Measures in rheumatoid arthritis: are we measuring too many parameters

Correlation of Hematological Indices and Acute-Phase Reactants in Rheumatoid Arthritis Patients on Disease-Modifying Antirheumatic Drugs: A Retrospective Cohort Analysis

Acute-phase markers are often used to evaluate the disease activity of rheumatoid arthritis (RA). Occasionally, the serum levels of acute-phase reactants remain normal in patients with obvious inflamed joints. Hematological indices derived from complete blood counts have been shown to correlate with disease activity. This provides a potential practical implementation in daily practice. Only a few studies have evaluated the relation between hematological indices and novel RA treatment (i.e., biological and targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs); no research has examined the changes in hematological indices in RA treatments longitudinally. We conducted a retrospective study involving 273 RA patients with b/tsDMARD treatment and followed them for at least a year. Baseline, 3-month, and 6-month lab data were collected. The results indicated a reduction in the neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), monocyte-lymphocyte ratio (MLR), and systemic immune-inflammation index (SII) post-treatment. Higher baseline PLRs and SIIs were associated with a more significant reduction in ESR at three months (η2 = 0.03/0.13, p = 0.21/0.023). NLR and SII correlated with CRP moderately at three months (r = 0.373/0.394, p < 0.001/< 0.001). A correlation comparison showed that the correlation of NLR and PLR with CRP differs during different periods (p = 0.037/0.004). Subgroup analysis revealed that the time effect on correlation is related to treatment with Janus kinase inhibitor and anti-interleukin-6 but not antitumor necrosis factors.

Low Serum BAFF Concentration Is Associated with Response to TNF Inhibitors in Seropositive Patients with Rheumatoid Arthritis

We investigated B-cell-activating factor (BAFF) in relation to response to treatment with TNF inhibitors (TNFis) in rheumatoid arthritis (RA). This was a longitudinal study including 158 patients with RA treated with TNFis and followed up for 6 months. Clinical response at 6 months of treatment was defined according to the EULAR criteria for good responders (GRs). BAFF concentration was measured in serum samples, collected at baseline and at 6 months. Associations with EULAR response were evaluated using univariable and multivariable logistic regression models. ROC analysis was performed to determine the optimal threshold of serum BAFF concentration associated with good EULAR response to treatment. After 6 months of TNFi treatment, 24% of patients were GRs. They had a lower BMI, lower baseline DAS28 and lower baseline serum BAFF concentration than non-responders. After 6 months of TNFi treatment, autoantibody-positive patients who attained GR had significantly lower serum BAFF concentrations compared with patients who did not. Serum BAFF < 968 pg/mL at 6 months represented the concentration likely to best discriminate between GR and non-GR at 6 months of TNFi treatment. Autoantibody-seropositive patients who had serum BAFF < 968 pg/mL at 6 months demonstrated a more than four-fold increased probability to be GRs compared with patients with higher BAFF concentrations. In conclusion, serum BAFF concentrations were associated with response to TNFis in seropositive RA patients, corroborating the importance of the B-cell compartment in RA.

Systemic inflammation response index (SIRI) as a novel biomarker in patients with rheumatoid arthritis: a multi-center retrospective study

OBJECTIVES

To evaluate the potential ability of systemic inflammation response index (SIRI) as a novel biomarker in patients with rheumatoid arthritis (RA) and explore the mechanisms.

METHOD

Patients fulfilling the 2010 ACR/EULAR classification criteria for RA were enrolled in this study. Demographic, clinical, and laboratory characteristics of all subjects were collected. Neutrophil/lymphocyte ratio (NLR), monocyte/lymphocyte ratio (MLR), platelet/lymphocyte ratio (PLR), and SIRI were calculated. Statistical analysis was performed, and P-values < 0.05 were considered statistically significant.

RESULTS

One thousand four hundred ninety-nine RA patients from five hospitals were included, with 366 healthy volunteers served as controls. The NLR, MLR, PLR, and SIRI significantly increased in RA patients. Receiver operating characteristics (ROC) curve analysis showed SIRI, and NLR could distinguish RA from healthy controls. Correlation analysis and multiple linear regression analysis indicated that SIRI and PLR positively correlated with disease activity in RA. The NLR, MLR, and SIRI increased significantly in patients with RA-associated interstitial lung disease (ILD). There was a good accuracy of SIRI in differentiating RA-ILD from RA patients without ILD. SIRI was also found to be higher in RA patients with tumor and could differentiate them from RA patients without tumor.

CONCLUSIONS

SIRI could be evaluated as a novel, non-invasive, and suitable biomarker for assisting in the diagnosis process and demonstrating the disease activity of RA, as well as predicting RA-ILD and tumor development of RA patients. Key Points • As a novel biomarker, systemic inflammation response index (SIRI) may assist in the diagnosis process and indicate the disease activity of RA patients • SIRI may predict the development of RA-associated interstitial lung disease (RA-ILD) and tumor in RA patients • SIRI is more satisfactory than other blood cells-based indexes in the assessment of RA patients.

Neutrophil-lymphocyte, platelet-lymphocyte and lymphocyte-monocyte ratios may not be useful markers to assess disease activity in rheumatoid arthritis: A STROBE-compliant article

The associations among the neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR) and lymphocyte-monocyte ratio (LMR) and disease activity in rheumatoid arthritis remains unclear.To evaluate these indicators as potential markers of disease activity in patients with rheumatoid arthritis (RA).This cross-sectional study included 547 adult patients with RA. The patients were divided into two groups according to the disease activity score (DAS) system: remission and disease activity. Differences in the NLR, PLR and LMR of the two groups were assessed. Correlations were analyzed using Spearman analysis, and receiver operating characteristic (ROC) curves were used to identify the sensitivity, specificity, and optimal cutoff values to differentiate active RA patients from inactive RA patients.There was a statistically significant difference in the NLR (4.2 ± 3.2 vs 3.4 ± 2.4, P = .034) and PLR (222.3 ± 136.4 vs 176.9 ± 89.8, P = .006) between the two groups, but not for the LMR (3.0 ± 1.8 vs 3.4 ± 2.4, P = .115). In addition, the DAS28 and traditional inflammatory markers, including ESR and CRP, were weakly positively correlated with the NLR and PLR. Based on the ROC curves, the NLR (sensitivity 31.8%, specificity 77.8%) and PLR (sensitivity 57.3%, specificity 63.9%) were less valuable than the ESR (sensitivity 67.2%, specificity 91.7%) and CRP (sensitivity 76.2%, specificity 91.7%) for differentiating inactive RA patients from active RA patients due to low sensitivity and specificity and combining NLR or PLR also cannot significantly improved the diagnostic value of ESR and CRP.NLR, PLR and LMR may not be an useful independent diagnostic or complementary marker for disease activity in RA patients.

A clinical model for identifying an inflammatory phenotype in mood disorders

Increasingly, clinical research has found inflammatory correlates of psychiatric disorders, particularly mood symptomatology. Biological measures may provide greater precision in many cases and may capture clinically-relevant inflammatory signposts, such as central obesity risk, inflammation-associated co-morbid medical conditions, or proinflammatory lifestyle choices. In order to expand understanding of the role of inflammation in mood disorders, we propose a more inclusive clinical model for capturing an inflammatory phenotype of depression by identifying clinically-relevant inflammatory phenotypes grounded in biology. Our model includes chronic conditions and lifestyle behaviors associated with clinically elevated inflammation in mood disorders. Elements of this "inflamed depression" model include: obesity, low HDL concentrations, elevated triglyceride concentrations, chronically elevated blood pressure, clinical diagnosis of hypothyroidism, migraines, rheumatoid arthritis, adult onset diabetes, inflammatory bowel diseases, inflammatory skin conditions, and lifestyle factors including smoking cigarettes and chronic stress.

Characterization of neutrophil-to-lymphocyte ratio as a measure of inflammation in rheumatoid arthritis

OBJECTIVES

The neutrophil to lymphocyte ratio (NLR) is one of the well-recognized sensitive measures of inflammation. This cross-sectional observational study was aimed at characterizing the relationship of NLR with the inflammatory markers erythrocyte sedimentation rate (ESR), C-reative protein (CRP), Disease Activity Score of 28 joints (DAS28)-CRP(3), joint counts and quality measures of rheumatoid arthritis (RA).

MATERIALS AND METHODS

Patients with RA were recruited in two phases. The following were assessed for all patients: joint count, pain by visual analogue scale (VAS), complete blood count, ESR, CRP and quality index assessment using the Short Form health survey (SF-36) questionnaire. A subgroup analysis was also performed to evaluate the association between NLR and cytokines.

RESULTS

Four hundred and eighty-nine subjects were recruited. Distribution of NLR values corresponded with DAS28-CRP(3) rather than CRP and ESR. A significant difference in VAS, swollen joint counts (SJC-28), inflammatory parameters and general health outcome measures was observed among the NLR groups. A weak correlation was observed between NLR and RA disease measures. It had least bias at lower ranges with DAS28-CRP(3) than CRP and ESR. The NLR cut-off value of 1.4 classified the patients in deep remission with 90% specificity, 24% sensitivity, likelihood ratio positive (LR+) 2.46 and likelihood ratio negative (LR-) 0.84. CRP was a significant baseline predictor of NLR. A significant influence of interleukin-6 on CRP was noted.

CONCLUSION

In contrast to the traditional markers, NLR may serve as a less expensive and effective measure of inflammation in RA. Its efficacy is comparable to that of CRP and it is not impacted by the cytokines influencing CRP and ESR.

A novel inflammatory biomarker, GlycA, associates with disease activity in rheumatoid arthritis and cardio-metabolic risk in BMI-matched controls

Background

RA and CVD both have inflammation as part of the underlying biology. Our objective was to explore the relationships of GlycA, a measure of glycosylated acute phase proteins, with inflammation and cardiometabolic risk in RA, and explore whether these relationships were similar to those for persons without RA.

Methods

Plasma GlycA was determined for 50 individuals with mild-moderate RA disease activity and 39 controls matched for age, gender, and body mass index (BMI). Regression analyses were performed to assess relationships between GlycA and important markers of traditional inflammation and cardio-metabolic health: inflammatory cytokines, disease activity, measures of adiposity and insulin resistance.

Results

On average, RA activity was low (DAS-28 = 3.0 ± 1.4). Traditional inflammatory markers, ESR, hsCRP, IL-1β, IL-6, IL-18 and TNF-α were greater in RA versus controls (P < 0.05 for all). GlycA concentrations were significantly elevated in RA versus controls (P = 0.036). In RA, greater GlycA associated with disease activity (DAS-28; R_DAS-28 = 0.5) and inflammation (R_ESR = 0.7, R_hsCRP = 0.7, R_IL-6 = 0.3: P < 0.05 for all); in BMI-matched controls, these inflammatory associations were absent or weaker (hsCRP), but GlycA was related to IL-18 (R_hsCRP = 0.3, R_IL-18 = 0.4: P < 0.05). In RA, greater GlycA associated with more total abdominal adiposity and less muscle density (R_{abdominal-adiposity} = 0.3, R_{muscle-density} = −0.3, P < 0.05 for both). In BMI-matched controls, GlycA associated with more cardio-metabolic markers: BMI, waist circumference, adiposity measures and insulin resistance (R = 0.3-0.6, P < 0.05 for all).

Conclusions

GlycA provides an integrated measure of inflammation with contributions from traditional inflammatory markers and cardio-metabolic sources, dominated by inflammatory markers in persons with RA and cardio-metabolic factors in those without.

MeCP2-Related Diseases and Animal Models

The role of epigenetics in human disease has become an area of increased research interest. Collaborative efforts from scientists and clinicians have led to a better understanding of the molecular mechanisms by which epigenetic regulation is involved in the pathogenesis of many human diseases. Several neurological and non-neurological disorders are associated with mutations in genes that encode for epigenetic factors. One of the most studied proteins that impacts human disease and is associated with deregulation of epigenetic processes is Methyl CpG binding protein 2 (MeCP2). MeCP2 is an epigenetic regulator that modulates gene expression by translating epigenetic DNA methylation marks into appropriate cellular responses. In order to highlight the importance of epigenetics to development and disease, we will discuss how MeCP2 emerges as a key epigenetic player in human neurodevelopmental, neurological, and non-neurological disorders. We will review our current knowledge on MeCP2-related diseases, including Rett Syndrome, Angelman Syndrome, Fetal Alcohol Spectrum Disorder, Hirschsprung disease, and Cancer. Additionally, we will briefly discuss about the existing MeCP2 animal models that have been generated for a better understanding of how MeCP2 impacts certain human diseases.

C-reactive protein and the biology of disease

The C-reactive protein (CRP) is a plasma protein of hepatic origin, belonging to pentraxin family and forms a major component of any inflammatory reaction. A key component of the innate immunity pathway, the concentration of CRP may rapidly increase to levels more than 1,000-folds above normal values as a consequence to tissue injury or infection. Although functioning as a classical mediator of innate immunity, it functions via interaction of components of both humoral and cellular effector systems of inflammation. Initially considered as an acute-phase marker in tissue injury, infection and inflammation, it now has a distinct status of a disease marker in cardiovascular diseases and is well known of its clinical and pathological significance. The present torrent of studies in a large number of diseases and associated conditions has highly elucidated the role of CRP as a therapeutic and research reagent. In this review, we focus our attention to role of CRP in health and disease. The future prospect of this review lies in the applicability of CRP as a molecule in understanding and monitoring of the biology of disease.

Identification of a specific haptoglobin C-terminal fragment in arthritic synovial fluid and its effect on interleukin-6 expression

Haptoglobin (Hp), a major acute-phase plasma protein, has been found in arthritic synovial fluid (SF). However, the function and structural modifications of Hp in arthritic SF are unknown. To investigate in vivo generation of modified Hp associated with inflammatory disease, we examined a new Hp isoform in SF from patients with rheumatoid arthritis (RA). Specific Hp fragments of 28 000 and 15 000 molecular weight were identified in SF of patients with RA, and the two polypeptides were presumed to be fragments of the Hp β-chain (43 000 MW) produced by cleavage with plasmin. The 15 000 MW fragment, which is a C-terminal region of Hp, was observed at higher frequency and levels in RA than in osteoarthritis. Plasmin activity was also higher in SF of RA patients. A recombinant 15 000 MW Hp fragment up-regulated interlukin-6 expression in monocytic cells. These findings indicate that the C-terminal Hp fragment is generated by plasmin in local inflammatory environments and acts as an inflammatory mediator. They further suggest that a specific Hp fragment might be applied as a novel biomarker for the diagnosis and prognosis of inflammatory diseases such as RA.

Genomic and systems approaches to translational biomarker discovery in immunological diseases

The high failure rate of new therapeutic mechanisms tested in clinical development has spurred an upsurge in research dedicated to discovering biomarker readouts that can improve decision-making. Increasingly, systems biology and genomic technologies, such as transcriptional profiling, are being leveraged to aid in the discovery of biomarker readouts. For inflammatory and immunological diseases, such as rheumatoid arthritis (RA) and asthma, progress has been made in developing biomarkers to monitor disease activity, prediction of response to therapy, and pharmacodynamic (PD) measurements. In this review, we discuss recent successes and challenges in these endeavors, highlighting the importance of human clinical studies of standard-of-care treatments in control subjects and patients with disease as the most direct path toward identifying useful translational biomarkers for clinical development.

Pharmacokinetic consideration of synthetic DMARDs in rheumatoid arthritis

INTRODUCTION

Current treatment strategy for rheumatoid arthritis (RA) focuses on tight disease control and remission. The present understanding of the immune-pathological process of RA, mechanism of synthetic DMARDs and the clinical experience of the drugs have raised certain concerns over their clinical use.

AREAS COVERED

The review summarizes latest concepts in the pathogenesis of RA, and the mechanism of action and pharmacokinetics of commonly used synthetic DMARDs. It also covers the principle of enzyme and receptor kinetics, and limitation of current knowledge on RA disease measures.

EXPERT OPINION

There is a need to rationalize the use of synthetic DMARDs to help improve RA treatment. One recommendation to assist the rationalization of this treatment is by the construction of suitable models of the disease process, thereby augmenting treatment options. Currently, the dosage and duration of this type of treatment is based on its overall effect and clinical outcome. Each DMARD will confer its effect on a specific component of the multilevel, multicellular, pathological process of RA. Furthermore, developing definitive biomarkers could help to better assess the disease at its various stages instead of using conventional RA measures for drug titration and to help in the rationalization of drug regimen. Integrating pharmacokinetic and pharmacodynamic properties into this model will also help in improving treatment outcomes.