Biomarkers of rheumatoid arthritis: recent progress

Association between the Platelet-Derived Growth Factor/Platelet-Derived Growth Factor Receptor System and Risk of Rheumatoid Arthritis: A Systematic Review and Meta-Analysis

This research examines the association between the platelet-derived growth factor/platelet-derived growth factor receptor (PDGF/PDGFR) system and rheumatoid arthritis (RA) susceptibility through a comprehensive search of the PubMed database to study the expression of the PDGF/PDGFR system in RA. Review Manager software version 5.3 was used for statistical analysis. Six eligible studies published in the English language were included, including 108 rheumatoid arthritis cases and 85 controls with the corresponding 126 and 97 tests, respectively, relating the expression of the PDGF/PDGFR system to the risk of RA. The overall results indicated a significant association between the PDGF/PDGFR system expression and RA (OR = 5.25, 95% CI: 3.00-9.18, p < 00001), RA patients in Asian countries (OR = 4.13, 95% CI = 2.04-8.39, p < 0.0001) and in Western countries (OR = 9.18, 95% CI = 2.04-8.39, p = 0.03), and only PDGF expression in RA patients (OR = 5.28, 95% CI = 2.73-10.21, p < 0.00001). Thus, only the PDGFR expression was insignificantly associated with RA susceptibility (OR = 9.25, 95% CI = 0.63-136.30, p = 0.11). Hence, the PDGF/PDGFR system most likely contributes to susceptibility to RA.

Dichotomy of Local Th1- and Systemic Th2/Th3-Dependent Types of Immune Response in Rheumatoid Arthritis

Biomarkers of activity of rheumatoid arthritis were analyzed in the blood serum and synovial fluid of affected joints in 84 patients. Significant differences between the serum and synovial fluid levels were revealed for 10 of 17 analyzed biomarkers; the levels of IgM and proinflammatory cytokines TNFα, IL-1β, IFNγ, and IL-6 were higher in the synovial fluid. The concentration of IL-10 in the synovial fluid was also elevated. In the peripheral blood, the content of antinuclear antibodies, circulating immune complexes, and cytokines IL-4 and TGF-β was elevated. These findings attest to the development of local Th1 type immune response in affected joints paralleled by compensatory elevation of immunosuppressive cytokine IL-10 and systemic Th2/Th3 type immune response (judging from peripheral blood parameters) in patients with rheumatoid arthritis.

Alterations in nucleotide-binding oligomerization domain-2 expression, pathway activation, and cytokine production in Yao syndrome

Yao syndrome (YAOS) is a systemic autoinflammatory disease (SAID), formerly termed nucleotide-binding oligomerization domain-2 (NOD2)-associated autoinflammatory disease. Due to the recent identification of YAOS, the molecular mechanisms underlying its disease pathogenesis are unclear. With specific NOD2 variants as characteristic genotypic features of YAOS, our study examined NOD2 expression, transcript splicing, signaling pathway activation, and cytokine profiles in peripheral blood mononuclear cells (PBMCs) from 10 YAOS patients and six healthy individuals. All participants were genotyped for NOD2 variants; all YAOS patients were heterozygous for the NOD2 IVS8⁺¹⁵⁸ variant (IVS8⁺¹⁵⁸) and four patients also carried a concurrent NOD2 R702W variant (IVS8⁺¹⁵⁸/R702W haplotype). Resembling other SAIDs, plasma levels of TNFα, IL-1β, IL-6, IFNγ, and S100A12 were unaltered in YAOS patients. Intron-8 splicing of NOD2 transcripts was unaffected by carriage of NOD2 IVS8⁺¹⁵⁸. However, NOD2 transcript level and basal p38 mitogen-activated protein kinase (MAPK) activity were significantly elevated in PBMCs from IVS8⁺¹⁵⁸ YAOS patients. Moreover, these patients' cells had elevated basal IL-6 secretion that was enhanced by muramyl dipeptide (MDP) stimulation. Tocilizumab treatment of a YAOS IVS8⁺¹⁵⁸ patient resulted in marked clinical improvement. In contrast, MDP-stimulated NF-κB activity was uniquely suppressed in haplotype IVS8⁺¹⁵⁸/R702W patients, as was TNFα secretion. Our study demonstrates for the first time that NOD2 expression and pathway activation are aberrant in YAOS, and specific NOD2 genotypes result in distinct NOD2 expression and cytokine profiles. These findings may also help select therapeutic strategies in the future.

Clinical Utility of MBDA Panel in the Management of Adult Onset Still's Disease

BACKGROUND:

Adult Onset Still’s disease (AOSD) carries an expansive presentation – typically featuring a triad of fevers, myalgia/arthralgia, and a rash – which can be mistaken for infectious or malignant etiology. As such, the role of reliable biomarkers becomes critical in the diagnosis and management of AOSD. The employment of MBDA panel may be of clinical utility in AOSD management, as we describe two cases where its application drives treatment plan.

METHODS:

We describe two cases where application of MBDA panel – such as Vectra DA –assisted with disease management.

RESULTS:

Case 1 features a 68-year-old male who presented with recurrent fevers, malaise, and a rash for three weeks. He was found to have an elevated ferritin level (15,599 ng/mL) with elevated acute phase reactants, consistent with AOSD. Vectra DA score was 77 at time of diagnosis. After treatment (see table), repeat Vectra DA at follow-up was 15. Case 2 features a 25-year-old female with history of juvenile idiopathic arthritis (then inactive) who presented with fevers, malaise, and rash. She was found to have an elevated ferritin level (321 ng/mL) with elevated acute phase reactants, also consistent with AOSD. Her Vectra DA score was 80 at peak of symptoms. She underwent appropriate treatment (see table), and repeat Vectra DA at follow-up was 17.

CONCLUSION:

A deeper consideration should be placed on the value of MBDA as a monitoring tool in the management of AOSD, specifically when pertaining to patient’s responsiveness to therapies.

Integrated biomarker profiling of smokers with periodontitis

BACKGROUND

In the context of precision medicine, understanding patient-specific variation is an important step in developing targeted and patient-tailored treatment regimens for periodontitis. While several studies have successfully demonstrated the usefulness of molecular expression profiling in conjunction with single classifier systems in discerning distinct disease groups, the majority of these studies do not provide sufficient insights into potential variations within the disease groups.

AIM

The goal of this study was to discern biological response profiles of periodontitis and non-periodontitis smoking subjects using an informed panel of biomarkers across multiple scales (salivary, oral microbiome, pathogens and other markers).

MATERIAL & METHODS

The investigation uses a novel ensemble classification approach (SVA-SVM) to differentiate disease groups and patient-specific biological variation of systemic inflammatory mediators and IgG antibody to oral commensal and pathogenic bacteria within the groups.

RESULTS

Sensitivity of SVA-SVM is shown to be considerably higher than several traditional independent classifier systems. Patient-specific networks generated from SVA-SVM are also shown to reveal crosstalk between biomarkers in discerning the disease groups. High-confidence classifiers in these network abstractions comprised of host responses to microbial infection elucidated their critical role in discerning the disease groups.

CONCLUSIONS

Host adaptive immune responses to the oral colonization/infection contribute significantly to creating the profiles specific for periodontitis patients with potential to assist in defining patient-specific risk profiles and tailored interventions.

Biomarkers in rheumatic diseases: how can they facilitate diagnosis and assessment of disease activity?

Serological and proteomic biomarkers can help clinicians diagnose rheumatic diseases earlier and assess disease activity more accurately. These markers have been incorporated into the recently revised classification criteria of several diseases to enable early diagnosis and timely initiation of treatment. Furthermore, they also facilitate more accurate subclassification and more focused monitoring for the detection of certain disease manifestations, such as lung and renal involvement. These biomarkers can also make the assessment of disease activity and treatment response more reliable. Simultaneously, several new serological and proteomic biomarkers have become available in the routine clinical setting--for example, a protein biomarker panel for rheumatoid arthritis and a myositis antibody panel for dermatomyositis and polymyositis. This review will focus on commercially available antibody and proteomic biomarkers in rheumatoid arthritis, systemic lupus erythematosus, systemic sclerosis (scleroderma), dermatomyositis and polymyositis, and axial spondyloarthritis (including ankylosing spondylitis). It will discuss how these markers can facilitate early diagnosis as well as more accurate subclassification and assessment of disease activity in the clinical setting. The ultimate goal of current and future biomarkers in rheumatic diseases is to enable early detection of these diseases and their clinical manifestations, and to provide effective monitoring and treatment regimens that are tailored to each patient's needs and prognosis.

Targeted salivary biomarkers for discrimination of periodontal health and disease(s)

Generally, clinical parameters are used in dental practice for periodontal disease, yet several drawbacks exist with the clinical standards for addressing the needs of the public at large in determining the current status/progression of the disease, and requiring a significant amount of damage before these parameters can document disease. Therefore, a quick, easy and reliable method of assessing and monitoring periodontal disease should provide important diagnostic information that improves and speeds treatment decisions and moves the field closer to individualized point-of-care diagnostics.

OBJECTIVE

This report provides results for a saliva-based diagnostic approach for periodontal health and disease based upon the abundance of salivary analytes coincident with disease, and the significant progress already made in the identification of discriminatory salivary biomarkers of periodontitis.

METHODS

We evaluated biomarkers representing various phases of periodontitis initiation and progression (IL-1ß, IL-6, MMP-8, MIP-1α) in whole saliva from 209 subjects categorized with periodontal health, gingivitis, and periodontitis.

RESULTS

Evaluation of the salivary analytes demonstrated utility for individual biomarkers to differentiate periodontitis from health. Inclusion of gingivitis patients into the analyses provided a more robust basis to estimate the value of each of these analytes. Various clinical and statistical approaches showed that pairs or panels of the analytes were able to increase the sensitivity and specificity for the identification of disease.

CONCLUSIONS

Salivary concentrations of IL-1ß, IL-6, MMP-8, MIP-1α alone and in combination are able to distinguish health from gingivitis and periodontitis. The data clearly demonstrated a heterogeneity in response profiles of these analytes that supports the need for refinement of the standard clinical classifications if we are to move toward precision/personalized dentistry for the twenty-first century.