Diagnostic performance of anti-cyclic citrullinated peptide and rheumatoid factor in patients with rheumatoid arthritis

Successful Treatment of Ultrasound-confirmed Synovitis in Anti-MDA5 Antibody-positive Clinically Amyopathic Dermatomyositis with Corticosteroid Therapy

Anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive clinically amyopathic dermatomyositis (CADM) is a subtype of dermatomyositis without severe myositis but with characteristic cutaneous manifestations and severe interstitial lung disease. Joint symptoms can occur in patients with anti-MDA5 antibody-positive CADM. However, the treatment strategy and utility of ultrasound for treating joint symptoms remain unknown. We herein report an 85-year-old man with anti-MDA5 antibody-positive CADM who presented with ultrasound-confirmed synovitis that improved with medium-dose corticosteroid therapy.

Discriminating between Homogeneous (AC-1) and Dense Fine Speckled (AC-2) Antinuclear Antibody Patterns: Re-Evaluation of Immunofluorescence Imaging

Antinuclear antibodies (ANAs) are essential diagnostic markers in systemic autoimmune rheumatic diseases. Among the 30 ANA patterns, homogeneous (AC-1) and dense fine speckled (AC-2) should be focused on owing to their somewhat indistinct presentation in immunofluorescence imaging and distinct correlation with clinical conditions. This study aimed to develop a flowchart to guide discrimination between AC-1 and AC-2 patterns and to re-evaluate ANA samples according to this flowchart to verify its detection ability. We re-evaluated immunofluorescence imaging of 62 ANA blood samples simultaneously subjected to solid-phase assays for autoantibodies against dsDNA, nucleosomes, histones, and DFS70. The results showed statistically significant odd ratios (ORs) of detection of anti-DFS70 using AC-2 after re-evaluation of total samples (OR 101.9, 95% CI 11.7-886.4, p-value < 0.001) and subgroup analysis of patients' samples (OR 53.8, 95% CI 5.9-493.6, p-value < 0.001). The OR of anti-nucleosome/histone/dsDNA detection using AC-1 in re-evaluated data increased to 5.43 (95% CI 1.00-29.61, p-value = 0.05). In the analysis of specific autoantibodies, more than half of the samples with an AC-2 pattern (54.2%) had specific autoantibodies other than anti-DFS70. We conclude that the flowchart for discriminating between AC-1 and AC-2 ANA patterns in this study is a viable practical guide for other laboratories when encountering equivocal ANA results.

DNA Hypomethylation in the TNF-Alpha Gene Predicts Rheumatoid Arthritis Classification in Patients with Early Inflammatory Symptoms

Biomarkers for the classification of rheumatoid arthritis (RA), and particularly for anti-citrullinated peptide antibody (ACPA)-negative patients, remain an important hurdle for the early initiation of treatment. Taking advantage of DNA-methylation patterns specific to early RA, quantitative methylation-specific qPCR (qMSP) offers a robust technology for the development of biomarkers. We developed assays and established their value as RA classification biomarkers.

METHODS

DNA-methylation data were screened to select candidate CpGs to design qMSP assays. Eight assays were developed and tested on two early inflammatory arthritis cohorts. Logistic regression and bootstrapping were used to demonstrate the added value of the qMSP assays.

RESULT

Differentially methylated CpG data were screened for candidate CpG, thereby meeting the qMSP assay requirements. The top CpG candidate was in the TNF gene, for which we successfully developed a qMSP assay. Significantly lower DNA-methylation levels were observed in RA (p < 4 × 10-9), with a high predictive value (OR < 0.54/AUC < 0.198) in both cohorts (n = 127/n = 157). Regression using both datasets showed improved accuracy = 87.7% and AUC = 0.944 over the model using only clinical variables (accuracy = 85.2%, AUC = 0.917). Similar data were obtained in ACPA-negative patients (n = 167, accuracy = 82.6%, AUC = 0.930) compared to the clinical variable model (accuracy = 79.5%, AUC = 0.892). Bootstrapping using 2000 datasets confirmed that the AUCs for the clinical+TNF-qMSP model had significant added value in both analyses.

CONCLUSION

The qMSP technology is robust and can successfully be developed with a high specificity of the TNF qMSP assay for RA in patients with early inflammatory arthritis. It should assist classification in ACPA-negative patients, providing a means of reducing time to diagnosis and treatment.

A machine learning model identifies patients in need of autoimmune disease testing using electronic health records

Systemic autoimmune rheumatic diseases (SARDs) can lead to irreversible damage if left untreated, yet these patients often endure long diagnostic journeys before being diagnosed and treated. Machine learning may help overcome the challenges of diagnosing SARDs and inform clinical decision-making. Here, we developed and tested a machine learning model to identify patients who should receive rheumatological evaluation for SARDs using longitudinal electronic health records of 161,584 individuals from two institutions. The model demonstrated high performance for predicting cases of autoantibody-tested individuals in a validation set, an external test set, and an independent cohort with a broader case definition. This approach identified more individuals for autoantibody testing compared with current clinical standards and a greater proportion of autoantibody carriers among those tested. Diagnoses of SARDs and other autoimmune conditions increased with higher model probabilities. The model detected a need for autoantibody testing and rheumatology encounters up to five years before the test date and assessment date, respectively. Altogether, these findings illustrate that the clinical manifestations of a diverse array of autoimmune conditions are detectable in electronic health records using machine learning, which may help systematize and accelerate autoimmune testing.

Peripheral ulcerative keratitis, nodular episcleritis, and pulmonary nodules as the initial signs of rheumatic arthritis: A Case Report

Background

Rheumatoid vasculitis (RV) is a rare but potentially devastating complication of rheumatoid arthritis (RA). It typically occurs in patients with extra-articular manifestations. Here we reported a case of PUK with nodular episcleritis and pulmonary nodules that occurred in the same patient without joint involvement.

Case presentation

A 43-year-old Chinese woman, exhibited a partial crescent-shaped marginal corneal ulcer in the right eye at admission and the ulcer developed rapidly into nearly 360-degree ulcers in both eyes within one week. Nodular episcleritis was observed in the right eye. Conjunctival biopsy revealed vasculitis. Her rheumatoid factor (RF) and anti-cyclic citrullinated protein antibody were positive, while anti-neutrophilic cytoplasmic antibody (c-ANCA) and anti-protease 3 were negative. Pulmonary nodules were found, without joint involvement. The ocular condition did not relieve under the topical and systemic use of corticosteroids, or under other immunosuppressive agents until the infliximab therapy. PUK recurrence was observed after the discontinuation of infliximab.

Conclusions

Rapidly deteriorated PUK with nodular episcleritis and pulmonary nodules occurred in the same patient is a special case of RA without joint involvement. This case reinforces the concept that RV may be the initial sign of RA. Infliximab can be used to prevent further progress of RA-related PUK in some refractory cases.

Anti-cyclic citrullinated peptide antibody (ACPA) and Rheumatoid arthritis: Clinical relevance

Rheumatoid Arthritis (RA) is the most common auto-immune, chronic inflammatory joint disease. Predominantly a musculoskeletal condition with a wide spectrum of skeletal and extra-skeletal manifestations, RA has a significant footfall in orthopaedic clinical practice worldwide. RA is essentially a clinical diagnosis; however, laboratory and radiographic investigations can provide complementary diagnostic and prognostic information about the disease. Early diagnosis and initiation of appropriate management are crucial since RA patients can develop chronic, erosive arthritis if left untreated or if treatment is delayed. Rheumatoid Factor (RF) antibody test is routinely employed for diagnostic purposes in patients with suspected RA. However, RF is present only in 70%-80% of patients with RA and can be non-specific. Therefore, Anti-cyclic citrullinated peptide antibody (ACPA), a novel immunological marker for RA is increasingly being utilised to provide higher specificity and a better prognostic indicator in RA patients. We describe the immunological basis of ACPA test and highlight its current applications in the diagnosis, prognosis and monitoring of RA in clinical practice.

Diagnostic value of anti-cyclic citrullinated peptide antibody combined with rheumatoid factor in rheumatoid arthritis in Asia: a meta-analysis

Objective

This meta-analysis explored the diagnostic value of anti-cyclic citrullinated peptide antibody (anti-CCP) and rheumatoid factor (RF) for rheumatoid arthritis (RA) in the Asian population.

Methods

Embase, Medline, Cochrane Library, Chinese Science and Technology Periodicals, China National Knowledge Infrastructure, and China Wanfang Databases were searched from 1 January 2000 to 1 February 2021 to collect studies on the combined detection of anti-CCP and RF for diagnosing RA. The sensitivity, specificity, diagnostic odds ratio (DOR), positive likelihood ratio (+LR), and negative likelihood ratio (−LR) were combined and analyzed. Summary receiver operating characteristic (SROC) curves were drawn.

Results

Twenty-four published papers were analyzed, including 21 combined in series and 8 combined in parallel. In the tandem analysis, the sensitivity = 0.64 [95% confidence interval (CI): 0.58–0.70], specificity = 0.97 (95%CI: 0.95–0.98), +LR = 19.70 (95%CI: 12.74–30.46), −LR = 0.37 (95%CI: 0.31–0.43), DOR = 53.43 (95%CI: 34.46–82.40), and area under the SROC curve = 0.89. In the parallel combination, the sensitivity = 0.87 (95%CI: 0.80–0.92), specificity = 0.76 (95%CI: 0.67–0.84), +LR = 3.68 (95%CI: 2.62–5.17), −LR = 0.17 (95%CI: 0.11–0.26), DOR = 21.56 (95%CI: 11.63–39.99), and area under the SROC curve = 0.89.

Conclusion

Anti-CCP and RF combined detection improves the diagnostic efficiency of RA, providing a potential strategy for early clinical screening in the Asian population.

This trial was retrospectively registered in the INPLASY/Research Registry (https: //inplasy.com/) with the registration number INPLASY202180106.

Prevalence and relevant factors of positive RF in brucellosis patients with arthralgia

Background

Brucellosis is a critical zoonotic disease in the world, it is the non-specific arthralgia that make brucellosis patients easily misdiagnosed as rheumatoid arthritis (RA) in endemic regions. Elevated rheumatoid factor (RF) is an essential indicator of RA, and the RF in brucellosis patients is significantly higher than healthy people. Therefore, this study further explored the distribution of RF and the relevant factors of the RF positivity in brucellosis patients with arthralgia, in order to strengthen the recognition of physicians for brucellosis patients with RF positivity, especially in brucellosis-endemic areas, so as to avoid misdiagnosis and untimely treatment that may lead to malignant outcomes.

Methodology and principal findings

The medical records of all 572 brucellosis inpatients were collected in the Sixth People’s Hospital of Shenyang, China from 2015 to 2016. After excluding 106 patients without arthralgia, 5 patients who unwilling to perform RF testing and 16 patients with diseases that may affect RF, 445 brucellosis inpatients with arthralgia were involved in this retrospective cross-sectional study. 143 (32.1%) patients with RF >10 IU/ml were classified into the RF positive group, with an average level of 16.5[12.2, 34.7] IU/ml, of which 45 (10.1%) patients were high-positive with RF >30 IU/ml. Multivariate logistic regression model was used to further analyze the relevant factors of the RF positivity and found that age, wrist joint pain and elevated C-reactive protein (CRP) were positively associated with RF positivity, with OR of 1.02 (P = 0.024), 8.94 (P = 0.008) and 1.79 (P = 0.019), respectively.

Conclusion

The prevalence of positive RF in brucellosis patients with arthralgia was critical, nearly one-third of patients had RF positive. Elderly men brucellosis patients with arthralgia, wrist joint pain and elevated CRP were at high risk of positive RF. It is reminded that physicians should focus on differential diagnosis during clinical diagnosis and treatment, especially in brucellosis-endemic regions.

Brucellosis is a highly contagious zoonosis caused by Brucella spp., which compromises to organs and systems, causing non-specific symptoms such as fever, headache, sweating, fatigue, myalgia and arthralgia. Similarly, patients with rheumatoid arthritis (RA) may also have the above non-specific symptoms. It is precisely because of the non-specificity and similarity of symptoms that brucellosis patients were easily misdiagnosed and failed to receive timely treatment, resulting in neurosis, chronic fatigue syndrome, endocarditis and other adverse outcomes. However, rheumatoid factor (RF) is an essential indicator of RA, and the RF in brucellosis patients is significantly higher than healthy people. In order to strengthen the recognition of physicians for brucellosis patients with RF positivity, we conducted this research and found that the prevalence of positive RF in brucellosis patients with arthralgia was common and critical. Elderly men brucellosis patients with arthralgia, wrist joint pain and elevated CRP were at high risk of positive RF. It is reminded that physicians should pay attention to the possibility of brucellosis during clinical diagnosis and treatment, especially in brucellosis-endemic regions, which had certain clinical significance.

14-3-3η Protein in Rheumatoid Arthritis: Promising Diagnostic Marker and Independent Risk Factor for Osteoporosis

BACKGROUND

Early identification and disease monitoring are challenges facing rheumatologists in the management of rheumatoid arthritis (RA).

METHODS

We utilized enzyme-linked immunosorbent assay (ELISA) to determine 14-3-3η and anticyclic citrullinated peptide antibody (anti-CCP) levels, with rheumatoid factor (RF) level detected by rate nephelometry. The diagnostic value of each index was determined via receiver operating characteristic (ROC) curve, and the association between 14-3-3η and osteoporosis was assessed using multiple logistic regression analysis.

RESULTS

Serum levels of 14-3-3η were 3.26 ng per mL in patients with RA. These levels were helpful in identifying patients with the disease, with the area under the curve (AUC) being 0.879 and 0.853, respectively, from all healthy control individuals and patients with RA. Combining 14-3-3η with RF or anti-CCP increased the diagnostic rate. Logistic regression analysis identified 14-3-3η as an independent risk factor for RA-related osteoporosis (odds ratio [OR], 1.503; 95% confidence interval [CI], 1.116-2.025; P <.01).

CONCLUSIONS

Serum 14-3-3η detection by itself or combined with other serum indices was helpful in differentiating patients with RA. Also, it was a promising biomarker for disease monitoring in RA.

Assessment of Serum Lipid Profiles and High-sensitivity C-reactive Protein Among Patients Suffering from Rheumatoid Arthritis at Tikur Anbessa Specialized Hospital, Addis Ababa, Ethiopia: A Cross-Sectional Study

Background

Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by severe joint pain, swelling, damage, and disability which leads to joint destruction and loss of function. The complication of RA is associated with cardiovascular diseases, particularly due to systemic inflammation and dyslipidemia. The purpose of this study was to assess the development of atherosclerosis, which acts as a major risk factor for cardiovascular complications in RA patients.

Methods

A hospital-based cross-sectional study was conducted at the Rheumatology Clinic of Tikur Anbessa Specialized Hospital. The study made a comparison of risk factors (dyslipidemia and inflammatory status) between individuals having RA as a case group and apparently healthy individuals as a control group. Simple descriptive statistics, one-way ANOVA, independent sample t-test and multivariate analysis were utilized for statistical analysis. p-value of <0.05 at the 95% confidence level was considered as statistically significant.

Results

The result of this study demonstrated that there was a significant elevation of mean ±SD of TC, TC/HDL, LDL/HDL, and lowered value of HDL-C was seen among RA patients than controls (P-value <0.05). The mean ±SD of inflammatory marker, high-sensitivity C-reactive protein (hsCRP), was significantly higher among RA patients compared to controls (P<0.05). HDL-C had a significant negative correlation with a hsCRP whereas TC/HDL-C and LDL/HDL-C had a significant positive correlation with hsCRP (P<0.05).

Conclusion

In this study, RA patients had lipid abnormalities and elevated systemic inflammation than controls. An increase in hsCRP and dyslipidemia status among RA patients indicates the possible development of an atherosclerotic event. Therefore, assessment of lipid profiles and hsCRP in early RA patients may be helpful to assess the possible development of cardiovascular complications.

Autoantibodies as Diagnostic Markers and Mediator of Joint Inflammation in Arthritis

Rheumatoid arthritis is a systemic, polygenic, and multifactorial syndrome characterized by erosive polyarthritis, damage to joint architecture, and presence of autoantibodies against several self-structures in the serum and synovial fluid. These autoantibodies (anticitrullinated protein/peptide antibodies (ACPAs), rheumatoid factors (RF), anticollagen type II antibodies, antiglucose-6 phosphate isomerase antibodies, anticarbamylated protein antibodies, and antiacetylated protein antibodies) have different characteristics, diagnostic/prognostic value, and pathological significance in RA patients. Some of these antibodies are present in the patients' serum several years before the onset of clinical disease. Various genetic and environmental factors are associated with autoantibody production against different autoantigenic targets. Both the activating and inhibitory FcγRs and the activation of different complement cascades contribute to the downstream effector functions in the antibody-mediated disease pathology. Interplay between several molecules (cytokines, chemokines, proteases, and inflammatory mediators) culminates in causing damage to the articular cartilage and bones. In addition, autoantibodies are proven to be useful disease markers for RA, and different diagnostic tools are being developed for early diagnosis of the clinical disease. Recently, a direct link was proposed between the presence of autoantibodies and bone erosion as well as in the induction of pain. In this review, the diagnostic value of autoantibodies, their synthesis and function as a mediator of joint inflammation, and the significance of IgG-Fc glycosylation are discussed.

Management of rheumatoid arthritis: 2019 updated consensus recommendations from the Hong Kong Society of Rheumatology

The expanding range of treatment options for rheumatoid arthritis (RA), from conventional synthetic disease-modifying antirheumatic drugs (DMARDs) to biological DMARDs (bDMARDs), biosimilar bDMARDs, and targeted synthetic DMARDs, has improved patient outcomes but increased the complexity of treatment decisions. These updated consensus recommendations from the Hong Kong Society of Rheumatology provide guidance on the management of RA, with a focus on how to integrate newly available DMARDs into clinical practice. The recommendations were developed based on evidence from the literature along with local expert opinion. Early diagnosis of RA and prompt initiation of effective therapy remain crucial and we suggest a treat-to-target approach to guide optimal sequencing of DMARDs in RA patients to achieve tight disease control. Newly available DMARDs are incorporated in the treatment algorithm, resulting in a greater range of second-line treatment options. In the event of treatment failure or intolerance, switching to another DMARD with a similar or different mode of action may be considered. Given the variety of available treatments and the heterogeneity of patients with RA, treatment decisions should be tailored to the individual patient taking into consideration prognostic factors, medical comorbidities, drug safety, cost of treatment, and patient preference.

Role of rheumatoid factor isotypes and anti-citrullinated peptide antibodies in the differential diagnosis of non-selected patients with inflammatory arthralgia

BACKGROUND/OBJECTIVES

Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by swelling, tenderness and destruction of synovial joints, leading to severe disability and premature mortality. The aim of the study was to determine the diagnostic accuracy of the 3 isotypes of rheumatoid factor (RF), anti-citrullinated peptide antibodies (ACPA) and the combination of both, for the diagnosis of rheumatoid arthritis (RA) in non-selected patients with inflammatory arthralgia.

METHODS

We include 129 patients with inflammatory Arthalgia from a third level reference Center of rheumatic diseases in Monterrey, México. Their samples were analyzed for RF isotypes (IgA, IgG, and IgM) by ELISA (EUROINMUN), using a cut-off of 20IU/ml, and for ACPA's 5IU/ml; a medical examination was performed to obtain the definitive diagnoses of the patients. Data analysis was carried out using ROC curves for the measurement of sensitivity, specificity, for diagnostic accuracy to verify if the use of 3 RF isotypes and ACPA had a better prediction for the diagnosis of RA than use only one isotype and the ACPA alone.

RESULTS

The ROC showed a sensitivity and specificity of the different antibodies with different cut-off points, being the best for the IgM with 0.802 followed by ACPA, IgA and IgG with 0.771, 0.63, and 0.728 respectively without statistical difference, the sensitivity and specificity of the combination of the 4 antibodies were 81.4 and 73.66%.

CONCLUSION

In non-selected patients with inflammatory arthralgia, the combination of ACPA and isotypes of RF did not demonstrate more sensibility and specificity than IgM isoform of rheumatoid factor measurement only. We recommend that in the clinical scenario of arthralgia, where the diagnoses are Lupus, Sjogren syndrome and Osteoarthritis, RF IgM isoform is used followed by ACPA.

Risk of rheumatoid arthritis in patients with hepatitis C virus infection receiving interferon-based therapy: a retrospective cohort study using the Taiwanese national claims database

OBJECTIVES

To illuminate the association between interferon-based therapy (IBT) and the risk of rheumatoid arthritis (RA) in patients infected with hepatitis C virus (HCV).

DESIGN, SETTING, PARTICIPANTS AND INTERVENTIONS

This retrospective cohort study used Taiwan's Longitudinal Health Insurance Database 2005 that included 18 971 patients with HCV infection between 1 January 1997 and 31 December 2012. We identified 1966 patients with HCV infection who received IBT (treated cohort) and used 1:4 propensity score-matching to select 7864 counterpart controls who did not receive IBT (untreated cohort).

OUTCOME MEASURES

All study participants were followed until the end of 2012 to calculate the incidence rate and risk of incident RA.

RESULTS

During the study period, 305 RA events (3.1%) occurred. The incidence rate of RA was significantly lower in the treated cohort than the untreated cohort (4.0 compared with 5.5 per 1000 person-years, p<0.018), and the adjusted HR remained significant at 0.63 (95% CI 0.43 to 0.94, p=0.023) in a Cox proportional hazards regression model. Multivariate stratified analyses revealed that the attenuation in RA risk was greater in men (0.35; 0.15 to 0.81, p=0.014) and men<60 years (0.29; 0.09 to 0.93, p=0.036).

CONCLUSIONS

This study demonstrates that IBT may reduce the risk of RA and contributes to growing evidence that HCV infection may lead to development of RA.

Computed tomography of pulmonary changes in rheumatoid arthritis: carcinoembryonic antigen (CEA) as a marker of airway disease

Rheumatoid arthritis (RA) classically affects the joints, but can present extra-articular manifestations, including pulmonary disease. The present study aimed to identify possible risk factors or laboratory markers for lung involvement in RA, particularly the presence of rheumatoid factor (RF), anti-citrullinated peptide antibodies (ACPA), and tumor markers, by correlating them with changes observed on chest high-resolution computerized tomography (HRCT). This cross-sectional study involved RA patients who were examined and questioned by a specialist physician and later subjected to chest HRCT and blood collection for measurement of C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), rheumatoid factor (RF), ACPA (anti-vimentin and/or anti-CCP3), and the tumor markers carcinoembryonic antigen (CEA), CA 125, CA 15-3, and CA 19-9. A total of 96 patients underwent chest HRCT. The most frequent findings were bronchial thickening (27/28.1 %) and bronchiectasis (25/26 %). RF was present in 63.2 % of patients (55/87), and ACPA (anti-vimentin or anti-CCP3) was present in 72.7 % of patients (64/88). CEA levels were high in 14 non-smokers (37.8 %) and 23 smokers (62.2 %). CA-19-9 levels were high in 6 of 86 patients (7.0 %), CA 15-3 levels were high in 3 of 85 patients (3.5 %), and CA 125 levels were high in 4 of 75 patients (5.3 %). Multivariate analysis indicated a statistically significant association between high CEA levels and the presence of airway changes in patients with RA (p = 0.048). CEA can serve as a predictor of lung disease in RA and can help identify individuals who require more detailed examination for the presence of respiratory disorders.