RF-positive Rheumatoid Arthritis Patients Research Articles

Association of RIPK1 and RIPK2 Gene Polymorphisms with Rheumatoid Arthritis in a Chinese Han Population.

Rheumatoid arthritis (RA) is a systemic autoimmune disease with an obscure pathogenesis. This study aims to identify the susceptibility conferred by specific single nucleotide polymorphisms (SNPs), namely rs17548629 within the RIPK1 gene and rs10094579 within the RIPK2 gene, in RA. Additionally, it investigates the associations between inflammatory markers and biochemical parameters at various stages of the disease. We analyzed 394 patients with RA and 258 normal controls (NCs), examining SNPs within the RIPK1 (rs17548629) and RIPK2 (rs10094579) genes using polymerase chain reaction (PCR) and sequencing techniques. Profiles of RA patients were evaluated for inflammatory markers, including C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR), as well as biochemical parameters such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), urea, glucose, uric acid, and creatinine. Additionally, disease-specific indicators included cyclic citrullinated peptide (CCP), rheumatoid factor (RF), antinuclear antibodies (ANA), and anti-keratin antibodies. The Disease Activity Score 28 (DAS28), based on ESR, was used to categorize RA patients into groups of high, moderate, or low disease activity. We found a significant association between the RIPK1 rs17548629 genotype and RA in the additive model (p < 0.001; OR = 3.23), over-dominant model (p < 0.001; OR = 0.27), and dominant model (p < 0.001; OR = 3.94). The frequency of the C allele at rs17548629 was significantly higher in NCs than in RA patients (p < 0.001; OR = 0.322). When compared with normal controls, the RIPK1 rs17548629 genotype demonstrated significant associations with both anti-CCP-positive RA patients (p < 0.001) and anti-CCP-negative RA patients (p < 0.001). Similarly, this genotype was associated with RF-positive RA patients (p < 0.001). Furthermore, the RIPK2 rs10094579 genotype was significantly associated with CRP levels in RA patients with low disease activity in the over-dominant model (p = 0.029; OR = 0.065, adjusted for age and sex). The presence of the RIPK1 rs17548629 genotype is associated with RA under additive, co-dominant, and dominant models. The T allele mutation at rs17548629 increases the risk of RA in the Chinese population. The RIPK1 rs17548629 genotype was identified as being associated with RF-positive RA patients, whereas no significant association was observed in RF-negative individuals. These findings suggest that this SNP may modulate the risk of RA in an RF-dependent manner. Furthermore, the RIPK2 rs10094579 genotype correlates with CRP levels in RA patients exhibiting low disease activity. This association underscores the necessity for caution when reducing the dosage of therapy in RA patients with low disease activity who carry the CA genotype at RIPK2 rs10094579. Additional research is warranted to explore other genotypes that may influence RA susceptibility and to refine potential treatment strategies.

Heterophilic Interference of Rheumatoid Factor in TSH Immunometric Assay: A Cross-Sectional Observational Study.

Considering the inherent vulnerability of immunoassays for heterophilic interference and the potential of Rheumatoid Factor (RF) to act as a heterophile-like antibody, we conducted this study to investigate if RF leads to any such heterophilic interference in seropositive rheumatoid arthritis (RA) patients. The study was done on the TSH assay as it is a noncompetitive, double antibody sandwich assay, which is known to be vulnerable to heterophilic interference. In this cross-sectional observational study, eighty-four consecutive newly diagnosed RF-positive RA patients underwent TSH, Free T4, and anti-TPO estimation using the chemiluminescence technique (CLIA) on Siemens Immulite 1000 platform. The samples were screened for TSH interference using four methods: 1) analysis on a different platform, 2) assessment of linearity using doubling dilutions, 3) polyethylene glycol (PEG) precipitation, and 4) addition of a commercial blocker. Ten samples had a loss of linearity on serial dilution, indicating potential interference. After heterophile blocker treatment, five cases exhibited interference. One patient had diagnostic interpretation discordance on the second platform. No sample on PEG precipitation suggested the influence of antibodies. It is worth noting that even in cases where interference was suspected, the clinical interpretation was largely unaffected by the correction of TSH values based on mean dilution or measurement after heterophile blocker treatment. RF can cause heterophilic interference in TSH immunoassays used commercially. However, in most cases, this interference does not affect clinical decision-making.

Elevated serum soluble CD27 levels are associated with both disease activity and humoral immune activity in patients with rheumatoid arthritis.

To investigate the serum level of soluble CD27 (sCD27) and its potential clinical significance in rheumatoid arthritis (RA). Serum sCD27 levels in RA patients, idiopathic inflammatory myopathy (IIM) patients, systemic lupus erythematosus (SLE) patients and healthy controls (HCs) were detected by enzyme-linked immunosorbent assay. The medical information and laboratory data of the patients were collected. Serum sCD27 levels in RA patients with different clinical features were analysed, as was the correlation between the clinical data and serum sCD27 levels. Independent samples t test, the Mann-Whitney U-test or Wilcoxon signed-rank test, and Spearman correlation were used for statistical analysis. Levels of sCD27 were elevated in RA patients (3898 [2525, 5834] pg/mL) compared with IIM patients (2467 [1939, 3324] pg/mL) or HCs (1659 ± 648 pg/mL) (p 0.001). In addition, serum sCD27 levels correlated with age, erythrocyte sedimentation rate, C-reactive protein (CRP), rheumatoid factor (RF), immunoglobulin A, immunoglobulin G, complement 4 and disease activity score in 28 joints in RA patients. Levels of sCD27 were higher in RF-positive RA patients (6054 ± 5842 pg/mL) than in RF-negative patients (3902 ± 2098 pg/mL), and a similar finding was also observed in anti-cyclic citrullinated peptide (anti-CCP) antibody-positive (5810 ± 5671 pg/mL) and anti-CCP-negative (4183 ± 2187 pg/mL) RA patients. Serum ESR, RF, IgA, IgG levels and DAS28-CRP were elevated in RA patients with higher sCD27 levels than in those with lower sCD27 levels (p<0.01). Serum sCD27 might be a promising biomarker that reflects both disease activity and humoral immunity activity in RA.

Syndecan-4 is correlated with disease activity and serological characteristic of rheumatoid arthritis

ObjectivesTo describe the feature of expression of syndecan-4 in serum, synovial fluid (SF) and synovium in rheumatoid arthritis (RA) patients, and to analyze the correlation of syndecan-4 with disease activity and serological characteristic of RA.MethodsSyndecan-4 in sera of 60 RA patients, 20 osteoarthritis (OA) patients, 20 healthy controls, and in SF of 25 RA patients and 25 OA patients were tested by enzyme linked immunosorbant assay. The expressions of syndecan-4 in synovium of RA and OA patients were detected by immunohistochemistry. The expression of syndecan-4 on synovial fibroblasts from RA and OA patients were detected by immunofluorescence. The correlation between serum syndecan-4 concentration and disease activity were analyzed in RA patients.ResultsThe serum syndedcan-4 concentration was significantly higher in RA patients than in OA patients and healthy controls, and was higher in rheumatoid factor (RF)-positive RA patients than in RF-negative ones. Syndecan-4 concentration in SF of RA patients was comparable with OA patients. Syndecan-4 expression in synovial tissue was similar between RA and OA patients. The syndecan-4 concentration was significantly lower in SF than in serum of RA and OA patients. Syndecan-4 concentration in both serum and SF was positively correlated with disease activity of RA patients.ConclusionThe serum syndecan-4 concentration was higher in RA patients than in OA patients, and significantly higher in RF-positive RA patients than in RF-negative ones. Syndecan-4 concentration in both serum and SF was positively correlated with disease activity of RA patients.

Rheumatoid factor and falsely elevated results in commercial immunoassays: data from an early arthritis cohort

The aim of the study was to assess RF cross-reactivity to animal antibodies used in immunoassays, and to test if selected commercial immunoassays are vulnerable to interference from RF, causing false test results. Our study included samples from patients with RF-positive rheumatoid arthritis (RA) and controls (patients with RF-negative RA and psoriatic arthritis), included in an early arthritis-cohort. Reactivity to mouse IgG1, mouse IgG2a, rabbit IgG, bovine IgG, sheep/goat IgG and human IgG was analysed using in-house interference assays. RF-positive sera with strong reactivity to mouse IgG1 were analysed in three commercial immunoassays. To reveal interference, results before and after addition of blocking aggregated murine IgG1 were compared. Samples from 124 RF-positive RA patients and 66 controls were tested. We found considerably stronger reactivity toward animal antibodies, particularly mouse IgG1 (73% vs. 12%) and rabbit IgG (81% vs. 6%), in sera from RF-positive RA-patients compared to controls (p < 0.001). After selecting samples for testing in commercial assays, interference was revealed in 6/30 sera in the Architect β-hCG assay, 7/10 sera in the 27-plex cytokine assays, and in 2/33 samples in the Elecsys Soluble Transferrin Receptor assay. Our study revealed considerable RF reactivity to animal antibodies used in immunoassays and RF was associated with falsely elevated results in immunoassays used in clinical care and research. Clinicians, laboratorians, researchers and assay manufacturers must be alert to the risk of falsely elevated test results in RF-positive RA patients.

Serum levels of 14-3-3η are associated with increased disease risk, activity and duration of rheumatoid arthritis in Chinese patients.

The aim of the present study was to determine the association between serum 14-3-3η expression levels and disease risk, inflammation level and disease duration in Chinese patients with rheumatoid arthritis (RA). A total of 45 Chinese patients with RA, 45 patients with osteoarthritis (OA) and 44 age- and sex-matched (with the RA group) healthy control (HC) subjects were consecutively recruited for the present case-controlled study. In addition, the demographic and clinicopathological characteristics of the patients with RA were collected. Serum samples were obtained from patients with RA, patients with OA and the HCs, and the serum levels of 14-3-3η were determined by ELISA. Compared with that in the OA patients (P=0.006) and HCs (P<0.001), 14-3-3η expression was significantly increased in RA patients, and receiver operating characteristics (ROC) analysis indicated that it served as a potential predictive marker for the risk of RA. In patients with RA, serum levels of 14-3-3η were positively correlated with disease duration (P=0.003), erythrocyte sedimentation rate (P=0.006) and disease activity score in 28 joints (P=0.025). The proportion of rheumatoid factor (RF)-positive patients (P=0.023) and anti-citrullinated protein antibody (ACPA)-positive patients (P=0.002) with RA was increased (when 14-3-3η expression was increased) compared with RF-negative patients or ACPA-negative patients, respectively. Of note, 14-3-3η serum levels were able to distinguish patients with established RA (disease duration, >2 years) from patients with early RA (disease duration, ≤2 years) with an AUC of 0.759 (95% CI, 0.612-0.905), and the sensitivity and the specificity at the best cut-off point (14-3-3η=0.613 ng/ml) were 79.3 and 75.0%, respectively. Furthermore, 14-3-3η was able to differentiate between RF-positive RA patients and RF-negative patients or HCs. In conclusion, circulating 14-3-3η expression may serve as a novel biomarker for disease risk and activity of RA in Chinese patients.

Does immunological remission, defined as disappearance of autoantibodies, occur with current treatment strategies? A long-term follow-up study in rheumatoid arthritis patients who achieved sustained DMARD-free status

ObjectivesSustained disease-modifying antirheumatic drug (DMARD)-free status, the sustained absence of synovitis after cessation of DMARD therapy, is infrequent in autoantibody-positive rheumatoid arthritis (RA), but approximates cure (ie, disappearance of signs...

Only rheumatoid factor-positive subset of anti-citrullinated peptide/protein antibody-negative rheumatoid arthritis may seroconvert to anti-citrullinated peptide/protein antibody-positive.

Anti-citrullinated peptide/protein antibody (ACPA) has been reported to occur in about 60% of patients with early rheumatoid arthritis (RA), and about 80% in patients with established RA. While ACPA seroconversion is possible, previous reports have shown that it rarely occurs. We retrospectively determined the proportion of patients who underwent ACPA seroconversion and described the clinical characteristics of these cases. ACPA-negative RA patients who had undergone ACPA assessment more than once with an interval of 3 months or longer were investigated for ACPA seroconversion. The clinical characteristics of seroconverted patients were assessed. In 149 ACPA-negative RA patients, only eight patients (5.4%) converted to ACPA-positive during follow-up. We found that all eight of the seroconverted cases were positive for rheumatoid factor (RF) and showed bone erosions by X-ray. Of 56 ACPA-negative RF-positive RA patients, 14.3% of them seroconverted to ACPA-positive. None of the ACPA-negative RF-negative RA patients seroconverted to ACPA-positive. The proportion of total RA patients who experienced seroconversion from ACPA-negative to ACPA-positive was 5.4%. When ACPA-negative RA patients were subdivided into RF-negative and RF-positive subsets, only the RF-positive subset seroconverted to ACPA-positive. These results imply that RF-negative and RF-positive patients are distinct subsets within ACPA-negative RA patients.

Enhanced neutrophil phagocytic capacity in rheumatoid arthritis related to the autoantibodies rheumatoid factor and anti-cyclic citrullinated peptides.

BackgroundThere is no consensus on the mechanisms by which anti-cyclic citrullinated peptide antibodies (anti-CCP) and rheumatoid factor (RF) influence the pathogenesis of rheumatoid arthritis (RA). The current study verified if the presence of RF or anti-CCP is associated with phagocytic capacity and reactive oxygen species (ROS) production by phagocytes in RA patients to better clarify the role played by these antibodies in pathogenesis of the disease.MethodsA cohort of 30 RA patients followed from early stages of the disease were characterized by positivity for RF or anti-CCP, disease activity score (DAS-28), health assessment questionnaire (HAQ), use of synthetic or biologic therapy, lifestyle, comorbidities and radiographic erosions. Phagocytic capacity against Saccharomyces cerevisiae and superoxide anion production were assessed in RA patients and compared with 20 healthy controls. Phagocytic capacity and superoxide anion production were also compared between RF- and anti-CCP-positive and -negative RA patients.ResultsAnti-CCP- and RF-positive RA patients had higher neutrophil phagocytic capacity than anti-CCP- (p = 0.005) and RF (p = 0.005)-negative individuals through pattern-recognition receptors. As assessed via pattern recognition or opsonin receptors, neutrophils and monocytes from RA patients presented overall higher phagocytic capacity than neutrophils and monocytes from healthy controls (p < 0.05). Furthermore, RA patients also showed a higher capacity for producing cytotoxic oxygen radicals (p = 0.0026). Phagocytosis and superoxide anion production did not correlate with any of the clinical variables analyzed in this study.ConclusionsThis study showed increased phagocytosis by neutrophils in RA patients who were positive for anti-CCP and RF autoantibodies. Furthermore, there was an overall hyperactivation of the phagocytes in RA patients. Our data suggest that anti-CCP and RF may indirectly enhance the inflammation cascade involving neutrophils and may indirectly sustain tissue damage in RA. Targeting the production of these autoantibodies may be a promising strategy in the management of RA.

SAT0002 ACPA-negative rheumatoid arthritis consists of two genetically distinct subsets based on RF positivity

BackgroundHLA-DRB1, especially the shared epitope (SE), is strongly associated with rheumatoid arthritis (RA) [1]. However, recent studies have shown that SE is at most weakly associated with RA without anti-citrullinated...

Performance of hands and feet radiographs in differentiation of psoriatic arthritis from rheumatoid arthritis

The purpose of this study was to determine useful radiographic findings for differentiating psoriatic arthritis (PsA) from rheumatoid factor (RF)-positive or -negative rheumatoid arthritis (RA) in Japanese patients. We accrued 85 patients with PsA. Controls included 135 patients with RA (85 RF-positive, 50 RF-negative) matched for gender and disease duration with PsA patients. Radiographs of hands and feet were obtained, and distal interphalangeal (DIP) erosive disease, joint osteolysis, tuft osteolysis, juxta-articular bony proliferation (JBP), periosteal new bone formation and bony ankylosis, which were identified using the definitions developed by an earlier study, were compared between the PsA and RA groups. For radiographic features of hands, the frequencies of JBP, periosteal new bone, and diffuse soft tissue swelling of the fingers were significantly higher in PsA patients than in RF-positive RA patients. However, only the frequency of JBP significantly differed between PsA and RF-negative RA patients. In feet, the frequencies of DIP erosive disease, tuft osteolysis, JBP, and diffuse soft tissue swelling of the toes were significantly higher in PsA patients than in RF-positive RA patients. However, only the frequency of JBP significantly differed between PsA and RF-negative RA patients. JBP was the most important radiographic feature for discriminating PsA from both RF-positive and -negative RA, confirming the study by the CASPAR group that showed that JBP is the only radiologic feature that can discriminate PsA from other inflammatory arthritides. This study showed the utility of plain radiographs for diagnosis of PsA.

ACPA-Negative RA Consists of Two Genetically Distinct Subsets Based on RF Positivity in Japanese

HLA-DRB1, especially the shared epitope (SE), is strongly associated with rheumatoid arthritis (RA). However, recent studies have shown that SE is at most weakly associated with RA without anti-citrullinated peptide/protein antibody (ACPA). We have recently reported that ACPA-negative RA is associated with specific HLA-DRB1 alleles and diplotypes. Here, we attempted to detect genetically different subsets of ACPA-negative RA by classifying ACPA-negative RA patients into two groups based on their positivity for rheumatoid factor (RF). HLA-DRB1 genotyping data for totally 954 ACPA-negative RA patients and 2,008 healthy individuals in two independent sets were used. HLA-DRB1 allele and diplotype frequencies were compared among the ACPA-negative RF-positive RA patients, ACPA-negative RF-negative RA patients, and controls in each set. Combined results were also analyzed. A similar analysis was performed in 685 ACPA-positive RA patients classified according to their RF positivity. As a result, HLA-DRB1*04:05 and *09:01 showed strong associations with ACPA-negative RF-positive RA in the combined analysis (p = 8.8×10−6 and 0.0011, OR: 1.57 (1.28–1.91) and 1.37 (1.13–1.65), respectively). We also found that HLA-DR14 and the HLA-DR8 homozygote were associated with ACPA-negative RF-negative RA (p = 0.00022 and 0.00013, OR: 1.52 (1.21–1.89) and 3.08 (1.68–5.64), respectively). These association tendencies were found in each set. On the contrary, we could not detect any significant differences between ACPA-positive RA subsets. As a conclusion, ACPA-negative RA includes two genetically distinct subsets according to RF positivity in Japan, which display different associations with HLA-DRB1. ACPA-negative RF-positive RA is strongly associated with HLA-DRB1*04:05 and *09:01. ACPA-negative RF-negative RA is associated with DR14 and the HLA-DR8 homozygote.

Efficacy of rituximab in the treatment of rheumatoid arthritis. Influence of serologic status, coprescription of methotrexate and prior TNF-alpha inhibitors exposure

PurposeRituximab has been shown to be efficient in the treatment of rheumatoid arthritis (RA) when associated with methotrexate (MTX). The purpose of this study was to evaluate the response to this treatment in daily practice in the following three specific situations: rheumatoid factor (RF)-negative RA patients, rituximab monotherapy patients and TNFα inhibitors-naive patients. MethodsThis retrospective observational study is an exploratory analysis of the response to rituximab. One thousand milligrams (1000mg) of rituximab was administered twice at an interval of 15 days. Therapeutic response was determined at mean 20 weeks after the infusion on the basis of DAS28 scores and EULAR response criteria. ResultsOne hundred and eight patients were included in the study and the responses of 95 of these were evaluated. Of the latter, 75% were EULAR responders. There was no significant difference in EULAR response between patients treated with rituximab and MTX (73.8%) and those who had received rituximab alone (79.3%). Similarly, there was no difference in the number of EULAR responders between patients who had received TNF inhibitor beforehand (74.1%) and those who had not (78.6%). However, interval to retreatment was significantly shorter in TNF inhibitor-naive patients. Lastly, a significant difference (P=0.02) in EULAR response rate was observed between RF-positive patients (84.8%) and RF-negative patients (57.9%). Interval to retreatment was also significantly shorter in RF-negative patients. ConclusionIn our experience, while our RTX efficacy findings appear to be consistent with the results of comparable controlled trials, whether or not in association with MTX, or with prior administration of one or several TNF inhibitors, RF-positive RA patients exhibited a higher EULAR response rate than RF-negative RA patients.

The HALT Polycystic Kidney Disease Trials

Two HALT PKD trials will investigate interventions that potentially slow kidney disease progression in hypertensive autosomal dominant polycystic kidney disease (ADPKD) patients. Studies were designed in early and later stages of ADPKD to assess the impact of intensive blockade of the renin-angiotensin-aldosterone system and level of BP control on progressive renal disease. Design, settings, participants, and measurements: PKD-HALT trials are multicenter, randomized, double-blind, placebo-controlled trials studying 1018 hypertensive ADPKD patients enrolled over 3 yr with 4 to 8 yr of follow-up. In study A, 548 participants, estimated GFR (eGFR) of >60 ml/min per 1.73 m(2) were randomized to one of four arms in a 2-by-2 design: combination angiotensin converting enzyme inhibitor (ACEi) and angiotensin receptor blocker (ARB) therapy versus ACEi monotherapy at two levels of BP control. In study B, 470 participants, eGFR of 25 to 60 ml/min per 1.73 m2 compared ACEi/ARB therapy versus ACEi monotherapy, with BP control of 120 to 130/70 to 80 mmHg. Primary outcomes of studies A and B are MR-based percent change kidney volume and a composite endpoint of time to 50% reduction of baseline estimated eGFR, ESRD, or death, respectively. This report describes design issues related to (1) novel endpoints such as kidney volume, (2) home versus office BP measures, and (3) the impact of RAAS inhibition on kidney and patient outcomes, safety, and quality of life. HALT PKD will evaluate potential benefits of rigorous BP control and inhibition of the renin-angiotensin-aldosterone system on kidney disease progression in ADPKD.

Alanine Aminopeptidase, γ-Glutamyl Transferase and β2-microglobulin as Diagnostic Markers in Patients with Rheumatoid Arthritis

Alanine Aminopeptidase, γ-Glutamyl Transferase and β2-microglobulin as Diagnostic Markers in Patients with Rheumatoid Arthritis The purpose of this research is to evaluate the values of alanine aminopeptidase (AAP), γ-glutamyl transferase (γ-GT), and β2-Microglobulin in urine (β2-M), in untreated rheumatoid arthritis (RA) and to define the effect of untreated rheumatoid arthritis on the tubular function and brush border region. We used a kinetic assay for AAP, standard methods by the IFCC for γ-glutamyl transferase and MEIA for the determination of β2-Microglobulin in urine in 70 participants (35 untreated RA patients, 35 healthy individuals). From the total of 35 RA patients, 24 patients had AAP (sensitivity of the test 68.57%), 16 patients had γ-GT enzymuria (sensitivity of the test 45.71%), while the presence of β2-Microglobulin in urine was found in a very low percentage. Out of 18 RF negative patients, 14 patients are AAP positive, 10 patients were γ-GT positive, while the presence of β2-Microglobulin in urine was not detected. Among 17 RF positive RA patients, the presence of AAP was noticed in 10, the presence of γ-GT in 6 patients, while the presence of β2-Microglobulin in urine was not detected. AAP has higher sensitivity than γ-GT and β2-Microglobulin in the detection of asymptomatic renal lesions in untreated RA.

Elevated levels of IgM and IgA antibodies to Proteus mirabilis and IgM antibodies to Escherichia coli are associated with early rheumatoid factor (RF)-positive rheumatoid arthritis

Antibodies to Proteus mirabilis were previously detected in patients with established rheumatoid arthritis (RA). We examined the prevalence of antibodies to P. mirabilis and their associations with RA in early synovitis patients. Two hundred and forty-six patients with inflammatory arthritis for less than 1 yr were prospectively evaluated for 1 yr. Of these patients, 30% had rheumatoid factor (RF)-positive RA, 16% RF-negative RA, 17% a spondyloarthropathy and 37% undifferentiated arthritis. Serum antibodies to P. mirabilis, Escherichia coli and other potentially arthritogenic organisms (Chlamydia, Salmonella, Shigella, Campylobacter, Yersinia and parvovirus B19) and for antibodies specific for immunoglobulin (Ig) G damaged with advanced glycation end-products (anti-IgG-AGE) were measured. IgM and IgA anti-Proteus antibodies were significantly higher in patients with RF-positive RA compared with all other patient groups (P < 0.0005 and P < 0.005). Anti-P. mirabilis IgG, and IgG, IgA, and IgM antibodies to other potentially arthritogenic pathogens did not differ in the patient groups. IgM antibodies to E. coli were elevated in RF-positive RA patients. Anti-P. mirabilis IgM and IgA results were not explained by false-positive reactions, because after absorption of RF there was no decrease in antibodies to Proteus in 10 of 12 patients. Proteus and E. coli antibodies were highest in patients positive for both RF and anti-IgG-AGE antibodies (P<0.001). Patients with erosions tended to have higher IgA anti-Proteus titres, but no association with the shared HLA epitope or treatment was detected. Anti-P. mirabilis IgM and IgA and anti-E. coli IgM antibody elevations are associated with early seropositive RA and the presence of anti-IgG-AGE antibodies. The role that P. mirabilis or E. coli plays in early RF-positive RA requires further investigation.

Advanced glycation end-product (AGE)-damaged IgG and IgM autoantibodies to IgG-AGE in patients with early synovitis.

Advanced glycation end-product (AGE)-damaged IgG occurs as a result of hyperglycemia and/or oxidative stress. Autoantibodies to IgG-AGE were previously demonstrated in patients with severe, longstanding rheumatoid arthritis (RA). We investigated whether IgG-AGE and anti-IgG-AGE antibodies were present early in the course of RA and other inflammatory arthropathies. We prospectively followed a cohort of 238 patients with inflammatory arthritis of duration less than 1 year. Patients were evaluated clinically and serologically, and radiographs were obtained at initial and 1-year visits. Sera were assayed for IgG-AGE and anti-IgG-AGE antibodies by enzyme-linked immunosorbent assay (ELISA). Rheumatoid factor (RF) was determined by nephelometry and ELISA. Of all patients, 29% had RF-positive RA, 15% had RF-negative RA, 18% had spondyloarthropathy, and 38% had undifferentiated arthritis. IgG-AGE was present in 19% of patients, and was similar in amount and frequency in all groups. Patients with elevated IgG-AGE levels had significantly higher levels of the inflammatory markers C-reactive protein and erythrocyte sedimentation rate, but there was no correlation with blood glucose levels. Overall, 27% of the patients had IgM anti-IgG-AGE antibodies. These antibodies were highly significantly associated with RFs (P < 0.0001) and with swollen joint count (P < 0.01). In early onset arthritis, IgG damaged by AGE was detected in all patient groups. The ability to make IgM anti-IgG-AGE antibodies, however, was restricted to a subset of RF-positive RA patients with more active disease. The persistence of the anti-IgG-AGE response was more specific to RA, and was transient in the patients with spondyloarthropathy and with undifferentiated arthritis who were initially found to be positive for anti-IgG-AGE antibodies.

Prevalence of Mutilans-like Hand Deformities in Patients with Seropositive Rheumatoid Arthritis: A prospective 20-year study

This study examined radiographically the prevalence of arthritis mutilans hand deformities in an inception cohort of 68 rheumatoid arthritis (RA) patients. Hand deformities of 103 RF-positive RA patients were evaluated after 8 years, 83 patients after 15 years and 68 patients 20 years after entry. The grade of destruction in the hand joints was assessed by the Larsen method and Larsen scores of 0-50 were determined for both PIP (+IP) and MCP joints. At the end point, 3 patients had Larsen scores > or =40 for both PIP and MCP joints. These three patients had severe resorption in most of the finger joints, but did not demonstrate classical opera-glass hand. The prevalence of mutilans-like hand deformities with RA was 3/68 (4.4%) in a prospective 20-year study.

HLA-DR/DQ/DP interactions in rheumatoid arthritis.

Rheumatoid arthritis (RA) is associated with the presence of particular HLA-DRB1 alleles. In order to characterize HLA-DQB1 and/or-DPB1 alleles that contribute to disease susceptibility besides HLA-DRB1 alleles, we have analysed the HLA-DRB1, -DQB1 and -DPB1 polymorphism in 84 RA patients and 135 controls. HLA typing for HLA-DRB1 and -DQB1 alleles was performed using sequence-specific primers in combination with sequence-based typing. HLA-DPB1 alleles were characterized by reverse dot-blot hybridization. Our data confirm the predominant role of the (Q)R/KRAA sequence from AA position 70-74 of the HLA-DRB chain for disease susceptibility. In particular, the lysine (K) substitution at position 71 was highly significantly associated with RA. Analysis of the DQB1 locus revealed no association with RA when linkage disequilibrium between HLA-DRB1 and -DQB1 alleles was considered. In contrast, we observed an increased frequency of HLA-DPB1*0401 among (Q)R/KRAA-positive patients. (Q)R/KRAA-negative RA patients exhibited an overrepresentation of HLA-DPB1*0201 and HLA-DPB1*0601. Rheumatoid factor (RF) production correlated with the presence of the disease-associated (Q)R/KRAA amino acid cassette of the HLA-DRB chain. When HLA-DPB1 allele frequencies were compared between RF-positive and RF-negative RA patients, we observed an increased frequency of HLA-DPB1*0401 among RF-positive RA patients and HLA-DPB1*0201 among RF-negative patients. These results suggest that besides the predominent role of HLA-DR molecules in RA, HLA-DP molecules may have an influence on disease susceptibility and could modulate disease progression. HLA-DPB1*0401 may function in addition to HLA-DRB1*04, whereas HLA-DPB1*0201 and -DPB1*0601 may represent additional risk factors among (Q)R/KRAA-negative RA patients.

Destruction of the First Carpometacarpal Joint Behaves Differently from that of the Entire Carpus in Rheumatoid Arthritis

The aim of our study was to examine the radiographic changes of the wrist and the first carpometacarpal (CMC I) joints in rheumatoid arthritis (RA) occurring over 20 years. The wrists of 83 RF positive RA patients with recent (≤6 months) arthritis were evaluated radiographically at onset, at 1, 3, 8, and 15 years and of 68 patients 20 years from entry. In hands where wrist fusion was performed, follow-up continued until the arthrodesis. Larsen grading for the wrist joints and modified grades for the ipsilateral CMC I joints were compared. Larsen grades of both wrists differed highly significantly (p<0.001) from the grades of the ipsilateral CMC 1 joints after 3 years and up to end of the study.In conclusion destruction of the CMC 1 does not proceed uniformly with destruction of the entire carpus and it would be beneficial to classify it separately.