Structural basis for the allosteric regulation and dynamic assembly of DNMT3B.

Oligomerization of DNMT3B, a mammalian de novo DNA methyltransferase, critically regulates its chromatin targeting and DNA methylation activities. However, how the N-terminal PWWP and ADD domains interplay with the C-terminal methyltransferase (MTase) domain in regulating the dynamic assembly of DNMT3B remains unclear. Here, we report the cryo-EM structure of DNMT3B under various oligomerization states. The ADD domain of DNMT3B interacts with the MTase domain to form an autoinhibitory conformation, resembling the previously observed DNMT3A autoinhibition. Our combined structural and biochemical study further identifies a role for the PWWP domain and its associated ICF mutation in the allosteric regulation of DNMT3B tetramer, and a differential functional impact on DNMT3B by potential ADD-H3K4me0 and PWWP-H3K36me3 bindings. In addition, our comparative structural analysis reveals a coupling between DNMT3B oligomerization and folding of its substrate-binding sites. Together, this study provides mechanistic insights into the allosteric regulation and dynamic assembly of DNMT3B.

Perceptions of racism in healthcare among patients with systemic lupus erythematosus: a cross-sectional study.

BACKGROUND: Racial disparities in the clinical outcomes of systemic lupus erythematosus (SLE) exist. Perceived racial discrimination may contribute to disparities in health. OBJECTIVES: To determine if perceived racism in healthcare differs by race among patients with SLE and to evaluate its contribution to racial disparities in SLE-related outcomes. METHODS: 163 African-American (AA) and 180 white (WH) patients with SLE were enrolled. Structured interviews and chart reviews were done to determine perceptions of racism, SLE-related outcomes (Systemic Lupus International Collaborating Clinics (SLICC) Damage Index, SLE Disease Activity, Center for Epidemiologic Studies-Depression (CES-D)), and other variables that may affect perceptions of racism. Serial hierarchical multivariable logistic regression models were conducted. Race-stratified analyses were also performed. RESULTS: 56.0% of AA patients compared with 32.8% of WH patients had high perceptions of discrimination in healthcare (p<0.001). This difference remained (OR 4.75 (95% CI 2.41 to 8.68)) after adjustment for background, identity and healthcare experiences. Female gender (p=0.012) and lower trust in physicians (p<0.001) were also associated with high perceived racism. The odds of having greater disease damage (SLICC damage index ≥2) were higher in AA patients than in WH patients (crude OR 1.55 (95% CI 1.01 to 2.38)). The odds of having moderate to severe depression (CES-D ≥17) were also higher in AA patients than in WH patients (crude OR 1.94 (95% CI 1.26 to 2.98)). When adjusted for sociodemographic and clinical characteristics, racial disparities in disease damage and depression were no longer significant. Among AA patients, higher perceived racism was associated with having moderate to severe depression (adjusted OR 1.23 (95% CI 1.05 to 1.43)) even after adjusting for sociodemographic and clinical variables. CONCLUSIONS: Perceptions of racism in healthcare were more common in AA patients than in WH patients with SLE and were associated with depression. Interventions aimed at modifiable factors (eg, trust in providers) may reduce higher perceptions of race-based discrimination in SLE.

Prevention of stroke in rheumatoid arthritis.

OPINION STATEMENT: Recognizing that systemic inflammation is a major contributor to the increased risk of cardiovascular disease (CVD), including stroke, in rheumatoid arthritis (RA) serves as the basis for prevention strategies for cerebrovascular disease in RA. In addition to traditional cardiovascular risk factors, recognize that RA may be an independent risk factor for cerebrovascular accident (CVA). The risk of CVD should be assessed in each patient with RA, utilizing modified risk score calculators. Careful monitoring and control of systemic inflammation should be undertaken in conjunction with assessing each patient's CVD risk, acknowledging the benefits and risks of specific RA-directed therapies. Emphasis should be given to early and aggressive control of inflammation in RA patients, particularly those with seropositivity, increased inflammatory markers, long disease duration (>10 years), and/or extra-articular manifestations. In RA patients requiring glucocorticoid therapy, attempts should be made to use or wean to the minimal effective dose (preferably less than 7.5 mg/day). It should be recognized that both disease-modifying antirheumatic drugs (DMARDs), particularly methotrexate, and tumor necrosis factor (TNF)-alpha inhibitors partially mitigate the risk of CVD. In patients with inadequate control of inflammation with DMARDs, consideration should be given to switch to anti-TNF agents earlier in the disease process. Modifiable risk factors should be addressed as per guidelines for the general population. Active RA may be considered as a risk equivalent to diabetes mellitus when applying these guidelines. With regard to lipid management and use of statin therapy, further studies are required given the apparent "lipid paradox" in RA. Use of aspirin for primary prevention in RA has not been well studied; however, when aspirin is used for secondary prevention, one should recognize that concomitant use of nonsteroidal anti-inflammatory drugs (NSAIDs) may decrease the antiplatelet effect. Given the cardiovascular risk associated with NSAIDs, the lowest possible dose for the shortest time should be used.

Body mass index and the risk of giant cell arteritis: results from a prospective study.

OBJECTIVE: The aim of this study was to examine potential risk factors for GCA in a nested case-control study based on two prospective health surveys. METHODS: We used two population-based health surveys, the Malmö Preventive Medicine Program (MPMP) and the Malmö Diet Cancer Study (MDCS). Individuals who developed GCA after inclusion were identified by linking the MPMP and MDCS databases to several patient administrative registers. A structured review of the medical records of all identified cases was performed. Four controls for every confirmed case, matched for sex, year of birth and year of screening, were selected from the corresponding databases. Potential predictors of GCA were examined in conditional logistic regression models. RESULTS: Eighty-three patients (70% women, 64% biopsy positive, mean age at diagnosis 71 years) had a confirmed diagnosis of GCA after inclusion in the MPMP or MDCS. A higher BMI was associated with a significantly reduced risk of subsequent development of GCA [odds ratio (OR) 0.91/kg/m(2) (95% CI 0.84, 0.98)]. Smoking was not a risk factor for GCA overall [OR 1.36 (95% CI 0.77, 2.57)], although there was a trend towards an increased risk in female smokers [OR 2.14 (95% CI 0.97, 4.68)]. In multivariate analysis, adjusted for smoking and level of formal education, the inverse association between BMI and GCA remained significant (P = 0.027). CONCLUSION: In this study, GCA was predicted by a lower BMI at baseline. Potential explanations include an effect of reduced adipose tissue on hormonal pathways regulating inflammation.

Increased prevalence of diastolic dysfunction in rheumatoid arthritis.

OBJECTIVE: To compare the prevalence of left ventricular (LV) diastolic dysfunction in subjects with and without rheumatoid arthritis (RA), among those with no history of heart failure (HF), and to determine risk factors for diastolic dysfunction in RA. METHODS: A cross-sectional, community-based study comparing cohorts of adults with and without RA and without a history of HF was carried out. Standard two-dimensional/Doppler echocardiography was performed in all participants. Diastolic dysfunction was defined as impaired relaxation (with or without increased filling pressures) or advanced reduction in compliance or reversible or fixed restrictive filling. RESULTS: The study included 244 subjects with RA and 1448 non-RA subjects. Mean age was 60.5 years in the RA cohort (71% female) and 64.9 years (50% female) in the non-RA cohort. The vast majority (>98%) of both cohorts had preserved ejection fraction (EF> or =50%). Diastolic dysfunction was more common in subjects with RA at 31% compared with 26% (age and sex adjusted) in non-RA subjects (OR=1.6; 95% CI 1.2 to 2.4). Patients with RA had significantly lower LV mass, higher pulmonary arterial pressure and higher left atrial volume index than non-RA subjects. RA duration and interleukin 6 (IL-6) level were independently associated with diastolic dysfunction in RA even after adjustment for cardiovascular risk factors. CONCLUSION: Subjects with RA have a higher prevalence of diastolic dysfunction than those without RA. RA duration and IL-6 are independently associated with diastolic dysfunction, suggesting the impact of chronic autoimmune inflammation on myocardial function in RA. Clinical implications of these findings require further investigation.

Could accelerated aging explain the excess mortality in patients with seropositive rheumatoid arthritis?

OBJECTIVE: To determine whether the mortality pattern in patients with seropositive rheumatoid arthritis (RA) is consistent with the concept of accelerated aging, by comparing the observed mortality rates in patients with RA with the age-accelerated mortality rates from the general population. METHODS: A population-based inception cohort of patients with seropositive RA (according to the American College of Rheumatology 1987 criteria) was assembled and followed up for vital status until July 1, 2008. The expected mortality rate was obtained by applying the death rates from the general population to the age, sex, and calendar year distribution of the RA population. The observed mortality was estimated using Kaplan-Meier methods. Acceleration factors for the expected mortality were estimated in accelerated failure time models. RESULTS: A total of 755 patients with seropositive RA (mean age 55.6 years, 69% women) were followed up for a mean of 12.5 years, during which 315 patients died. The expected median survival was age 82.4 years, whereas the median survival of the RA patients was age 76.7 years. Results of statistical modeling suggested that, in terms of mortality rates, patients with RA were effectively 2 years older than actual age at RA incidence, and thereafter the patients underwent 11.4 effective years of aging for each 10 years of calendar time. CONCLUSION: The overall observed mortality experience of patients with seropositive RA is consistent with the hypothesis of accelerated aging. The causes of accelerated aging in RA deserve further investigation.

Autoantibodies and the risk of cardiovascular events.

OBJECTIVE: Inflammation and autoimmunity are associated with increased cardiovascular (CV) risk in patients with rheumatoid arthritis. This association may also be present in those without rheumatic diseases. Our purpose was to determine whether rheumatoid factor (RF), antinuclear antibody (ANA), and cyclic citrullinated peptide antibody (CCP) positivity are associated with increased risk of CV events and overall mortality in those with and without rheumatic diseases. METHODS: We performed a population-based cohort study of all subjects who had a RF and/or ANA test performed between January 1, 1990, and January 1, 2000, and/or CCP test performed between September 1, 2003, and January 1, 2005, with followup until April 1, 2007. Outcomes were ascertained using diagnostic indices from complete medical records, including CV events [myocardial infarction (MI), heart failure (HF), and peripheral vascular disease (PVD)] and mortality. Cox models were used to analyze the data. RESULTS: There were 6783 subjects with RF, 7852 with ANA, and 299 with CCP testing. Of these, 10.4%, 23.9%, and 14.7% were positive for RF, ANA, and CCP, respectively. Adjusting for age, sex, calendar year, comorbidity, and rheumatic disease, RF and ANA positivity were significant predictors of CV events [hazard ratio (HR) 1.24 and 1.26] and death (HR 1.43 and 1.18). Adjusting for age, CCP positivity was associated with CV events, but this association was not statistically significant (HR 3.1; 95% CI 0.8, 12.3). CONCLUSION: RF and ANA positivity are significant predictors of CV events and mortality in both those with and those without rheumatic diseases. These results support the role of immune dysregulation in the etiology of CV disease.

Noninfectious ascending aortitis: a case series of 64 patients.

OBJECTIVE: To identify the clinical presentation and histopathologic characteristics of noninfectious ascending aortitis. METHODS: A retrospective medical record and histopathology review was performed of patients with histologic evidence of active noninfectious aortitis who underwent ascending aortic aneurysm resection at Mayo Clinic between January 1, 2000, and February 28, 2006. Clinicopathologic features were recorded, including demographics, clinical presentation, laboratory, imaging findings, histopathology, complications, treatment, and outcome. RESULTS: Sixty-four patients (50% women) were identified; the majority were Caucasian (83%) and elderly (mean age 69.1 yrs). Upon initial presentation, 45% had aneurysm-related symptoms, 33% were asymptomatic, 12.5% had constitutional symptoms, 4.7% had symptoms referable to cranial arteries, and 9.4% had polymyalgia rheumatica (PMR) symptoms. The majority (81%) were of "isolated" variant, with no rheumatologic history. Mean preoperative erythrocyte sedimentation rate was 16.2 +/- 23.3 mm/h (n = 20). Additional vascular imaging abnormalities were present in 72% of patients, including stenoses and/or ectasia of major aortic branches and descending thoracic or abdominal aneurysms. Giant cells were seen in 71.9%. Median followup time was 15.4 months, during which 6 (9.4%) patients died. Only 22 (34%) patients received corticosteroids, with uncertain effect on development of recurrent aneurysms, rupture, or dissections. CONCLUSION: Noninfectious ascending aortitis frequently occurs even in the absence of history, symptoms, or signs of giant cell arteritis (GCA) or PMR. When discovered, such patients should be followed closely, as a majority have additional vascular abnormalities. More studies are needed to determine optimal strategies for surveillance, detection, and treatment of ascending aortitis, which may represent a clinical entity distinct from classical GCA.

Cardiovascular risk factors and acute-phase response in idiopathic ascending aortitis: a case control study.

INTRODUCTION: Idiopathic aortitis is a rare condition characterized by giant cell or lymphoplasmacytic inflammation of the aorta. The purpose of this study was to describe risk factors for the development of idiopathic aortitis. METHODS: We conducted a case control study of 50 patients who were age-matched with two control subjects with non-inflammatory ascending aortic aneurysms. We examined whether the prevalences of gender, hypertension, hyperlipidemia, diabetes mellitus, smoking, family history of any aortic aneurysms, and elevated inflammatory markers differed between cases and controls. RESULTS: The mean age of cases was 71.6 +/- 8.9 years and that of controls was 71.1 +/- 8.9 years. We found female gender (odds ratio [OR] 2.41, 95% confidence interval [CI] 1.20 to 4.85; P = 0.014) and active smoking (OR 3.37, 95% CI 1.12 to 10.08; P = 0.03) to be associated with idiopathic aortitis. The association with smoking persisted after adjustment for gender (OR 3.24, 95% CI 1.05 to 9.96; P = 0.04). There was a trend toward lower prevalence of diabetes mellitus in cases (OR 0.39, 95% CI 0.11 to 1.43; P = 0.16) but no difference in prevalences of other risk factors. The median pre-operative erythrocyte sedimentation rate (ESR) was 20 mm/hour in cases (n = 13) and 9 mm/hour in controls (n = 22). The median pre-operative C-reactive protein (CRP) levels were 12 mg/L in cases (n = 8) and 3 mg/L in controls (n = 6) (normal: <8 mg/L). A higher proportion of cases versus controls had elevations in ESR (38% versus 9%; P = 0.075) and CRP (62% versus 0%; P = 0.031). CONCLUSIONS: Gender and smoking may interact in complex mechanisms with immune and proteolytic pathways in older, less distensible thoracic aortas. Elevated acute-phase reactants as a marker of systemic inflammation may be present in some patients.

Surgical management of ascending aortic aneurysm due to non-infectious aortitis.

OBJECTIVES: We reviewed the spectrum of disease and early outcomes of patients undergoing ascending aortic surgery for Giant cell aortitis (GCA). DESIGN: Of 1 259 patients undergoing repair of ascending aortic aneurysms between January 1993 and July 2006, 100 had histologic evidence of GCA or lymphoplasmacytic aortitis. RESULTS: Operative Mortality was 4% (4/100). One patient underwent aortoplasty and aortic valve replacement (AVR). Among 99 patients undergoing graft replacement of the ascending aorta, distal disease required hemiarch replacement in 33 and total arch replacement in 14. Proximal aneurismal disease of the root was managed by mechanical or biological root replacement (n=18), Yacoub remodeling (n=2) or David reimplantation (n=9). Another 12 patients had separate AVR and ascending graft, while 26 had AR corrected by restoration of proper sinotubular junction diameter. In total, of 63 patients with AR, 38 had a valve-preserving procedure (61%). CONCLUSIONS: Ascending aortic aneurismal disease due to GCA is frequently associated with proximal and/or distal disease. Valve sparing procedures are technically feasible for many, although late durability is uncertain.

Rhino-orbitocerebral mucormycosis caused by Apophysomyces elegans.

Rhino-orbitocerebral mucormycosis (ROCM) caused by more common zygomycetes (e.g., Mucor) is known to cause rapidly fatal infections in immunocompromised patients. Apophysomyces elegans is an emerging zygomycete that has been reported to cause invasive cutaneous and rhino-orbitocerebral infections in immunocompetent individuals. Limited data exist describing the syndrome of ROCM caused by A. elegans. We describe a recent case and performed a comprehensive literature review to delineate the clinical characteristics of ROCM caused by A. elegans. Our case is a 50-year-old man with diabetes mellitus who presented with facial pain and right eye proptosis. Endoscopic sinus sampling revealed A. elegans. He was treated with liposomal amphotericin B and multiple debridements, with no disease on 1.5-year follow-up examination. Seven cases were identified on literature review, including the present case. Most patients (86%) were male, with a mean age of 40 years. Most patients (71%) did not have predisposing medical conditions. Three patients had predisposing head trauma. All presented with facial and/or periorbital pain. All had magnetic resonance imaging or computed tomography of the head showing intraorbital and/or sinus inflammation. Diagnosis was confirmed by histopathology and deep tissue culture in all cases. All patients required eye exenteration and extensive surgical debridement, in addition to intravenous amphotericin B. Six of the seven patients (86%) recovered. ROCM caused by A. elegans is rarely reported in the literature. Most such infections occurred in immunocompetent patients, often after facial trauma. Survival in ROCM caused by A. elegans is favorable in reported cases, with prompt surgical debridement and antifungal therapy.

Incidence of noncardiac vascular disease in rheumatoid arthritis and relationship to extraarticular disease manifestations.

OBJECTIVE: To investigate the incidence of noncardiac vascular disease in patients with rheumatoid arthritis (RA) and its relationship to systemic extraarticular disease in a community-based cohort. METHODS: A retrospective medical record review of 609 patients with incident RA diagnosed during 1955-1994 was carried out in Olmsted County, Minnesota. Patients were followed up from 1955 to 2000 (median followup 11.8 years). Incident noncardiac vascular disease and severe extraarticular RA manifestations (including pericarditis, pleuritis, and vasculitis) were recorded according to predefined criteria, and incidence rates were estimated. Using Cox proportional hazards models, the risk (hazard ratio [HR]) of developing vascular events was assessed in patients with and without severe extraarticular RA. RESULTS: Cerebrovascular and peripheral arterial events occurred in 139 patients (22.8%). The 30-year cumulative incidence rates of peripheral arterial events, cerebrovascular events, and venous thromboembolic events were estimated to be 19.6%, 21.6%, and 7.2%, respectively. The presence of severe extraarticular RA manifestations was found to be associated with all subgroups of noncardiac vascular disease except cerebrovascular disease alone (HR 2.3, 95% confidence interval [95% CI] 1.2-4.3 for peripheral arterial events; HR 3.7, 95% CI 1.3-10.3 for venous thromboembolic events; HR 1.5, 95% CI 0.7-3.2 for cerebrovascular events) after adjusting for age, sex, body mass index, smoking, and rheumatoid factor status. CONCLUSION: This is the first study to assess the incidence of noncardiac vascular disease in RA. Severe extraarticular RA was associated with all forms of noncardiac vascular disease except cerebrovascular disease alone. Similar to cardiac disease, the excess risk of noncardiac vascular disease in RA is likely to be related, in part, to the systemic inflammation associated with the extraarticular manifestations of RA.