Portable Mid-Infrared Spectroscopy Combined with Chemometrics to Diagnose Fibromyalgia and Other Rheumatologic Syndromes Using Rapid Volumetric Absorptive Microsampling.

The diagnostic criteria for fibromyalgia (FM) have relied heavily on subjective reports of experienced symptoms coupled with examination-based evidence of diffuse tenderness due to the lack of reliable biomarkers. Rheumatic disorders that are common causes of chronic pain such as rheumatoid arthritis, systemic lupus erythematosus, osteoarthritis, and chronic low back pain are frequently found to be comorbid with FM. As a result, this can make the diagnosis of FM more challenging. We aim to develop a reliable classification algorithm using unique spectral profiles of portable FT-MIR that can be used as a real-time point-of-care device for the screening of FM. A novel volumetric absorptive microsampling (VAMS) technique ensured sample volume accuracies and minimized the variation introduced due to hematocrit-based bias. Blood samples from 337 subjects with different disorders (179 FM, 158 non-FM) collected with VAMS were analyzed. A semi-permeable membrane filtration approach was used to extract the blood samples, and spectral data were collected using a portable FT-MIR spectrometer. The OPLS-DA algorithm enabled the classification of the spectra into their corresponding classes with 84% accuracy, 83% sensitivity, and 85% specificity. The OPLS-DA regression plot indicated that spectral regions associated with amide bands and amino acids were responsible for discrimination patterns and can be potentially used as spectral biomarkers to differentiate FM and other rheumatic diseases.

Performance of the 2019 American College of Rheumatology/European League Against Rheumatism Classification Criteria for IgG4-Related Disease in a Latin American Cohort.

BACKGROUND/OBJECTIVE: The 2019 American College of Rheumatology/European League Against Rheumatism Classification Criteria (2019 AECC) for IgG4-related disease (IgG4-RD) is considered a significant advancement in the study of this condition. Most studies evaluating their performance have focused on White and Asian patients, leaving a knowledge gap regarding Latin American populations. Therefore, this study aimed to assess the performance of the 2019 AECC for IgG4-RD in a cohort of Latin American patients. METHODS: A multicenter medical records review study was conducted, involving centers from Argentina, Chile, Mexico, Peru, and Uruguay. Data on IgG4-RD patients and mimicker conditions were collected through a standardized online form. The criterion standard for diagnosing IgG4-RD was based on the fulfillment of the Comprehensive Diagnostic Criteria for IgG4-RD and/or the Consensus Statement on Pathology. The 2019 AECC was retrospectively applied. RESULTS: We included 300 patients, with 180 (60%) having IgG4-RD and 120 (40%) having mimicker conditions. The 2019 AECC had a sensitivity of 66.7% and a specificity of 100%. Sensitivity increased to 73.3% when disease-specific autoantibody items were removed, without affecting specificity. The true-positive cases had more involved organs, a higher availability of biopsy results, and were more likely to belong to the Mikulicz/systemic and proliferative phenotypes. CONCLUSIONS: The use of the 2019 AECC for IgG4-RD in a Latin American population confirms its high specificity in excluding those without the disease. The presence of concomitant autoimmune diseases and clinically nonsignificant disease-specific autoantibodies excludes a significant number of patients from fulfilling the criteria.

DFS70 Autoantibodies: Clinical Utility in Antinuclear Antibody Testing.

BACKGROUND: Screening for antinuclear antibodies (ANA) by indirect immunofluorescence (IIF) on HEp-2 cells is helpful for the diagnosis and classification of ANA-associated rheumatic diseases, including systemic lupus erythematosus, Sjögren syndrome, mixed connective tissue disease, systemic sclerosis, and inflammatory myopathies. The dense fine speckled (DFS) pattern is a special HEp-2 IIF pattern (produced by anti-DFS70 antibodies) because it is not associated with a specific medical condition and therefore can obfuscate interpretation. CONTENT: In this paper, detection methods for and clinical associations of anti-DFS70 antibodies are reviewed. SUMMARY: The target antigen of the antibodies that cause the DFS pattern is a 70 kDa protein (DFS70). Commercial methods that detect antibodies to full-length or truncated DFS70 are available for use in clinical laboratories (ELISA, chemiluminescence, dot/line blot). Anti-DFS70 can be found in (apparently) healthy individuals (with a higher frequency in young individuals and in females), in several (inflammatory) conditions and in malignancy. There is no clinical association that is well-established. Special attention (and critical reflection) is given to the observation that monospecific anti-DFS70 (i.e., in the absence of antibodies that are linked to ANA-associated rheumatic diseases) is rarely found in ANA-associated rheumatic diseases.

Impact of Risk Factors on COVID-19 Outcomes in Unvaccinated People With Rheumatic Diseases: A Comparative Analysis of Pandemic Epochs Using the COVID-19 Global Rheumatology Alliance Registry.

OBJECTIVE: Approximately one third of individuals worldwide have not received a COVID-19 vaccine. Although studies have investigated risk factors linked to severe COVID-19 among unvaccinated people with rheumatic diseases (RDs), we know less about whether these factors changed as the pandemic progressed. We aimed to identify risk factors associated with severe COVID-19 in unvaccinated individuals in different pandemic epochs corresponding to major variants of concern. METHODS: Patients with RDs and COVID-19 were entered into the COVID-19 Global Rheumatology Alliance Registry between March 2020 and June 2022. An ordinal logistic regression model (not hospitalized, hospitalized, and death) was used with date of COVID-19 diagnosis, age, sex, race and/or ethnicity, comorbidities, RD activity, medications, and the human development index (HDI) as covariates. The main analysis included all unvaccinated patients across COVID-19 pandemic epochs; subanalyses stratified patients according to RD types. RESULTS: Among 19,256 unvaccinated people with RDs and COVID-19, those who were older, male, had more comorbidities, used glucocorticoids, had higher disease activity, or lived in lower HDI regions had worse outcomes across epochs. For those with rheumatoid arthritis, sulfasalazine and B-cell-depleting therapy were associated with worse outcomes, and tumor necrosis factor inhibitors were associated with improved outcomes. In those with connective tissue disease or vasculitis, B-cell-depleting therapy was associated with worse outcomes. CONCLUSION: Risk factors for severe COVID-19 outcomes were similar throughout pandemic epochs in unvaccinated people with RDs. Ongoing efforts, including vaccination, are needed to reduce COVID-19 severity in this population, particularly in those with medical and social vulnerabilities identified in this study.

Perimenopause in women with rheumatologic diseases: a spotlight on an under-addressed transition.

Abundant research has been published describing the effects invoked during menopause across different organ systems. Changing levels of estrogen and progesterone result in bidirectional alterations of immune cell pathways. Overall, the net trend dampens immunoregulation and promotes inflammation. In paradigmatic rheumatologic diseases, the combined effect is far from predictable. While some features may abate during menopause, studies have shown a general increased frequency toward disease exacerbation. Similarly, while impossible to isolate the ramifications of menopause in women with fibromyalgia, a tendency toward enhanced symptoms is unquestionably apparent. Furthermore, the comorbidities accrued by increasing age and the consequences of long-term medication use may also confound this picture. Periodic rheumatologic visits are warranted, with clinical assessments directed toward a multi-disciplinary approach. Ultimately, while an arsenal of effective tools is available for caring for these women and their underlying conditions, more studies are needed to better clarify how the different stages surrounding perimenopause affect subpopulations with rheumatic diseases and fibromyalgia-related disorders so that clinical course can be predicted and addressed prior to the emergence of symptomatology.

Are the cut-offs of the rheumatoid factor and anti-cyclic citrullinated peptide antibody different to distinguish rheumatoid arthritis from their primary differential diagnoses?

OBJECTIVE: Rheumatoid factor (RF) and anti-cyclic citrullinated peptide antibody (anti-CCP) are commonly used for diagnosis of rheumatoid arthritis (RA), although other rheumatic diseases with arthritis can test positive. This study aimed to determine the cutoff values for RF and anti-CCP with the best diagnostic performance in a sample of patients with RA, compared with other rheumatic diseases. METHODS: This was a descriptive, prospective study. EUROINMMUN enzyme-linked immunosorbent assays for RF isotypes immunoglobulin (Ig) A (IgA), IgG and IgM and third-generation assay IgG for anti-CCP were used in serum samples of patients with RA, other rheumatic diseases and healthy subjects. The cutoff with the best diagnostic performance was determined by the Youden Index and receiver operating characteristic analysis Results: Three hundred and thirty-two serum samples were analysed. The cutoffs proposed in our population were for RF in RA patients versus other rheumatic diseases, and healthy subjects IgM 135 IU/mL, for each disease, compared with RA, were psoriatic arthritis (Psa) IgA 47.2 IU/mL, clinically suspicious arthralgia (CSA) IgA 39.5 IU/mL, primary Sjögren's syndrome (pSS) IgM 180.6 IU/mL, systemic lupus erythematosus (SLE) IgA 42.6 IU/mL, primary fibromyalgia (pFM) IgM 68.6 IU/mL, osteoarthritis (OA) IgM 48 IU/mL, gout IgM 117 IU/mL and healthy IgM 16.3 IU/mL. For anti-CCP, in RA patients versus other rheumatic diseases, and healthy subjects 6.95 IU/mL, for each disease, compared with RA, were Psa 6.8 IU/mL, CSA 9.95 IU/mL, pSS 20.7 IU/mL, SLE 6 IU /mL, pFM 11.8 IU/mL, OA 11.9 IU/mL, gout 5 IU/mL and healthy 5 IU/mL. CONCLUSION: Irrespective of the manufacturer's suggested cutoff, the RA versus differential diagnosis cutoffs must be considered.

What the rheumatologist needs to know about skin biopsy.

The skin biopsy plays an important and powerful role in helping diagnose rheumatic diseases that present with cutaneous findings. As the skin is a very accessible organ, and the skin biopsy can be performed quickly as an in-office procedure, the skin biopsy is utilized frequently in patients with rheumatic diseases. However, the more challenging aspects of performing the biopsy, such as identifying the type of biopsy to perform, the site (s) to biopsy, the type of media to use, and the interpretation of histopathologic data are nuanced and require considerable thought. In this review, we discuss the common skin findings in rheumatic diseases and the general indications for skin biopsies in these diseases. We then summarize how to perform various skin biopsy techniques and how to select the biopsy technique. Finally, we discuss important rheumatic disease-specific considerations for skin biopsy, including where to biopsy and how to interpret the pathologic reports.

Consistency between the 2016 ACR criteria and a previous diagnosis or hypothesis of fibromyalgia in a specialised referral clinic.

OBJECTIVES: Fibromyalgia (FM) is a complex syndrome whose hallmark features are chronic widespread pain, sleep disturbances, fatigue and cognitive dysfunctions. However, it is still difficult to apply validated diagnostic criteria. The aim of this study is to examine the accuracy of a previous diagnosis/diagnostic hypothesis of FM according to the 2016 ACR diagnostic criteria. METHODS: All of the patients newly referred to a private rheumatological clinic with the specific request for a consultation because if FM over an 18-month period were evaluated by means of a standardised protocol in order to determine whether they fulfilled the 2016 ACR diagnostic criteria for FM. They were initially divided into three groups: those with a previous diagnosis of FM (group 1), those with a physician's diagnostic hypothesis of FM (group 2) and those who personally hypothesised FM (group 3). They were subsequently classified as having FM, IFM (borderline scores) or not having FM (non-FM) on the basis of the 2016 ACR diagnostic criteria. RESULTS: The study involved 216 patients (25 males and 191 females): 112 in group 1, 49 in group 2, and 55 in group 3. Only 89 patients (41.2%) fulfilled the ACR criteria; 42 (19.44%) met the study protocol-defined scores for IFM; and 85 (39.35%) were diagnosed as not having FM. Only 50% of the patients with a previous diagnosis of FM fulfilled the ACR criteria, and just under 25% did not have FM. Almost 50% of the patients with a physician's diagnostic hypotheses of FM did not have FM, whereas 20% of the patients who personally hypothesised FM fulfilled the ACR criteria. GP scores and TPCs were significantly different (FM > IFM, FM > non-FM, and IFM > non-FM) as were WPI, SSS and PSD scores for FM > IFM group. Rheumatologists made the previous diagnosis in 92.85% of patients, 53.84% of whom met the ACR criteria and about 20% did not have FM; and as many as 37.5% of the patients with a previous diagnosis made by a non-rheumatologist did not have FM. The non-FM patients were given 84 alternative diagnoses, 78.5% of which referred to rheumatic diseases. One hundred and thirty-one patients had 86 closely pain-related co-morbidities, 94.1% of which were rheumatic diseases. CONCLUSIONS: Our findings confirm the inaccuracy of FM diagnoses and highlights the possibility that in everyday clinical practice, they are not always made with reference to very specific criteria and that there is a high risk of classifying non-FM patients as having FM. They also underline the importance of an accurate differential diagnosis. Separately classifying as IFM those patients who do not meet the ACR criteria, but have clinical findings indicating FM, may help to prevent their exclusion from specific treatment(s).

"Dr ChatGPT": Is it a reliable and useful source for common rheumatic diseases?

AIM: It is inevitable that artificial intelligence applications will be used as a source of information in the field of health in the near future. For this reason, we aimed to evaluate whether ChatGPT, a new Large Language Model, can be used to obtain information about common rheumatic diseases. MATERIALS AND METHODS: Common rheumatic diseases were identified using the American College of Rheumatology and European League against Rheumatism guidelines. Osteoarthritis (OA), rheumatoid arthritis, ankylosing spondylitis (AS), systemic lupus erythematosus, psoriatic arthritis, fibromyalgia syndrome, and gout were identified by using Google trends for the four most frequently searched keywords on Google. The responses were evaluated with seven-point Likert-type reliability and usefulness scales developed by us. RESULTS: The highest score in terms of reliability was OA (mean ± standard deviation 5.62 ± 1.17), whereas the highest score in terms of usefulness was AS (mean 5.87 ± 0.17). There was no significant difference in the reliability and usefulness of the answers given by the ChatGPT (p = .423 and p = .387, respectively). All scores ranged between 4 and 7. CONCLUSIONS: Although ChatGPT is reliable and useful for patients to obtain information about rheumatic diseases, it should be kept in mind that it may give false and misleading answers.

Beliefs, Experiences, and Openness Regarding Dietary Interventions: Data From an Urban Hispanic Population With Rheumatic Disease in the US.

OBJECTIVE: To obtain descriptive data on the beliefs, behaviors, and openness regarding dietary changes for rheumatic diseases in an urban US Hispanic patient population with rheumatic disease as foundational data for future intervention design. METHODS: We distributed a voluntary survey to our primarily Hispanic population at an outpatient rheumatology clinic for 19 weeks. This survey queried individuals' behaviors as they related to dietary intake used for the treatment of rheumatic disease, perceptions of the effect of food groups on rheumatic disease activity, barriers to physician-recommended diets, and willingness to try future interventions. We used descriptive statistics and Pearson's chi-square test to evaluate associations. RESULTS: More than 40% of survey respondents from our primarily (88%) Hispanic population noted a link between what they ate and their underlying rheumatic disease activity. More than one-third of patients had, at some point, modified dietary intake to affect their rheumatic disease. Vegetables, fruit, and white meats were commonly reported to improve disease, while red meat and processed foods were reported to worsen disease. Barriers to following a prespecified diet included cost and lack of knowledge. More than 70% of respondents indicated willingness to attempt certain eating patterns should it help their underlying rheumatic disease. CONCLUSION: In this primarily Hispanic rheumatic disease patient population, many have not only noted a correlation between dietary intake and rheumatic disease activity but are also open to future nutrition-related interventions. As this population experiences poor rheumatic disease outcomes and a high rate of lifestyle-related comorbidities, an intervention to optimize healthy eating patterns would likely be beneficial as well as acceptable.

Immune Checkpoint Inhibitor Related Rheumatological Complications: Cooperation between Rheumatologists and Oncologists.

In cancer, immune checkpoint inhibitors (ICIs) improve patient survival but may lead to severe immune-related adverse events (irAEs). Rheumatic irAEs are a distinct entity that are much more common in a real-life than in clinical trial reports due to their unspecific symptoms and them being a rare cause of hospitalization. This review focuses on an interdisciplinary approach to the management of rheumatic irAEs, including cooperation between oncologists, rheumatologists, and immunologists. We discuss the immunological background of rheumatic irAEs, as well as their unique clinical characteristics, differentiation from other irAEs, and treatment strategies. Importantly, steroids are not the basis of therapy, and nonsteroidal anti-inflammatory drugs should be administered in the front line with other antirheumatic agents. We also address whether patients with pre-existing rheumatic autoimmune diseases can receive ICIs and how antirheumatic agents can interfere with ICIs. Interestingly, there is a preclinical rationale for combining ICIs with immunosuppressants, particularly tumor necrosis factor α and interleukin 6 inhibitors. Regardless of the data, the mainstay in managing irAEs is interdisciplinary cooperation between oncologists and other medical specialties.

Cancer screening in chronic inflammatory rheumatic diseases.

Cancer is a major public health concern, and screening for cancer is a on-going issue in our practice. The risk of cancer in patients with chronic inflammatory rheumatic diseases varies according to their personal medical history, underlying rheumatic disease and its treatment. However, to date, no rheumatology learned society has established specific recommendations for cancer screening in patients with chronic inflammatory rheumatic diseases. In this review, we provide an overview of the risk of cancer in chronic inflammatory rheumatic diseases (related to the disease itself or its treatment), cancer screening in the general population and in immunocompromised subjects, and cancer screening in patients with chronic inflammatory rheumatic diseases.

Circulating Calprotectin (cCLP) in autoimmune diseases.

BACKGROUND AND AIM: Calprotectin (CLP) is a heterodimeric complex formed by two S100 proteins (S100A8/A9), which plays a pivotal role in innate immunity. Due to its intrinsic cytotoxic and proinflammatory properties, CLP controls cell differentiation, proliferation and NETosis and has been associated with a wide range of rheumatic diseases. Our review summarizes the widespread interest in circulating CLP (cCLP) as a biomarker of neutrophil-related inflammation, in autoimmune rheumatic disease (ARD) and non-ARD. METHODS: A thorough literature review was performed using PubMed and EMBASE databases searching for circulating calprotectin and synonyms S100A8/A9, myeloid-related protein 8/14 (MRP8/MRP14), calgranulin A/B and L1 protein in addition to specific ARDs and autoimmune non-rheumatic diseases. We selected only English-language articles and excluded abstracts without the main text. RESULTS: High cCLP serum levels are associated with worse structural outcomes in rheumatoid arthritis and to a lesser extent, in spondyloarthritis. In addition, cCLP can predict disease relapse in some autoimmune diseases including systemic lupus erythematosus (SLE), anti-neutrophil cytoplasmic antibodies-associated vasculitis (AAV) and some severe manifestations of connective tissue diseases, such as glomerulonephritis in SLE, AAV, juvenile idiopathic arthritis, adult-onset Still's disease and lung fibrosis in systemic sclerosis. Therefore, cCLP levels enable the identification of patients who need an accurate and tight follow-up. The clinical usefulness of cCLP as an inflammatory marker has been suggested for inflammatory/autoimmune non-rheumatic diseases, and especially for the monitoring of the inflammatory bowel diseases patients. Currently, there are only a few studies that evaluated the cCLP efficacy as a clinical biomarker in inflammatory/autoimmune non-rheumatic diseases with controversial results. Future studies are warranted to better clarify the role of cCLP in relation to the disease severity in myasthenia gravis, multiple sclerosis, chronic inflammatory demyelinating polyneuropathy, Graves' orbitopathy, autoimmune bullous diseases and uveitis. CONCLUSION: Our literature review supports a relevant role of cCLP as potential prognostic biomarker mirroring local or systemic inflammation, especially in chronic inflammatory rheumatic diseases.

Identifying and Managing Nociplastic Pain in Individuals With Rheumatic Diseases: A Narrative Review.

Chronic pain is a burdensome and prevalent symptom in individuals with rheumatic disease. The International Association for the Study of Pain classifies pain into 3 descriptive categories: nociceptive, neuropathic, and nociplastic. These categories are intended to provide information about the mechanisms underlying the pain, which can then serve as targets for drug or non-drug treatments. This review describes the 3 types of pain as they relate to patients seen by rheumatology health care providers. The focus is on identifying individuals with nociplastic pain, which can either occur in isolation as in fibromyalgia, or as a comorbidity in individuals with primary autoimmune conditions, such as rheumatoid arthritis and systemic lupus erythematosus. Practical information about how rheumatology health care providers can approach and manage chronic pain is also provided.

Clinical Visit Frequencies in Rheumatology: A Systematic Literature Review.

OBJECTIVE: Clinical visits are a fundamental aspect of rheumatic disease care, but recommendations for appropriate visit frequencies are largely absent from guidelines, scarcely studied, and inconsistently reported. The aim of this systematic review was to summarize the evidence pertaining to visit frequencies for major rheumatic diseases. METHODS: This systematic review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Title/abstract screening, full-text screening, and extraction were carried out by 2 independent authors. Annual visit frequencies were either extracted or calculated and stratified by disease type and country of study. Weighted mean annual visit frequencies were calculated. RESULTS: A total of 273 relevant manuscript records were screened, and 28 were included after applying selection criteria. The included studies were equally divided between US and non-US and were published between 1985 and 2021. Most (n = 16) focused on rheumatoid arthritis (RA), systemic lupus erythematosus (SLE; n = 5), and fibromyalgia (FM; n = 4). For RA, the average annual visit frequencies were 5.25 for US rheumatologists, 4.80 for US non-rheumatologists, 3.29 for non-US rheumatologists, and 2.74 for non-US non-rheumatologists. For SLE, annual visit frequencies for non-rheumatologists were much higher than for US rheumatologists (12.3 versus 3.24). For FM, annual visit frequencies were 1.80 for US rheumatologists and 0.40 for non-US rheumatologists. There was a decreasing trend of visit frequency to rheumatologists from 1982 to 2019. CONCLUSION: Evidence for rheumatology clinical visits was limited and heterogeneous on a global scale. However, general trends suggest more frequent visits in the US and less frequent visits in recent years.

[Recommendations for the diagnosis and treatment of rheumatic diseases-related hemophagocytic syndrome in China].

Hemophagocytic syndrome (HPS), which is currently named as hemophagocytic lymphohistiocytosis (HLH), is a hyperinflammatory syndrome characterized by persistent fever, hepatosplenomegaly, pancytopenia and hemophagocytosis found in bone marrow, liver, spleen and lymph nodes due to excessive activation of macrophages and cytotoxic T cells. Macrophage activation syndrome (MAS) is a specific form of HLH induced by autoinflammatory/autoimmune disorders which can be life-threatening and requires multiple disciplines. In order to improve clinicians' understanding of MAS and standardize the clinical diagnosis and treatment practice of MAS, the rheumatology branch of Chinese Rheumatology Association organized domestic experts to formulate the diagnosis and treatment standard, in order to improve the diagnosis and treatment level of MAS and improve the prognosis of patients.

[Paraneoplastic syndromes in rheumatology]. / Paraneoplastische Syndrome in der Rheumatologie.

Paraneoplastic syndromes in rheumatology are a group of canonical rare rheumatic diseases with musculoskeletal involvement that occur in close temporal and causal association with malignancies. Knowledge of these possibly enables a prognostically relevant early diagnosis of the underlying malignant disease. In the era of immune checkpoint inhibitor treatment, there are first indications of an increase in the incidence and severity of paraneoplastic syndromes, so that they are becoming of increasing importance for the practicing rheumatologist. These nine syndromes, paraneoplastic arthritis, palmar fasciitis and polyarthritis, remitting seronegative symmetrical synovitis with pitting edema, pancreatic panniculitis with polyarthritis, paraneoplastic vasculitis, cancer-associated myositis, hypertrophic osteoarthropathy (Marie-Bamberger), eosinophilic fasciitis and tumor-induced osteomalacia, usually occur with characteristic courses and sometimes pathognomonic clinical manifestations, which are presented in this article accompanied by the rational use of a diagnostic algorithm for tumor detection. With frequently disappointing therapeutic response to glucocorticoids, nonsteroidal antirheumatic drugs and immunosuppressants, treatment of the underlying malignant disease represents the crucial step in the treatment of paraneoplastic syndromes.

Exploring High-Throughput Immunoassays for Biomarker Validation in Rheumatic Diseases in the Context of the Human Proteome Project.

Rheumatic diseases are high prevalence pathologies with different etiology and evolution and low sensitivity in clinical diagnosis. Therefore, it is necessary to develop an early diagnosis method which allows personalized treatment, depending on the specific pathology. The biology/disease initiative, at Human Proteome Project, is an integrative approach to identify relevant proteins in the human proteome associated with pathologies. A previously reported literature data mining analysis, which identified proteins related to osteoarthritis (OA), rheumatoid arthritis (RA), and psoriatic arthritis (PSA) was used to establish a systematic prioritization of potential biomarkers candidates for further evaluation by functional proteomics studies. The aim was to study the protein profile of serum samples from patients with rheumatic diseases such as OA, RA, and PSA. To achieve this goal, customized antibody microarrays (containing 151 antibodies targeting 121 specific proteins) were used to identify biomarkers related to early and specific diagnosis in a screening of 960 serum samples (nondepleted) (OA, n = 480; RA, n = 192; PSA, n = 288). This functional proteomics screening has allowed the determination of a panel (30 serum proteins) as potential biomarkers for these rheumatic diseases, displaying receiver operating characteristics curves with area under the curve values of 80-90%.

Paraneoplastic musculoskeletal disorders: review and update for radiologists.

Rheumatic paraneoplastic syndromes are rare syndromes that occur at distant sites from the underlying tumor and may involve the bones, joints, fasciae, muscles, or vessels. In the absence of a known tumor, early recognition of a rheumatic syndrome as paraneoplastic permits dedicated work-up for, and potentially early treatment of an occult malignancy. Although there is a continuously growing list of paraneoplastic rheumatic disorders, not all of these disorders have a well-established association with a neoplastic process. The goals of this article are to review the clinical characteristics, diagnostic work-up, and imaging findings of well-documented rheumatic paraneoplastic disorders.