RF-positive Rheumatoid Arthritis Research Articles

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.

The Protective Effect of HLA-DRB1 and HLA-DQB1 Alleles to ACPA-Positive and RF-Positive RA in Albanian Population

BACKGOUND: The prevalence of rheumatoid arthritis (RA) and its specific autoantibodies varies in different populations. This variability depends on the genetic polymorphism of the immune response genes among which the HLA system plays a major role. AIM: We conducted a preliminary study of the distribution of HLA-DRB1 and HLA-DQB1 first field level alleles in a sample of 100 Albanian patients with RA. METHODS: In this context, we studied the HLA-DRB1 and HLA-DQB1 first-level allele frequencies in 100 Albanian patients with RA and considering their rheumatoid factor (RF) and anti-citrullinated peptide antibodies (ACPA) serologic subgroups. We compared them with the respective frequencies in a population of 191 Albanian individuals without known pathology. RESULTS: No differences were found between the controls and the RA patient group, but three statistically significant differences were found: an increase in DRB1*04 among ACPA-positive, RF-positive and ACPA-positive/RF-positive patients, a significant decrease in DRB1*11 among ACPA-positive/RF-positive, and also a decrease in DRB1*13 among RF-positive patient subgroups. The frequencies of DRB1 allotypes in ACPA+ and RF+ patients compared to their counterpart ACPA− and RF−patient subgroups showed the predisposing effect of HLA-DRB1*04 for ACPA and RF seropositivity (p, respectively, 0.0008 and 0.0017) and the protective role of HLA-DRB1*11 for ACPA and RF positivity (p, respectively, 0.007 and 0.02). The same protective role from the RF positivity is also found with the HLA-DRB1*13 alleles (p = 0.007). As far as the DQB1 locus is concerned, a protective association has been found between the HLA-DQB1*06 alleles with both RF+ and RF+ ACPA+ positivity (p, respectively, 0.05 and 0.04) when comparing the control group with the respective RA patient subgroups. In ACPA+ and RF+ patients compared to the ACPA− and RF− patient subgroups, the only detected difference was between RF (+) and RF (−) patients (p =0.04). CONCLUSION: The relatively low frequencies of DRB1*04 and high (DRB1*11 and DRB1*13) in the Albanian population might explain the rather low positivity rate of ACPA and RF antibodies among the Albanian RA patients. Our study demonstrates that DRB1*11, DRB1*13 and DQB1*06 may be negatively associated with RA. Conversely, DRB1*04 may confer susceptibility to RA in Albanian population.

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.

Associations of genetic polymorphisms within MALAT1, UCA1, FAM211A-AS1 and AC000111.6 with genetic susceptibility to rheumatoid arthritis

Recently, several long non-coding RNAs (lncRNAs) including MALAT1, UCA1, ENST00000483588, and ENST00000456270 have been implicated in the pathogenesis of rheumatoid arthritis (RA), and we hypothesized that polymorphisms within these lncRNA genes might be genetic modifiers for the development of RA. A total of 10 potentially functional single-nucleotide polymorphisms (SNPs) were selected and genotyped in 1198 participants, including 594 RA patients and 604 healthy controls. Significant associations of FAM211A-AS1 rs2882581 (G vs. A, OR = 1.31, 95%CI 1.07–1.62, p = .01; G/G + A/G vs. A/A, OR = 1.40, 95%CI 1.08–1.83, p = .01), rs3744281 (T vs. A, OR = 1.25, 95%CI 1.02–1.54, p = .03; T/T vs. A/T + A/A, OR = 1.69, 95%CI 1.01–2.82, p = 4.59 × 10−2), and rs3760235 (A vs. G, OR = 1.32, 95%CI 1.04–1.68, p = .02; A/A vs. A/G + G/G, OR = 1.32, 95%CI 1.00–1.74, p = 4.89 × 10−2) with RF-positive RA were found. Functional annotation results indicated that these identified polymorphisms might regulate the expression of FAM211A-AS1 and nearby genes via impacting on transcription factor binding. Taken together, our results indicated that FAM211A-AS1 rs2882581, rs3744281, and rs3760235 were involved in the genetic background of RF-positive RA.

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.

Association Study of PTPN22 (rs2476601) and PADI4 (rs2240340) Polymorphisms with Rheumatoid Arthritis in Algerian Population

An association between protein tyrosine phosphatase 22 (PTPN22) and Peptidylarginine deiminase 4 (PADI4) genes with rheumatoid arthritis (RA) has been demonstrated in several populations. The present study investigated whether PTPN22 and PADI4 genes polymorphisms were involved in the genetic predisposition to RA in the Algerian patients. Materials and methods: The PADI4_94 (rs2240340) and the PTPN22 (rs2476601) Single Nucleotide Polymorphisms (SNPs) were genotyped in 300 RA patients and 306 healthy controls by real time polymerase chain reaction method (TaqMan Assays). The relationships between Anti-Citrullinated Peptide Antibody (ACPA) positivity, Rheumatoid Factor (RF) positivity and genotypes were statistically analyzed. Results: There was no significant association between the PTPN22, PADI4 SNP and RA susceptibility in our population (p>0.05). No association with ACPA profile with either PTPN22 or PADI4 was detected (p>0.05). However, our results showed a strong association of PTPN22 minor T allele with RF positive disease (OR=8.53 (95% CI 1.34-354.9), p=0.013); also, a significant association was shown between CT genotype of PTPN22 SNP and RF positive RA (OR=8.01 (95% CI 1.22-336.5), p=0.018). Conclusion: Our findings indicated that PTPN22 and PADI4 polymorphisms were unlikely to play an important role in the susceptibility to RA in Algerian population but PTPN22 polymorphism T allele may predispose individuals to RF positive RA.

Is the epidemiology of rheumatoid arthritis changing? Results from a population-based incidence study, 1985–2014

ObjectivesTo examine trends in the incidence of rheumatoid arthritis (RA) from 2005 to 2014 overall and by serological status as compared with 1995–2004 and 1985–1994.MethodsWe evaluated RA incidence trends in...

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...

Influence of Cigarette Smoking on Rheumatoid Arthritis Risk in the Han Chinese Population.

Cigarette smoking has been shown in European populations to be associated with rheumatoid arthritis (RA) susceptibility. This study aims to examine the association of smoking with RA in the Han Chinese population. 718 Han Chinese RA patients and 404 healthy controls were studied. The associations of cigarette smoking (current, former or ever vs. never smokers, and pack-years of exposure) with RA, anti-cyclic citrullinated peptide antibody (ACPA) positive RA, IgM rheumatoid factor (RF) positive RA, and baseline radiographic erosions (modified van der Heijde-Sharp scores) were assessed. The interaction between smoking and the HLA-DRB1 shared epitope (SE) in RA was also examined. In this study, 11 (1.53%) cases and 6 (1.49%) controls were former smokers (p = 0.95), while 95 (13.23%) cases and 48 (11.88%) controls were current smokers (p = 0.52). Trends toward associations between smoking status (ever vs. never) with RA-overall (p = 0.15, OR = 1.44), ACPA-positive RA (p = 0.24, OR = 1.37), RF-positive RA (p = 0.14, OR = 1.46), or the presence of radiographic erosions (p = 0.66, OR = 1.28) were observed although individually here were not statistically significant. There was no evidence of statistical interaction between smoking status (ever vs. never) and SE for all RA, ACPA-positive RA, ACPA-negative RA, RF-positive RA, RF-negative RA (p = 0.37, 0.50, 0.24, 0.26, and 0.81 respectively), and the 95% CI for the attributable proportion for all interactions included 0. This is the first study to examine the association of cigarette smoking with RA in the Han Chinese population. This study shows a trend toward an interaction between smoking and SE carriage influencing the risk of RA, though findings were not statistically significant. It is possible that in the presence of universal exposure to heavy air pollution the effect of smoking on RA risk may be obscured.

Antibodies to Cyclic Citrullinated Peptides in Patients With Juvenile Idiopathic Arthritis and Patients With Rheumatoid Arthritis: Shared Expression of the Inherently Autoreactive 9G4 Idiotype.

Antibodies to cyclic citrullinated peptides (anti-CCP) in rheumatoid arthritis (RA) can express the inherently autoreactive gene VH 4-34, detected using the rat monoclonal antibody 9G4. Patients with the polyarticular subtype of juvenile idiopathic arthritis (JIA) share some but not all of the features of adult patients with RA. This study was undertaken to compare serologic findings for rheumatoid factor (RF), anti-CCP, and 9G4-expressing anti-CCP in a large JIA cohort with a cohort of adult RA patients. Serum from 88 patients with polyarticular JIA, 29 patients with enthesitis-related arthritis, 38 patients with extended oligoarthritis, 31 adolescent controls, 35 patients with RA, and 30 adult controls were tested for RF, for IgG, IgA, and IgM anti-CCP, and for 9G4-expressing anti-CCP by enzyme-linked immunosorbent assay. Total serum 9G4-positive IgM was also measured. Of 65 patients with RF-negative polyarticular JIA, 4 (6.2%) were IgG anti-CCP positive. Sera from 20 of 23 patients with RF-positive polyarticular JIA (87.0%), 24 of 35 patients with RA (68.6%), and 1 patient with extended oligoarthritis contained IgG anti-CCP. IgA and IgM anti-CCP levels were lower in the adolescent group (P < 0.01). Levels of 9G4-expressing anti-CCP were higher in patients with RF-positive polyarticular JIA than in those with RF-negative polyarticular JIA (P < 0.0001). Median levels of 9G4-expressing anti-CCP in patients with RF-positive polyarticular JIA and those with RA did not differ. Expression of 9G4 on serum total IgM was greater in patients with RF-positive polyarticular JIA than other adolescent groups (P < 0.01), but similar to adult RF-positive RA. In healthy individuals, 9G4-positive B cells comprise 5-10% of the peripheral blood pool but serum immunoglobulins utilizing VH 4-34 are disproportionately low. The idiotope recognized by 9G4 was detected on anti-CCP antibodies in >80% of patients with RF-positive polyarticular JIA. VH 4-34 usage by anti-CCP in both JIA and RA patients suggest elicitation of these autoantibodies through shared pathogenic B cell selection processes.

Calprotectin levels in rheumatoid arthritis and their correlation with disease activity: a meta-analysis

ABSTRACTObjective: We evaluated the relationship between calprotectin levels and rheumatoid arthritis (RA), and the correlation between plasma/serum calprotectin and RA activity.Methods: We searched PUBMED, EMBASE, and Cochrane databases and performed meta-analyses comparing plasma/serum or synovial fluid calprotectin levels in RA patients and controls, and correlation coefficients between calprotectin levels and disease activity for 28 joints (DAS28) as well as C-reactive protein (CRP) in RA patients.Results: Sixteen studies including 849 RA patients and 266 controls were available for meta-analysis. Meta-analysis showed that calprotectin levels were significantly higher in the RA group than in the control group (SMD = 2.337, 95% CI = 1.544–3.130, p < 1.0 × 10–8). Stratification by rheumatoid factor (RF) status revealed significantly elevated calprotectin levels in the RF-positive RA group compared to that of the RF-negative RA group (SMD = 0.574, 95% CI = 0.345–0.804, p = 9.2 × 10–7). Meta-analysis of correlation coefficients identified a significant positive correlation between calprotectin levels and CRP or DAS28 (correlation coefficient for CRP = 0.566, 95% CI = 0.512–0.615, p < 1.0 × 10–8; correlation coefficient for DAS28 = 0.438, 95% CI = 0.269–0.518, p = 2.5 × 10–6). Calprotectin levels in synovial fluid were significantly higher in the RA group than in the control group (SMD = 2.891, 95% CI = 1.067–4.715, p = 0.002).Conclusions: Our meta-analysis demonstrates that circulating and synovial fluid calprotectin levels are high in patients with RA, and that circulating calprotectin levels positively correlate with RA activity.

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.

Human leukocyte antigen-G polymorphism influences the age of onset and autoantibody status in rheumatoid arthritis.

The study was conducted to investigate the frequency of three gene polymorphisms in the 3'-untranslated region (3'-UTR) of human leucocyte antigen-G (HLA-G) gene in south Indian patients with rheumatoid arthritis (RA) and analyze their influence on disease susceptibility, phenotype and treatment response. HLA-G 14 bp insertion (Ins)/deletion (del) (rs66554220), HLA-G +3142G>C (rs1063320) and +3187A>G (rs9380142) polymorphism was analyzed in 221 RA patients and 200 healthy controls. Frequency of HLA-G genotypes or alleles did not differ between patients and controls. Analysis based on rheumatoid factor (RF) status revealed that the frequency of allele 'A' (rs9380142) was significantly higher in RF-positive than in RF-negative patients [84% vs 74%, Yates-corrected P value (Pc) = 0.04, odds ratio (OR) = 1.8, 95% confidence interval (CI) = 1.0-3.2]. A similar difference was maintained in RF-positive female patients than their RF-negative counterparts (83% vs 71%, Pc = 0.02, OR = 1.9, 95% CI = 1.0 to 3.4) and between RF-positive and RF-negative young onset RA (YORA) patients (84% vs 73%, Pc = 0.03, OR = 1.9, 95% CI = 1.0-3.2), suggesting that rs9380142 polymorphism influenced RF status. The 14 bp Ins allele of rs66554220 was significantly more prevalent in RF-positive YORA than in RF-positive late onset RA (LORA) patients (51% vs 25%, P = 0.03, OR = 3.1, 95% CI = 1.1-9.8). Frequency of the four major haplotypes [InsGA (48%), DelGA (22%), DelCG (18%), DelCA (9.7%)] observed did not differ between cases and controls. HLA-G does not appear to be a risk factor for development of RA in south Indian Tamils but may act as a genetic modifier of clinical phenotype in terms of autoantibody production, gender preference and age at disease onset.

THU0462 Anti-Citrullinated Peptide/Protein Antibody (ACPA)-Negative RA Shares Large Proportion of Susceptibility Genes with Acpa-Positive RA

BackgroundSusceptibility genes for anti-citrullinated peptide/protein antibodies (ACPA)-positive rheumatoid arthritis (RA) have been successfully discovered by the development of genome-wide association studies (GWAS). However, little is known about the genetic background...

Adverse Pregnancy Outcomes and Risk of Subsequent Rheumatoid Arthritis

Pregnancy and reproductive outcomes have been associated with altered risk of some autoimmune diseases, including rheumatoid arthritis (RA). We sought to determine whether prior pregnancy resulting in a low birth weight (LBW) infant or preterm birth is associated with a risk of subsequent RA in the mother. We conducted an analysis of RA risk in parous women from a population-based prospective study of newly diagnosed cases of RA and age-matched healthy controls. The primary outcome measure was disease status (RA versus control), with exposures of prior preterm birth and prior delivery of an infant with LBW (≤2,500 gm), very low birth weight (VLBW; ≤1,500 gm), or extremely low birth weight (ELBW; ≤1,000 gm). A preplanned analysis including only rheumatoid factor (RF)-positive RA cases was also conducted. A total of 202 RA cases and 1,102 controls were analyzed. Prior delivery of an infant with ELBW was associated with RA in the mother (relative risk [RR] 3.7 [95% confidence interval (95% CI) 1.0-13.2]). Prior VLBW (RR 4.0 [95% CI 1.3-11.4]) and ELBW (RR 5.5 [95% CI 1.4-22.5]) infants were associated with RF-positive RA. Prior LBW deliveries and preterm births were more common among RA cases than controls, but the differences were not statistically significant. Compared to those with uncomplicated pregnancies, women with a prior VLBW or ELBW delivery had a higher risk of RA, particularly RF-positive RA. This association may reflect common risk factors for pregnancy complications and RA. Alternatively, complicated pregnancy itself may confer risk of subsequent RA.

A1.29 In rheumatoid arthritis, smoking is not primarily associated with anti-citrullinaged protein antibodies, but with the presence of several autoantibodies

Background and ObjectivesIn rheumatoid arthritis (RA), smoking has been described to be specifically associated with the presence of anti-citrullinated protein antibodies (ACPA). However, smoking has also been shown to be...

Association between functional Fc receptor-like 3 (FCRL3) −169 C/T polymorphism and susceptibility to seropositive rheumatoid arthritis in Asians: A meta-analysis

The aim of this study was to determine whether the functional Fc receptor like-3 (FCRL3) -169 C/T polymorphism confers susceptibility to rheumatoid arthritis (RA). A meta-analysis was conducted on the associations between the FCRL3 -169 C/T polymorphism and RA. A total of 17 comparison studies including 11,170 patients and 11,142 controls were considered in the meta-analysis. The meta-analysis showed no association between RA and the FCRL3 -169 C allele in study subjects (OR = 1.046, 95% CI = 0.997-1.098, p = 0.068). Stratification by ethnicity indicated an association between the FCRL3 -169 C allele and RA in Asians (OR = 1.101, 95% CI = 1.035-1.174, p = 0.002), but not in Europeans. Stratification of patients according to the presence of rheumatoid factor (RF) revealed a different significant association between the C allele and RA in RF-positive and RF-negative RA patients. Stratification by ethnicity indicated an association between the FCRL3 -169 C allele and RF-positive RA in Asians (OR = 1.093, 95% CI = 1.004-1.189, p = 0.040), but not in Europeans. This meta-analysis demonstrates that the FCRL3 -169 C/T polymorphism may confer susceptibility to seropositive RA in Asians.