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 (HBL1-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 HBL6months 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 HBL6months (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 HBL1-year data, HBL1-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 HBL6months data and 2-year radiographic data, HBL6months was independently associated with ∆TSS after 2 years (ß = -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 HBL1-year, irrespective of adalimumab; HBL6months was independently associated with ∆TSS after 2 years.

Short- and long-term efficacy of intra-articular injections with betamethasone as part of a treat-to-target strategy in early rheumatoid arthritis: impact of joint area, repeated injections, MRI findings, anti-CCP, IgM-RF and CRP.

OBJECTIVE: To investigate the short-term and long-term efficacy of intra-articular betamethasone injections, and the impact of joint area, repeated injections, MRI pathology, anticyclic citrullinated peptide (CCP) and immunoglobulin M rheumatoid factor (IgM-RF) status in patients with early rheumatoid arthritis (RA). METHODS: During 2 years of follow-up in the CIMESTRA trial, 160 patients received intra-articular betamethasone in up to four swollen joints/visit in combination with disease-modifying antirheumatic drugs. Short-term efficacy was assessed by EULAR good response. Long-term efficacy by Kaplan-Meier plots of the joint injection survival (ie, the time between injection and renewed flare). Potential predictors of joint injection survival were tested. RESULTS: 1373 Unique joints (ankles, elbows, knees, metacarpophalangeal (MCP), metatarsophalangeal, proximal interphalangeal (PIP), shoulders, wrists) were injected during 2 years. 531 Joints received a second injection, and 262 a third. At baseline, the median numbers of injections (dose of betamethasone) was 4 (28 mg), declining to 0 (0 mg) at subsequent visits. At weeks 2, 4 and 6, 50.0%, 58.1% and 61.7% had achieved a EULAR good response. After 1 and 2 years, respectively, 62.3% (95% CI 58.1% to 66.9%) and 55.5% (51.1% to 60.3%) of the joints injected at baseline had not relapsed. All joint areas had good 2-year joint injection survival, longest for the PIP joints: 73.7% (79.4% to 95.3%). 2-Year joint injection survival was higher for first injections: 56.6% (53.7% to 59.8%) than for the second: 43.4% (38.4% to 49.0%) and the third: 31.3% (25.0% to 39.3%). Adverse events were mild and transient. A high MRI synovitis score of MCP joints and anti-CCP-negativity were associated with poorer joint injection survival, whereas IgM-RF and C-reactive protein were not. CONCLUSION: In early RA, intra-articular injections of betamethasone in small and large peripheral joints resulted in rapid, effective and longlasting inflammatory control. The cumulative dose of betamethasone was low, and the injections were well tolerated.

Cartilage oligomeric matrix protein associates differentially with erosions and synovitis and has a different temporal course in cyclic citrullinated peptide antibody (anti-CCP)-positive versus anti-CCP-negative early rheumatoid arthritis.

OBJECTIVE: Cyclic citrullinated peptide antibody (anti-CCP)-positive and anti-CCP-negative rheumatoid arthritis (RA) have been suggested as 2 distinctive disease subsets with respect to disease activity and prognosis. Previously, we proposed that anti-CCP antibodies might have a chondrocyte-suppressive effect. We aimed to compare circulating cartilage oligomeric matrix protein (COMP), a marker of cartilage turnover, in untreated anti-CCP-positive and anti-CCP-negative RA, and to study the temporal pattern of COMP through 4 years of treatment, including the relationship to imaging and clinical findings. METHODS: A total of 160 patients with newly diagnosed RA who were naive to disease-modifying antirheumatic drugs were included in the CIMESTRA trial. Ninety healthy blood donors served as controls. Demographic and disease measures including Disease Activity Score in 28 joints, IgM rheumatoid factor, anti-CCP, Health Assessment Questionnaire, visual analog scale scores for pain and global and physician assessment, and magnetic resonance imaging (MRI) of the nondominant hand were recorded at baseline. COMP in serum was measured by ELISA at inclusion and serially through 4 years. RESULTS: Median baseline COMP was higher in patients with RA [9.8 U/l (interquartile range 8.96, 10.5)] compared with controls [8.3 U/l (IQR 7.84, 8.9); p < 0.001] and remained elevated at 4 years [10.8 U/l (IQR 10.2, 11.7); p < 0.001]. At baseline, anti-CCP-positive patients had lower COMP than anti-CCP-negative patients (p = 0.048). In anti-CCP-positive patients, COMP exhibited a parabolic course over 4 years, while COMP in anti-CCP-negative patients had an almost linear course. In anti-CCP-positive patients, COMP was associated with MRI edema and erosion score, while COMP was correlated with synovitis score in anti-CCP-negative individuals. CONCLUSION: Our study provides additional evidence for the existence of different disease pathways in anti-CCP-positive and anti-CCP-negative subsets of RA, and evidence that anti-CCP antibodies may be implicated in the disease process by modifying cartilage metabolism.

Uncoupling of collagen II metabolism in newly diagnosed, untreated rheumatoid arthritis is linked to inflammation and antibodies against cyclic citrullinated peptides.

OBJECTIVE: To investigate the relationship between markers of collagen II synthesis and degradation with disease activity measures, autoantibodies, and radiographic outcomes in a 4-year protocol on patients with early rheumatoid arthritis (RA) who are naïve to disease-modifying antirheumatic drugs. METHODS: One hundred sixty patients with newly diagnosed, untreated RA entered the Cyclosporine, Methotrexate, Steroid in RA (CIMESTRA) trial. Disease activity and radiograph status were measured at baseline and 4 years. The N-terminal propeptide of collagen IIA (PIIANP) and the cross-linked C-telopeptide of collagen II (CTX-II) were quantified at baseline by ELISA. PIIANP was also assayed at 2 and 4 years. Anticyclic citrullinated peptide (anti-CCP) was recorded at baseline. An uncoupling index for cartilage collagen metabolism was calculated from PIIANP and CTX-II measurements. RESULTS: PIIANP was low at diagnosis and 4 years on (p < 0.001), irrespective of treatment and disease activity. PIIANP was lowest in anti-CCP positive patients (p = 0.006), and there was a negative correlation between PIIANP and anti-CCP titers (rho = -0.25, p 0.002). CTX-II was increased (p < 0.001) and correlated positively with disease activity and radiographic progression, but not with anti-CCP (p = 0.93). The uncoupling index was not superior to CTX-II in predicting radiographic changes. CONCLUSION: These results suggest that cartilage collagen formation and degradation are unbalanced when RA is diagnosed. The different associations of collagen II anabolism (PIIANP) and collagen II degradation (CTX-II) with anti-CCP, synovitis, and radiographic progression indicate that at this early stage of RA, cartilage collagen degradation is mainly driven by synovitis, while anti-CCP antibodies may interfere with cartilage regeneration by inhibiting collagen IIA formation. Trial registration j.nr NCT00209859.

Circulating surfactant protein -D is low and correlates negatively with systemic inflammation in early, untreated rheumatoid arthritis.

INTRODUCTION: Surfactant protein D (SP-D) is a collectin with immuno-regulatory functions, which may depend on oligomerization. Anti-microbial and anti-inflammatory properties have been attributed to multimeric SP-D variants, while trimeric subunits per se have been suggested to enhance inflammation. Previously, we reported low circulating SP-D in early rheumatoid arthritis (RA), and the present investigation aims to extend these data by serial SP-D serum measurements, studies on synovial fluid, SP-D size distribution and genotyping in patients with early RA. METHODS: One-hundred-and-sixty disease-modifying antirheumatic drug (DMARD) naïve RA patients with disease duration less than six months were studied prospectively for four years (CIMESTRA (Ciclosporine, Methotrexate, Steroid in RA) trial) including disease activity measures (C-reactive protein, joint counts and Health Assessment Questionnaire (HAQ) score), autoantibodies, x-ray findings and SP-D. SP-D was quantified by enzyme-linked immunosorbent assay (ELISA) and molecular size distribution was assessed by gel filtration chromatography. Further, SP-D Met11Thr single nucleotide polymorphism (SNP) analysis was performed. RESULTS: Serum SP-D was significantly lower in RA patients at baseline compared with healthy controls (P < 0.001). SP-D increased slightly during follow-up (P < 0.001), but was still subnormal at four years after adjustment for confounders (P < 0.001). SP-D in synovial fluid was up to 2.5-fold lower than in serum. While multimeric variants were detected in serum, SP-D in synovial fluid comprised trimeric subunits only. There were no significant associations between genotype distribution and SP-D. Baseline SP-D was inversely associated to CRP and HAQ score. A similar relationship was observed regarding temporal changes in SP-D and CRP (zero to four years). SP-D was not associated to x-ray findings. CONCLUSIONS: This study confirms that circulating SP-D is persistently subnormal in early and untreated RA despite a favourable therapeutic response obtained during four years of follow-up. SP-D correlated negatively to disease activity measures, but was not correlated with x-ray progression or SP-D genotype. These observations suggest that SP-D is implicated in RA pathogenesis at the protein level. The exclusive presence of trimeric SP-D in affected joints may contribute to the maintenance of joint inflammation. TRIAL REGISTRATION: (j.nr NCT00209859).

Changes in plasma IL-6, plasma VEGF and serum YKL-40 during Treatment with Etanercept and Methotrexate or Etanercept alone in Patients with Active Rheumatoid Arthritis Despite Methotrexate Therapy.

Changes in plasma IL-6, plasma VEGF and serum YKL-40 were determined in rheumatoid arthritis (RA) patients during treatment with etanercept alone or in combination with methotrexate. Twenty-five patients with active RA (DAS28 >/= 3.2) were randomized to receive etanercept (25 mg sc. biweekly) plus methotrexate (n = 12) or etanercept alone (n = 13). Plasma IL-6, plasma VEGF and serum YKL-40 were determined by ELISA. The 3 biomarkers and DAS28 scores were evaluated at baseline and after 4, 8, 12 and 16 weeks of treatment. At inclusion all patients had significantly (p < 0.001) elevated plasma IL-6, plasma VEGF and serum YKL-40 compared to healthy subjects. Eighteen patients responded to treatment (pooled data from both treatment groups), and they had significant (p < 0.05 to p < 0.001) decreases in plasma IL-6, plasma VEGF, serum YKL-40, ESR and DAS28 after 4 weeks of treatment and throughout the study (except serum YKL-40 at week 16). Plasma IL-6 showed the largest reductions. Non-responders had unchanged biomarkers. At week 16 the patients with DAS28 < 3.2 had lower levels compared to baseline values in plasma IL-6 (p = 0.005), plasma VEGF (p = 0.014), and ESR (p = 0.024).Plasma IL-6, plasma VEGF and serum YKL-40, which reflect different aspects of the inflammatory process, may provide useful information regarding early differentiation of responders from non-responders.

Mannose-binding lectin gene polymorphisms are associated with disease activity and physical disability in untreated, anti-cyclic citrullinated peptide-positive patients with early rheumatoid arthritis.

OBJECTIVE: To study the association between polymorphisms in the mannose-binding lectin gene (MBL2) and disease activity, physical disability, and joint erosions in patients with newly diagnosed rheumatoid arthritis (RA). METHODS: Patients with early RA (n=158) not previously treated with disease modifying antirheumatic drugs, participating in a treatment trial (CIMESTRA study) were examined at inclusion for MBL2 pooled structural genotypes (O/O, A/O, A/A), regulatory MBL2 promoter polymorphism in position -221 (XX, XY, YY), anti-cyclic citrullinated peptide 2 antibodies (anti-CCP2), disease activity by Disease Activity Score-28 (DAS28 score), physical disability by Health Assessment Questionnaire (HAQ) score, and erosive changes in hands and feet (Sharp-van der Heijde score). RESULTS: Eight patients were homozygous MBL2 defective (O/O), 101 belonged to an intermediate group, and 49 were MBL2 high producers (YA/YA). Anti-CCP was present in 93 patients (59%). High scores of disease activity, C-reactive protein-based DAS28 (p=0.02), and physical disability by HAQ (p=0.01) were associated with high MBL2 expression genotypes in a gene-dose dependent way, but only in anti-CCP-positive patients. At this early stage of the disease there was no association with erosion score from radiographs. CONCLUSION: The results point to a synovitis-enhancing effect of MBL in anti-CCP-positive RA, whereas such an effect was not demonstrated for joint erosions.

Biomarkers of inflammation in patients with unclassified polyarthritis and early rheumatoid arthritis. Relationship to disease activity and radiographic outcome.

OBJECTIVE: To determine plasma interleukin 6 (pIL-6), plasma vascular endothelial growth factor (pVEGF), and serum (s) YKL-40 in patients with early rheumatoid arthritis (RA) and unclassified polyarthritis (PA), and investigate their relationship with radiographic outcome. METHODS: pIL-6 and pVEGF were determined by ELISA and sYKL-40 by an in-house radioimmunoassay in 51 patients with early RA and 21 with PA. Patients were followed with clinical and biochemical measurement every month for 2 years. Conventional radiographs of hands, wrists, and forefeet were scored according to the Larsen method, and magnetic resonance imaging of 2nd to 5th metacarpophalangeal joints of the dominant hand were evaluated for presence or absence of bone erosions. RESULTS: Baseline pIL-6, pVEGF, sYKL-40, C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) were elevated in RA patients compared to healthy persons (p < 0.001), but were not in patients with PA. Patients with early RA had higher pIL-6 (p = 0.007), pVEGF (p = 0.02), and sYKL-40 (p = 0.024) compared to PA patients. pIL-6, sYKL-40, CRP, and ESR but not pVEGF decreased in patients that responded to treatment after 2 years. The mean value of pIL-6 during the first and second year were higher in patients with early RA with progression in bone erosions (n = 14) compared to early RA patients without progression (n = 30; first year 8.4 vs 2.8 ng/l, p = 0.04; second year 6.1 vs 3.6 ng/l, p = 0.03). CONCLUSION: Plasma IL-6 was the only biomarker related to treatment response and progressive erosive disease in patients with early RA, but it may not give additional information compared to CRP in relation to disease activity and treatment response.

Keitel Functional Test for patients with rheumatoid arthritis: translation, reliability, validity, and responsiveness.

BACKGROUND AND PURPOSE: The purpose of this study was to translate the German Keitel Functional Test (KFT) into Danish and test it for reliability, concurrent and predictive validity, and responsiveness in patients with rheumatoid arthritis (RA). METHODS: Translation of the KFT was performed according to international recommendations, and the translated version was tested twice by 2 observers for intraobserver and interobserver reliability, with a 1-week interval between assessments, in 20 patients with RA with stable disease activity. Validity was investigated by studying 2 patient groups: (1) 15 patients with long-lasting (median=6 years) active RA, tested before and after 2, 6, and 14 weeks of anti-tumor necrosis factor alpha (TNF-alpha) inhibitor therapy, and (2) 35 patients with early (median=0.25 year) RA, tested at years 0, 0.5, 1, and 2. Twenty-three patients in the early RA group also were tested at year 7. KFT, conventional clinical and biochemical markers of disease activity, and Health Assessment Questionnaire (HAQ) were used. RESULTS: The translated KFT showed good intraobserver reliability (intraclass correlation coefficients [ICC]=.90 and .95, coefficient of variation [CV]=3.5%) and interobserver reliability (ICC=.99 and .92, CV=3.5%), and the KFT correlated with several measures of disease activity and, most closely, with the HAQ. The KFT was, in contrast to clinical disease activity measures, not sensitive to changes over time. Only baseline KFT data were significantly related to functional changes over a long period of time as measured by the KFT, and only in the early RA group. DISCUSSION AND CONCLUSION: The Danish translation of the KFT showed good reliability, acceptable concurrent validity, very poor responsiveness, and inconclusive results concerning predictive validity. The results of this study do not support the use of the KFT for monitoring function in clinical practice, as an outcome measure in clinical trials, or as a predictor of functional changes.

No erosive progression revealed by MRI in rheumatoid arthritis patients treated with etanercept, even in patients with persistent MRI and clinical signs of joint inflammation.

The aim of this study is to investigate the course of magnetic resonance imaging (MRI) signs of inflammatory and destructive changes in rheumatoid arthritis (RA) wrist and metacarpophalangeal (MCP) joints during etanercept treatment. MRI of the non-dominant wrist and second to fifth MCP joints was performed in five clinical active RA patients before and 4 and 16 weeks after initiation of etanercept treatment. MRI was evaluated according to the EULAR-OMERACT RA MRI reference image atlas. The median 28-joint count disease activity score (DAS28; erythrocyte sedimentation rate based) was 5.6 (range 5.0-6.8) at baseline and 3.5 (1.5-4.1) at week 16 (decreased in all patients compared to baseline, Wilcoxon-Pratt, p < 0.05). The median MRI synovitis score was 18 (14-21), 18 (10-20) and 16 (10-20) at baseline, week 4 and 16, respectively (decreased in all patients compared to baseline, Wilcoxon-Pratt, p < 0.05), while corresponding MRI bone oedema scores were 4 (0-13), 3 (0-9) and 1 (0-3; NS). The median MRI bone erosion score was 27 (11-111; NS) at all time points. Four patients had identical total bone erosion scores at baseline and week 16, whereas one patient showed a reduced score. In conclusion, one patient showed erosive regression, while no patient showed erosive progression on MRI during 16 weeks of etanercept therapy; even though clinical and MRI signs of joint inflammation remained. This small study supports that erosive progression judged by MRI is minimal in RA patients treated with etanercept, even in joints with persistent inflammation.

Combination treatment with methotrexate, cyclosporine, and intraarticular betamethasone compared with methotrexate and intraarticular betamethasone in early active rheumatoid arthritis: an investigator-initiated, multicenter, randomized, double-blind, parallel-group, placebo-controlled study.

OBJECTIVE: To investigate whether disease control can be achieved in early active rheumatoid arthritis (RA) by treatment with methotrexate and intraarticular betamethasone, and whether the addition of cyclosporine to the regimen has any additional effect. METHODS: Patients (n = 160) were randomized to receive methotrexate 7.5 mg/week plus cyclosporine 2.5 mg/kg of body weight/day (combination therapy) or methotrexate plus placebo-cyclosporine (monotherapy). At weeks 0, 2, 4, 6, and 8 and every 4 weeks thereafter, betamethasone was injected into swollen joints (maximum 4 joints or 4 ml per visit). Beginning at week 8, if synovitis was present, the methotrexate dosage was increased stepwise up to 20 mg/week, with a subsequent stepwise increase in the cyclosporine or placebo-cyclosporine dosage up to 4 mg/kg. RESULTS: At 52 weeks, 20% improvement according to the American College of Rheumatology criteria (ACR20) was achieved in 85% of the combination therapy group versus 68% of the monotherapy group (P = 0.02). The median individual overall ACR response (ACR-N) in the 2 groups was 80.0% (interquartile range 40.1-91.8%) and 54.5% (interquartile range 2.4-87.8%), respectively (P = 0.025). At 48 and 52 weeks, ACR remission criteria were met in 35% of the combination therapy group and 28% of the monotherapy group. Progression in the Larsen score at 52 weeks was -0.2 +/- 6.5 and 0.4 +/- 6.9 (mean +/- SD) in the combination therapy and monotherapy groups, respectively. Serum creatinine levels increased by 7%, and hypertrichosis was more prevalent, in the combination therapy group. CONCLUSION: Combined treatment with methotrexate and intraarticular glucocorticoid showed excellent disease control and stopped the progression of erosions in patients with early active RA, who had a poor prognosis. Addition of cyclosporine improved the ACR20 and ACR-N responses, whereas the ACR50 and ACR70 responses, remission rates, and radiographic changes did not differ between the 2 study groups.

Periodontal and hematological characteristics associated with aggressive periodontitis, juvenile idiopathic arthritis, and rheumatoid arthritis.

BACKGROUND: Periodontitis shares several clinical and pathogenic characteristics with chronic arthritis, and there is some degree of coexistence. The aims of this study were to elucidate whether patients with localized aggressive periodontitis (LAgP), generalized aggressive periodontitis (GAgP), juvenile idiopathic arthritis (JIA), and rheumatoid arthritis (RA) share periodontal and hematological characteristics distinguishing them from individuals free of diseases. METHODS: The study population consisted of white adults (or=4 mm, CAL>or=2 mm, and ABL>or=2 mm compared to controls. The percentage of sites with CAL>or=2 mm significantly correlated with the levels of IgM-RF and IgA-RF. Missing teeth in JIA and RA patients were not lost due to periodontitis. Patients with GAgP showed higher levels of leukocytes, including neutrophils, and CRP compared to controls. In part, JIA and RA patients showed similar results. CONCLUSIONS: Young adults with RA may develop periodontal destruction, and these patients require professional attention. Both differences and similarities in periodontal and hematological variables were seen in individuals with periodontitis, JIA, and RA.

Connective tissue metabolism in patients with unclassified polyarthritis and early rheumatoid arthritis. Relationship to disease activity, bone mineral density, and radiographic outcome.

OBJECTIVE: To assess the applicability of serum concentrations of markers of synovial inflammation, cartilage, and bone metabolism in relation to conventional markers of disease activity, bone mineral density (BMD) of the hand, and radiographic outcome. METHODS: Biochemical markers of collagen tissue metabolism were measured in 72 patients with symmetrically swollen and tender second and third metacarpophalangeal or proximal interphalangeal joints for at least 4 weeks and less than 2 years. At 2 years, 51 patients fulfilled the American College Rheumatology criteria for rheumatoid arthritis (RA) and 21 patients had unclassified polyarthritis. Patients with RA were divided into groups according to the mean disease activity and to magnetic resonance imaging and radiographically detected bone erosions in the hands. RESULTS: Patients with RA had significantly higher serum concentrations of matrix metalloproteinase-3 (MMP-3) at baseline and higher mean concentrations of serum MMP-3 and pyridinoline (Pyd) during the first 6 and 12 months than patients with unclassified polyarthritis. RA patients with persistent disease activity and erosive disease had significantly higher concentrations of serum MMP-3 and Pyd than patients with no disease activity or nonerosive disease. Significant mutual correlations between serum MMP-3 and Pyd and C-reactive protein and erythrocyte sedimentation rate were observed. The mean values of MMP-3 and Pyd correlated significantly to the alpha coefficient of the digital x-ray radiogrammetry (DXR-BMD). CONCLUSION: Serum MMP-3 and Pyd varied according to disease activity, periarticular osteoporosis measured by DXR, and radiographic outcome, and thus appear to supplement the conventional markers of disease activity for monitoring patients with RA.

Blood cell gene expression profiling in rheumatoid arthritis. Discriminative genes and effect of rheumatoid factor.

UNLABELLED: To study the pathogenic importance of the rheumatoid factor (RF) in rheumatoid arthritis (RA) and to identify genes differentially expressed in patients and healthy individuals, total RNA was isolated from peripheral blood mononuclear cells (PBMC) from eight RF-positive and six RF-negative RA patients, and seven healthy controls. Gene expression of about 10,000 genes were examined using oligonucleotide-based DNA chip microarrays. The analyses showed no significant differences in PBMC expression patterns from RF-positive and RF-negative patients. However, comparisons of gene expression patterns from all fourteen RA patients and healthy controls identified a subset of discriminative genes. These results were validated by real time reverse transcription polymerase chain reaction (RT-PCR) on another group of RA patients and healthy controls. This confirmed that the following genes had a significantly higher expression in RA patients than in healthy controls: CD14 antigen, defensin alpha-1 and alpha-3 (DEFA), fatty-acid-Coenzyme A ligase, long-chain 2 (FACL), ribonuclease 2 (RNASE2), S100 calcium-binding protein A8 and A12 (S100A8 and S100A12). In contrast, the expression of MHC class II, DQ beta1 (HLA-DQB1) was significantly reduced in RA patients compared to healthy controls. CONCLUSIONS: With the analytical procedure employed, we did not find any indication that RF-positive and RF-negative RA are two fundamentally different diseases. Most of the genes discriminative between RA patients and healthy individuals are known to be involved in immunoinflammatory responses, especially those related to altered phagocytic functions.