A loss-of-function CCR2 variant is associated with lower cardiovascular risk

Background and Aims

Ample evidence links CCL2, a key chemokine governing monocyte trafficking, with atherosclerosis. However, it remains unknown whether targeting the CCL2 receptor CCR2 could provide protection against cardiovascular disease.

Methods

Computationally predicted damaging (REVEL>0.5) variants within CCR2 were detected in whole-exome-sequencing data from 454,775 UK Biobank participants and tested for association with cardiovascular endpoints in gene-burden tests. Given the key role of CCR2 in monocyte mobilization, variants associated with lower monocyte count were prioritized for experimental validation. The response to CCL2 of human cells transfected with these variants was tested in migration and cAMP assays. Validated loss-of-function variants were tested for association with cardiovascular endpoints, atherosclerosis burden, and vascular risk factors. Significant associations were replicated in six independent datasets (n=1,062,595).

Results

Carriers of 45 predicted damaging CCR2 variants were at lower risk of myocardial infarction and coronary artery disease. One of these variants (M249K) was associated with lower monocyte count and decreased signaling and chemoattraction in response to CCL2. While M249K showed no association with conventional vascular risk factors, it was consistently associated with a lower risk of myocardial infarction (Odds Ratio: 0.66 95% Confidence Interval: 0.54-0.81,p=6.1×10-5) and coronary artery disease(Odds Ratio: 0.74 95% Confidence Interval: 0.62-0.87, p=2.9×10-4) in the UK Biobank and in six replication cohorts. In a phenome-wide association study, there was no evidence of higher infections risk among M249K carriers.

Conclusions

Carriers of an experimentally confirmed loss-of-function CCR2 variant are at a lower lifetime risk of myocardial infarction and coronary artery disease without carrying a higher infection risk. Our findings provide genetic support for the translational potential of CCR2-targeting as an atheroprotective approach.

A novel application of data-consistent inversion to overcome spurious inference in genome-wide association studies

The genome-wide association studies (GWAS) typically use linear or logistic regression models to identify associations between phenotypes (traits) and genotypes (genetic variants) of interest. However, the use of regression with the additive assumption has potential limitations. First, the normality assumption of residuals is the one that is rarely seen in practice, and deviation from normality increases the Type-I error rate. Second, building a model based on such an assumption ignores genetic structures, like, dominant, recessive, and protective-risk cases. Ignoring genetic variants may result in spurious conclusions about the associations between a variant and a trait. We propose an assumption-free model built upon data-consistent inversion (DCI), which is a recently developed measure-theoretic framework utilized for uncertainty quantification. This proposed DCI-derived model builds a nonparametric distribution on model inputs that propagates to the distribution of observed data without the required normality assumption of residuals in the regression model. This characteristic enables the proposed DCI-derived model to cover all genetic variants without emphasizing on additivity of the classic-GWAS model. Simulations and a replication GWAS with data from the COPDGene demonstrate the ability of this model to control the Type-I error rate at least as well as the classic-GWAS (additive linear model) approach while having similar or greater power to discover variants in different genetic modes of transmission.

Early Evidence of Chronic Obstructive Pulmonary Disease Obscured by Race-Specific Prediction Equations

Rationale: The identification of early chronic obstructive pulmonary disease (COPD) is essential to appropriately counsel patients regarding smoking cessation, provide symptomatic treatment, and eventually develop disease-modifying treatments. Disease severity in COPD is defined using race-specific spirometry equations. These may disadvantage non-White individuals in diagnosis and care. Objectives: Determine the impact of race-specific equations on African American (AA) versus non-Hispanic White individuals. Methods: Cross-sectional analyses of the COPDGene (Genetic Epidemiology of Chronic Obstructive Pulmonary Disease) cohort were conducted, comparing non-Hispanic White (n = 6,766) and AA (n = 3,366) participants for COPD manifestations. Measurements and Main Results: Spirometric classifications using race-specific, multiethnic, and "race-reversed" prediction equations (NHANES [National Health and Nutrition Examination Survey] and Global Lung Function Initiative "Other" and "Global") were compared, as were respiratory symptoms, 6-minute-walk distance, computed tomography imaging, respiratory exacerbations, and St. George's Respiratory Questionnaire. Application of different prediction equations to the cohort resulted in different classifications by stage, with NHANES and Global Lung Function Initiative race-specific equations being minimally different, but race-reversed equations moving AA participants to more severe stages and especially between the Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage 0 and preserved ratio impaired spirometry groups. Classification using the established NHANES race-specific equations demonstrated that for each of GOLD stages 1-4, AA participants were younger, had fewer pack-years and more current smoking, but had more exacerbations, shorter 6-minute-walk distance, greater dyspnea, and worse BODE (body mass index, airway obstruction, dyspnea, and exercise capacity) scores and St. George's Respiratory Questionnaire scores. Differences were greatest in GOLD stages 1 and 2. Race-reversed equations reclassified 774 AA participants (43%) from GOLD stage 0 to preserved ratio impaired spirometry. Conclusions: Race-specific equations underestimated disease severity among AA participants. These effects were particularly evident in early disease and may result in late detection of COPD.

Type 2 Diabetes Modifies the Association of CAD Genomic Risk Variants With Subclinical Atherosclerosis

BACKGROUND

Individuals with type 2 diabetes (T2D) have an increased risk of coronary artery disease (CAD), but questions remain about the underlying pathology. Identifying which CAD loci are modified by T2D in the development of subclinical atherosclerosis (coronary artery calcification [CAC], carotid intima-media thickness, or carotid plaque) may improve our understanding of the mechanisms leading to the increased CAD in T2D.

METHODS

We compared the common and rare variant associations of known CAD loci from the literature on CAC, carotid intima-media thickness, and carotid plaque in up to 29 670 participants, including up to 24 157 normoglycemic controls and 5513 T2D cases leveraging whole-genome sequencing data from the Trans-Omics for Precision Medicine program. We included first-order T2D interaction terms in each model to determine whether CAD loci were modified by T2D. The genetic main and interaction effects were assessed using a joint test to determine whether a CAD variant, or gene-based rare variant set, was associated with the respective subclinical atherosclerosis measures and then further determined whether these loci had a significant interaction test.

RESULTS

Using a Bonferroni-corrected significance threshold of P<1.6×10-4, we identified 3 genes (ATP1B1, ARVCF, and LIPG) associated with CAC and 2 genes (ABCG8 and EIF2B2) associated with carotid intima-media thickness and carotid plaque, respectively, through gene-based rare variant set analysis. Both ATP1B1 and ARVCF also had significantly different associations for CAC in T2D cases versus controls. No significant interaction tests were identified through the candidate single-variant analysis.

CONCLUSIONS

These results highlight T2D as an important modifier of rare variant associations in CAD loci with CAC.

Race-Specific Spirometry Equations Do Not Improve Models of Dyspnea and Quantitative Chest CT Phenotypes

BACKGROUND

Race-specific spirometry reference equations are used globally to interpret lung function for clinical, research, and occupational purposes, but inclusion of race is under scrutiny.

RESEARCH QUESTION

Does including self-identified race in spirometry reference equation formation improve the ability of predicted FEV1 values to explain quantitative chest CT abnormalities, dyspnea, or Global Initiative for Chronic Obstructive Lung Disease (GOLD) classification?

STUDY DESIGN AND METHODS

Using data from healthy adults who have never smoked in both the National Health and Nutrition Survey (2007-2012) and COPDGene study cohorts, race-neutral, race-free, and race-specific prediction equations were generated for FEV1. Using sensitivity/specificity, multivariable logistic regression, and random forest models, these equations were applied in a cross-sectional analysis to populations of individuals who currently smoke and individuals who formerly smoked to determine how they affected GOLD classification and the fit of models predicting quantitative chest CT phenotypes or dyspnea.

RESULTS

Race-specific equations showed no advantage relative to race-neutral or race-free equations in models of quantitative chest CT phenotypes or dyspnea. Race-neutral reference equations reclassified up to 19% of Black participants into more severe GOLD classes, while race-neutral/race-free equations may improve model fit for dyspnea symptoms relative to race-specific equations.

INTERPRETATION

Race-specific equations offered no advantage over race-neutral/race-free equations in three distinct explanatory models of dyspnea and chest CT scan abnormalities. Race-neutral/race-free reference equations may improve pulmonary disease diagnoses and treatment in populations highly vulnerable to lung disease.

Heterogeneity and Progression of Chronic Obstructive Pulmonary Disease: Emphysema-Predominant and Non-Emphysema-Predominant Disease

While variation in emphysema severity between patients with chronic obstructive pulmonary disease (COPD) is well-recognized, clinically applicable definitions of the emphysema-predominant disease (EPD) and non-emphysema-predominant disease (NEPD) subtypes have not been established. To study the clinical relevance of the EPD and NEPD subtypes, we tested the association of these subtypes with prospective decline in forced expiratory volume in 1 second (FEV1) and mortality among 3,427 subjects with Global Initiative for Chronic Obstructive Lung Disease (GOLD) spirometric grade 2-4 COPD at baseline in the Genetic Epidemiology of COPD (COPDGene) Study, an ongoing national multicenter study that started in 2007. NEPD was defined as airflow obstruction with less than 5% computed tomography (CT) quantitative densitometric emphysema at -950 Hounsfield units, and EPD was defined as airflow obstruction with 10% or greater CT emphysema. Mixed-effects models for FEV1 demonstrated larger average annual FEV1 loss in EPD subjects than in NEPD subjects (-10.2 mL/year; P < 0.001), and subtype-specific associations with FEV1 decline were identified. Cox proportional hazards models showed higher risk of mortality among EPD patients versus NEPD patients (hazard ratio = 1.46, 95% confidence interval: 1.34, 1.60; P < 0.001). To determine whether the NEPD/EPD dichotomy is captured by previously described COPDGene subtypes, we used logistic regression and receiver operating characteristic (ROC) curve analysis to predict NEPD/EPD membership using these previous subtype definitions. The analysis generally showed excellent discrimination, with areas under the ROC curve greater than 0.9. The NEPD and EPD COPD subtypes capture important aspects of COPD heterogeneity and are associated with different rates of disease progression and mortality.

Multi-ancestry genome-wide study identifies effector genes and druggable pathways for coronary artery calcification

Coronary artery calcification (CAC), a measure of subclinical atherosclerosis, predicts future symptomatic coronary artery disease (CAD). Identifying genetic risk factors for CAC may point to new therapeutic avenues for prevention. Currently, there are only four known risk loci for CAC identified from genome-wide association studies (GWAS) in the general population. Here we conducted the largest multi-ancestry GWAS meta-analysis of CAC to date, which comprised 26,909 individuals of European ancestry and 8,867 individuals of African ancestry. We identified 11 independent risk loci, of which eight were new for CAC and five had not been reported for CAD. These new CAC loci are related to bone mineralization, phosphate catabolism and hormone metabolic pathways. Several new loci harbor candidate causal genes supported by multiple lines of functional evidence and are regulators of smooth muscle cell-mediated calcification ex vivo and in vitro. Together, these findings help refine the genetic architecture of CAC and extend our understanding of the biological and potential druggable pathways underlying CAC.

Suspected Bronchiectasis and Mortality in Adults With a History of Smoking Who Have Normal and Impaired Lung Function : A Cohort Study

BACKGROUND

Bronchiectasis in adults with chronic obstructive pulmonary disease (COPD) is associated with greater mortality. However, whether suspected bronchiectasis-defined as incidental bronchiectasis on computed tomography (CT) images plus clinical manifestation-is associated with increased mortality in adults with a history of smoking with normal spirometry and preserved ratio impaired spirometry (PRISm) is unknown.

OBJECTIVE

To determine the association between suspected bronchiectasis and mortality in adults with normal spirometry, PRISm, and obstructive spirometry.

DESIGN

Prospective, observational cohort.

SETTING

The COPDGene (Genetic Epidemiology of Chronic Obstructive Pulmonary Disease) study.

PARTICIPANTS

7662 non-Hispanic Black or White adults, aged 45 to 80 years, with 10 or more pack-years of smoking history. Participants who were former and current smokers were stratified into normal spirometry (n = 3277), PRISm (n = 986), and obstructive spirometry (n = 3399).

MEASUREMENTS

Bronchiectasis identified by CT was ascertained using artificial intelligence-based measurements of an airway-to-artery ratio (AAR) greater than 1 (AAR >1), a measure of bronchial dilatation. The primary outcome of "suspected bronchiectasis" was defined as an AAR >1 of greater than 1% plus 2 of the following: cough, phlegm, dyspnea, and history of 2 or more exacerbations.

RESULTS

Among the 7662 participants (mean age, 60 years; 52% women), 1352 (17.6%) had suspected bronchiectasis. During a median follow-up of 11 years, 2095 (27.3%) died. Ten-year mortality risk was higher in participants with suspected bronchiectasis, compared with those without suspected bronchiectasis (normal spirometry: difference in mortality probability [Pr], 0.15 [95% CI, 0.09 to 0.21]; PRISm: Pr, 0.07 [CI, -0.003 to 0.15]; obstructive spirometry: Pr, 0.06 [CI, 0.03 to 0.09]). When only CT was used to identify bronchiectasis, the differences were attenuated in the normal spirometry (Pr, 0.04 [CI, -0.001 to 0.08]).

LIMITATIONS

Only 2 racial groups were studied. Only 1 measurement was used to define bronchiectasis on CT. Symptoms of suspected bronchiectasis were nonspecific.

CONCLUSION

Suspected bronchiectasis was associated with a heightened risk for mortality in adults with normal and obstructive spirometry.

PRIMARY FUNDING SOURCE

National Heart, Lung, and Blood Institute.

Genome-wide association meta-analysis identifies 17 loci associated with nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is common and partially heritable and has no effective treatments. We carried out a genome-wide association study (GWAS) meta-analysis of imaging (n = 66,814) and diagnostic code (3,584 cases versus 621,081 controls) measured NAFLD across diverse ancestries. We identified NAFLD-associated variants at torsin family 1 member B (TOR1B), fat mass and obesity associated (FTO), cordon-bleu WH2 repeat protein like 1 (COBLL1)/growth factor receptor-bound protein 14 (GRB14), insulin receptor (INSR), sterol regulatory element-binding transcription factor 1 (SREBF1) and patatin-like phospholipase domain-containing protein 2 (PNPLA2), as well as validated NAFLD-associated variants at patatin-like phospholipase domain-containing protein 3 (PNPLA3), transmembrane 6 superfamily 2 (TM6SF2), apolipoprotein E (APOE), glucokinase regulator (GCKR), tribbles homolog 1 (TRIB1), glycerol-3-phosphate acyltransferase (GPAM), mitochondrial amidoxime-reducing component 1 (MARC1), microsomal triglyceride transfer protein large subunit (MTTP), alcohol dehydrogenase 1B (ADH1B), transmembrane channel like 4 (TMC4)/membrane-bound O-acyltransferase domain containing 7 (MBOAT7) and receptor-type tyrosine-protein phosphatase δ (PTPRD). Implicated genes highlight mitochondrial, cholesterol and de novo lipogenesis as causally contributing to NAFLD predisposition. Phenome-wide association study (PheWAS) analyses suggest at least seven subtypes of NAFLD. Individuals in the top 10% and 1% of genetic risk have a 2.5-fold to 6-fold increased risk of NAFLD, cirrhosis and hepatocellular carcinoma. These genetic variants identify subtypes of NAFLD, improve estimates of disease risk and can guide the development of targeted therapeutics.

Use of the Spirometric "Fixed-Ratio" Underdiagnoses COPD in African-Americans in a Longitudinal Cohort Study

BACKGROUND

COPD diagnosis is tightly linked to the fixed-ratio spirometry criteria of FEV1/FVC < 0.7. African-Americans are less often diagnosed with COPD.

OBJECTIVE

Compare COPD diagnosis by fixed-ratio with findings and outcomes by race.

DESIGN

Genetic Epidemiology of COPD (COPDGene) (2007-present), cross-sectional comparing non-Hispanic white (NHW) and African-American (AA) participants for COPD diagnosis, manifestations, and outcomes.

SETTING

Multicenter, longitudinal US cohort study.

PARTICIPANTS

Current or former smokers with ≥ 10-pack-year smoking history enrolled at 21 clinical centers including over-sampling of participants with known COPD and AA. Exclusions were pre-existing non-COPD lung disease, except for a history of asthma.

MEASUREMENTS

Subject diagnosis by conventional criteria. Mortality, imaging, respiratory symptoms, function, and socioeconomic characteristics, including area deprivation index (ADI). Matched analysis (age, sex, and smoking status) of AA vs. NHW within participants without diagnosed COPD (GOLD 0; FEV1 ≥ 80% predicted and FEV1/FVC ≥ 0.7).

RESULTS

Using the fixed ratio, 70% of AA (n = 3366) were classified as non-COPD, versus 49% of NHW (n = 6766). AA smokers were younger (55 vs. 62 years), more often current smoking (80% vs. 39%), with fewer pack-years but similar 12-year mortality. Density distribution plots for FEV1 and FVC raw spirometry values showed disproportionate reductions in FVC relative to FEV1 in AA that systematically led to higher ratios. The matched analysis demonstrated GOLD 0 AA had greater symptoms, worse DLCO, spirometry, BODE scores (1.03 vs 0.54, p < 0.0001), and greater deprivation than NHW.

LIMITATIONS

Lack of an alternative diagnostic metric for comparison.

CONCLUSIONS

The fixed-ratio spirometric criteria for COPD underdiagnosed potential COPD in AA participants when compared to broader diagnostic criteria. Disproportionate reductions in FVC relative to FEV1 leading to higher FEV1/FVC were identified in these participants and associated with deprivation. Broader diagnostic criteria for COPD are needed to identify the disease across all populations.

Longitudinal Assessment of Multimorbidity Medication Patterns among Smokers in the COPDGene Cohort

Background and objectives: Chronic obstructive pulmonary disease (COPD) is usually comorbid with other chronic diseases. We aimed to assess the multimorbidity medication patterns and explore if the patterns are similar for phase 1 (P1) and 5-year follow-up phase 2 (P2) in the COPDGene cohort. Materials and Methods: A total of 5564 out of 10,198 smokers from the COPDGene cohort who completed 2 visits, P1 and P2 visits, with complete medication use history were included in the study. We conducted latent class analysis (LCA) among the 27 categories of chronic disease medications, excluding COPD treatments and cancer medications at P1 and P2 separately. The best number of LCA classes was determined through both statistical fit and interpretation of the patterns. Results: We found four classes of medication patterns at both phases. LCA showed that both phases shared similar characteristics in their medication patterns: LC0: low medication; LC1: hypertension (HTN) or cardiovascular disease (CVD)+high cholesterol (Hychol) medication predominant; LC2: HTN/CVD+type 2 diabetes (T2D) +Hychol medication predominant; LC3: Hychol medication predominant. Conclusions: We found similar multimorbidity medication patterns among smokers at P1 and P2 in the COPDGene cohort, which provides an understanding of how multimorbidity medication clustered and how different chronic diseases combine in smokers.

Artificial Intelligence-based CT Assessment of Bronchiectasis: The COPDGene Study

Background CT is the standard method used to assess bronchiectasis. A higher airway-to-artery diameter ratio (AAR) is typically used to identify enlarged bronchi and bronchiectasis; however, current imaging methods are limited in assessing the extent of this metric in CT scans. Purpose To determine the extent of AARs using an artificial intelligence-based chest CT and assess the association of AARs with exacerbations over time. Materials and Methods In a secondary analysis of ever-smokers from the prospective, observational, multicenter COPDGene study, AARs were quantified using an artificial intelligence tool. The percentage of airways with AAR greater than 1 (a measure of airway dilatation) in each participant on chest CT scans was determined. Pulmonary exacerbations were prospectively determined through biannual follow-up (from July 2009 to September 2021). Multivariable zero-inflated regression models were used to assess the association between the percentage of airways with AAR greater than 1 and the total number of pulmonary exacerbations over follow-up. Covariates included demographics, lung function, and conventional CT parameters. Results Among 4192 participants (median age, 59 years; IQR, 52-67 years; 1878 men [45%]), 1834 had chronic obstructive pulmonary disease (COPD). During a 10-year follow-up and in adjusted models, the percentage of airways with AARs greater than 1 (quartile 4 vs 1) was associated with a higher total number of exacerbations (risk ratio [RR], 1.08; 95% CI: 1.02, 1.15; P = .01). In participants meeting clinical and imaging criteria of bronchiectasis (ie, clinical manifestations with ≥3% of AARs >1) versus those who did not, the RR was 1.37 (95% CI: 1.31, 1.43; P < .001). Among participants with COPD, the corresponding RRs were 1.10 (95% CI: 1.02, 1.18; P = .02) and 1.32 (95% CI: 1.26, 1.39; P < .001), respectively. Conclusion In ever-smokers with chronic obstructive pulmonary disease, artificial intelligence-based CT measures of bronchiectasis were associated with more exacerbations over time. Clinical trial registration no. NCT00608764 © RSNA, 2022 Supplemental material is available for this article. See also the editorial by Schiebler and Seo in this issue.

Prevalence of abnormal spirometry in individuals with a smoking history and no known obstructive lung disease

INTRODUCTION

Recent evidence suggests a high prevalence of undiagnosed chronic obstructive pulmonary disease (COPD). These individuals are at risk of exacerbations and delayed treatment. We analyzed an at-risk population for the prevalence of abnormal spirometry to provide clarity into who should undergo early spirometry.

METHODS

We analyzed data from the COPDGene study. Participants with ≥10 pack-years of smoking were included. Individuals with self-reported or physician-diagnosed COPD, asthma, chronic bronchitis, emphysema and/or were on inhalers were excluded. Parsimonious multivariable logistic regression models identified factors associated with abnormal spirometry, defined as either airflow obstruction (AFO) or preserved ratio impaired spirometry. Variables were selected for the final model using a stepwise backward variable elimination process which minimized Akaike information criterion (AIC). Similarly, during the 5-year follow-up period, we assessed factors associated with incident diagnosis of COPD.

RESULTS

Of 5055 individuals, 1064 (21%) had undiagnosed AFO. Age, pack-years, current smoking and a history of acute bronchitis were associated with AFO while body mass index, female sex, and Black race were inversely associated. Among 2800 participants with 5-year follow-up, 532 (19%) had an incident diagnosis of COPD. Associated risk factors included mMRC ≥2, chronic productive cough, respiratory exacerbations during the follow-up period, and abnormal spirometry. Age was inversely associated.

CONCLUSIONS

The prevalence of undiagnosed COPD is high in at-risk populations. We found multiple factors associated with undiagnosed COPD and incident diagnosis of COPD at follow up. These results can be used to identify those at risk for undiagnosed COPD to facilitate earlier diagnosis and treatment.

Multi-ancestry transcriptome-wide association analyses yield insights into tobacco use biology and drug repurposing

Most transcriptome-wide association studies (TWASs) so far focus on European ancestry and lack diversity. To overcome this limitation, we aggregated genome-wide association study (GWAS) summary statistics, whole-genome sequences and expression quantitative trait locus (eQTL) data from diverse ancestries. We developed a new approach, TESLA (multi-ancestry integrative study using an optimal linear combination of association statistics), to integrate an eQTL dataset with a multi-ancestry GWAS. By exploiting shared phenotypic effects between ancestries and accommodating potential effect heterogeneities, TESLA improves power over other TWAS methods. When applied to tobacco use phenotypes, TESLA identified 273 new genes, up to 55% more compared with alternative TWAS methods. These hits and subsequent fine mapping using TESLA point to target genes with biological relevance. In silico drug-repurposing analyses highlight several drugs with known efficacy, including dextromethorphan and galantamine, and new drugs such as muscle relaxants that may be repurposed for treating nicotine addiction.

Genetic diversity fuels gene discovery for tobacco and alcohol use

Tobacco and alcohol use are heritable behaviours associated with 15% and 5.3% of worldwide deaths, respectively, due largely to broad increased risk for disease and injury1-4. These substances are used across the globe, yet genome-wide association studies have focused largely on individuals of European ancestries5. Here we leveraged global genetic diversity across 3.4 million individuals from four major clines of global ancestry (approximately 21% non-European) to power the discovery and fine-mapping of genomic loci associated with tobacco and alcohol use, to inform function of these loci via ancestry-aware transcriptome-wide association studies, and to evaluate the genetic architecture and predictive power of polygenic risk within and across populations. We found that increases in sample size and genetic diversity improved locus identification and fine-mapping resolution, and that a large majority of the 3,823 associated variants (from 2,143 loci) showed consistent effect sizes across ancestry dimensions. However, polygenic risk scores developed in one ancestry performed poorly in others, highlighting the continued need to increase sample sizes of diverse ancestries to realize any potential benefit of polygenic prediction.

Rare genetic variants explain missing heritability in smoking

Common genetic variants explain less variation in complex phenotypes than inferred from family-based studies, and there is a debate on the source of this 'missing heritability'. We investigated the contribution of rare genetic variants to tobacco use with whole-genome sequences from up to 26,257 unrelated individuals of European ancestries and 11,743 individuals of African ancestries. Across four smoking traits, single-nucleotide-polymorphism-based heritability ([Formula: see text]) was estimated from 0.13 to 0.28 (s.e., 0.10-0.13) in European ancestries, with 35-74% of it attributable to rare variants with minor allele frequencies between 0.01% and 1%. These heritability estimates are 1.5-4 times higher than past estimates based on common variants alone and accounted for 60% to 100% of our pedigree-based estimates of narrow-sense heritability ([Formula: see text], 0.18-0.34). In the African ancestry samples, [Formula: see text] was estimated from 0.03 to 0.33 (s.e., 0.09-0.14) across the four smoking traits. These results suggest that rare variants are important contributors to the heritability of smoking.

Relationship Between a Vitamin D Genetic Risk Score and Autoantibodies Among First-Degree Relatives of Probands With Rheumatoid Arthritis and Systemic Lupus Erythematosus

Objective

Higher 25-hydroxyvitamin D (25(OH)D) levels have been associated with reduced risk for autoimmune diseases and are influenced by vitamin D metabolism genes. We estimated genetically-determined vitamin D levels by calculating a genetic risk score (GRS) and investigated whether the vitamin D GRS was associated with the presence of autoantibodies related to rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) in those at increased risk for developing RA and SLE, respectively.

Methods

In this cross-sectional study, we selected autoantibody positive (aAb+) and autoantibody negative (aAb-) individuals from the Studies of the Etiologies of Rheumatoid Arthritis (SERA), a cohort study of first-degree relatives (FDRs) of individuals with RA (189 RA aAb+, 181 RA aAb-), and the Lupus Family Registry and Repository (LFRR), a cohort study of FDRs of individuals with SLE (157 SLE aAb+, 185 SLE aAb-). Five SNPs known to be associated with serum 25(OH)D levels were analyzed individually as well as in a GRS: rs4588 (GC), rs12785878 (NADSYN1), rs10741657 (CYP2R1), rs6538691 (AMDHD1), and rs8018720 (SEC23A).

Results

Both cohorts had similar demographic characteristics, with significantly older and a higher proportion of males in the aAb+ FDRs. The vitamin D GRS was inversely associated with RA aAb+ (OR = 0.85, 95% CI = 0.74-0.99), suggesting a possible protective factor for RA aAb positivity in FDRs of RA probands. The vitamin D GRS was not associated with SLE aAb+ in the LFRR (OR = 1.09, 95% CI = 0.94-1.27). The SEC23A SNP was associated with RA aAb+ in SERA (OR = 0.65, 95% CI = 0.43-0.99); this SNP was not associated with SLE aAb+ in LFRR (OR = 1.41, 95% CI = 0.90 - 2.19).

Conclusion

Genes associated with vitamin D levels may play a protective role in the development of RA aAbs in FDRs of RA probands, perhaps through affecting lifelong vitamin D status. The GRS and the SEC23A SNP may be of interest for future investigation in pre-clinical RA. In contrast, these results do not support a similar association in SLE FDRs, suggesting other mechanisms involved in the relationship between vitamin D and SLE aAbs not assessed in this study.

Pre-Clinical Autoimmunity in Lupus Relatives: Self-Reported Questionnaires and Immune Dysregulation Distinguish Relatives Who Develop Incomplete or Classified Lupus From Clinically Unaffected Relatives and Unaffected, Unrelated Individuals

Systemic lupus erythematosus (SLE) is propelled by pathogenic autoantibody (AutoAb) and immune pathway dysregulation. Identifying populations at risk of reaching classified SLE is essential to curtail inflammatory damage. Lupus blood relatives (Rel) have an increased risk of developing SLE. We tested factors to identify Rel at risk of developing incomplete lupus (ILE) or classified SLE vs. clinically unaffected Rel and healthy controls (HC), drawing from two unique, well characterized lupus cohorts, the lupus autoimmunity in relatives (LAUREL) follow-up cohort, consisting of Rel meeting &lt;4 ACR criteria at baseline, and the Lupus Family Registry and Repository (LFRR), made up of SLE patients, lupus Rel, and HC. Medical record review determined ACR SLE classification criteria; study participants completed the SLE portion of the connective tissue disease questionnaire (SLE-CSQ), type 2 symptom questions, and provided samples for assessment of serum SLE-associated AutoAb specificities and 52 plasma immune mediators. Elevated SLE-CSQ scores were associated with type 2 symptoms, ACR scores, and serology in both cohorts. Fatigue at BL was associated with transition to classified SLE in the LAUREL cohort (p≤0.01). Increased levels of BLyS and decreased levels of IL-10 were associated with type 2 symptoms (p&lt;0.05). SLE-CSQ scores, ACR scores, and accumulated AutoAb specificities correlated with levels of multiple inflammatory immune mediators (p&lt;0.05), including BLyS, IL-2Rα, stem cell factor (SCF), soluble TNF receptors, and Th-1 type mediators and chemokines. Transition to SLE was associated with increased levels of SCF (p&lt;0.05). ILE Rel also had increased levels of TNF-α and IFN-γ, offset by increased levels of regulatory IL-10 and TGF-β (p&lt;0.05). Clinically unaffected Rel (vs. HC) had higher SLE-CSQ scores (p&lt;0.001), increased serology (p&lt;0.05), and increased inflammatory mediator levels, offset by increased IL-10 and TGF-β (p&lt;0.01). These findings suggest that Rel at highest risk of transitioning to classified SLE have increased inflammation coupled with decreased regulatory mediators. In contrast, clinically unaffected Rel and Rel with ILE demonstrate increased inflammation offset with increased immune regulation, intimating a window of opportunity for early intervention and enrollment in prevention trials.

Significant Spirometric Transitions and Preserved Ratio Impaired Spirometry Among Ever Smokers

BACKGROUND

Emerging data from longitudinal studies suggest that preserved ratio impaired spirometry (PRISm), defined by proportionate reductions in FEV₁ and FVC, is a heterogeneous population with frequent transitions to other lung function categories relative to individuals with normal and obstructive spirometry. Controversy regarding the clinical significance of these transitions exists (eg, whether transitions merely reflect measurement variability or noise).

RESEARCH QUESTION

Are individuals with PRISm enriched for transitions associated with substantial changes in lung function?

STUDY DESIGN AND METHODS

Current and former smokers enrolled in the Genetic Epidemiology of COPD (COPDGene) study with spirometry available in phases 1 through 3 (enrollment, 5-year follow-up, and 10-year follow-up) were analyzed. Postbronchodilator lung function categories were as follows: PRISm (FEV₁ < 80% predicted with FEV₁/FVC ratio ≥ 0.7), Global Initiative for Chronic Obstructive Lung Disease grade 0 (FEV₁ ≥ 80% predicted and FEV₁/FVC ≥ 0.7), and obstruction (FEV₁/FVC < 0.7). Significant transition status was affirmative if a subject belonged to two or more spirometric categories and had > 10% change in FEV₁ % predicted and/or FVC % predicted between consecutive visits. Ever-PRISm was present if a subject had PRISm at any visit. Logistic regression examined the association between significant transitions and ever-PRISm status, adjusted for age, sex, race, FEV₁ % predicted, current smoking, pack-years, BMI, and ever-positive bronchodilator response.

RESULTS

Among subjects with complete data (N = 1,775) over 10.1 ± 0.4 years of follow-up, the prevalence of PRISm remained consistent (10.4%-11.3%) between phases 1 through 3, but nearly one-half of subjects with PRISm transitioned into or out of PRISm at each visit. Among all subjects, 19.7% had a significant transition; ever-PRISm was a significant predictor of significant transitions (unadjusted OR, 10.3; 95% CI, 7.9-13.5; adjusted OR, 14.9; 95% CI, 10.9-20.7). Results were similar with additional adjustment for radiographic emphysema and gas trapping, when lower limit of normal criteria were used to define lung function categories, and when FEV₁ alone (regardless of change in FVC % predicted) was used to define significant transitions.

INTERPRETATION

PRISm is an unstable group, with frequent significant transitions to both obstruction and normal spirometry over time.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov; No.: NCT000608764; URL: www.

CLINICALTRIALS

gov.

Pulmonary Arterial Pruning and Longitudinal Change in Percent Emphysema and Lung Function: The Genetic Epidemiology of COPD Study

BACKGROUND

Pulmonary endothelial damage has been shown to precede the development of emphysema in animals, and vascular changes in humans have been observed in COPD and emphysema.

RESEARCH QUESTION

Is intraparenchymal vascular pruning associated with longitudinal progression of emphysema on CT imaging or decline in lung function over 5 years?

STUDY DESIGN AND METHODS

The Genetic Epidemiology of COPD Study enrolled ever smokers with and without COPD from 2008 through 2011. The percentage of emphysema-like lung, or "percent emphysema," was assessed at baseline and after 5 years on noncontrast CT imaging as the percentage of lung voxels < -950 Hounsfield units. An automated CT imaging-based tool assessed and classified intrapulmonary arteries and veins. Spirometry measures are postbronchodilator. Pulmonary arterial pruning was defined as a lower ratio of small artery volume (< 5 mm2 cross-sectional area) to total lung artery volume. Mixed linear models included demographics, anthropomorphics, smoking, and COPD, with emphysema models also adjusting for CT imaging scanner and lung function models adjusting for clinical center and baseline percent emphysema.

RESULTS

At baseline, the 4,227 participants were 60 ± 9 years of age, 50% were women, 28% were Black, 47% were current smokers, and 41% had COPD. Median percent emphysema was 2.1 (interquartile range, 0.6-6.3) and progressed 0.24 percentage points/y (95% CI, 0.22-0.26 percentage points/y) over 5.6 years. Mean FEV1 to FVC ratio was 68.5 ± 14.2% and declined 0.26%/y (95% CI, -0.30 to -0.23%/y). Greater pulmonary arterial pruning was associated with more rapid progression of percent emphysema (0.11 percentage points/y per 1-SD increase in arterial pruning; 95% CI, 0.09-0.16 percentage points/y), including after adjusting for baseline percent emphysema and FEV1. Arterial pruning also was associated with a faster decline in FEV1 to FVC ratio (-0.04%/y per 1-SD increase in arterial pruning; 95% CI, -0.008 to -0.001%/y).

INTERPRETATION

Pulmonary arterial pruning was associated with faster progression of percent emphysema and more rapid decline in FEV1 to FVC ratio over 5 years in ever smokers, suggesting that pulmonary vascular differences may be relevant in disease progression.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT00608764; URL: www.clinicaltrials.gov.

Small Airway Disease and Emphysema Are Associated with Future Exacerbations in Smokers with CT-derived Bronchiectasis and COPD: Results from the COPDGene Cohort

Background Chronic obstructive pulmonary disease (COPD) and bronchiectasis can overlap and share pathologic features, such as small airway disease (SAD). Whether the presence of SAD and emphysema in smokers with CT-derived bronchiectasis is associated with exacerbations is unknown. Purpose To assess whether SAD and emphysema in smokers with CT-derived bronchiectasis are associated with future exacerbations. Materials and Methods SAD and emphysema were quantified using the parametric response map method in former and current heavy smokers with and without bronchiectasis at CT from the COPDGene Study (from July 2009 to July 2018). Exacerbations were prospectively assessed through biannual follow-up. An exacerbation was defined as an increase in or new onset of respiratory symptoms treated with antibiotics and/or corticosteroids. Severe exacerbations were defined as those that required hospitalization. The association of a high burden of SAD (≥15.6%) and high burden of emphysema (≥5%) at CT with exacerbations was assessed with generalized linear mixed models. Results Of 737 participants, 387 (median age, 64 years [interquartile range, 58-71 years]; 223 women) had CT-derived bronchiectasis. During a 9-year follow-up, after adjustment for age, sex, race, body mass index, current smoking status, pack-years, exacerbations before study entry, forced expiratory volume in 1 second, or FEV₁, and bronchiectasis severity CT score, high burden of SAD and high burden of emphysema were associated with a higher number of exacerbations per year (relative risk [RR], 1.89 [95% CI: 1.54, 2.33] and 1.37 [95% CI: 1.13, 1.66], respectively; P ≤ .001 for both). Results were comparable among participants with bronchiectasis meeting criteria for COPD (n = 197) (RR, 1.67 [95% CI: 1.23, 2.27] for high burden of SAD and 1.51 [95% CI: 1.20, 1.91] for high burden of emphysema; P ≤ .001 for both). Conclusion In smokers with CT-derived bronchiectasis and chronic obstructive pulmonary disease, structural damage to lung parenchyma and small airways was associated with a higher number of exacerbations per year. Clinical trial registration no. NCT00608764 © RSNA, 2021.

Respiratory exacerbations are associated with muscle loss in current and former smokers

OBJECTIVES

Muscle wasting is a recognised extra-pulmonary complication in chronic obstructive pulmonary disease and has been associated with increased risk of death. Acute respiratory exacerbations are associated with reduction of muscle function, but there is a paucity of data on their long-term effect. This study explores the relationship between acute respiratory exacerbations and long-term muscle loss using serial measurements of CT derived pectoralis muscle area (PMA).

DESIGN AND SETTING

Participants were included from two prospective, longitudinal, observational, multicentre cohorts of ever-smokers with at least 10 pack-year history.

PARTICIPANTS

The primary analysis included 1332 (of 2501) participants from Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints (ECLIPSE) and 4384 (of 10 198) participants from Genetic Epidemiology of COPD (COPDGene) who had complete data from their baseline and follow-up visits.

INTERVENTIONS

PMA was measured on chest CT scans at two timepoints. Self-reported exacerbation data were collected from participants in both studies through the use of periodic longitudinal surveys.

MAIN OUTCOME MEASURES

Age-related and excess muscle loss over time.

RESULTS

Age, sex, race and body mass index were associated with baseline PMA. Participants experienced age-related decline at the upper end of reported normal ranges. In ECLIPSE, the exacerbation rate over time was associated with an excess muscle area loss of 1.3% (95% CI 0.6 to 1.9, p<0.001) over 3 years and in COPDGene with an excess muscle area loss of 2.1% (95% CI 1.2 to 2.8, p<0.001) over 5 years. Excess muscle area decline was absent in 273 individuals who participated in pulmonary rehabilitation.

CONCLUSIONS

Exacerbations are associated with accelerated skeletal muscle loss. Each annual exacerbation was associated with the equivalent of 6 months of age-expected decline in muscle mass. Ameliorating exacerbation-associated muscle loss represents an important therapeutic target.

rs641738C>T near MBOAT7 is associated with liver fat, ALT and fibrosis in NAFLD: A meta-analysis

BACKGROUND & AIMS

A common genetic variant near MBOAT7 (rs641738C>T) has been previously associated with hepatic fat and advanced histology in NAFLD; however, these findings have not been consistently replicated in the literature. We aimed to establish whether rs641738C>T is a risk factor across the spectrum of NAFLD and to characterise its role in the regulation of related metabolic phenotypes through a meta-analysis.

METHODS

We performed a meta-analysis of studies with data on the association between rs641738C>T genotype and liver fat, NAFLD histology, and serum alanine aminotransferase (ALT), lipids or insulin. These included directly genotyped studies and population-level data from genome-wide association studies (GWAS). We performed a random effects meta-analysis using recessive, additive and dominant genetic models.

RESULTS

Data from 1,066,175 participants (9,688 with liver biopsies) across 42 studies were included in the meta-analysis. rs641738C>T was associated with higher liver fat on CT/MRI (+0.03 standard deviations [95% CI 0.02-0.05], p_z = 4.8×10^-5) and diagnosis of NAFLD (odds ratio [OR] 1.17 [95% CI 1.05-1.3], p_z = 0.003) in Caucasian adults. The variant was also positively associated with presence of advanced fibrosis (OR 1.22 [95% CI 1.03-1.45], p_z = 0.021) in Caucasian adults using a recessive model of inheritance (CC + CT vs. TT). Meta-analysis of data from previous GWAS found the variant to be associated with higher ALT (p_z = 0.002) and lower serum triglycerides (p_z = 1.5×10^-4). rs641738C>T was not associated with fasting insulin and no effect was observed in children with NAFLD.

CONCLUSIONS

Our study validates rs641738C>T near MBOAT7 as a risk factor for the presence and severity of NAFLD in individuals of European descent.

LAY SUMMARY

Fatty liver disease is a common condition where fat builds up in the liver, which can cause liver inflammation and scarring (including 'cirrhosis'). It is closely linked to obesity and diabetes, but some genes are also thought to be important. We did this study to see whether one specific change ('variant') in one gene ('MBOAT7') was linked to fatty liver disease. We took data from over 40 published studies and found that this variant near MBOAT7 is linked to more severe fatty liver disease. This means that drugs designed to work on MBOAT7 could be useful for treating fatty liver disease.

Expanding the genetic architecture of nicotine dependence and its shared genetics with multiple traits

Cigarette smoking is the leading cause of preventable morbidity and mortality. Genetic variation contributes to initiation, regular smoking, nicotine dependence, and cessation. We present a Fagerström Test for Nicotine Dependence (FTND)-based genome-wide association study in 58,000 European or African ancestry smokers. We observe five genome-wide significant loci, including previously unreported loci MAGI2/GNAI1 (rs2714700) and TENM2 (rs1862416), and extend loci reported for other smoking traits to nicotine dependence. Using the heaviness of smoking index from UK Biobank (N = 33,791), rs2714700 is consistently associated; rs1862416 is not associated, likely reflecting nicotine dependence features not captured by the heaviness of smoking index. Both variants influence nearby gene expression (rs2714700/MAGI2-AS3 in hippocampus; rs1862416/TENM2 in lung), and expression of genes spanning nicotine dependence-associated variants is enriched in cerebellum. Nicotine dependence (SNP-based heritability = 8.6%) is genetically correlated with 18 other smoking traits (rg = 0.40-1.09) and co-morbidities. Our results highlight nicotine dependence-specific loci, emphasizing the FTND as a composite phenotype that expands genetic knowledge of smoking.

A Risk Prediction Model for Mortality Among Smokers in the COPDGene® Study

BACKGROUND

Risk factor identification is a proven strategy in advancing treatments and preventive therapy for many chronic conditions. Quantifying the impact of those risk factors on health outcomes can consolidate and focus efforts on individuals with specific high-risk profiles. Using multiple risk factors and longitudinal outcomes in 2 independent cohorts, we developed and validated a risk score model to predict mortality in current and former cigarette smokers.

METHODS

We obtained extensive data on current and former smokers from the COPD Genetic Epidemiology (COPDGene®) study at enrollment. Based on physician input and model goodness-of-fit measures, a subset of variables was selected to fit final Weibull survival models separately for men and women. Coefficients and predictors were translated into a point system, allowing for easy computation of mortality risk scores and probabilities. We then used the SubPopulations and InteRmediate Outcome Measures In COPD Study (SPIROMICS) cohort for external validation of our model.

RESULTS

Of 9867 COPDGene participants with standard baseline data, 17.6% died over 10 years of follow-up, and 9074 of these participants had the full set of baseline predictors (standard plus 6-minute walk distance and computed tomography variables) available for full model fits. The average age of participants in the cohort was 60 for both men and women, and the average predicted 10-year mortality risk was 18% for women and 25% for men. Model time-integrated area under the receiver operating characteristic curve statistics demonstrated good predictive model accuracy (0.797 average), validated in the external cohort (0.756 average). Risk of mortality was impacted most by 6-minute walk distance, forced expiratory volume in 1 second and age, for both men and women.

CONCLUSIONS

Current and former smokers exhibited a wide range of mortality risk over a 10- year period. Our models can identify higher risk individuals who can be targeted for interventions to reduce risk of mortality, for participants with or without chronic obstructive pulmonary disease (COPD) using current Global initiative for obstructive Lung Disease (GOLD) criteria.

Machine Learning Characterization of COPD Subtypes: Insights From the COPDGene Study

COPD is a heterogeneous syndrome. Many COPD subtypes have been proposed, but there is not yet consensus on how many COPD subtypes there are and how they should be defined. The COPD Genetic Epidemiology Study (COPDGene), which has generated 10-year longitudinal chest imaging, spirometry, and molecular data, is a rich resource for relating COPD phenotypes to underlying genetic and molecular mechanisms. In this article, we place COPDGene clustering studies in context with other highly cited COPD clustering studies, and summarize the main COPD subtype findings from COPDGene. First, most manifestations of COPD occur along a continuum, which explains why continuous aspects of COPD or disease axes may be more accurate and reproducible than subtypes identified through clustering methods. Second, continuous COPD-related measures can be used to create subgroups through the use of predictive models to define cut-points, and we review COPDGene research on blood eosinophil count thresholds as a specific example. Third, COPD phenotypes identified or prioritized through machine learning methods have led to novel biological discoveries, including novel emphysema genetic risk variants and systemic inflammatory subtypes of COPD. Fourth, trajectory-based COPD subtyping captures differences in the longitudinal evolution of COPD, addressing a major limitation of clustering analyses that are confounded by disease severity. Ongoing longitudinal characterization of subjects in COPDGene will provide useful insights about the relationship between lung imaging parameters, molecular markers, and COPD progression that will enable the identification of subtypes based on underlying disease processes and distinct patterns of disease progression, with the potential to improve the clinical relevance and reproducibility of COPD subtypes.

Genome-Wide Association Study Identifies Loci for Liver Enzyme Concentrations in Mexican Americans: The GUARDIAN Consortium

OBJECTIVE

Populations of Mexican American ancestry are at an increased risk for nonalcoholic fatty liver disease. The objective of this study was to determine whether loci in known and novel genes were associated with variation in aspartate aminotransferase (AST) (n = 3,644), alanine aminotransferase (ALT) (n = 3,595), and gamma-glutamyl transferase (GGT) (n = 1,577) levels by conducting the first genome-wide association study (GWAS) of liver enzymes, which commonly measure liver function, in individuals of Mexican American ancestry.

METHODS

Levels of AST, ALT, and GGT were determined by enzymatic colorimetric assays. A multi-cohort GWAS of individuals of Mexican American ancestry was performed. Single-nucleotide polymorphisms (SNP) were tested for association with liver outcomes by multivariable linear regression using an additive genetic model. Association analyses were conducted separately in each cohort, followed by a nonparametric meta-analysis.

RESULTS

In the PNPLA3 gene, rs4823173 (P = 3.44 × 10^-10 ), rs2896019 (P = 7.29 × 10^-9 ), and rs2281135 (P = 8.73 × 10^-9 ) were significantly associated with AST levels. Although not genome-wide significant, these same SNPs were the top hits for ALT (P = 7.12 × 10^-8 , P = 1.98 × 10^-7 , and P = 1.81 × 10^-7 , respectively). The strong correlation (r²  = 1.0) for these SNPs indicated a single hit in the PNPLA3 gene. No genome-wide significant associations were found for GGT.

CONCLUSIONS

PNPLA3, a locus previously identified with ALT, AST, and nonalcoholic fatty liver disease in European and Japanese GWAS, is also associated with liver enzymes in populations of Mexican American ancestry.

Clinical Epidemiology of COPD: Insights From 10 Years of the COPDGene Study

The Genetic Epidemiology of COPD (COPDGene) study is a noninterventional, multicenter, longitudinal analysis of > 10,000 subjects, including smokers with a ≥ 10 pack-year history with and without COPD and healthy never smokers. The goal was to characterize disease-related phenotypes and explore associations with susceptibility genes. The subjects were extensively phenotyped with the use of comprehensive symptom and comorbidity questionnaires, spirometry, CT scans of the chest, and genetic and biomarker profiling. The objective of this review was to summarize the major advances in the clinical epidemiology of COPD from the first 10 years of the COPDGene study. We highlight the influence of age, sex, and race on the natural history of COPD, and the impact of comorbid conditions, chronic bronchitis, exacerbations, and asthma/COPD overlap.

Association of Epstein-Barr virus serological reactivation with transitioning to systemic lupus erythematosus in at-risk individuals

Objective.

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease with unknown etiology. Epstein-Barr virus (EBV) is an environmental factor associated with SLE. EBV maintains latency in B cells with frequent reactivation measured by antibodies against viral capsid antigen (VCA) and early antigen (EA). In this study, we determined whether EBV reactivation and single nucleotide polymorphisms (SNPs) in EBV-associated host genes are associated with SLE transition.

Methods.

SLE patient relatives (n=436) who did not have SLE at baseline were re-contacted after 6.3 (±3.9) years and evaluated for interim transitioning to SLE (≥4 cumulative ACR criteria); 56 (13%) transitioned to SLE prior to the follow-up visit. At both visits, detailed demographic, environmental, clinical information, and blood samples were obtained. Antibodies against viral antigens were measured by ELISA. SNPs in IL10, CR2, TNFAIP3, and CD40 genes were typed by ImmunoChip™. Generalized estimating equations were used to test associations between viral antibody levels and transitioning to SLE.

Results.

Mean baseline VCA IgG (4.879±1.797 vs 3.866±1.795, p=0.0003) and EA IgG (1.192±1.113 vs 0.7774±0.8484, p=0.0236) levels were higher in transitioned compared to autoantibody negative non-transition relatives. Increased VCA IgG and EA IgG were associated with transitioning to SLE (OR 1.28 95%CI 1.07–1.53 p=0.007, OR 1.43 95%CI 1.06–1.93 p=0.02, respectively). Significant interactions were observed between CD40 variant rs48100485 and VCA IgG levels, and IL10 variant rs3024493 and VCA IgA levels in transitioning to SLE.

Conclusion.

Heightened serologic reactivation of EBV increases the probability of transitioning to SLE in unaffected SLE relatives.

Latent autoimmunity across disease-specific boundaries in at-risk first-degree relatives of SLE and RA patients

BACKGROUND

Autoimmune disease prevention requires tools to assess an individual's risk of developing a specific disease. One tool is disease-associated autoantibodies, which accumulate in an asymptomatic preclinical period. However, patients sometimes exhibit autoantibodies associated with a different disease classification. When and how these alternative autoantibodies first appear remain unknown. This cross-sectional study characterizes alternative autoimmunity, and associated genetic and environmental factors, in unaffected first-degree relatives (FDRs) of patients, who exhibit increased future risk for the same disease.

METHODS

Samples (n = 1321) from disease-specific autoantibody-positive (aAb+) systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and type 1 diabetes (T1D) patients; and unaffected aAb+ and autoantibody-negative (aAb-) SLE and RA FDRs were tested for SLE, RA, and T1D aAbs, as well as anti-tissue transglutaminase, anti-cardiolipin and anti-thyroperoxidase. FDR SLE and RA genetic risk scores (GRS) were calculated.

FINDINGS

Alternative autoimmunity occurred in SLE patients (56%) and FDRs (57·4%), RA patients (32·6%) and FDRs (34·8%), and T1D patients (43%). Expanded autoimmunity, defined as autoantibodies spanning at least two other diseases, occurred in 18·5% of SLE patients, 16·4% of SLE FDRs, 7·8% of RA patients, 5·3% of RA FDRs, and 10·8% of T1D patients. SLE FDRs were more likely to have alternative (odds ratio [OR] 2·44) and expanded (OR 3·27) autoimmunity than RA FDRs. Alternative and expanded autoimmunity were associated with several environmental exposures. Alternative autoimmunity was associated with a higher RA GRS in RA FDRs (OR 1·41), and a higher SLE GRS in aAb+ RA FDRs (OR 1·87), but not in SLE FDRs.

INTERPRETATION

Autoimmunity commonly crosses disease-specific boundaries in systemic (RA, SLE) and organ-specific (T1D) autoimmune diseases. Alternative autoimmunity is more common in SLE FDRs than RA FDRs, and is influenced by genetic and environmental factors. These findings have substantial implications for preclinical disease pathogenesis and autoimmune disease prevention studies. FUND: NIH U01AI101981, R01AR051394, U19AI082714, P30AR053483, P30GM103510, U54GM104938, U01AI101934, R01AI024717, U01AI130830, I01BX001834, & U01HG008666.

Screening characteristics for enrichment of individuals at higher risk for transitioning to classified SLE

OBJECTIVE

Further prospective study is needed to elucidate the etiology and natural history of systemic lupus erythematosus development. The clinical complexity of this heterogeneous disease makes study design challenging. Our objective was to ascertain useful screening factors for identifying at-risk individuals for follow-up rheumatologic assessment or inclusion in prospective studies.

METHODS

We attempted to re-contact 3823 subjects with a family history of systemic lupus erythematosus, who did not meet American College of Rheumatology systemic lupus erythematosus classification at a baseline study visit; 436 agreed to follow-up participation an average of 6.3 years after baseline. In total, 56 of these individuals had transitioned to classified systemic lupus erythematosus (≥ 4 cumulative American College of Rheumatology criteria, verified by medical record review) by the time of follow up. Generalized estimating equations assessed associations between our dichotomous outcome of transitioning to systemic lupus erythematosus with baseline characteristics, including ANA positivity, Connective Tissue Disease Screening questionnaire systemic lupus erythematosus score, and number of American College of Rheumatology criteria. We analyzed predictive accuracy of characteristics on transitioning.

RESULTS

ANA positivity, Connective Tissue Disease Screening questionnaire systemic lupus erythematosus score categorization of possible or probable systemic lupus erythematosus, and greater number of American College of Rheumatology criteria at baseline were each associated with transitioning to systemic lupus erythematosus classification. Being ANA positive and having confirmed immunologic criteria at baseline had the highest positive predictive value and specificity for transitioning to systemic lupus erythematosus. American College of Rheumatology Connective Tissue Disease Screening questionnaire systemic lupus erythematosus score categorization of possible or probable systemic lupus erythematosus had a better positive predictive value, negative predictive value, sensitivity, and specificity than ANA positivity.

CONCLUSION

Given limited resources, identifying individuals for follow up based on the systemic lupus erythematosus portion of the Connective Tissue Disease Screening questionnaire could be an efficient way to identify family members at highest risk of disease transition.

Association studies of up to 1.2 million individuals yield new insights into the genetic etiology of tobacco and alcohol use

Tobacco and alcohol use are leading causes of mortality that influence risk for many complex diseases and disorders1. They are heritable2,3 and etiologically related4,5 behaviors that have been resistant to gene discovery efforts6-11. In sample sizes up to 1.2 million individuals, we discovered 566 genetic variants in 406 loci associated with multiple stages of tobacco use (initiation, cessation, and heaviness) as well as alcohol use, with 150 loci evidencing pleiotropic association. Smoking phenotypes were positively genetically correlated with many health conditions, whereas alcohol use was negatively correlated with these conditions, such that increased genetic risk for alcohol use is associated with lower disease risk. We report evidence for the involvement of many systems in tobacco and alcohol use, including genes involved in nicotinic, dopaminergic, and glutamatergic neurotransmission. The results provide a solid starting point to evaluate the effects of these loci in model organisms and more precise substance use measures.

The triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) ratio as a predictor of insulin resistance, β-cell function, and diabetes in Hispanics and African Americans

OBJECTIVE

The TG/HDL-C ratio is used as a marker of insulin resistance (IR) in Caucasians; however, there is limited data in other ethnic groups. We hypothesized that the TG/HDL-C ratio is associated with IR in Hispanics and African Americans (AA).

RESEARCH DESIGN AND METHODS

Data from the Insulin Resistance Atherosclerosis Family Study was examined for associations between TG/HDL-C ratio and IR, β-cell function and incident diabetes in non-diabetic Hispanics (n = 872, 63% female) and AA (n = 371, 61% female). Insulin sensitivity index (S_I) and disposition index (DI) from frequently-sampled intravenous glucose tolerance tests were used as markers of IR and β-cell function respectively. Incident type 2 diabetes was determined by fasting glucose ≥ 126 mg/dl or initiation of anti-hyperglycemia agents over 5 year follow-up.

RESULTS

Higher TG/HDL-C ratio was associated with IR in Hispanic and AA men and women (P < 0.0002), as well as β-cell function in Hispanic women and AA men and women (P < 0.02). TG/HDL-C predicted incident type 2 diabetes in women (area under the curves 0.703 and 0.795 for Hispanics and AA respectively).

CONCLUSIONS

Similar to Caucasians, the TG/HDL-C ratio can be used to identify IR in Hispanics and AA, and may predict type 2 diabetes in women.

Pulmonary Subtypes Exhibit Differential Global Initiative for Chronic Obstructive Lung Disease Spirometry Stage Progression: The COPDGene® Study

Rationale

We classified individuals into pulmonary disease subtypes based on 2 underlying pathophysiologic disease axes (airway-predominant and emphysema-predominant) and their increased mortality risk. Our next objective was to determine whether some subcomponents of these subtypes are additionally associated with unique patterns of Global initiative for chronic Obstructive Lung Disease (GOLD) spirometry stage progression.

Methods

After accounting for intra-individual measurement variability in spirometry measures between baseline (Phase 1) and the 5-year follow up (Phase 2) of the COPD Genetic Epidemiology (COPDGene^®) study, 4615 individuals had complete data that would characterize patterns of disease progression over 5 years (2033 non-Hispanic whites; 827 African Americans; 48% female). Individuals could express increased risk for mortality on one or both of the primary subtype axes (airway-predominant or emphysema-predominant) and thus they were further classified into 6 groups: high-risk airway-predominant disease only (APD-only), moderate-risk airway-predominant disease only (MR-APD-only), high-risk emphysema-predominant disease only (EPD-only), combined high-risk airway- and emphysema-predominant disease (combined APD-EPD), combined moderate-risk airway- and emphysema-predominant disease (combined MR-APD-EPD), and no high-risk pulmonary subtype. Outcomes were dichotomized for GOLD spirometry stage progression from Phase 1 to Phase 2. Logistic regression of the progression outcomes on the pulmonary subtypes were adjusted for age, sex, race, and change in smoking status.

Results

The MR-APD-only group was associated with conversion from GOLD 0 to preserved ratio-impaired spirometry (PRISm) status (odds ratio [OR] 11.3, 95% confidence interval [CI] 5.7-22.1) and GOLD 0 to GOLD 2-4 (OR 6.0, 95% CI 2.0-18.0). The EPD-only group was associated with conversion from GOLD 0 to GOLD 1 (OR 2.4, 95% CI 1.2-4.6), and GOLD 1 to GOLD 2-4 (OR 2.6, 95% CI 1.0-6.9). Conversion between PRISm and GOLD 2-4 (31%-38%) occurred in both the APD-only and the MR-APD-only groups.

Conclusion

Differential conversion occurs from GOLD 0 to PRISm and GOLD 0 to GOLD 1 based on groups expressing airway-predominant disease or emphysema-predominant disease independently or in combination. Airway-predominant and emphysema-predominant subtypes are highly important in determining patterns of early disease progression.

Subtypes of COPD Have Unique Distributions and Differential Risk of Mortality

Background

Previous attempts to explore the heterogeneity of chronic obstructive pulmonary disease (COPD) clustered individual patients using clinical, demographic, and disease features. We developed continuous multidimensional disease axes based on radiographic and spirometric variables that split into an airway-predominant axis and an emphysema-predominant axis.

Methods

The COPD Genetic Epidemiology study (COPDGene^®) is a cohort of current and former smokers, > 45 years, with at least 10 pack years of smoking history. Spirometry measures, blood pressure and body mass were directly measured. Mortality was assessed through continuing longitudinal follow-up and cause of death was adjudicated. Among 8157 COPDGene^® participants with complete spirometry and computed tomography (CT) measures, the top 2 deciles of the airway-predominant and emphysema-predominant axes previously identified were used to categorize individuals into 3 groups having the highest risk for mortality using Cox proportional hazard ratios. These groups were also assessed for causal mortality. Biomarkers of COPD (fibrinogen, soluble receptor for advanced glycation end products [sRAGE], C-reactive protein [CRP], clara cell secretory protein [CC16], surfactant-D [SP-D]) were compared by group.

Findings

High-risk subtype classification was defined for 2638 COPDGene^® participants who were in the highest 2 deciles of either the airway-predominant and/or emphysema-predominant axis (32% of the cohort). These high-risk participants fell into 3 groups: airway-predominant disease only (APD-only), emphysema-predominant disease only (EPD-only) and combined APD-EPD. There was 26% mortality for the APD-only group, 21% mortality for the EPD-only group, and 54% mortality for the combined APD-EPD group. The APD-only group (n=1007) was younger, had a lower forced expiratory volume in 1 second (FEV₁) percent (%) predicted and a strong association with the preserved ratio-impaired spirometry (PRISm) quadrant. The EPD-only group (n=1006) showed a relatively higher FEV₁ % predicted and included largely GOLD stage 0, 1 and 2 partipants. Individuals in each of the 3 high-risk groups were at greater risk for respiratory mortality, while those in the APD-only group were additionally at greater risk for cardiovascular mortality. Biomarker analysis demonstrated a significant association of the APD-only group with CRP, and sRAGE demonstrated greatest significance with both the EPD-only and the combined APD-EPD groups.

Interpretation

Among current and former smokers, individuals in the highest 2 deciles for mortality risk on the airway-predominant axis and the emphysema-predominant axis have unique associations to spirometric patterns, different imaging characteristics, biomarkers and causal mortality.

Identification of Chronic Obstructive Pulmonary Disease Axes That Predict All-Cause Mortality: The COPDGene Study

Chronic obstructive pulmonary disease (COPD) is a syndrome caused by damage to the lungs that results in decreased pulmonary function and reduced structural integrity. Pulmonary function testing (PFT) is used to diagnose and stratify COPD into severity groups, and computed tomography (CT) imaging of the chest is often used to assess structural changes in the lungs. We hypothesized that the combination of PFT and CT phenotypes would provide a more powerful tool for assessing underlying morphologic differences associated with pulmonary function in COPD than does PFT alone. We used factor analysis of 26 variables to classify 8,157 participants recruited into the COPDGene cohort between January 2008 and June 2011 from 21 clinical centers across the United States. These factors were used as predictors of all-cause mortality using Cox proportional hazards modeling. Five factors explained 80% of the covariance and represented the following domains: factor 1, increased emphysema and decreased pulmonary function; factor 2, airway disease and decreased pulmonary function; factor 3, gas trapping; factor 4, CT variability; and factor 5, hyperinflation. After more than 46,079 person-years of follow-up, factors 1 through 4 were associated with mortality and there was a significant synergistic interaction between factors 1 and 2 on death. Considering CT measures along with PFT in the assessment of COPD can identify patients at particularly high risk for death.

Genome-wide association study across European and African American ancestries identifies a SNP in DNMT3B contributing to nicotine dependence

Cigarette smoking is a leading cause of preventable mortality worldwide. Nicotine dependence, which reduces the likelihood of quitting smoking, is a heritable trait with firmly established associations with sequence variants in nicotine acetylcholine receptor genes and at other loci. To search for additional loci, we conducted a genome-wide association study (GWAS) meta-analysis of nicotine dependence, totaling 38,602 smokers (28,677 Europeans/European Americans and 9925 African Americans) across 15 studies. In this largest-ever GWAS meta-analysis for nicotine dependence and the largest-ever cross-ancestry GWAS meta-analysis for any smoking phenotype, we reconfirmed the well-known CHRNA5-CHRNA3-CHRNB4 genes and further yielded a novel association in the DNA methyltransferase gene DNMT3B. The intronic DNMT3B rs910083-C allele (frequency=44-77%) was associated with increased risk of nicotine dependence at P=3.7 × 10-8 (odds ratio (OR)=1.06 and 95% confidence interval (CI)=1.04-1.07 for severe vs mild dependence). The association was independently confirmed in the UK Biobank (N=48,931) using heavy vs never smoking as a proxy phenotype (P=3.6 × 10-4, OR=1.05, and 95% CI=1.02-1.08). Rs910083-C is also associated with increased risk of squamous cell lung carcinoma in the International Lung Cancer Consortium (N=60,586, meta-analysis P=0.0095, OR=1.05, and 95% CI=1.01-1.09). Moreover, rs910083-C was implicated as a cis-methylation quantitative trait locus (QTL) variant associated with higher DNMT3B methylation in fetal brain (N=166, P=2.3 × 10-26) and a cis-expression QTL variant associated with higher DNMT3B expression in adult cerebellum from the Genotype-Tissue Expression project (N=103, P=3.0 × 10-6) and the independent Brain eQTL Almanac (N=134, P=0.028). This novel DNMT3B cis-acting QTL variant highlights the importance of genetically influenced regulation in brain on the risks of nicotine dependence, heavy smoking and consequent lung cancer.

Less than 7 hours of sleep per night is associated with transitioning to systemic lupus erythematosus

Background The role of sleep in the etiology of systemic lupus erythematosus (SLE) has not been well studied. We examined whether sleep duration was associated with subsequent transitioning to SLE in individuals at risk for SLE. Methods Four hundred and thirty-six relatives of SLE patients who did not have SLE themselves at baseline were evaluated again an average of 6.3 (± 3.9) years later. Fifty-six individuals transitioned to SLE (≥ 4 cumulative American College of Rheumatology (ACR) criteria). Sleep duration, medication use and medical history were assessed by questionnaire; ACR criteria were confirmed by medical record review. Vitamin D was measured by ELISA. Generalized estimating equations, accounting for correlation within families, assessed associations between baseline sleep and the outcome of transitioning to SLE. Results Reporting sleeping less than 7 hours per night at baseline was more common in those who subsequently transitioned than those who did not transition to SLE (55% versus 32%, p = 0.0005; OR: 2.8, 95% CI 1.6-4.9). Those who transitioned to SLE were more likely to sleep less than 7 hours per night than those who did not transition to SLE adjusting for age, sex and race (OR: 2.8, 95% CI 1.6-5.1). This association remained after individual adjustment for conditions and early symptoms that could affect sleep, including prednisone use, vitamin D deficiency and number of ACR criteria (OR: 2.0, 95% CI 1.1-4.2). Conclusion Lack of sleep may be associated with transitioning to SLE, independent of early clinical manifestations of SLE that may influence sleep duration. Further evaluation of sleeping patterns and biomarkers in at-risk individuals is warranted.

Association of Directly Measured Plasma Free 25(OH)D With Insulin Sensitivity and Secretion: The IRAS Family Study

OBJECTIVES

We aimed to compare the associations of directly measured plasma free 25-hydroxyvitamin D [25(OH)D] and total 25(OH)D concentrations with insulin sensitivity (SI) and β-cell function in nondiabetic Hispanics and African Americans. We hypothesized that directly measured free 25(OH)D would be more strongly associated with these measures of glucose homeostasis and that associations would differ by race.

DESIGN

We studied 1189 nondiabetic participants in the Insulin Resistance Atherosclerosis Study Family Study using data from baseline examinations from 2000 to 2002. SI, acute insulin response, and disposition index (DI) were determined from frequently sampled intravenous glucose tolerance tests. Plasma free and total 25(OH)D concentrations were measured by enzyme-linked immunosorbent assay and radioimmunoassay, respectively.

RESULTS

The median concentrations of plasma free 25(OH)D were 3.46 pg/mL for Hispanics and 2.17 pg/mL for African Americans (P < 0.0001), whereas the median concentrations of plasma total 25(OH)D were 16 ng/mL for Hispanics and 10 ng/mL for African Americans (P < 0.0001). Plasma free and total 25(OH)D were both positively associated with SI and DI in generalized estimating equations adjusted for demographic and lifestyle factors. After further adjustment with body mass index, the associations were no longer statistically significant, except for a significant association between plasma free 25(OH)D and SI. There was no effect modification by ethnicity on any of the exposure-outcome associations.

CONCLUSIONS

Our data showed that plasma free 25(OH)D had a slightly stronger association with SI compared with plasma total 25(OH)D, although the difference was modest and there were no marked differences in the associations between Hispanics and African Americans.

Discerning Risk of Disease Transition in Relatives of Systemic Lupus Erythematosus Patients Utilizing Soluble Mediators and Clinical Features

OBJECTIVE

Systemic lupus erythematosus (SLE) and other autoimmune diseases cause significant morbidity. Identifying populations at risk of developing SLE is essential for curtailing irreversible inflammatory damage. The aim of this study was to identify factors associated with transition to classified disease that would inform our understanding of the risk of SLE.

METHODS

Previously identified blood relatives of patients with SLE, who had <4 American College of Rheumatology (ACR) classification criteria for SLE at baseline, were enrolled in this follow-up study (n = 409 unaffected relatives). Participants provided detailed family, demographic, and clinical information, including the SLE-specific portion of the Connective Tissue Disease Screening Questionnaire (SLE-CSQ). Serum and plasma samples were tested for the presence of lupus-associated autoantibodies and 52 soluble mediators. Generalized estimating equations (GEEs) were applied to identify factors predictive of disease transition.

RESULTS

Of the 409 unaffected relatives of SLE patients, 45 (11%) had transitioned to classified SLE at follow-up (mean time to follow-up 6.4 years). Relatives who transitioned to SLE displayed more lupus-associated autoantibody specificities and higher SLE-CSQ scores (P < 0.0001) at baseline than did relatives who did not transition. Importantly, those who had developed SLE during the follow-up period also had elevated baseline plasma levels of inflammatory mediators, including B lymphocyte stimulator, stem cell factor (SCF), and interferon-associated chemokines (P ≤ 0.02), with concurrent decreases in the levels of regulatory mediators, transforming growth factor β (TGFβ), and interleukin-10 (P ≤ 0.03). GEE analyses revealed that baseline SLE-CSQ scores or ACR scores (number of ACR criteria satisfied) and plasma levels of SCF and TGFβ, but not autoantibodies, were significant and independent predictors of SLE transition (P ≤ 0.03).

CONCLUSION

Preclinical alterations in levels of soluble mediators may predict transition to classified disease in relatives of SLE patients. Thus, immune perturbations precede SLE classification and can help identify high-risk relatives for rheumatology referral and potential enrollment in prevention trials.

IMPACT OF GLUCOSE MANAGEMENT TEAM ON OUTCOMES OF HOSPITALIZARON IN PATIENTS WITH TYPE 2 DIABETES ADMITTED TO THE MEDICAL SERVICE

OBJECTIVE

To improve glycemic control of hospitalized patients with diabetes and hyperglycemia, many medical centers have established dedicated glucose management teams (GMTs). However, the impact of these specialized teams on clinical outcomes has not been evaluated.

METHODS

We conducted a retrospective study of 440 patients with type 2 diabetes admitted to the medical service for cardiac or infection-related diagnosis. The primary endpoint was a composite outcome of several well-recognized markers of morbidity, consisting of: death during hospitalization, transfer to intensive care unit, initiation of enteral or parenteral nutrition, line infection, new in-hospital infection or infection lasting more than 20 days of hospitalization, deep venous thrombosis or pulmonary embolism, rise in plasma creatinine, and hospital re-admissions.

RESULTS

Medical housestaff managed the glycemia in 79% of patients (usual care group), while the GMT managed the glycemia in 21% of patients (GMT group). The primary outcome was similar between cohorts (0.95 events per patient versus 0.99 events per patient in the GMT and usual care cohorts, respectively). For subanalysis, the subjects in both groups were stratified into those with average glycemia of <180 mg/dL versus those with glycemia >180 mg/dL. We found a significant beneficial impact of glycemic management by the GMT on the composite outcome in patients with average glycemia >180 mg/dL during their hospital stay. The number of patients who met primary outcome was significantly higher in the usual care group (40 of 83 patients, 48%) than in the GMT-treated cohort (8 of 33 patients, 25.7%) (P<.02).

CONCLUSION

Our data suggest that GMTs may have an important role in managing difficult-to-control hyperglycemia in the inpatient setting.

ABBREVIATIONS

BG = blood glucose GMT = glucose management team HbA1c = hemoglobin A1c ICU = intensive care unit POC = point of care T2D = type 2 diabetes.

Combined role of vitamin D status and CYP24A1 in the transition to systemic lupus erythematosus

OBJECTIVE

We examined whether measures of vitamin D were associated with transitioning to systemic lupus erythematosus (SLE) in individuals at risk for SLE.

METHODS

436 individuals who reported having a relative with SLE but who did not have SLE themselves were evaluated at baseline and again an average of 6.3 (±3.9) years later. Fifty-six individuals transitioned to SLE (≥4 cumulative American College of Rheumatology criteria). 25-Hydroxyvitamin D (25[OH]D) levels were measured by ELISA. Six single-nucleotide polymorphisms in four vitamin D genes were genotyped. Generalised estimating equations, adjusting for correlation within families, were used to test associations between the vitamin D variables and the outcome of transitioning to SLE.

RESULTS

Mean baseline 25[OH]D levels (p=0.42) and vitamin D supplementation (p=0.65) were not different between those who did and did not transition to SLE. Vitamin D deficiency (25[OH]D <20 ng/mL) was greater in those who transitioned compared with those who did not transition to SLE (46% vs 33%, p=0.05). The association between 25[OH]D and SLE was modified by CYP24A1 rs4809959, where for each additional minor allele increased 25[OH]D was associated with decreased SLE risk: zero minor alleles (adjusted OR: 1.03, CI 0.98 to 1.09), one minor allele (adjusted OR: 1.01, CI 0.97 to 1.05) and two minor alleles (adjusted OR: 0.91, CI 0.84 to 0.98). Similarly, vitamin D deficiency significantly increased the risk of transitioning to SLE in those with two minor alleles at rs4809959 (adjusted OR: 4.90, CI 1.33 to 18.04).

CONCLUSIONS

Vitamin D status and CYP24A1 may have a combined role in the transition to SLE in individuals at increased genetic risk for SLE.

Blood relatives with incomplete lupus are distinguished from unaffected relatives and relatives with classified disease by altered autoantibodies, soluble inflammatory and regulatory mediators, and clinical features

Blood relatives (Rel) of lupus patients have increased risk of systemic lupus erythematosus (SLE). Some have autoantibodies and clinical features, but do not meet ≥ 4 ACR criteria needed to reach SLE classification (incomplete lupus, ILE). This study examined individuals enrolled in the Lupus Family Registry and Repository who only met 3 ACR classification criteria during medical record review. ILE patients (n=77) were matched to unaffected Rel and unrelated controls (Ctls), with a subset of ILE patients (n=55) matched to medical record-confirmed SLE patients. ILE patients had significantly higher SLE-specific screening questionnaire (CSQ) scores than unaffected Rel and Ctls (p≤0.0001). A number of soluble mediators that positively correlated with CSQ scores were highest in ILE patients, including SCF (p=0.0001), BLyS (p=0.0018), MCP-3 (p=0.0167), and TNFRI (p=0.0196), as well as ANA titer (p&lt;0.01) and number of lupus-associated autoantibodies (p&lt;0.01). Comparing ILE vs. SLE patients, SLE patients had higher rates of arthritis, serositis, and renal disease (p≤0.004), number of autoantibody specificities (p&lt;0.004), and levels of BLyS (p=0.0138), IL-2Rα (p=0.0201), IP-10 (p=0.0269), and TNFRII (p=0.0309). Yet, ILE patients had higher levels of the regulatory mediator TGF-β (p=0.0454). Identification of factors which discern relatives at increased risk of transitioning to classified SLE may be beneficial to curtail inflammatory damage.

Pulmonary Predictors of Incident Diabetes in Smokers

BACKGROUND

Diabetes mellitus and its complications are a large and increasing burden for health care worldwide. Reduced pulmonary function has been observed in diabetes (both type 1 and type 2), and this reduction is thought to occur prior to diagnosis. Other measures of pulmonary health are associated with diabetes, including lower exercise tolerance, greater dyspnea, lower quality of life (as measured by the St. George's Respiratory Questionaire [SGRQ]) and susceptibility to lung infection and these measures may also predate diabetes diagnosis.

METHODS

We examined 7080 participants in the COPD Genetic Epidemiology (COPDGene) study who did not report diabetes at their baseline visit and who provided health status updates during 4.2 years of longitudinal follow-up (LFU). We used Cox proportional hazards modeling, censoring participants at final LFU contact, reported mortality or report of incident diabetes to model predictors of diabetes. These models were constructed using known risk factors as well as proposed markers related to pulmonary health, forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), FEV₁/FVC, respiratory exacerbations (RE), 6-minute walk distance (6MWD), pulmonary associated quality of life (as measured by the SGRQ), corticosteroid use, chronic bronchitis and dyspnea.

RESULTS

Over 21,519 person years of follow-up, 392 of 7080 participants reported incident diabetes which was associated with expected predictors; increased body mass index (BMI), high blood pressure, high cholesterol and current smoking status. Age, gender and accumulated smoking exposure were not associated with incident diabetes. Additionally, preserved ratio with impaired spirometry (PRISm) pattern pulmonary function, reduced 6MWD and any report of serious pulmonary events were associated with incident diabetes.

CONCLUSIONS

This cluster of pulmonary indicators may aid clinicians in identifying and treating patients with pre- or undiagnosed diabetes.

Lower omega-3 fatty acids are associated with the presence of anti-cyclic citrullinated peptide autoantibodies in a population at risk for future rheumatoid arthritis: a nested case-control study

OBJECTIVE

The aim of this study was to investigate omega-3 fatty acid (FA) supplement use and omega-3 FAs in erythrocyte membranes [omega-3 FA % in erythrocyte membranes (RBC)] and their association with anti-CCP autoantibodies in a population without RA, but who are at genetic risk for RA.

METHODS

The multicentre Studies of the Etiology of RA (SERA) cohort includes RA-free subjects who are first-degree relatives of RA probands or are enriched with the HLA-DR4 allele. In a nested case-control study, 30 SERA cases were identified who were anti-CCP2 antibody positive. We further identified 47 autoantibody negative controls, frequency matched to cases on age at study visit, sex, race and study site. Anti-CCP2 status, self-reported omega-3 FA supplement use and omega-3 FA % in RBCs were obtained from a single visit.

RESULTS

Anti-CCP2 positive cases were less likely than controls to report omega-3 FA supplement use (odds ratio: 0.14; 95% CI 0.03, 0.68). In addition, the likelihood of anti-CCP2 positivity was inversely associated with total omega-3 FA % in RBCs (odds ratio: 0.47; 95% CI 0.24, 0.92, for a s.d. increase).

CONCLUSION

The inverse association between anti-CCP2 positivity and self-reported omega-3 FA supplement use and omega-3 FA % in RBCs suggests that omega-3 FAs may protect against the development of RA-related autoimmunity in pre-clinical RA.