Factors associated with influenza and pneumococcal vaccine uptake among rheumatoid arthritis patients in Denmark invited to participate in a pneumococcal vaccine trial (Immunovax_RA)

OBJECTIVE

This study investigates predictors of influenza and pneumococcal vaccine coverage among rheumatoid arthritis (RA) patients, and explores possible differences according to type of RA therapy.

METHOD

RA patients from two clinics in the region of Southern Denmark were informed about the survey during scheduled follow-up visits. The questionnaire included questions concerning previous influenza and pneumococcal vaccine uptake, attitudes about vaccination, and socio-demographic factors. Factors associated with recalled vaccine uptake were assessed by multivariate logistic regression.

RESULTS

A total of 192 RA patients completed the survey, 134 (70%) of whom were women and 90 (47%) were aged ≥ 65 years. Sixty-seven patients (35%) received conventional disease-modifying anti-rheumatic drugs (cDMARDs) and 125 (65%) combination therapy with biological disease-modifying anti-rheumatic drugs (bDMARDs). Self-reported uptake of vaccination against seasonal influenza ever was 59% overall; 57% among patients receiving cDMARDs and 61% in patients receiving bDMARDs. Self-reported vaccine uptake against pneumococcal diseases was only 6% overall. Older age, educational level, and information and recommendation by a specialist or general physician were positively associated with influenza vaccine uptake, while there was no significant difference in vaccine uptake according to RA treatment type. Reasons for not being vaccinated included fear of adverse effects, lack of information and recommendation, and perception of good health.

CONCLUSION

We observed a low prevalence of influenza and in particular of pneumococcal vaccinations among RA patients receiving immunosuppressive drugs, with no difference in coverage according to type of RA therapy. More population-specific evidence to support recommendations is required to increase awareness among patients and physicians.

Physical Characteristics of a Citrullinated Pro-Filaggrin Epitope Recognized by Anti-Citrullinated Protein Antibodies in Rheumatoid Arthritis Sera

Rheumatoid arthritis (RA) is an autoimmune disease of complex etiology. A characteristic feature of a subset of RA is the presence of anti-citrullinated protein antibodies (ACPA), which correlate with a progressive disease course. In this study, we employed streptavidin capture enzyme-linked immunosorbent assay to analyze ACPA reactivity. Using the pro-filaggrin peptide HQCHQEST-Cit-GRSRGRCGRSGS, as template, we analyzed the reactivity of RA sera and healthy donor sera to various peptides in order to determine the physical characteristics of the citrullinated pro-filaggrin epitope and to examine whether biotin labelling influence antibody recognition. The full-length cyclic pro-filaggrin peptide and a linear form with a N-terminal biotin, was recognized to the same level, whereas, a notable difference in ACPA reactivity to the linear peptides with a C-terminal biotin was found, probably due to steric hindrance. Screening of linear and cyclic truncated peptides, revealed that small cyclic peptides containing 10–12 amino acids are favored over the linear. Moreover, the charged amino acids C-terminal to citrulline were found to be essential for antibody reactivity, most important was the charged amino acid in position 4 C-terminal to citrulline. Collectively, peptide structure, length, the presence of charged amino acids and biotin labelling markedly influence antibody reactivity. In relation to the clinical diagnostics of ACPA, these findings may reflect the differences in diagnostic assays used for detection of ACPA, which relates to differences in sensitivity and specificity dependent on the assay applied.

Hand bone loss in early rheumatoid arthritis during a methotrexate-based treat-to-target strategy with or without adalimumab-a substudy of the optimized treatment algorithm in early RA (OPERA) trial

This study aims to investigate 1-year hand bone loss (HBL_1-year) in early rheumatoid arthritis (RA) patients treated with a methotrexate (MTX) and intra-articular triamcinolone treat-to-target strategy +/- adalimumab and to determine if HBL_6months is associated with radiographic progression after 2 years. In a clinical trial (OPERA) of 180 treatment-naive early RA patients, bone mineral density (BMD) was estimated from hand radiographs with digital X-ray radiogrammetry (DXR) at baseline, after 6 (n = 90) and 12 months (n = 70) of follow-up. Baseline and 2-year radiographs were scored according to the Sharp/van der Heijde method. Baseline characteristics and HBL_6months (0-6 months changes in DXR-BMD) were investigated as predictors of structural damage by univariate linear (∆ total Sharp/van der Heijde score (TSS) as dependent variable) and logistic (+/-radiographic progression (∆TSS >0) as dependent variable) regression analyses. Variables with p < 0.10 were included in multivariable models. In 70 patients with available HBL_1-year data, HBL_1-year was median (interquartile range (IQR)) -1.9 (-3.3; -0.26 mg/cm²) in the MTX + placebo group and -1.8 (-3.6; 0.06) mg/cm² in the MTX + adalimumab group, p = 0.98, Wilcoxon signed-rank. Increased HBL (compared to general population reference values) was found in 26/37 and 23/33 patients in the MTX + placebo and MTX + adalimumab groups, chi-squared = 0.99. In 90 patients with HBL_6months data and 2-year radiographic data, HBL_6months was independently associated with ∆TSS after 2 years (β = -0.086 (95% confidence interval = -0.15; -0.025) TSS unit/mg/cm² increase, p = 0.006) but not with presence of radiographic progression (∆TSS >0) (OR 0.96 (0.92-1.0), p = 0.10). In early RA patients treated with a methotrexate-based treat-to-target strategy, the majority of patients had increased HBL_1-year, irrespective of adalimumab; HBL_6months was independently associated with ∆TSS after 2 years.

Effect of a treat-to-target strategy based on methotrexate and intra-articular betamethasone with or without additional cyclosporin on MRI-assessed synovitis, osteitis, tenosynovitis, bone erosion, and joint space narrowing in early rheumatoid arthritis: results from a 2-year randomized double-blind placebo-controlled trial (CIMESTRA)

OBJECTIVES

To investigate whether a treat-to-target strategy based on methotrexate (MTX) and intra-articular (IA) betamethasone suppresses magnetic resonance imaging (MRI)-determined measures of disease activity and reduces joint destruction in early rheumatoid arthritis (eRA) patients, and to investigate whether concomitant cyclosporin A (CyA) provides an additional effect.

METHOD

In the 2-year randomized, double-blind, treat-to-target trial CIMESTRA, 160 patients with eRA (< 6 months) were randomized to MTX, intra-articular betamethasone and CyA, or placebo CyA. A total of 129 patients participated in the MRI substudy, and had contrast-enhanced MR images of the non-dominant hand at months 0, 6, 12, and 24. MR images were evaluated for osteitis, synovitis, tenosynovitis, bone erosion, and joint space narrowing (JSN), using validated scoring methods.

RESULTS

Significant reductions were seen at 6 months in all inflammatory parameters [synovitis, mean change -1.6 (p < 0.001, Wilcoxon), tenosynovitis, -3.5 (p < 0.001), and osteitis, -1.3 (p < 0.05)] and at 12/24 months in synovitis and tenosynovitis [-1.6/-2.2 and -3.6/-3.8, respectively; all p < 0.001]. MRI signs of inflammation were not fully eliminated, and increases in erosion and JSN scores were observed at 6 months [0.4 (p < 0.01)/0.1 (p < 0.05)], 12 months [0.8 (p < 0.001)/0.3 (p < 0.01)], and 24 months [1.0 (p < 0.001)/0.4 (p < 0.001)]. Clinical measures decreased significantly (p < 0.001) at all time points. There were no consistent statistically significant differences between treatment groups.

CONCLUSIONS

In this eRA treat-to-target trial, MTX and intra-articular glucocorticoids markedly reduced, but did not eliminate, MRI osteitis, synovitis, and tenosynovitis. Accordingly, minimal but statistically significant increases in bone erosion and JSN were observed. No additional effect of CyA was demonstrated.

Establishment of age- and sex-adjusted reference data for hand bone mass and investigation of hand bone loss in patients with rheumatoid arthritis treated in clinical practice: an observational study from the DANBIO registry and the Copenhagen Osteoarthritis Study

Background

Rheumatoid arthritis is characterised by progressive joint destruction and loss of periarticular bone mass. Hand bone loss (HBL) has therefore been proposed as an outcome measure for treatment efficacy. A definition of increased HBL adjusted for age- and sex-related bone loss is lacking. In this study, we aimed to: 1) establish reference values for normal hand bone mass (bone mineral density measured by digital x-ray radiogrammetry (DXR-BMD)); and 2) examine whether HBL is normalised in rheumatoid arthritis patients during treatment with tumour necrosis factor alpha inhibitors (TNFI).

Methods

DXR-BMD was measured from hand x-rays in a reference cohort (1485 men/2541 women) without arthritis randomly selected from an urban Danish population. Sex- and age-related HBL/year was estimated. DXR-BMD was measured in rheumatoid arthritis patients (n = 350: at start of TNFI, and ~2 years after TNFI start), of which 135 patients had three x-rays (~2 years prior to TNFI, at start of TNFI, and ~2 years after TNFI start). Individual HBL/year prior to and during TNFI was calculated and compared to reference values.

Results

Estimated HBL/year varied strongly with age and sex. Compared to the reference values, 75 % of 135 patients had increased HBL prior to TNFI treatment and 59 % had increased HBL during TNFI treatment (p = 0.17, Chi-squared). In 38 % (38/101) of patients with increased HBL, HBL was normalised during TNFI treatment, whereas 47 % (16/34) of patients with normal HBL prior to TNFI had increased HBL during TNFI treatment. In the 350 patients, increased HBL during TNFI was associated with time-averaged 28-joint disease activity score (odds ratio 1.69 (95 % Confidence Interval 1.34-2.15)/unit increase, p < 0.001), and patients in time-averaged remission had lower HBL than patients without remission (0.0032 vs. 0.0058 g/cm²/year; p < 0.001, Mann-Whitney).

Conclusions

We established age- and sex-specific reference values for DXR-BMD in a large cohort without arthritis. HBL was increased in the majority of rheumatoid arthritis patients initiating TNFI in clinical practice, and only normalised in a minority during TNFI.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-016-0952-y) contains supplementary material, which is available to authorized users.

Application of synthetic peptides for detection of anti-citrullinated peptide antibodies

Anti-citrullinated protein antibodies (ACPAs) are a hallmark of rheumatoid arthritis (RA) and represent an important tool for the serological diagnosis of RA. In this study, we describe ACPA reactivity to overlapping citrullinated Epstein-Barr virus nuclear antigen-1 (EBNA-1)-derived peptides and analyze their potential as substrates for ACPA detection by streptavidin capture enzyme-linked immunosorbent assay. Using systematically overlapping peptides, containing a 10 amino acid overlap, labelled with biotin C-terminally or N-terminally, sera from 160 individuals (RA sera (n=60), healthy controls (n=40), systemic lupus erythematosus (n=20), Sjögren's syndrome (n=40)) were screened for antibody reactivity. Antibodies to a panel of five citrullinated EBNA-1 peptides were found in 67% of RA sera, exclusively of the IgG isotype, while 53% of the patient sera reacted with a single peptide, ARGGSRERARGRGRG-Cit-GEKR, accounting for more than half of the ACPA reactivity alone. Moreover, these antibodies were detected in 10% of CCP2-negative RA sera. In addition, 47% of the RA sera reacted with two or three citrullinated EBNA-1 peptides from the selected peptide panel. Furthermore, a negative correlation between the biotin attachment site and the location of citrulline in the peptides was found, i.e. the closer the citrulline was located to biotin, the lower the antibody reactivity. Our data suggest that citrullinated EBNA-1 peptides may be considered a substrate for the detection of ACPAs and that the presence of Epstein-Barr virus may play a role in the induction of these autoantibodies.

Is urate crystal precipitation a predictor of cardiovascular risk in hyperuricemic patients? A Danish cohort study

Introduction

There is increasing evidence that both hyperuricemia and gout increase the risk of cardiovascular morbidity and mortality. Whether urate crystal precipitation confers a particular risk above what is already inherent in having hyperuricemia is not well established. We conducted this cohort study to establish whether the presence of monosodium urate crystal precipitation per se is associated with increased risk of cardiovascular diseases among hyperuricemic patients.

Methods

We identified hyperuricemic individuals who had joint fluid examinations for urate crystals. Individuals with intra-articular urate crystals were matched by propensity score to individuals without crystals and compared with respect to a composite cardiovascular endpoint. Included in the propensity score model were potential confounders retrieved from four different health care registries.

Results

We identified 862 hyperuricemic patients having urate crystal examination. After propensity score matching, we could include 317 patients with urate crystals matched 1:1 to patients without urate crystals. We found no difference between the two groups with respect to cardiovascular outcomes (hazard ratios = 0.86; 95 % confidence interval (CI) 0.52 - 1.43) or death (hazard ratio 0.74; CI 0.45 - 1.21).

Conclusion

The presence of urate crystal precipitations does not seem to confer a particular cardiovascular risk in hyperuricemic patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-015-0822-z) contains supplementary material, which is available to authorized users.

Clinical and radiographic outcome of a treat-to-target strategy using methotrexate and intra-articular glucocorticoids with or without adalimumab induction: a 2-year investigator-initiated, double-blinded, randomised, controlled trial (OPERA)

OBJECTIVES

To study clinical and radiographic outcomes after withdrawing 1 year's adalimumab induction therapy for early rheumatoid arthritis (eRA) added to a methotrexate and intra-articular triamcinolone hexacetonide treat-to-target strategy (NCT00660647).

METHODS

Disease-modifying antirheumatic drug (DMARD)-naive patients with eRA started methotrexate (20 mg/week) and intra-articular triamcinolone (20 mg/ml) for 2 years. In addition, they were randomised to receive placebo adalimumab (DMARD group, n=91) or adalimumab (40 mg/every other week) (DMARD+adalimumab group, n=89) during the first year. Sulfasalazine and hydroxychloroquine were added if disease activity persisted after 3 months. During year 2, synthetic DMARDs continued. Adalimumab was (re)initiated if active disease reoccurred. Clinical response, remission, disability, quality of life and radiographic changes were assessed.

RESULTS

One year after adalimumab withdrawal, treatment profiles and clinical responses did not differ between groups. In the DMARD/DMARD+adalimumab groups, the median 2-year methotrexate dose was 20/20 mg/week (p=0.45), triple DMARD therapy had been initiated in 33/27 patients (p=0.49), adalimumab was (re)initiated in 12/12 patients and cumulative triamcinolone dose was 160/120 mg (p=0.15). The treatment target (disease activity score, 4 variables, C-reactive protein (DAS28CRP) ≤3.2 or DAS28>3.2 without swollen joints) was achieved at all visits in ≥85% of patients in year 2; remission rates were DAS28CRP<2.6:69%/66%; Clinical Disease Activity Index ≤2.8:55%/57%; Simplified Disease Activity Index <3.3:54%/49%; American College of Rheumatology/European League against Rheumatism (28 joints):44%/45% (p=0.66-1.00). Radiographic progression (Δtotal Sharp score/year) was similar 1.31/0.53 (p=0.12). Erosive progression (Δerosion score (ES)/year) was year 1:0.57/0.06 (p=0.02); year 2:0.38/0.05 (p=0.005). Proportion of patients without erosive progression (ΔES≤0) was year 1: 59%/76% (p=0.03); year 2:64%/79% (p=0.04).

CONCLUSIONS

An aggressive triamcinolone and synthetic DMARD treat-to-target strategy in eRA provided excellent 2-year clinical and radiographic disease control independent of adalimumab induction therapy. ES progression was slightly less during and following adalimumab induction therapy.

TRIAL REGISTRATION NUMBER

NCT00660647.

Within-day variation and influence of physical exercise on circulating Galectin-3 in patients with rheumatoid arthritis and healthy individuals

Galectin-3 has been suggested as a pro-inflammatory mediator in rheumatoid arthritis (RA). Previous studies have reported overexpression of Galectin-3 in RA synovitis and increased levels in synovial fluid and serum in long-standing RA compared with osteoarthritis and healthy controls. Our objectives were to study whether serum Galectin-3 (1) exhibits circadian variation and/or (2) responds to exercise in RA and controls. The study on circadian patterns (1) comprised eleven patients with newly diagnosed RA, disease duration less than 6 months (ERA), 10 patients with long-standing RA [5-15 years (LRA)] and 16 self-reportedly healthy control subjects. During 24 h, 7 blood samples were drawn at 3-h intervals starting at 10 a.m. through 10 p.m. and at 7 and 10 a.m. on the following day. The study on the effect of physical activity (2) included 10 patients with ERA, 10 with LRA and 14 controls. The participants underwent a standardized exercise programme and four blood samples were drawn before, during and after exercise. Serum Galectin-3 was quantified by ELISA (R&D systems). (1) Galectin-3 was increased at baseline in both RA subsets (P = 0.08). There were no diurnal oscillations (P = 0.85). Day-to-day variation amounted to 3%. (2) Baseline Galectin-3 was increased in LRA versus controls and ERA (P < 0.01 and 0.05). Physical exercise induced 10-15% Galectin-3 increments in RA and controls (P < 0.001) peaking after 1-3 h. To conclude, Galectin-3 did not exhibit circadian variation. Day-to-day variation was 3%. Exercise elicited comparable increments in patients with RA of short and long duration and controls, approaching normal after 1-3 h.

The Smart Floor: How a Public-Private Partnership co-developed a heterogeneous healthcare technology system

Currently, a wide variety of healthcare technologies are being implemented in private homes, hospitals, nursing homes, etc. with the triple aim of improving people's health, improving the quality of care, and reducing costs related to healthcare services. In this chapter, we discuss how different actors in a public-private partnership co-developed a heterogeneous system around the Smart Floor to ensure that both new healthcare practices and residents' routines were inscribed into the new healthcare technology. We argue that implementing the Smart Floor was not just a question of buying a technology and integrating it during construction-it required co-development with the healthcare staff. The floor is more than a technology placed under the floor surface in a resident's apartment; rather, it is a heterogeneous network of human and non-human actors communicating with each other. In this chapter, we illustrate how the heterogeneous technological system was co-developed and redesigned during knowledge sharing processes with companies, lead-users, and healthcare staff. We also discuss how care practices have changed as a result of the Smart Floor system. In particular, healthcare staff members no longer feel a need to disturb elderly residents with routine in-person checks. Domesticating the technologies for different groups of actors required not only coordinating communication among sensors, the interface, the portable nurse call (smartphones), and alarms, but also accepting the use of surveillance technology.

Which Factors Influence Radiographic Progression During Treatment with Tumor Necrosis Factor Inhibitors in Clinical Practice? Results from 930 Patients with Rheumatoid Arthritis in the Nationwide Danish DANBIO Registry

Objective.

To investigate baseline characteristics associated with radiographic progression and the effect of disease activity, drug, switching, and withdrawal on radiographic progression in tumor necrosis factor (TNF) inhibitor-naive patients with rheumatoid arthritis (RA) followed for about 2 years after anti-TNF initiation in clinical practice.

Methods.

DANBIO-registered patients with RA who had available radiographs (anti-TNF initiation and ∼2 yrs followup) were included. Radiographs were scored, blinded to chronology with the Sharp/van der Heijde method and linked with DANBIO data. Baseline characteristics were investigated with univariate regression and significant variables included in a multivariable logistic regression analysis with ± radiographic progression [Δ total Sharp score (TSS) > 0] as dependent variable. Effect of time-averaged C-reactive protein (CRP), 28-joint Disease Activity Score with CRP (DAS28-CRP), and treatment status at followup were investigated with univariate regression analysis.

Results.

The study included 930 patients. They were 75% women, 79% positive for IgM-rheumatoid factor (IgM-RF), median age was 57 yrs (range 19–88), disease duration 9 yrs (1–59), DAS28-CRP 5.0 (1.4–7.8), TSS median 15 [3–45 interquartile range (IQR)] and mean 31 (SD 40). Patients started treatment with infliximab (59%), etanercept (18%), or adalimumab (23%). At followup (median 526 days, IQR 392–735), 61% were treated with the initial anti-TNF, 29% had switched TNF inhibitor, and 10% had withdrawn. Twenty-seven percent of patients had progressed radiographically. ΔTSS was median 0.0 [0.0–0.5 IQR/mean 0.6 (SD 2.4)] units/year. Higher TSS, older age, positive IgM-RF, and concomitant prednisolone at baseline were associated with radiographic progression. Time-averaged DAS28-CRP and time-averaged CRP, but not type of TNF inhibitor, were associated with radiographic progression. Patients who stopped/switched during followup progressed more than patients who continued treatment.

Conclusion.

High TSS, older age, IgM-RF positivity, and concomitant prednisolone were associated with radiographic progression during 2 years of followup of 930 anti-TNF–treated patients with RA in clinical practice. High disease activity and switching/stopping anti-TNF treatment were associated with radiographic progression.

Interactions between smoking, increased serum levels of anti-CCP antibodies, rheumatoid factors, and erosive joint disease in patients with early, untreated rheumatoid arthritis

OBJECTIVES

To determine to what extent shared epitopes, smoking, and anti-cyclic citrullinated peptide (anti-CCP) antibodies are associated with disease activity and erosive disease in patients with rheumatoid arthritis (RA) at disease onset.

METHOD

RA patients not previously treated with disease-modifying anti-rheumatic drugs (DMARDs) and with a disease duration of < 6 months (CIMESTRA study) were examined for shared epitopes, anti-CCP antibodies, immunoglobulin M rheumatoid factor (IgM-RF) and IgA-RF, radiographic erosive changes in hands and feet, and clinical disease activity.

RESULTS

The study comprised 153 patients, of whom 104 (68%) were ever-smokers. The prevalence of patients with 0, 1, or 2 shared epitopes was 40 (48%), 71 (49%), and 33 (23%), respectively. Anti-CCP antibodies, IgM-RF, and IgA-RF were present in 89 (58%), 99 (65%), and 82 (54%) patients, respectively. Among smokers, erosive disease was associated with anti-CCP antibodies [odds ratio (OR) 3.9, 95% confidence interval (CI) 1.6-9.3], IgM-RF (OR 4.9, 95% CI 1.9-12), and IgA-RF (OR 2.8, 95% CI 1.2-6.4) but absent with regard to shared epitopes. Among never-smokers, erosive disease was not associated with either shared epitopes or antibodies. All antibody levels measured were associated with smoking and shared epitopes.

CONCLUSIONS

Shared epitopes and smoking were associated with the production of anti-CCP antibodies and rheumatoid factors of IgM and IgA isotypes, which again were associated with erosive disease at presentation only in smokers. As shared epitopes and smoking were not directly associated with erosive disease, smoking may enhance the development of erosive disease in RA at different levels or through separate pathways.

Eosinophilia in routine blood samples as a biomarker for solid tumor development - A study based on the Copenhagen Primary Care Differential Count (CopDiff) Database

BACKGROUND

Eosinophilia may represent an early paraclinical sign of malignant disease and a host anti-tumor effect. The association between eosinophilia and the development of solid tumors has never before been examined in an epidemiological setting. The aim of the present study was to investigate eosinophilia in routine blood samples as a potential biomarker of solid tumor development in a prospective design.

MATERIAL AND METHODS

From the Copenhagen Primary Care Differential Count (CopDiff) Database, we identified 356 196 individuals with at least one differential cell count (DIFF) encompassing the eosinophil count during 2000-2007. From these, one DIFF was randomly chosen and categorized according to no (< 0.5 × 10(9)/l), mild (≥ 0.5-1.0 × 10(9)/l) or severe (≥ 1.0 × 10(9)/l) eosinophilia. From the Danish Civil Registration System and the Danish Cancer Registry we ascertained all-cause death and solid tumors within the first three years following the DIFF. Using multivariable logistic regression, odds ratios (OR) were calculated and adjusted for previous eosinophilia, sex, age, year, month, C-reactive protein, previous cancer and Charlson's Comorbidity Index.

RESULTS

The risk of bladder cancer was increased with mild eosinophilia [OR 1.93 (CI 1.29-2.89), p = 0.0013]. No associations with eosinophilia were observed for the remaining solid cancers.

CONCLUSION

We demonstrate that eosinophilia in routine blood samples associates with an increased risk of bladder cancer. Our data emphasize that additional preclinical studies are needed in order to shed further light on the role of eosinophils in carcinogenesis, where it is still unknown whether the cells contribute to tumor immune surveillance or neoplastic evolution.

Risk of lymphoma and solid cancer among patients with rheumatoid arthritis in a primary care setting

BACKGROUND

Several studies have demonstrated an association between rheumatoid arthritis (RA) and lymphoproliferative malignancies, but pathogenic mechanisms remain unclear. We investigated 1) the risk of lymphoproliferative malignancies and solid tumors in adults with RA identified in primary care and 2) the possible mediating role of blood eosinophilia in the clonal evolution of cancer in these patients.

METHODS

From the Copenhagen Primary Care Differential Count (CopDiff) Database, we identified 356,196 individuals with at least one differential cell count (DIFF) encompassing the eosinophil count between 2000-2007. From these, one DIFF was randomly chosen (the index DIFF). By linking to the Danish National Patient Register, we categorized the selected individuals according to known longstanding (≥3 years) or recent onset (<3 years) RA prior to the index DIFF. In addition, the cohort was stratified according to management in primary or secondary care. From the Danish Cancer Registry we ascertained malignancies within four years following the index DIFF. Using multivariable logistic regression, odds ratios (OR) were calculated and adjusted for sex, age, year, month, eosinophilia, comorbid conditions and C-reactive protein (CRP).

RESULTS

921 patients had recent onset RA and 2,578 had longer disease duration. Seventy three percent of RA patients were managed in primary care. After adjustment for sex, age, year, and month, neither recent onset nor long-standing RA was associated with incident lymphoproliferative malignancies or solid cancers. These risk estimates did not change when eosinophilia, CRP, and comorbidities were included in the models.

CONCLUSIONS

In this large cohort of patients with RA of short or long duration recruited from a primary care resource, RA was not associated with an increased risk of lymphoproliferative or solid cancers during 4 years of follow-up, when the models were adjusted for confounders. Blood eosinophilia could not be identified as a mediator of cancer development in the present setting.