To examine the relationship of Porphyromonas gingivalis (Pg) with the presence of autoantibodies in individuals at risk for rheumatoid arthritis (RA).
Participants included: 1) a cohort enriched with HLA-DR4 and 2) those at risk for RA by virtue of having a first-degree relative with RA. None satisfied 1987 ACR RA classification criteria. Autoantibodies measured included anti-citrullinated protein antibody (ACPA) and rheumatoid factor (RF; nephelometry, IgA, IgM, IgG). Individuals were considered autoantibody positive (n = 113) with ≥ 1 positive autoantibody with individuals further categorized as `high-risk' (n = 38; positive ACPA or ≥ 2 RF assays). Autoantibody negative individuals served as comparators (n = 171). Antibody to Pg, P. intermedia (Pi), and F. nucleatum (Fn) were measured. Associations of bacterial antibodies with group status were examined using logistic regression.
Anti-Pg concentrations were higher in high-risk (p = 0.011) and autoantibody positive group (p = 0.010) than in the autoantibody negative group. There were no group differences in anti-Pi or anti-Fn concentrations. After multivariable adjustment, anti-Pg concentrations (but not anti-Pi or anti-Fn) were significantly associated with autoantibody positive and high-risk status (p < 0.05).
Immunity to Pg, but not Pi or Fn, is significantly associated with the presence of RA-related autoantibodies in individuals at risk for RA. These results support the hypothesis that infection with Pg may play a central role in the early loss of tolerance to self-antigens in RA pathogenesis.
rheumatoid arthritis; periodontitis; Porphyromonas gingivalis; Prevotella intermedia; Fusobacterium nucleatum; rheumatoid factor; anti-citrullinated protein antibody
To determine whether shared epitope (SE)–containing HLA–DRB1 alleles are associated with rheumatoid arthritis (RA) in African Americans and whether their presence is associated with higher degrees of global (genome-wide) genetic admixture from the European population.
In this multicenter cohort study, African Americans with early RA and matched control subjects were analyzed. In addition to measurement of serum anti–cyclic citrullinated peptide (anti-CCP) antibodies and HLA–DRB1 genotyping, a panel of >1,200 ancestry-informative markers was analyzed in patients with RA and control subjects, to estimate the proportion of European ancestry.
The frequency of SE-containing HLA–DRB1 alleles was 25.2% in African American patients with RA versus 13.6% in control subjects (P = 0.00005). Of 321 patients with RA, 42.1% had at least 1 SE-containing allele, compared with 25.3% of 166 control subjects (P = 0.0004). The mean estimated percent European ancestry was associated with SE-containing HLA–DRB1 alleles in African Americans, regardless of disease status (RA or control). As reported in RA patients of European ancestry, there was a significant association of the SE with the presence of the anti-CCP antibody: 86 (48.9%) of 176 patients with anti-CCP antibody–positive RA had at least 1 SE allele, compared with 36 (32.7%) of 110 patients with anti-CCP antibody–negative RA (P = 0.01, by chi-square test).
HLA–DRB1 alleles containing the SE are strongly associated with susceptibility to RA in African Americans. The absolute contribution is less than that reported in RA among populations of European ancestry, in which ~50–70% of patients have at least 1 SE allele. As in Europeans with RA, the SE association was strongest in the subset of African American patients with anti-CCP antibodies. The finding of a higher degree of European ancestry among African Americans with SE alleles suggests that a genetic risk factor for RA was introduced into the African American population through admixture, thus making these individuals more susceptible to subsequent environmental or unknown factors that trigger the disease.
Rapidly predicting future outcomes based upon short-term clinical response would be helpful to optimize RA management in early disease.
To derive and validate a clinical prediction rule to predict low disease activity (LDA) at 1 year among patients participating in the Treatment of Early Aggressive Rheumatoid Arthritis (TEAR) trial escalating RA therapy by adding either etanercept (E) or sulfasalazine + hydroxychloroquine [triple therapy (TT)] after 6 months of methotrexate (MTX) therapy.
Eligible subjects included in the derivation cohort (used for model building, n=186) were participants with moderate or higher disease activity (DAS28ESR>3.2) despite 24 weeks of MTX monotherapy who added either etanercept or sulfasalazine+hydroxychloroquine. Clinical characteristics measured within the next 12 weeks were used to predict LDA 1 year later using multivariable logistic regression. Validation was performed in the cohort of TEAR patients randomized to initially receive either MTX+E or TT.
The derivation cohort yielded three prediction models of varying complexity that included age, DAS28 at various time points, body mass index, and ESR (AUROC up to 0.83). Accuracy of the prediction models ranged between 80 and 95% in both derivation and validation cohorts, depending on the complexity of the model and the cutpoints chosen for response and non-response. Approximately 80% of patients could be predicted to be responders or non-responders at week 12.
Clinical data collected early after starting or escalating DMARD/biologic treatment could accurately predict LDA at 1 year in early RA patients. For patients predicted to be non-responders, treatment could be changed at 12 weeks to optimize outcomes.
rheumatoid arthritis; prediction; anti-TNF; triple therapy
To examine whether polymorphisms in genes coding for drug metabolizing enzymes (DMEs) impact rheumatoid arthritis (RA) risk due to cigarette smoking in African Americans.
Smoking status was evaluated in African American RA cases and non-RA controls categorized as heavy (≥ 10 pack-years) vs. other. Individuals were genotyped for a homozygous deletion polymorphism in glutathione S-transferase Mu-1 (GSTM1-null) in addition to tagging single nucleotide polymorphisms (SNPs) in N-acetyltransferase (NAT)1, NAT2, and epoxide hydrolase (EPXH1). Associations of genotypes with RA were examined using logistic regression and gene-smoking interactions were assessed.
There were no significant associations of any DME genotype with RA. After adjustment for multiple comparisons, there were significant additive interactions between heavy smoking and NAT2 SNPs rs9987109 (Padd = 0.000003) and rs1208 (Padd = 0.00001); attributable proportions (APs) due to interaction ranged from 0.61 to 0.67. None of the multiplicative gene-smoking interactions examined remained significant after adjustment for multiple testing in overall disease risk. There was no evidence of significant gene-smoking interactions in analyses of GSTM1-null, NAT1, or EPXH1. DME gene-smoking interactions were similar when cases were limited to anti-citrullinated protein antibody (ACPA) positive individuals.
Among African Americans, RA risk imposed by heavy smoking appears to be mediated in part by genetic variation in NAT2. While further studies are needed to elucidate mechanisms underpinning these interactions, these SNPs appear to identify African American smokers at a much higher risk for RA with relative risks that are at least two-fold higher compared to non-smokers lacking these risk alleles.
rheumatoid arthritis; African Americans; cigarette smoking; anti-CCP antibody; drug metabolizing enzyme; N-acetyltransferase; epoxide hydrolase; glutathione S-transferase
To describe use of the ACR/EULAR (AE) rheumatoid arthritis (RA) remission criteria in clinical practice.
We examined remission in the US Veterans Affairs RA (VARA) registry of 1,341 patients (91% men) with 9,700 visits and a community rheumatology practice (ARCK) of 1,168 patients (28% men) with 6,362 visits. We studied cross-sectional and cumulative probabilities, agreement among various remission criteria, and aspects of reliability using Boolean definitions and CDAI and SDAI methods proposed by AE.
By AE definition for community practice (swollen and tender joints ≤1, patient global ≤1), cross-sectional remission was 7.5% (6.4, 8.7) for ARCK and 8.9% (7.9, 9.9) for VARA. Cumulative or remission at any observation was 18.0% (ARCK) and 24.4% (VARA) over a mean of 2.2 years. Addition of ESR or CRP to criteria reduced remission to 5.0-6.2%, and use of CDAI/SDAI increased proportions to 6.9-10.1%. 1.8%-4.6% of patients met remission criteria at ≥2 visits. Agreement between criteria definitions was good by Kappa and Jaccard measures. Among patients in remission, the probability of a remission lasting 2 years was 6.0%-14.1%. Among all patients the probability of a remission lasting 2 years was <3%. Remission and examination results varied substantially among physicians by multilevel analyses.
Cross-sectional remission occurs at 5.0%-10.1%, with cumulative remission 2-3 times greater. Long-term remissions are rare. Problems with reliability and agreement limit criteria usefulness in the individual patient. However, the criteria can be an effective method for measuring clinical status and treatment effect in groups of patients in the community.
Rheumatoid arthritis; Remission; Reliability
Findings that African-American race/ethnicity is associated with higher concentrations of serum urate have not been adjusted for possible confounding factors or have not explored this question as a primary outcome. We tested this hypothesis in a bi-racial cohort of younger African-American and white men and women.
Data from 5,049 participants at the Coronary Artery Risk Development in Young Adults (CARDIA) cohort baseline (1985 to1986) and follow-up for up to 20 years of individuals without hyperuricemia (defined as a serum urate of 6.8 mg/dL or more) at baseline were utilized. We determined associations between race, serum urate and the development of hyperuricemia in sex-specific cross-sectional and longitudinal analyses. Confounding factors examined included: age at enrollment, body mass index, development of hypertension, glomerular filtration rate, medication use, diet and alcohol intake and menopausal symptoms in women.
Referent to whites, African-American men and women had significantly lower concentrations of serum urate at baseline. African-American men had an essentially equal risk of developing incident hyperuricemia during follow-up compared with white men (multivariable adjusted HR = 1.12 (0.88 to1.40)). African-American women developed a significantly increased risk of hyperuricemia when compared to white women (HR = 2.31 (1.34 to 3.99)).
Young African-American men and women had lower concentrations of serum urate than whites. During longitudinal follow-up, African-American women had a significantly increased risk of developing hyperuricemia when compared with white women, a difference that was not observed in men. Differences in production of serum urate or a more rapid decline in fractional excretion of serum urate are potential, albeit still unproven, explanations for these findings in African-American women.
Objectives. To examine the all-cause mortality rate and factors associated with mortality in US veteran men with RA.
Methods. Men with RA were enrolled and followed until death or censoring. Vital status was ascertained through systematic record review and standardized mortality ratios (SMRs) were calculated using US life tables for men. Multivariate Cox proportional hazards regression was used to examine the independent associations of patient factors including socio-demographics, comorbidity, measures of RA disease activity/severity and medication use with mortality. Measures of RA disease activity and medications were examined as time-varying factors.
Results. A total of 138 deaths were observed during 2314 patient-years of follow-up (n = 1015 patients), corresponding to a crude morality rate of 5.9 deaths per 100 patient-years (95% CI 5.0, 7.0) and an SMR of 2.1 (95% CI 1.8, 2.5). After multivariate adjustment, factors independently associated with higher mortality risk in men with RA included older age, Caucasian race, low body weight, an increased frequency of rheumatology visits, higher ESR and RF concentrations, increased DAS28, subcutaneous nodules and prednisone use. In contrast, MTX use [hazard ratio (HR) 0.63; 95% CI 0.42, 0.96] was associated with ∼40% lower mortality risk.
Conclusion. Mortality rates among US male veterans with RA are more than twice those of age-matched men in the general population. These results suggest that optimizing disease control, particularly with regimens that include MTX and minimize glucocorticoid exposure, could improve long-term survival in this population.
Rheumatoid arthritis; Mortality; US veterans; Men; MTX; Glucocorticoids
To examine the associations of cigarette smoking with rheumatoid arthritis (RA) in African Americans and to determine to whether this association is impacted by HLA-DRB1 shared epitope (SE).
Smoking status, cumulative smoking exposure, and SE status were measured in African American patients with RA and in healthy controls. Associations of smoking with RA were examined using age- and gender-adjusted logistic regression. Additive and multiplicative SE-smoking interactions were examined.
After adjusting for age and gender, ever (OR = 1.45; 95% CI 1.07 to 1.97) and current smoking (OR = 1.56; 95% CI 1.07 to 2.26) were more common in African American RA cases (n = 605) than in controls (n = 255). The association of smoking with RA was limited to those with a cumulative exposure exceeding 10 pack-years, associations that were evident in both autoantibody positive and negative disease. There was evidence of a significant additive interaction between SE status and heavy smoking (≥ 10 pack-years) in RA risk (attributable proportion due to interaction [AP] of 0.58, p = 0.007) with an AP of 0.47 (p = 0.006) between SE status and ever smoking. There was no evidence of multiplicative interactions.
Among African Americans, cigarette smoking is associated not only with the risk of autoantibody positive RA but also with the risk of autoantibody negative disease. RA risk attributable to smoking is limited to African Americans with more than 10 pack-years of exposure and is more pronounced among individuals positive for HLA-DRB1 SE.
rheumatoid arthritis; African Americans; cigarette smoking; rheumatoid factor; anti-CCP antibody; HLA-DRB1 shared epitope
Minocycline and doxycycline are safe and moderately effective disease-modifying anti-rheumatic drugs (DMARDs) in the treatment of early, DMARD-naïve rheumatoid arthritis (RA), although little is known about their use outside clinical trials. We characterize the use of minocycline and doxycycline in community-dwelling RA patients by examining associated prescribing patterns, patient-level determinants of use, and side-effect profiles.
We studied 15,716 patients with RA observed between 1998 and 2009 while participating in a long-term US observational study.
Minocycline or doxycycline was prescribed by 18% of rheumatologists (interquartile range one to two patients per physician) to 9% of RA patients. Significant differences between minocycline-treated and doxycycline-treated patients and nontreated patients included age (58.4 years vs. 59.8 years), RA duration (14.8 years vs. 13.7 years), Caucasian race (93.7% vs. 89.7%), lifetime DMARDs and biologics (3.3 vs. 2.5), prednisone use (40.1% vs. 35.3%), and Medical Outcomes Study 36-Item Short Form Survey physical component summary score (35.0 vs. 36.4). In multivariable Cox regression, patients initiating minocycline or doxycycline had increased disease activity, more comorbidities, and a greater number of prior nonbiologic DMARDs. Side effects were reported by 17.8% of minocycline users and 11.8% of doxycycline users. Skin complaints accounted for 54% of minocycline patient-reported side effects. The most commonly effected organ systems for doxycycline were gastrointestinal (35.4%) and skin (33.7%). Approximately 75% of side effects were of mild or moderate severity.
Rheumatologists have not embraced minocycline or doxycycline as primary treatment options for RA and reserve their use primarily in patients with long-standing, refractory disease. These drugs are generally well tolerated, with skin complaints, nausea, and dizziness being the most common patient-reported side effects.
Administrative claims data have not commonly been used to study the clinical effectiveness of medications for rheumatoid arthritis (RA) because of the lack of a validated algorithm for this outcome. We created and tested a claims-based algorithm to serve as a proxy for the clinical effectiveness of RA medications.
We linked Veterans Health Administration (VHA) medical and pharmacy claims for RA patients participating in the longitudinal Department of Veterans Affairs (VA) RA registry (VARA). Among individuals for whom treatment with a new biologic agent or nonbiologic disease-modifying agent in rheumatic disease (DMARD) was being initiated and with registry follow-up at 1 year, VARA and administrative data were used to create a gold standard for the claims-based effectiveness algorithm. The gold standard outcome was low disease activity (LDA) (Disease Activity Score using 28 joint counts (DAS28) ≤ 3.2) or improvement in DAS28 by > 1.2 units at 12 ± 2 months, with high adherence to therapy. The claims-based effectiveness algorithm incorporated biologic dose escalation or switching, addition of new disease-modifying agents, increase in oral glucocorticoid use and dose as well as parenteral glucocorticoid injections.
Among 1,397 patients, we identified 305 eligible biologic or DMARD treatment episodes in 269 unique individuals. The patients were primarily men (94%) with a mean (± SD) age of 62 ± 10 years. At 1 year, 27% of treatment episodes achieved the effectiveness gold standard. The performance characteristics of the effectiveness algorithm were as follows: positive predictive value, 76% (95% confidence interval (95% CI) = 71% to 81%); negative predictive value, 90% (95% CI = 88% to 92%); sensitivity, 72% (95% CI = 67% to 77%); and specificity, 91% (95% CI = 89% to 93%).
Administrative claims data may be useful in evaluating the effectiveness of medications for RA. Further validation of this effectiveness algorithm will be useful in assessing its generalizability and performance in other populations.
rheumatoid arthritis; comparative effectiveness; administrative claims data; biologic
To examine the prevalence of vitamin D insufficiency and the associations of vitamin D concentration with disease status in African Americans with rheumatoid arthritis (RA).
Study participants (n = 266) were enrolled in the Consortium for the Longitudinal Evaluation of African Americans with Early RA (CLEAR) Registry. 25(OH)-D was measured on baseline plasma and associations of 25(OH)-D with disease status (baseline and at 3 years disease duration) were examined using univariate and multivariate regression.
The prevalence of 25(OH)-D insufficiency (≤ 37.5 nmol/L or 15 ng/ml) was 50%, with the highest prevalence in winter. In unadjusted analyses, vitamin D concentrations were inversely associated with baseline pain (p = 0.04), swollen joints (p = 0.04), and Disease Activity Score (DAS-28, p = 0.05) but not with measures at 3 years disease duration. There were no multivariate associations of 25(OH)-D with any disease measures at baseline or at 3 years with the exception of a positive borderline association with rheumatoid factor positivity at enrollment (p = 0.05).
Vitamin D insufficiency is common in African Americans with recent-onset RA. Unadjusted associations of circulating vitamin D with baseline pain, swollen joints, and DAS-28 were explained by differences in season, age, and gender and were not significant in multivariate analyses. In contrast to reports of Northern Europeans with early inflammatory arthritis, there are not strong associations of 25(OH)-D concentration with symptoms or disease severity in African Americans with RA.
rheumatoid arthritis; vitamin D; African American; disease activity; severity
To examine associations of anti-cyclic citrullinated peptide antibody (aCCP) and rheumatoid factor (RF) concentrations with future disease burden in patients with rheumatoid arthritis (RA).
Outcome measures were examined in U.S. veterans with RA and included: 1) proportion of observation in remission (Disease Activity Score [DAS]28 ≤ 2.6), 2) remission for ≥ 3 consecutive months, and 3) area under the curve [AUC] for DAS28. Associations of autoantibody concentration (per 100 unit increments) with outcomes were examined using multivariate regression.
Patients (n = 855) were predominantly men (91%) with mean (SD) age of 66 (11) years and 2.3 (1.2) years of follow-up. Most were aCCP (75%) and RF (80%) positive. After multivariate adjustment, aCCP (OR 0.93; 95% CI 0.91-0.96) and RF concentrations (OR 0.92; 95% CI 0.90-0.95) were associated with a lower odds of remission, a lower proportion of observation in remission (p = 0.054 and p = 0.014, respectively), and greater AUC DAS28 (p = 0.05 and p = 0.002, respectively). In aCCP+ / RF- patients, higher aCCP concentrations were associated with an increased likelihood of remission (OR 1.10; 95% CI 1.00-1.20). Among aCCP- / RF+ patients, higher RF concentrations trended towards an inverse association with remission (OR 0.81; 95% CI 0.58-1.13).
aCCP concentrations (particularly in RF positive patients) are associated with poor prognosis in U.S. veterans with RA. Analyses of autoantibody discordant patients suggest that RF concentrations may be a stronger predictor of disease burden than aCCP concentration.
rheumatoid arthritis; cyclic citrullinated peptide; rheumatoid factor; disease activity; clinical remission
Hydroxychloroquine (HCQ) is an antimalarial agent that is commonly used to treat rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). The present report documents a case of hypoglycaemia due to HCQ in a patient with SLE and diabetes mellitus type 2, in which the HCQ completely replaced the need for daily subcutaneous insulin.
Total shoulder arthroplasties (TSA) are being performed more commonly for treatment of arthritis, although fewer than either hip (THA) or knee (TKA) arthroplasties. Total shoulder arthroplasty also provides general health improvements that are comparable to THA. One study suggests TSAs are associated with lower morbidity and mortality than THAs and TKAs. To confirm and extend that study, we therefore examined the association of patient characteristics (sociodemographics, comorbid illness, and other risk factors) with 30-day complications for patients undergoing TSAs, THAs, or TKAs. We used data from the Veterans Administration (VA) National Surgical Quality Improvement Program (NSQIP) for fiscal years 1999 to 2006. Sociodemographics, comorbidities, health behaviors, operative factors, and complications (mortality, return to the operating room, readmission within 14 days, cardiovascular events, and infections) were available for 10,407 THAs, 23,042 TKAs, and 793 TSAs. Sociodemographic features were comparable among groups. The mean operative time was greater for TSAs (3.0 hours) than for TKAs (2.2 hours) and THAs (2.4 hours). The 30-day mortality rates were 1.2%, 1.1%, and 0.4% for THAs, TKAs, and TSAs, respectively. The corresponding postoperative complication rates were 7.6%, 6.8%, and 2.8%. Adjusting for multiple risk factors, complications, readmissions, and postoperative stays were less for TSAs versus THAs and TKAs. In a VA population, TSAs required more operative time but resulted in shorter stays, fewer complications, and fewer readmissions than THAs and TKAs.
Level of Evidence: Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.
To describe a large, multi-center prospective cohort study of first-degree relatives (FDRs) of probands with rheumatoid arthritis (RA), and outline the utility of such a study in investigating the natural history of RA development.
1058 FDRs, none of whom met the American College of Rheumatology (ACR) criteria for RA, have been enrolled into a prospective study investigating genetic and environmental influences on the development of RA-related autoimmunity. Demographic, epidemiologic, genetic, autoantibody, and physical examination data from the initial study enrollment visit is described for these FDRs, and the relationship is examined between genetic factors, autoantibodies, inflammation, and joint disease.
Fifty-five percent of FDRs have ≥1 copy of the shared epitope (SE); 20% have ≥1 copy of PTPN22 polymorphism; ~16% are positive for rheumatoid factor (RF, including isotypes), and/or anti-cyclic citrullinated peptide (anti-CCP) antibody. RF-IgM positivity is associated with ≥1 tender joint/s on examination (OR 2.50, 95% CI 1.27 to 4.89, p<0.01), and elevated levels of CRP (OR 5.31, 95% CI 1.45 to 19.52, p = 0.01).
FDRs without RA demonstrate high prevalence of genetic risk factors and RA-related autoantibodies. Additionally, RF association with tender joints and elevated CRP suggests autoantibodies are a valid intermediate marker of RA-related autoimmunity in this cohort. This prospective FDR cohort will be a valuable resource for evaluating the relationship between genetic, epidemiologic factors and the development of RA-related autoimmunity.
rheumatoid arthritis; epidemiology; environmental factors; first-degree relatives; pre-clinical rheumatoid arthritis
A deletion polymorphism in glutathione S-transferase Mu-1 (GSTM1-null) has previously been implicated to play a role in rheumatoid arthritis (RA) risk and progression, although no prior investigations have examined its associations with anticitrullinated protein antibody (ACPA) positivity. The purpose of this study was to examine the associations of GSTM1-null with ACPA positivity in RA and to assess for evidence of interaction between GSTM1 and HLA-DRB1 shared epitope (SE).
Associations of GSTM1-null with ACPA positivity were examined separately in two RA cohorts, the Veterans Affairs Rheumatoid Arthritis (VARA) registry (n = 703) and the Study of New-Onset RA (SONORA; n = 610). Interactions were examined by calculating an attributable proportion (AP) due to interaction.
A majority of patients in the VARA registry (76%) and SONORA (69%) were positive for ACPA with a similar frequency of GSTM1-null (53% and 52%, respectively) and HLA-DRB1 SE positivity (76% and 71%, respectively). The parameter of patients who had ever smoked was more common in the VARA registry (80%) than in SONORA (65%). GSTM1-null was significantly associated with ACPA positivity in the VARA registry (odds ratio (OR), 1.45; 95% confidence interval (CI), 1.02 to 2.05), but not in SONORA (OR, 1.00; 95% CI, 0.71 to 1.42). There were significant additive interactions between GSTM1 and HLA-DRB1 SE in the VARA registry (AP, 0.49; 95% CI, 0.21 to 0.77; P < 0.001) in ACPA positivity, an interaction replicated in SONORA (AP, 0.38; 95% CI, 0.00 to 0.76; P = 0.050).
This study is the first to show that the GSTM1-null genotype, a common genetic variant, exerts significant additive interaction with HLA-DRB1 SE on the risk of ACPA positivity in RA. Since GSTM1 has known antioxidant functions, these data suggest that oxidative stress may be important in the development of RA-specific autoimmunity in genetically susceptible individuals.
The purpose of the present manuscript is to test the hypothesis that arthrotropic localization and synovial cell internalization account for the unique capacity of N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer-dexamethasone conjugate (P-Dex, a macromolecular prodrug of dexamethasone) to induce sustained amelioration of joint inflammation and inhibition of tissue damage in an animal model of inflammatory arthritis.
Rats with adjuvant-induced arthritis (AA) were treated with P-Dex, free dexamethasone, saline or HPMA homopolymer. To define the biodistribution of P-Dex, conjugates with different imaging labels were given to AA rats and analyzed. Isolated joint tissues were evaluated by fluorescence-activated cell sorting (FACS) and immunohistochemical staining. Cellular uptake of P-Dex and its effects on apoptosis and production of proinflammatory cytokines were examined using human monocyte-macrophages and fibroblasts.
A single systemic administration of P-Dex completely suppressed AA for >20 days. Magnetic resonance imaging demonstrated higher HPMA copolymer influx into the inflamed joints than the normal joints. Immunohistochemistry and FACS analyses of arthritic joints revealed extensive uptake of the polymer conjugate by synovial fibroblasts and myeloid lineage cells. The capacity of P-Dex to suppress inflammation was confirmed in monocyte-macrophage cultures in which P-Dex treatment resulted in suppression of lipopolysaccharide-induced IL-6 and TNFα release. Similarly, TNFα-induced expression of matrix metalloproteinases (MMP1 and MMP3) in synovial fibroblasts from a rheumatoid arthritis patient was suppressed by P-Dex. P-Dex showed no detectable effect on monocyte apoptosis.
P-Dex provides superior and sustained amelioration of AA compared with an equivalent dose of free dexamethasone. The arthrotropism and local retention of P-Dex is attributed to the enhanced vascular permeability in arthritic joints and the internalization of P-Dex by synovial cells. The uptake and processing of P-Dex by macrophages and fibroblasts, and downregulation of proinflammatory mediators, provides an explanation for the sustained anti-inflammatory efficacy of P-Dex in this model of inflammatory arthritis.
Antibody titers to P. gingivalis are increased in patients with rheumatoid arthritis and are associated with disease-specific autoimmunity.
Periodontitis (PD) has been implicated as a risk factor for rheumatoid arthritis (RA). We sought to characterize antibody titers to P. gingivalis (a pathogen in PD) in subjects with RA, PD, and in healthy controls and to examine their relationship with disease autoantibodies.
P. gingivalis antibody was measured in subjects with RA (n = 78), PD (n = 39), and in controls (n = 40). Group frequencies of bacterial titer elevations were compared using the Chi-square test and antibody titers were compared using non-parametric tests. Correlations of P. gingivalis titer with C-reactive protein (CRP), antibody to cyclic citrullinated peptide (anti-CCP), and rheumatoid factor (RF) were examined in those with RA while CRP and autoantibody concentrations were compared based on seropositivity to P. gingivalis.
Antibody titers to P. gingivalis were highest in PD, lowest in controls, and intermediate in RA (p = 0.0003). Elevations in P. gingivalis (titer ≥ 800) were more common in RA and PD (67% and 77%, respectively) than in controls (40%) (p = 0.002). In RA, there were significant correlations with P. gingivalis titer with CRP, anti-CCP-IgM, and -IgG-2. CRP (p = 0.006), anti-CCP-IgM (p = 0.01) and -IgG2 (p = 0.04) concentrations were higher in RA cases with P. gingivalis titers ≥ 800 compared to cases with titers < 800.
Antibodies to P. gingivalis are more common in RA subjects than controls, although lower than that in PD. Associations of P. gingivalis titers with RA-related autoantibody and CRP concentrations suggests that infection with this organism plays a role in disease risk and progression in RA.
periodontitis; rheumatoid arthritis; Porphyromonas gingivalis; anti-CCP; rheumatoid factor
To examine the association of smoking with clinical and serologic features in African Americans with recent-onset rheumatoid arthritis (RA) and to explore whether this association is dependent on the presence of the HLA-DRB1 shared epitope (SE).
In African Americans with recent-onset RA (n = 300), we examined the association of cigarette smoking (current vs. past vs. never and pack-years of exposure) with anti-CCP antibody, rheumatoid factor (RF) (-IgM and -IgA), rheumatoid nodules, and baseline radiographic erosions using logistic and cumulative logistic regression (adjusting for SE status). We also examined for evidence of interaction between smoking status and SE for all outcomes.
Although there was no association with RF-IgA seropositivity, current smokers were approximately twice as likely as never smokers to have higher IgA-RF concentrations (based on tertiles; OR = 1.74; 95% CI 1.05–2.88) and nodules (OR = 2.43; 95% CI 1.13–5.22). These associations were most pronounced in those with more than 20 pack-years of exposure. There was no association of smoking status or cumulative tobacco exposure with anti-CCP antibody, IgM-RF, or radiographic erosions. There was also no evidence of a biologic or statistical SE-smoking interaction for any of the outcomes examined.
This is the first study to systematically examine the association of cigarette smoking with RA-related features in African Americans. Cigarette smoking is associated with both subcutaneous nodules and higher serum concentrations of IgA-RF in African Americans with RA, associations that may have important implications for long-term outcomes in this population.
rheumatoid arthritis; African Americans; cigarette smoking; rheumatoid factor; anti-CCP antibody
Purpose: To examine the prevalence of osteopenia and/or osteoporosis among African Americans with early rheumatoid arthritis (RA) and to assess the effect of using race/ethnicity-specific normative data.
Methods: Bone mineral density (BMD) of the hip and spine was assessed in African Americans with early RA. To examine the impact of using different normative data on disease classification, we calculated two sets of T scores, the first using sex-matched reference data from Caucasians and the second using data from African Americans. Osteoporosis was defined as a BMD at either site ≥2.5 SD below the young adult mean. Osteopenia was defined as a BMD ≥1 SD and <2.5 SD below this mean.
Results: Using Caucasian referent data, 33% (n=48) of patients had osteopenia or worse (n=48, 32.9%) and 5% (n=8) were osteoporotic. With the use of African-American normative data, 55% (n=94) were osteopenic or worse, and 16% (n=27) were osteoporotic.
Conclusion: African Americans with RA are at risk of osteopenia and/or osteoporosis. Different diagnostic classifications may occur in this population based solely on the normative data used for assessing fracture risk. These results underscore the need for a standardized approach in defining osteopenia and osteoporosis in African Americans.
osteoporosis; osteopenia; African Americans; DXA; rheumatoid arthritis
PURPOSE: To examine the prevalence of osteopenia and/or osteoporosis among African Americans with early rheumatoid arthritis (RA) and to assess the effect of using race/ethnicity-specific normative data. METHODS: Bone mineral density (BMD) of the hip and spine was assessed in African Americans with early RA. To examine the impact of using different normative data on disease classification, we calculated two sets of T scores, the first using sex-matched reference data from Caucasians and the second using data from African Americans. Osteoporosis was defined as a BMD at either site > or =2.5 SD below the young adult mean. Osteopenia was defined as a BMD > or =1 SD and <2.5 SD below this mean. RESULTS: Using Caucasian referent data, 33% (n=48) of patients had osteopenia or worse (n=48, 32.9%) and 5% (n=8) were osteoporotic. With the use of African-American normative data, 55% (n=94) were osteopenic or worse, and 16% (n=27) were osteoporotic. CONCLUSION: African Americans with RA are at risk of osteopenia and/or osteoporosis. Different diagnostic classifications may occur in this population based solely on the normative data used for assessing fracture risk. These results underscore the need for a standardized approach in defining osteopenia and osteoporosis in African Americans.
Cigarette smoking has emerged as a risk factor for development of rheumatoid arthritis (RA). Recent studies have suggested that cigarette smoking may lead to lower treatment response rates with methotrexate (MTX) and some biologic agents in RA. Knowledge of whether tobacco exposure reduces treatment efficacy is important as smoking could represent a modifiable factor in optimizing RA treatment.
Study participants included patients with early RA (<3 years duration) enrolled in the Treatment of Early Aggressive RA (TEAR) trial, a randomized, blinded, placebo-controlled clinical trial (RCT) comparing early intensive therapy (MTX + etanercept or MTX + hydroxychloroquine + sulfasalazine [triple therapy]) versus initial treatment with MTX with step-up to MTX + etanercept or to triple therapy if still active at 24 weeks. Serum cotinine was measured using a commercially available ELISA at baseline and 48 weeks with detectable concentrations at both visits serving as indicator of smoking status. Mean Disease Activity Score (DAS-28) was compared by smoking status, adjusting for baseline disease activity.
Of 412 subjects included in the analysis, 293 (71%) were categorized as ‘non-smokers’ and 119 (29%) as ‘current smokers’. There were no differences in the mean DAS-28 between 48 and 102 weeks based on smoking status for the overall group (p=0.881) or by specific treatment assignment.
Among patients enrolled in a large RCT of early RA with poor prognostic factors, smoking status did not impact treatment responses for those receiving early combination or initial MTX with step-up therapy at 24 weeks if still active.
To examine the association between baseline bone mineral density (BMD) and radiographic damage at 3-year disease duration in a longitudinal cohort of African Americans (AAs) with recent-onset RA.
Participants (n=141) included AAs with < 2 years of disease duration. All patients underwent baseline BMD measurement (femoral neck and/or lumbar spine) using DXA. T-scores were calculated using AAs normative data. Patients were categorized as having osteopenia/osteoporosis (T score ≤ −1) or healthy. Hand/wrist radiographs, obtained at baseline and at 3-year disease duration, were scored using modified Sharp/van der Heijde method. The association between baseline BMD and total radiographic score at 3-year disease duration was examined using multivariable negative binomial regression.
At baseline, the mean age and disease duration were 52.4 years and 14.8 months respectively (85.1% women). Average total radiographic scores at baseline and 3-year disease duration were 2.4 and 5.7. In the final reduced multivariable model adjusting for age, gender, anti-cyclic citrullinated peptide antibody positivity, and the presence of radiographic damage at baseline, the total radiographic score at 3-years of disease duration in patients with osteopenia/osteoporosis at the femoral neck was twice that in patients with healthy bone density and the difference was statistically significant (p=0.0084). No association between lumbar spine osteopenia/osteoporosis and radiographic score was found.
These findings suggest that reduced generalized BMD may be a predictor of future radiographic damage and support the hypothesis that radiographic damage and reduced generalized BMD in RA patients may share a common pathogenic mechanism.