply this property to identify potential autoantigens in the kidney. Total proteins were extracted from mouse kidney tissues and loaded onto DS-Sepharose resins. Proteins without affinity were washed off the resins, whereas those with increasing DS-affinity were eluted with step gradients of increasing salt strength. Fractions with strong and moderate DS-affinity were sequenced by mass spectrometry and yielded 25 and 99 proteins, respectively. An extensive literature search was conducted to validate whether these had been previously reported as autoantigens. Of the 124 proteins, 79 were reported autoantigens, and 19 out of 25 of the strong-DS-binding ones were well-known autoantigens. Moreover, these proteins largely fell into the two most common autoantibody categories in autoimmune kidney diseases, including 40 ANA (anti-nuclear autoantibodies) and 25 GBM (glomerular basement membrane) autoantigens. In summary, this study compiles a large repertoire of potential autoantigens for autoimmune kidney diseases. This autoantigen-ome sheds light on the molecular etiology of autoimmunity and further supports our hypothesis DS-autoantigen complexes as a unifying principle of autoantigenicity.

The Natural History of Rheumatoid Arthritis

PURPOSE

This article reviews the phases of rheumatoid arthritis (RA) development in terms of the evolution of disease, with a focus on events that occur before the first appearance of clinically apparent inflammatory arthritis. This presynovitis period is defined in individuals who eventually develop classified RA as the pre-RA phase. We include additional discussion of the relevance of this model of RA development to the concept of disease prevention.

METHODS

The information provided in this review was identified through searches of the medical literature through MEDLINE and a review of references from published manuscripts as well as information obtained by the authors through attendance at various conferences and working groups related to pre-RA.

FINDINGS

It is now well established that RA develops in a series of phases. The first of these phases is believed to be the presence of genetic and/or environmental risk factors for RA in the absence of detectable systemic autoimmunity in the blood. After this phase, autoimmunity may be detectable through a variety of means (eg, autoantibodies, autoreactive cells) in peripheral blood; in addition, there is emerging evidence that perhaps initiation and early propagation of RA-related autoimmunity may occur at mucosal sites. The presence of autoimmunity detectable in the blood through serologic or other testing is followed in most individuals by a propagation phase that is characterized by an expansion of autoimmunity, inflammation, and symptoms. This transition may be associated with similar or different genetic and environmental factors that initially triggered autoimmunity, as well as continued mucosal inflammation and local RA-related autoantibody production. Eventually, clinically detectable inflammatory arthritis develops that can be classified as RA.

IMPLICATIONS

Understanding the phases of RA development are critical to the development of preventive strategies for this disease.

14-3-3η protein: a promising biomarker for rheumatoid arthritis

Effective management of rheumatoid arthritis (RA) depends on early identification followed by timely invention and proper monitoring of treatment responses which remain challenges facing rheumatologists for lacking biomarkers of high sensitivity and specificity. 14-3-3η has been reported to be a novel RA-related biomarker inducing the expression of multiple factors mediating the pathogenesis of RA, and increasing the diagnostic capture when combined with rheumatoid factor and anticyclic citrullinated peptide antibody. Besides, elevated serum 14-3-3η was relevant to more serious joint erosion and worse therapy outcomes. Here, we summarized the emerging knowledge regarding the roles 14-3-3η plays in RA and its clinical implications as diagnostic, prognostic and therapeutic response surrogate as well as potential drug target for RA.

Disclosure of Personalized Rheumatoid Arthritis Risk Using Genetics, Biomarkers, and Lifestyle Factors to Motivate Health Behavior Improvements: A Randomized Controlled Trial

OBJECTIVE

To determine the effect of disclosure of rheumatoid arthritis (RA) risk personalized with genetics, biomarkers, and lifestyle factors on health behavior intentions.

METHODS

We performed a randomized controlled trial among first-degree relatives without RA. Subjects assigned to the Personalized Risk Estimator for Rheumatoid Arthritis (PRE-RA) group received the web-based PRE-RA tool for RA risk factor education and disclosure of personalized RA risk estimates, including genotype/autoantibody results and behaviors (n = 158). Subjects assigned to the comparison arm received standard RA education (n = 80). The primary outcome was readiness for change based on the trans-theoretical model, using validated contemplation ladder scales. Increased motivation to improve RA risk-related behaviors (smoking, diet, exercise, or dental hygiene) was defined as an increase in any ladder score compared to baseline, assessed immediately, 6 weeks, and 6 months post-intervention. Subjects reported behavior change at each visit. We performed intent-to-treat analyses using generalized estimating equations for the binary outcome.

RESULTS

Subjects randomized to PRE-RA were more likely to increase ladder scores over post-intervention assessments (relative risk 1.23, 95% confidence interval [95% CI] 1.01, 1.51) than those randomized to nonpersonalized education. At 6 months, 63.9% of PRE-RA subjects and 50.0% of comparison subjects increased motivation to improve behaviors (age-adjusted difference 15.8%; 95% CI 2.8%, 28.8%). Compared to nonpersonalized education, more PRE-RA subjects increased fish intake (45.0% versus 22.1%; P = 0.005), brushed more frequently (40.7% versus 22.9%; P = 0.01), flossed more frequently (55.7% versus 34.8%; P = 0.004), and quit smoking (62.5% versus 0.0% among 11 smokers; P = 0.18).

CONCLUSION

Disclosure of RA risk personalized with genotype/biomarker results and behaviors increased motivation to improve RA risk-related behaviors. Personalized medicine approaches may motivate health behavior improvements for those at risk for RA and provide rationale for larger studies evaluating effects of behavior changes on clinical outcomes, such as RA-related autoantibody production or RA development.

Which patients presenting with arthralgia eventually develop rheumatoid arthritis? The current state of the art

Early initiation of treatment in patients with inflammatory arthritis at risk of persistence and/or erosive progression is important because it is associated with a reduced rate of progression of joint damage and functional disability. It has been proposed that a window of opportunity exists, during which disease processes are less matured and disease modification can be more effective. The phase of arthralgia preceding clinical arthritis is likely to be an important part of this window of opportunity, during which treatment might prevent progression to clinical arthritis. Several proof-of-concept trials in individuals with arthralgia are now evaluating this hypothesis. Central to such trials is the ability to identify groups at high risk of rheumatoid arthritis (RA) in whom preventive treatment can be tested. This review describes the relevance of adequate prediction making, as well as the accuracy of different types of predictors (including imaging and serological markers) with their value in predicting the progression of arthralgia to arthritis. Despite promising results, studies have been performed in heterogeneous patient populations and most findings have not been validated in independent studies. Future observational or preventive studies should be conducted with homogeneous patient groups (eg, patients fulfilling the European League Against Rheumatism criteria for arthralgia at risk of RA) in order to increase interstudy comparability and to allow result validation.

Preventing progression from arthralgia to arthritis: targeting the right patients

Early treatment is associated with improved outcomes in patients with rheumatoid arthritis (RA), suggesting that a 'window of opportunity', in which the disease is most susceptible to disease-modifying treatment, exists. Autoantibodies and markers of systemic inflammation can be present long before clinical arthritis, and maturation of the immune response seems to coincide with the development of RA. The pre-arthritis phase associated with symptoms such as as joint pain without clinical arthritis (athralgia) is now hypothesized to fall within the aforementioned window of opportunity. Consequently, disease modulation in this phase might prevent the occurrence of clinically apparent arthritis, which would result in a persistent disease course if untreated. Several ongoing proof-of-concept trials are now testing this hypothesis. This Review highlights the importance of adequate risk prediction for the correct design, execution and interpretation of results of these prevention trials, as well as considerations when translating these findings into clinical practice. The patients' perspectives are discussed, and the accuracy with which RA development can be predicted in patients presenting with arthralgia is evaluated. Currently, the best starting position for preventive studies is proposed to be the inclusion of patients with an increased risk of RA, such as those identified as fulfilling the EULAR definition of 'arthralgia suspicious for progression to RA'.

Autoimmune-autoinflammatory rheumatoid arthritis overlaps: a rare but potentially important subgroup of diseases

At the population level, rheumatoid arthritis (RA) is generally viewed as autoimmune in nature with a small subgroup of cases having a palindromic form or systemic autoinflammatory disorder (SAID) phenotype. Herein, we describe resistant cases of classical autoantibody associated RA that had clinical, genetic and therapeutic responses indicative of coexistent autoinflammatory disease. Five patients with clinically overlapping features between RA and SAID including polysynovitis and autoantibody/shared epitope positivity, and who had abrupt severe self-limiting attacks including fevers and serositis, are described. Mutations or single nucleotide polymorphisms in recognised autoinflammatory pathways were evident. Generally, these cases responded poorly to conventional Disease-modifying anti-rheumatic drugs (DMARD) treatment with some excellent responses to colchicine or interleukin 1 pathway blockade. A subgroup of RA cases have a mixed autoimmune-autoinflammatory phenotype and genotype with therapeutic implications.

Elevated serum 14-3-3η protein may be helpful for diagnosis of early rheumatoid arthritis associated with secondary osteoporosis in Chinese population

Osteoporosis (OP) is one of the signs of bone damage in rheumatoid arthritis (RA). The 14-3-3η protein is an inflammatory protein, which has been reported to be associated with rheumatoid arthritis (RA). This is to determine the serum levels of 14-3-3η protein, evaluate its diagnostic value in early RA, and clear out its significance in RA with secondary osteoporosis. Two hundred fifty-nine RA patients and 80 age and sex-matched healthy controls were included. Assays of serum 14-3-3η protein were done for all participants by enzyme-linked immunosorbent assay (ELISA). Dual-energy X-ray absorptiometry (DEXA) was used to measure bone mineral density (BMD). Serum 14-3-3η protein level was significantly high in RA (2.49/4.72), compared with controls (P < 0.0001). Positive rate of 14-3-3η protein in RA was 97.3%, which was higher than that in controls (χ ² = 276.641, P < 0.0001). Serum 14-3-3η protein level in early RA was significantly higher than that in established RA (3.91/4.82 vs 2.01/3.29, Z = 2.624, P < 0.05). The positive rate among three groups (normal control, early RA group, established RA group) differed from each other (χ ² = 131.396, P < 0.0001). Results of ROC curve indicated the cutoff point of 14-3-3η protein for diagnosis of early RA was 0.879 ng/ml (P < 0.0001). Linear correlation analysis found that serum 14-3-3η protein positively correlated with VAS and HAQ (P < 0.0001), negatively correlated with BMD at lumbar spine and femur in RA (P < 0.0001). Serum 14-3-3η protein among groups of bone mass normal (2.73/3.79), osteopenia (3.15/4.86), and osteoporosis (6.34/6.42) was different in early RA patients (χ ² = 7.974, P < 0.05). Serum 14-3-3η protein levels increase significantly in patients with RA (especially in early RA). There are close relationships between serum 14-3-3η protein and clinical symptoms and osteoporosis in patients with RA.