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.

Predicting Disease Activity in Rheumatoid Arthritis With the Fibromyalgia Survey Questionnaire: Does the Severity of Fibromyalgia Symptoms Matter?

OBJECTIVE: To determine if the degree of baseline fibromyalgia (FM) symptoms in patients with rheumatoid arthritis (RA), as indicated by the Fibromyalgia Survey Questionnaire (FSQ) score, predicts RA disease activity after initiation or change of a disease-modifying antirheumatic drug (DMARD). METHODS: One hundred ninety-two participants with active RA were followed for 12 weeks after initiation or change of DMARD therapy. Participants completed the FSQ at the initial visit. The Disease Activity Score in 28 joints using C-reactive protein (DAS28-CRP) was measured at baseline and follow-up to assess RA disease activity. We evaluated the association between baseline FSQ score and follow-up DAS28-CRP. As a secondary analysis, we examined the relationship between the 2 components of the FSQ, the Widespread Pain Index (WPI) and Symptom Severity Scale (SSS), with follow-up DAS28-CRP. Multiple linear regression analyses were performed, adjusting for clinical and demographic variables. RESULTS: In multiple linear regression models, FSQ score was independently associated with elevated DAS28-CRP scores 12 weeks after DMARD initiation (B = 0.04, P = 0.01). In secondary analyses, the WPI was significantly associated with increased follow-up DAS28-CRP scores (B = 0.08, P = 0.001), whereas the SSS was not (B = -0.03, P = 0.43). CONCLUSION: Higher levels of FM symptoms weakly predicted worse disease activity after treatment. The primary factor that informed the FSQ's prediction of disease activity was the spatial extent of pain, as measured by the WPI.

Disproportionate articular pain is a frequent phenomenon in rheumatoid arthritis and responds to treatment with sarilumab.

OBJECTIVES: In some patients with RA, joint pain is more severe than expected based on the amount of joint swelling [referred to as disproportionate articular pain (DP)]. We assessed DP prevalence and the effects of sarilumab, an IL-6 inhibitor, on DP. METHODS: Data from RA patients treated with placebo or 200 mg sarilumab in the phase 3 randomized controlled trials (RCTs) MOBILITY and TARGET, adalimumab 40 mg or sarilumab 200 mg in the phase 3 RCT MONARCH and sarilumab 200 mg in open-label extensions (OLEs) were used. DP was defined as an excess tender 28-joint count (TJC28) over swollen 28-joint count (SJC28) of ≥7 (TJC28 - SJC28 ≥ 7). Treatment response and disease activity were determined for patients with and without DP. RESULTS: Of 1531 sarilumab 200 mg patients from RCTs, 353 (23%) had baseline DP. On average, patients with DP had higher 28-joint DAS using CRP (DAS28-CRP) and pain scores than patients without DP, whereas CRP levels were similar. After 12 and 24 weeks, patients with baseline DP treated with sarilumab were more likely to be DP-free than those treated with placebo or adalimumab. In RCTs, more sarilumab-treated patients achieved low disease activity vs comparators, regardless of baseline DP status. In OLEs, patients were more likely to lose rather than gain DP status. CONCLUSION: About one-quarter of patients with RA experienced DP, which responded well to sarilumab. These data support the concept that other mechanisms (potentially mediated via IL-6) in addition to inflammation may contribute to DP in RA. TRIAL REGISTRATIONS: NCT01061736, NCT02332590, NCT01709578, NCT01146652.

Correlation of Fibromyalgia Survey Questionnaire and Quantitative Sensory Testing Among Patients With Active Rheumatoid Arthritis.

OBJECTIVE: Patients with rheumatoid arthritis (RA) commonly demonstrate disordered pain processing associated with high pain sensitization. Pain sensitization is often assessed using quantitative sensory testing (QST), which is burdensome to patients. The self-administered Fibromyalgia Survey Questionnaire (FSQ) has been proposed as a low-burden, surrogate measure of central pain sensitization. We examined the correlation between FSQ and QST in patients with active RA. METHODS: Participants in the Central Pain in Rheumatoid Arthritis (CPIRA) cohort underwent FSQ and QST evaluation at enrollment. QST measures included pressure pain threshold (PPT) at the thumb, trapezius, wrist, and knee; temporal summation (TS) at the wrist and arm; and conditioned pain modulation (CPM). Partial Spearman correlation between FSQ and each QST measure was assessed, adjusted for demographic factors, study site, disease characteristics, and pain catastrophizing. Sensitivity analyses included (1) stratified analysis by sex and (2) evaluation of how each component of FSQ associates with the QST measures. RESULTS: Among 285 participants with active RA, FSQ was weakly but statistically significantly correlated with PPT (r range = -0.31 to -0.21), and TS (r range = 0.13-0.15) at all sites in unadjusted analyses. After adjustment, statistically significant correlations persisted for TS at the wrist and PPT at all sites (except the thumb). Sensitivity analyses did not identify differences in association based on sex or with individual FSQ components. CONCLUSION: FSQ and QST were correlated among participants with active RA, but the strength of association was weak. QST and FSQ are not interchangeable measures of pain sensitization.

Pain Reduction in Rheumatoid Arthritis Patients Who Use Opioids: A Post Hoc Analysis of Phase 3 Trials of Baricitinib.

OBJECTIVE: Pain reduction with baricitinib was assessed in patients with rheumatoid arthritis (RA) who either used opioids or did not use opioids during three randomized, double-blind phase 3 trials. METHODS: Analysis populations were as follows: i) baricitinib 4 mg once daily versus placebo groups integrated from RA-BEAM (NCT01710358) for patients with inadequate response (IR) to methotrexate, RA-BUILD (NCT01721057) with IR to conventional disease-modifying antirheumatic drugs, and RA-BEACON (NCT01721044) with IR to at least one tumor necrosis factor inhibitors; ii) baricitinib 2 mg versus placebo from RA-BUILD and RA-BEACON; and iii) adalimumab 40 mg every other week versus placebo from RA-BEAM. Pain was measured by the Patient Assessment of Pain Visual Analog Scale. Analysis of covariance modeling assessed differences in pain reduction between treatments at each time point through Week 24, with an interaction term to test heterogeneous treatment effects across opioid users and nonusers. RESULTS: Baricitinib 4 mg had greater pain reduction versus placebo in opioid users and nonusers (P < 0.05) at all time points starting from Week 1; the pain reduction was similar between opioid users and nonusers. Baricitinib 2 mg had greater pain reduction versus placebo in opioid users and nonusers starting at Week 4. A significant difference in pain reduction was not observed for adalimumab versus placebo in the opioid users but was observed in nonusers at all time points. CONCLUSION: Pain reduction was observed and was similar between opioid users and nonusers with baricitinib 2 mg and 4 mg but not adalimumab in this post hoc analysis.

Fibromyalgianess and glucocorticoid persistence among patients with rheumatoid arthritis.

OBJECTIVES: Over one-third of patients with RA exhibit evidence of fibromyalgianess, which is associated with higher rates of disability and inadequate responsiveness to RA treatment. Patients with RA often remain on glucocorticoids long-term, despite the known risk of dose-dependent morbidity. We undertook this study to examine the relationship between fibromyalgianess and glucocorticoid persistence among RA patients. METHODS: We followed participants with active RA on oral prednisone for ∼3 months after initiating a new DMARD. Fibromyalgianess was measured using the Fibromyalgia Survey Questionnaire (FSQ), previously shown to correlate with key FM features often superimposed upon RA. Severity of fibromyalgianess was stratified as follows: FSQ <8 low, FSQ 8-10 moderate and FSQ >10 high/very high. The association between baseline fibromyalgianess and glucocorticoid persistence, defined as prednisone use at 3-month follow-up visit after DMARD initiation, was assessed using multiple logistic regression adjusted for baseline demographics, RA duration, serostatus and inflammatory activity assessed using swollen joint count and CRP. RESULTS: Of the 97 participants on prednisone at baseline, 65% were still taking prednisone at follow-up. Fifty-seven percent of participants with low baseline fibromyalgianess had persistent glucocorticoid use, compared with 84% of participants with high or very high fibromyalgianess. After adjustment for non-inflammatory factors and inflammatory activity, participants with high/very high baseline fibromyalgianess were more likely to be taking prednisone at follow-up relative to those with low fibromyalgianess [odds ratio 4.99 (95% CI 1.20, 20.73)]. CONCLUSION: High fibromyalgianess is associated with persistent glucocorticoid use, independent of inflammatory activity.

Use of prescription opioids among patients with rheumatic diseases compared to patients with hypertension in the USA: a retrospective cohort study.

OBJECTIVE: Long-term opioid prescribing has increased amid concerns over effectiveness and safety of its use. We examined long-term prescription opioid use among patients with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), psoriatic arthritis (PsA) and ankylosing spondylitis (AS), compared with patients with hypertension (HTN). METHODS: We used Truven MarketScan, a US commercial claims database (2003-2014) and identified RA, SLE, PsA and AS cohorts, each matched by age and sex to patients with HTN. We compared long-term opioid prescription use during 1 year of follow-up and used multivariable Poisson regression model to estimate the relative risk (RR) of receiving opioid prescriptions based on underlying disease cohort. RESULTS: We identified 181 710 RA (mean age 55.3±13.1, 77% female), 45 834 SLE (47.1±13.1, 91% female), 30 307 PsA (49.7±11.5, 51% female), 7686 AS (44.6±12.0, 39% female) and parallel numbers of age-matched and sex-matched patients with HTN. The proportion of patients receiving long-term opioid prescriptions, and other measures of opioid prescriptions were higher among rheumatic disease cohorts and highest in patients with AS. AS was associated with the highest RR of receiving long-term opioid prescriptions (RR 2.73, 95% CI 2.60 to 2.87) versus HTN, while RRs were 2.21 (2.16 to 2.25) for RA, 1.94 (1.87 to 2.00) for PsA and 1.82 (1.77 to 1.88) for SLE. CONCLUSIONS: Patients with rheumatic disease have higher rates of long-term opioid prescriptions, and patients with AS have the highest risk of receiving opioid prescriptions versus patients with HTN. Further studies investigating the effectiveness of disease-targeted treatments on decreasing opioid use in these four rheumatic diseases may provide strategies for reducing prescription opioids.

Utilizing a PTPN22 gene signature to predict response to targeted therapies in rheumatoid arthritis.

Despite the development of several targeted therapies for rheumatoid arthritis (RA), there is still no reliable drug-specific predictor to assist rheumatologists in selecting the most effective targeted therapy for each patient. Recently, a gene signature caused by impaired induction of PTPN22 in anti-CD3 stimulated peripheral blood mononuclear cells (PBMC) was observed in healthy at-risk individuals. However, the downstream target genes of PTPN22 and the molecular mechanisms regulating its expression are still poorly understood. Here we report that the PTPN22 gene signature is also present in PBMC from patients with active RA and can be reversed after effective treatment. The expression of PTPN22 correlates with that of more than 1000 genes in Th cells of anti-CD3 stimulated PBMC of healthy donors and is inhibited by TNFα or CD28 signals, but not IL-6, through distinct mechanisms. In addition, the impaired induction of PTPN22 in PBMC of patients with active RA can be normalized in vitro by several targeted therapies. More importantly, the in vitro normalization of PTPN22 expression correlates with clinical response to the targeted therapies in a longitudinal RA cohort. Thus, in vitro normalization of PTPN22 expression by targeted therapies can potentially be used to predict clinical response.

Association of Geography and Access to Health Care Providers With Long-Term Prescription Opioid Use in Medicare Patients With Severe Osteoarthritis: A Cohort Study.

OBJECTIVE: To evaluate the variation in long-term opioid use in osteoarthritis (OA) patients according to geography and health care access. METHODS: We designed an observational cohort study among OA patients undergoing total joint replacement (TJR) in the Medicare program (2010 through 2014). The independent variables of interest were the state of residence and health care access, which was quantified at the primary care service area (PCSA) level as categories of number of practicing primary care providers (PCPs) and categories of rheumatologists per 1,000 Medicare beneficiaries. The percentage of OA patients taking long-term opioids (≥90 days in the 360-day period immediately preceding TJR) within each PCSA was the outcome variable in a multilevel, generalized linear regression model, adjusting for case-mix at the PCSA level and for policies, including rigor of prescription drug monitoring programs and legalized medical marijuana, at the state level. RESULTS: A total of 358,121 patients with advanced OA, with a mean age of 74 years, were included from 4,080 PCSAs. The unadjusted mean percentage of long-term opioid users varied widely across states, ranging from 8.9% (Minnesota) to 26.4% (Alabama), and this variation persisted in the adjusted models. Access to PCPs was only modestly associated with rates of long-term opioid use between PCSAs with highest (>8.6) versus lowest (<3.6) concentration of PCPs (adjusted mean difference 1.4% [95% confidence interval 0.8%, 2.0%]), while access to rheumatologists was not associated with long-term opioid use. CONCLUSION: We note a substantial statewide variation in rates of long-term treatment with opioids in OA, which is not fully explained by the differences in access to health care providers, varying case-mix, or state-level policies.

Brain glial activation in fibromyalgia - A multi-site positron emission tomography investigation.

Fibromyalgia (FM) is a poorly understood chronic condition characterized by widespread musculoskeletal pain, fatigue, and cognitive difficulties. While mounting evidence suggests a role for neuroinflammation, no study has directly provided evidence of brain glial activation in FM. In this study, we conducted a Positron Emission Tomography (PET) study using [11C]PBR28, which binds to the translocator protein (TSPO), a protein upregulated in activated microglia and astrocytes. To enhance statistical power and generalizability, we combined datasets collected independently at two separate institutions (Massachusetts General Hospital [MGH] and Karolinska Institutet [KI]). In an attempt to disentangle the contributions of different glial cell types to FM, a smaller sample was scanned at KI with [11C]-L-deprenyl-D2 PET, thought to primarily reflect astrocytic (but not microglial) signal. Thirty-one FM patients and 27 healthy controls (HC) were examined using [11C]PBR28 PET. 11 FM patients and 11 HC were scanned using [11C]-L-deprenyl-D2 PET. Standardized uptake values normalized by occipital cortex signal (SUVR) and distribution volume (VT) were computed from the [11C]PBR28 data. [11C]-L-deprenyl-D2 was quantified using λ k3. PET imaging metrics were compared across groups, and when differing across groups, against clinical variables. Compared to HC, FM patients demonstrated widespread cortical elevations, and no decreases, in [11C]PBR28 VT and SUVR, most pronounced in the medial and lateral walls of the frontal and parietal lobes. No regions showed significant group differences in [11C]-L-deprenyl-D2 signal, including those demonstrating elevated [11C]PBR28 signal in patients (p's ≥ 0.53, uncorrected). The elevations in [11C]PBR28 VT and SUVR were correlated both spatially (i.e., were observed in overlapping regions) and, in several areas, also in terms of magnitude. In exploratory, uncorrected analyses, higher subjective ratings of fatigue in FM patients were associated with higher [11C]PBR28 SUVR in the anterior and posterior middle cingulate cortices (p's < 0.03). SUVR was not significantly associated with any other clinical variable. Our work provides the first in vivo evidence supporting a role for glial activation in FM pathophysiology. Given that the elevations in [11C]PBR28 signal were not also accompanied by increased [11C]-L-deprenyl-D2 signal, our data suggests that microglia, but not astrocytes, may be driving the TSPO elevation in these regions. Although [11C]-L-deprenyl-D2 signal was not found to be increased in FM patients, larger studies are needed to further assess the role of possible astrocytic contributions in FM. Overall, our data support glial modulation as a potential therapeutic strategy for FM.

Mixed-effects association of single cells identifies an expanded effector CD4+ T cell subset in rheumatoid arthritis.

High-dimensional single-cell analyses have improved the ability to resolve complex mixtures of cells from human disease samples; however, identifying disease-associated cell types or cell states in patient samples remains challenging because of technical and interindividual variation. Here, we present mixed-effects modeling of associations of single cells (MASC), a reverse single-cell association strategy for testing whether case-control status influences the membership of single cells in any of multiple cellular subsets while accounting for technical confounders and biological variation. Applying MASC to mass cytometry analyses of CD4+ T cells from the blood of rheumatoid arthritis (RA) patients and controls revealed a significantly expanded population of CD4+ T cells, identified as CD27- HLA-DR+ effector memory cells, in RA patients (odds ratio, 1.7; P = 1.1 × 10-3). The frequency of CD27- HLA-DR+ cells was similarly elevated in blood samples from a second RA patient cohort, and CD27- HLA-DR+ cell frequency decreased in RA patients who responded to immunosuppressive therapy. Mass cytometry and flow cytometry analyses indicated that CD27- HLA-DR+ cells were associated with RA (meta-analysis P = 2.3 × 10-4). Compared to peripheral blood, synovial fluid and synovial tissue samples from RA patients contained about fivefold higher frequencies of CD27- HLA-DR+ cells, which comprised ~10% of synovial CD4+ T cells. CD27- HLA-DR+ cells expressed a distinctive effector memory transcriptomic program with T helper 1 (TH1)- and cytotoxicity-associated features and produced abundant interferon-γ (IFN-γ) and granzyme A protein upon stimulation. We propose that MASC is a broadly applicable method to identify disease-associated cell populations in high-dimensional single-cell data.

Pathologically expanded peripheral T helper cell subset drives B cells in rheumatoid arthritis.

CD4+ T cells are central mediators of autoimmune pathology; however, defining their key effector functions in specific autoimmune diseases remains challenging. Pathogenic CD4+ T cells within affected tissues may be identified by expression of markers of recent activation. Here we use mass cytometry to analyse activated T cells in joint tissue from patients with rheumatoid arthritis, a chronic immune-mediated arthritis that affects up to 1% of the population. This approach revealed a markedly expanded population of PD-1hiCXCR5-CD4+ T cells in synovium of patients with rheumatoid arthritis. However, these cells are not exhausted, despite high PD-1 expression. Rather, using multidimensional cytometry, transcriptomics, and functional assays, we define a population of PD-1hiCXCR5- 'peripheral helper' T (TPH) cells that express factors enabling B-cell help, including IL-21, CXCL13, ICOS, and MAF. Like PD-1hiCXCR5+ T follicular helper cells, TPH cells induce plasma cell differentiation in vitro through IL-21 secretion and SLAMF5 interaction (refs 3, 4). However, global transcriptomics highlight differences between TPH cells and T follicular helper cells, including altered expression of BCL6 and BLIMP1 and unique expression of chemokine receptors that direct migration to inflamed sites, such as CCR2, CX3CR1, and CCR5, in TPH cells. TPH cells appear to be uniquely poised to promote B-cell responses and antibody production within pathologically inflamed non-lymphoid tissues.

Fibromyalgia and the Prediction of Two-Year Changes in Functional Status in Rheumatoid Arthritis Patients.

OBJECTIVE: Previous cross-sectional studies have shown that rheumatoid arthritis (RA) patients with fibromyalgia (FM) have higher disease activity, greater medical costs, and worse quality of life compared to RA patients without FM. We determined the impact of FM on 2-year changes in the functional status of RA patients in a prospective study. METHODS: Subjects included participants in the Brigham Rheumatoid Arthritis Sequential Study who were enrolled in a substudy of the effects of pain in RA. Subjects completed questionnaires, including the Multi-Dimensional Health Assessment Questionnaire (MDHAQ) and Polysymptomatic Distress (PSD) scale, semiannually, and underwent physical examination and laboratory tests yearly. RESULTS: Of the 156 included RA subjects, 16.7% had FM, while 83.3% did not. In a multivariable linear regression model adjusted for age, sex, race, baseline MDHAQ score, disease duration, rheumatoid factor/cyclic citrullinated peptide antibody seropositivity, disease activity, and psychological distress, RA patients with FM had a 0.14 greater 2-year increase in MDHAQ score than RA patients without FM (P = 0.021). In secondary analyses examining the association between continuous PSD scale score and change in MDHAQ, higher PSD scale scores were significantly associated with greater 2-year increases in MDHAQ score (ß coefficient 0.013, P = 0.011). CONCLUSION: Both the presence of FM and increasing number of FM symptoms predicted worsening of functional status among individuals with RA. Among individuals with RA and FM, the magnitude of the difference in changes in MDHAQ was 4- to 7-fold higher than typical changes in MDHAQ score among individuals with established RA.

A systematic review of psychosocial therapies for children with rheumatic diseases.

BACKGROUND: To assess the quality of evidence for the effects of psychosocial therapies on pain and function in children with rheumatic diseases. METHODS: We conducted a literature search of MEDLINE and PsycINFO for randomized clinical trials of psychosocial interventions for pain and disability in children with rheumatic diseases from January 1969 to September 2015. Studies with a sample size less than 10 subjects were excluded. Study quality was assessed using the Jadad score. RESULTS: Five articles met inclusion criteria, for a total of 229 patients, aged 5 to 18 years. Two studies included children with fibromyalgia. Three studies included children with juvenile arthritis. Neither study in fibromyalgia reported the statistical significance of immediate between-group pre-post changes in functioning or pain. One study examining the effects of an internet-based psychosocial intervention in children with juvenile arthritis reported significant differences in post-intervention pain scores (p = 0.03). However, 2 studies did not show improvements in pain scores among children with juvenile arthritis treated with psychosocial interventions vs. a wait-list control or vs. an active control (massage). No studies reported significant between-group differences for functional outcomes in children with juvenile arthritis. CONCLUSIONS: The available data were limited by the scarcity of randomized trials. Definite conclusions about the immediate effect of psychosocial interventions on pain and function in children with fibromyalgia could not be made because between-group comparisons of post-treatment change scores were not reported. For children with juvenile inflammatory arthritis, results of between-group comparisons for pain differed across studies, and analyses examining disability revealed no significant differences between groups.

Non-inflammatory Causes of Pain in Patients with Rheumatoid Arthritis.

Although pain in rheumatoid arthritis (RA) is frequently thought to be inflammatory in nature, the association between measures of inflammation and pain intensity is low. This observation is likely due to the multifactorial nature of pain. In addition to pain from joint inflammation, RA patients may also have pain due to structural damage or central etiologies, such as aberrancies in the central nervous system (CNS) pain regulatory pathways. These CNS pathways include mechanisms that facilitate pain, as well as mechanisms that inhibit pain. Other factors, such as sleep disturbances, depression, anxiety, and catastrophizing, may also impact the perception of pain in RA patients. Since pain is frequently used as a proxy for inflammation in the assessment of RA disease activity, it is important that patients and physicians recognize that not all pain is inflammatory, and alternative management strategies, other than escalating disease-modifying antirheumatic drug treatment, may need to be considered.

Post-Traumatic Stress Disorder and Risk for Incident Rheumatoid Arthritis.

OBJECTIVE: To examine the association between symptoms of post-traumatic stress disorder (PTSD) and rheumatoid arthritis (RA) risk in a prospective cohort and to characterize the role of smoking in this relationship. METHODS: A subset (n = 54,224) of the Nurses' Health Study II, a prospective cohort of female nurses, completed the Brief Trauma Questionnaire and a screen for PTSD symptoms. Participants were categorized based on trauma exposure and number of PTSD symptoms. Incident RA cases (n = 239) from 1989 to 2011 were identified. Cox proportional hazards models were used to calculate hazard ratios (HRs) and 95% confidence intervals (95% CIs) between PTSD symptoms and incident RA. To identify the impact of smoking, secondary and subgroup analyses were performed. In all analyses, PTSD and smoking were lagged 2 years before the development of RA. RESULTS: Compared to no history of trauma/PTSD symptoms, the HR for ≥4 PTSD symptoms and incident RA was 1.76 (95% CI 1.16-2.67) in models adjusted for age, race, and socioeconomic status. The risk for RA increased with an increasing number of PTSD symptoms (P = 0.01). When smoking was added to the model, the HR for RA remained elevated (HR 1.60 [95% CI 1.05-2.43]). In a subgroup analysis, excluding women who smoked before PTSD onset, results were unchanged (HR 1.68 [95% CI 1.04-2.70]). CONCLUSION: This study suggests that women with high PTSD symptomatology have an elevated risk for RA, independent of smoking, adding to emerging evidence that stress is an important determinant of physical health.

Effect of Milnacipran on Pain in Patients with Rheumatoid Arthritis with Widespread Pain: A Randomized Blinded Crossover Trial.

OBJECTIVE: Clinical trials have shown that serotonin norepinephrine reuptake inhibitors, such as milnacipran, decrease pain in noninflammatory pain conditions such as fibromyalgia and osteoarthritis. We examined the effect of milnacipran on self-reported pain intensity and experimental pain sensitivity among patients with rheumatoid arthritis (RA) with widespread pain and stable RA disease activity. METHODS: In this double-blind, crossover study, patients with RA with widespread pain, receiving a stable treatment regimen, were randomized (by a random number generator) to receive milnacipran 50 mg twice daily or placebo for 6 weeks, followed by a 3-week washout and crossed over to the other arm for the remaining 6 weeks. The primary outcome was change in average pain intensity, assessed by the Brief Pain Inventory short form. The sample size was calculated to detect a 30% improvement in pain with power = 0.80 and α = 0.05. RESULTS: Of the 43 randomized subjects, 41 received the study drug, and 32 completed the 15-week study per protocol. On a 0-10 scale, average pain intensity decreased by 0.39 (95% CI -1.27 to 0.49, p = 0.37) more points during 6 weeks of milnacipran treatment compared with placebo. In the subgroup of subjects with swollen joint count ≤ 1, average pain intensity decreased by 1.14 more points during 6 weeks of milnacipran compared with placebo (95% CI -2.26 to -0.01, p = 0.04). Common adverse events included nausea (26.8%) and loss of appetite (9.7%). CONCLUSION: Compared with placebo, milnacipran did not improve overall, self-reported pain intensity among subjects with widespread pain receiving stable RA medications. TRIAL REGISTRATION: ClinicalTrials.gov NCT01207453.

Multibiomarker disease activity score and C-reactive protein in a cross-sectional observational study of patients with rheumatoid arthritis with and without concomitant fibromyalgia.

OBJECTIVES: To examine the association between a multibiomarker disease activity (MBDA) score, CRP and clinical disease activity measures among RA patients with and without concomitant FM. METHODS: In an observational cohort of patients with established RA, we performed a cross-sectional analysis comparing MBDA scores with CRP by rank correlation and cross-classification. MBDA scores, CRP and clinical measures of disease activity were compared between patients with RA alone and RA with concomitant FM (RA and FM) by univariate and multivariate analyses. RESULTS: CRP was ⩽1.0 mg/dl for 184 of 198 patients (93%). MBDA scores correlated with CRP (r = 0.755, P < 0.001), but were often discordant, being moderate or high for 19%, 55% and 87% of patients with CRP ⩽0.1, 0.1 to ⩽0.3, or 0.3 to ⩽1.0 mg/dl, respectively. Among patients with CRP ⩽1.0 mg/dl, swollen joint count (SJC) increased linearly across levels of MBDA score, both with (P = 0.021) and without (P = 0.004) adjustment for CRP, whereas CRP was not associated with SJC. The 28-joint-DAS-CRP, other composite measures, and their non-joint-count component measures were significantly greater for patients with RA and FM (n = 25) versus RA alone (n = 173) (all P ⩽ 0.005). MBDA scores and CRP were similar between groups. CONCLUSION: MBDA scores frequently indicated RA disease activity when CRP did not. Neither one was significantly greater among patients with RA and FM versus RA alone. Thus, MBDA score may be a useful objective measure for identifying RA patients with active inflammation when CRP is low (⩽1.0 mg/dl), including RA patients with concomitant FM.