Biomarkers in rheumatoid arthritis

Structural equation modelling provides insights to understand the construct of chronic pain in women with rheumatoid arthritis

OBJECTIVES

We aimed to adopt a multidimensional approach and investigate the interconnections between biomarkers (cytokines, matrix metalloproteinases, and cortisol) and psychosocial aspects considering pain acceptance, the individual construct of pain perception in terms of blood inflammation biomarkers, anxiety, self-efficacy, and functional performance and to define the quality of life (QoL) in women with rheumatoid arthritis (RA).

METHODS

An observational cross-sectional study with a total of 42-RA participants, with chronic pain and 42-women without rheumatic diseases or chronic pain were included. A structural equation model was used to investigate the association between independent variables.

RESULTS

Women with RA presented high blood biomarker levels, representing an intense inflammatory process. The participants with RA reported moderate pain most of the time, a worsening QoL, functionality, engagement in activities, and a willingness to live with pain and self-efficacy. It was found that the higher the chronic pain, the greater the intensity of pain perceived by these women with RA, as well as, the worse the functionality, the higher the perceived pain.

CONCLUSIONS

The exacerbation of pain perception leads to worsening of the experience of chronic pain. The new construct of pain experience should include functionality as a crucial factor in understanding the mechanisms underlying pain.

Periodontitis is an inflammatory disease of oxidative stress: We should treat it that way

Periodontitis is a highly prevalent disease. As it progresses, it causes serious morbidity in the form of periodontal abscesses and tooth loss and, in the latter stages, pain. It is also now known that periodontitis is strongly associated with several nonoral diseases. Thus, patients with periodontitis are at greater risk for the development and/or exacerbation of diabetes, chronic obstructive pulmonary disease, and cardiovascular diseases, among other conditions. Although it is without question that specific groups of oral bacteria which populate dental plaque play a causative role in the development of periodontitis, it is now thought that once this disease has been triggered, other factors play an equal, and possibly more important, role in its progression, particularly in severe cases or in cases that prove difficult to treat. In this regard, we allude to the host response, specifically the notion that the host, once infected with oral periodontal pathogenic bacteria, will mount a defense response mediated largely through the innate immune system. The most abundant cell type of the innate immune system - polymorphonuclear neutrophils - can, when protecting the host from microbial invasion, mount a response that includes upregulation of proinflammatory cytokines, matrix metalloproteinases, and reactive oxygen species, all of which then contribute to the tissue damage and loss of teeth commonly associated with periodontitis. Of the mechanisms referred to here, we suggest that upregulation of reactive oxygen species might play one of the most important roles in the establishment and progression of periodontitis (as well as in other diseases of inflammation) through the development of oxidative stress. In this overview, we discuss both innate and epigenetic factors (eg, diabetes, smoking) that lead to the development of oxidative stress. This oxidative stress then provides an environment conducive to the destructive processes observed in periodontitis. Therefore, we shall describe some of the fundamental characteristics of oxidative stress and its effects on the periodontium, discuss the diseases and other factors that cause oxidative stress, and, finally, review potentially novel therapeutic approaches for the management (and possibly even the reversal) of periodontitis, which rely on the use of therapies, such as resveratrol and other antioxidants, that provide increased antioxidant activity in the host.

What is the added value of ultrasound joint examination for monitoring synovitis in rheumatoid arthritis and can it be used to guide treatment decisions? A systematic review and cost-effectiveness analysis

BACKGROUND

Synovitis (inflamed joint synovial lining) in rheumatoid arthritis (RA) can be assessed by clinical examination (CE) or ultrasound (US).

OBJECTIVE

To investigate the added value of US, compared with CE alone, in RA synovitis in terms of clinical effectiveness and cost-effectiveness.

DATA SOURCES

Electronic databases including MEDLINE, EMBASE and the Cochrane databases were searched from inception to October 2015.

REVIEW METHODS

A systematic review sought RA studies that compared additional US with CE. Heterogeneity of the studies with regard to interventions, comparators and outcomes precluded meta-analyses. Systematic searches for studies of cost-effectiveness and US and treatment-tapering studies (not necessarily including US) were undertaken.

MATHEMATICAL MODEL

A model was constructed that estimated, for patients in whom drug tapering was considered, the reduction in costs of disease-modifying anti-rheumatic drugs (DMARDs) and serious infections at which the addition of US had a cost per quality-adjusted life-year (QALY) gained of £20,000 and £30,000. Furthermore, the reduction in the costs of DMARDs at which US becomes cost neutral was also estimated. For patients in whom dose escalation was being considered, the reduction in number of patients escalating treatment and in serious infections at which the addition of US had a cost per QALY gained of £20,000 and £30,000 was estimated. The reduction in number of patients escalating treatment for US to become cost neutral was also estimated.

RESULTS

Fifty-eight studies were included. Two randomised controlled trials compared adding US to a Disease Activity Score (DAS)-based treat-to-target strategy for early RA patients. The addition of power Doppler ultrasound (PDUS) to a Disease Activity Score 28 joints-based treat-to-target strategy in the Targeting Synovitis in Early Rheumatoid Arthritis (TaSER) trial resulted in no significant between-group difference for change in Disease Activity Score 44 joints (DAS44). This study found that significantly more patients in the PDUS group attained DAS44 remission (p = 0.03). The Aiming for Remission in Rheumatoid Arthritis (ARCTIC) trial found that the addition of PDUS and grey-scale ultrasound (GSUS) to a DAS-based strategy did not produce a significant between-group difference in the primary end point: composite DAS of < 1.6, no swollen joints and no progression in van der Heijde-modified total Sharp score (vdHSS). The ARCTIC trial did find that the erosion score of the vdHS had a significant advantage for the US group (p = 0.04). In the TaSER trial there was no significant group difference for erosion. Other studies suggested that PDUS was significantly associated with radiographic progression and that US had added value for wrist and hand joints rather than foot and ankle joints. Heterogeneity between trials made conclusions uncertain. No studies were identified that reported the cost-effectiveness of US in monitoring synovitis. The model estimated that an average reduction of 2.5% in the costs of biological DMARDs would be sufficient to offset the costs of 3-monthly US. The money could not be recouped if oral methotrexate was the only drug used.

LIMITATIONS

Heterogeneity of the trials precluded meta-analysis. Therefore, no summary estimates of effect were available. Additional costs and health-related quality of life decrements, relating to a flare following tapering or disease progression, have not been included. The feasibility of increased US monitoring has not been assessed.

CONCLUSION

Limited evidence suggests that US monitoring of synovitis could provide a cost-effective approach to selecting RA patients for treatment tapering or escalation avoidance. Considerable uncertainty exists for all conclusions. Future research priorities include evaluating US monitoring of RA synovitis in longitudinal clinical studies.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42015017216.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.