Risk loci involved in giant cell arteritis susceptibility: a genome-wide association study

BACKGROUND

Giant cell arteritis is an age-related vasculitis that mainly affects the aorta and its branches in individuals aged 50 years and older. Current options for diagnosis and treatment are scarce, highlighting the need to better understand its underlying pathogenesis. Genome-wide association studies (GWAS) have emerged as a powerful tool for unravelling the pathogenic mechanisms involved in complex diseases. We aimed to characterise the genetic basis of giant cell arteritis by performing the largest GWAS of this vasculitis to date and to assess the functional consequences and clinical implications of identified risk loci.

METHODS

We collected and meta-analysed genomic data from patients with giant cell arteritis and healthy controls of European ancestry from ten cohorts across Europe and North America. Eligible patients required confirmation of giant cell arteritis diagnosis by positive temporal artery biopsy, positive temporal artery doppler ultrasonography, or imaging techniques confirming large-vessel vasculitis. We assessed the functional consequences of loci associated with giant cell arteritis using cell enrichment analysis, fine-mapping, and causal gene prioritisation. We also performed a drug repurposing analysis and developed a polygenic risk score to explore the clinical implications of our findings.

FINDINGS

We included a total of 3498 patients with giant cell arteritis and 15 550 controls. We identified three novel loci associated with risk of giant cell arteritis. Two loci, MFGE8 (rs8029053; p=4·96 × 10-8; OR 1·19 [95% CI 1·12-1·26]) and VTN (rs704; p=2·75 × 10-9; OR 0·84 [0·79-0·89]), were related to angiogenesis pathways and the third locus, CCDC25 (rs11782624; p=1·28 × 10-8; OR 1·18 [1·12-1·25]), was related to neutrophil extracellular traps (NETs). We also found an association between this vasculitis and HLA region and PLG. Variants associated with giant cell arteritis seemed to fulfil a specific regulatory role in crucial immune cell types. Furthermore, we identified several drugs that could represent promising candidates for treatment of this disease. The polygenic risk score model was able to identify individuals at increased risk of developing giant cell arteritis (90th percentile OR 2·87 [95% CI 2·15-3·82]; p=1·73 × 10-13).

INTERPRETATION

We have found several additional loci associated with giant cell arteritis, highlighting the crucial role of angiogenesis in disease susceptibility. Our study represents a step forward in the translation of genomic findings to clinical practice in giant cell arteritis, proposing new treatments and a method to measure genetic predisposition to this vasculitis.

FUNDING

Institute of Health Carlos III, Spanish Ministry of Science and Innovation, UK Medical Research Council, and National Institute for Health and Care Research.

A proteomics study of rheumatoid arthritis patients on etanercept identifies putative biomarkers associated with clinical outcome measures

OBJECTIVES

Biologic DMARDs (bDMARDs) are widely used in patients with RA, but response to bDMARDs is heterogeneous. The objective of this work was to identify pretreatment proteomic biomarkers associated with RA clinical outcome measures in patients starting bDMARDs.

METHODS

Sequential window acquisition of all theoretical fragment ion spectra mass spectrometry (SWATH-MS) was used to generate spectral maps of sera from patients with RA before and after 3 months of treatment with the bDMARD etanercept. Protein levels were regressed against RA clinical outcome measures, i.e. 28-joint DAS (DAS28) and its subcomponents and DAS28 <2.6 (i.e. remission). The proteins with the strongest evidence for association were analysed in an independent, replication dataset. Finally, subnetwork analysis was carried out using the Disease Module Detection algorithm and biological plausibility of identified proteins was assessed by enrichment analysis.

RESULTS

A total of 180 patients with RA were included in the discovery dataset and 58 in the validation dataset from a UK-based prospective multicentre study. Ten individual proteins were found to be significantly associated with RA clinical outcome measures. The association of T-complex protein 1 subunit η with DAS28 remission was replicated in an independent cohort. Subnetwork analysis of the 10 proteins from the regression analysis identified the ontological theme, with the strongest associations being with acute phase and acute inflammatory responses.

CONCLUSION

This longitudinal study of 180 patients with RA commencing etanercept has identified several putative protein biomarkers of treatment response to this drug, one of which was replicated in an independent cohort.

Adenosine metabolic signature in circulating CD4+ T cells predicts remission in rheumatoid arthritis

OBJECTIVES

Long-term outcomes in rheumatoid arthritis (RA) depend on early and effective disease control. Methotrexate (MTX) remains the first-line disease modifying therapy, however there are no biomarkers with which to identify those most likely to achieve remission. To address this unmet need we explored metabolic pathways involved in MTX mechanism of action within circulating CD4+T cells in a cohort of treatment naive patients with early RA.

METHODS

Purified CD4+T cells were isolated from peripheral blood of 68 patients with early RA commencing MTX. The expression of a range of putative MTX metabolism and mechanism of action targets were explored by flow-cytometry and transcriptional analysis. From these data significant predictors of Disease Activity Score 28-C reactive protein (DAS28-CRP) remission (<2.4 at 6 months) were determined by logistic regression (clinical; flow-cytometry data) and linear modelling (gene expression data).

RESULTS

Low baseline DAS28-CRP was associated with remission at 6 months (p=0.02). Expression of the ectonucleotidase CD39, involved in ATP-ADP conversion during adenosine synthesis, was higher on CD4+CD25 High regulatory T cells at baseline in those achieving remission (molecules of equivalent fluorescence 1264 vs 847; p=0.007). Expression of other adenosine signalling elements in CD4+T cells were also upregulated at baseline in patients achieving remission: AMPD1 (p<0.001), ADORA2b (p=0.039) and ADORA3 (p=0.047). When combined into a single predictive metric, a combination of these variables outperformed baseline DAS28-CRP in prediction of early remission (area under the curve 0.92 vs 0.67, p=0.001) CONCLUSIONS: Adenosine signalling is important in the achievement of early remission with MTX in RA and biomarkers of adenosine activity may hold utility for the stratification of therapy in early disease.

Automated multiclass segmentation, quantification, and visualization of the diseased aorta on hybrid PET/CT-SEQUOIA

BACKGROUND

Cardiovascular disease is the most common cause of death worldwide, including infection and inflammation related conditions. Multiple studies have demonstrated potential advantages of hybrid positron emission tomography combined with computed tomography (PET/CT) as an adjunct to current clinical inflammatory and infectious biochemical markers. To quantitatively analyze vascular diseases at PET/CT, robust segmentation of the aorta is necessary. However, manual segmentation is extremely time-consuming and labor-intensive.

PURPOSE

To investigate the feasibility and accuracy of an automated tool to segment and quantify multiple parts of the diseased aorta on unenhanced low-dose computed tomography (LDCT) as an anatomical reference for PET-assessed vascular disease.

METHODS

A software pipeline was developed including automated segmentation using a 3D U-Net, calcium scoring, PET uptake quantification, background measurement, radiomics feature extraction, and 2D surface visualization of vessel wall calcium and tracer uptake distribution. To train the 3D U-Net, 352 non-contrast LDCTs from (2-[18 F]FDG and Na[18 F]F) PET/CTs performed in patients with various vascular pathologies with manual segmentation of the ascending aorta, aortic arch, descending aorta, and abdominal aorta were used. The last 22 consecutive scans were used as a hold-out internal test set. The remaining dataset was randomly split into training (n = 264; 80%) and validation (n = 66; 20%) sets. Further evaluation was performed on an external test set of 49 PET/CTs. The dice similarity coefficient (DSC) and Hausdorff distance (HD) were used to assess segmentation performance. Automatically obtained calcium scores and uptake values were compared with manual scoring obtained using clinical softwares (syngo.via and Affinity Viewer) in six patient images. intraclass correlation coefficients (ICC) were calculated to validate calcium and uptake values.

RESULTS

Fully automated segmentation of the aorta using a 3D U-Net was feasible in LDCT obtained from PET/CT scans. The external test set yielded a DSC of 0.867 ± 0.030 and HD of 1.0 [0.6-1.4] mm, similar to an open-source model with a DSC of 0.864 ± 0.023 and HD of 1.4 [1.0-1.8] mm. Quantification of calcium and uptake values were in excellent agreement with clinical software (ICC: 1.00 [1.00-1.00] and 0.99 [0.93-1.00] for calcium and uptake values, respectively).

CONCLUSIONS

We present an automated pipeline to segment the ascending aorta, aortic arch, descending aorta, and abdominal aorta on LDCT from PET/CT and to accurately provide uptake values, calcium scores, background measurement, radiomics features, and a 2D visualization. We call this algorithm SEQUOIA (SEgmentation, QUantification, and visualizatiOn of the dIseased Aorta) and is available at https://github.com/UMCG-CVI/SEQUOIA. This model could augment the utility of aortic evaluation at PET/CT studies tremendously, irrespective of the tracer, and potentially provide fast and reliable quantification of cardiovascular diseases in clinical practice, both for primary diagnosis and disease monitoring.

Diagnostic delay is associated with uveitis and inflammatory bowel disease in AS: a study of extra-musculoskeletal manifestations in SpA

OBJECTIVES

To examine the prevalence of extra-musculoskeletal manifestations (EMM) and the association between diagnostic delay and their incidence in AS and PsA.

METHODS

This was a retrospective, cohort study comprising two single centre cohorts in Europe and one multicentre cohort in Latin America (RESPONDIA). Crude prevalence of EMMs (uveitis, IBD and psoriasis) was calculated across geographic area and adjusted by direct standardization. Cox proportional hazard analysis was performed to assess the association between diagnostic delay and EMM incidence.

RESULTS

Of 3553 patients, 2097 had AS and 1456 had PsA. The overall prevalence of uveitis was 22.9% (95% CI: 21.1, 24.8) in AS and 3.8% (95% CI: 2.9, 5.0) in PsA; 8.1% (95% CI: 7.0, 9.4) and 2.1% (1.3, 2.9), respectively, for IBD; and 11.0% (95% CI: 9.7, 12.4) and 94.6% (93.0, 95.9), respectively, for psoriasis. The EMM often presented before the arthritis (uveitis 45.1% and 33.3%, and IBD 37.4% and 70%, in AS and PsA, respectively). In the multivariable model, longer diagnostic delay (≥5 years) associated with more uveitis (hazard ratio [HR] 4.01; 95% CI: 3.23, 4.07) and IBD events (HR 1.85; 95% CI: 1.28, 2.67) in AS. Diagnostic delay was not significantly associated with uveitis (HR 1.57; 95% CI: 0.69, 3.59) or IBD events (HR 1.59; 95% CI: 0.39, 6.37) in PsA.

CONCLUSION

EMMs are more prevalent in AS than PsA and often present before the onset of the articular disease. A longer diagnostic delay is associated with the 'de novo' appearance of uveitis and IBD in AS, highlighting the need to enhance diagnostic strategies to shorten the time from first symptom to diagnosis in SpA.

Estimating overdiagnosis in giant cell arteritis diagnostic pathways using genetic data: genetic association study

OBJECTIVES

Giant cell arteritis (GCA) may be confirmed by temporal artery biopsy (TAB) but false negatives can occur. GCA may be overdiagnosed in TAB-negative cases, or if neither TAB nor imaging is done. We used Human Leucocyte Antigen (HLA) genetic association of TAB-positive GCA as an "unbiased umpire" test to estimate historic overdiagnosis of GCA.

METHODS

Patients diagnosed with GCA between 1990-2014 were genotyped. During this era, vascular imaging alone was rarely used to diagnose GCA. HLA region variants were jointly imputed from genome-wide genotypic data of cases and controls. Per-allele frequencies across all HLA variants with p< 1.0x1 0 -5 were compared with population control data to estimate overdiagnosis rates in cases without a positive TAB.

RESULTS

Genetic data from 663 GCA patients were compared with data from 2619 population controls. TAB-negative GCA (n = 147) and GCA without TAB result (n = 160) had variant frequencies intermediate between TAB-positive GCA (n = 356) and population controls. For example, the allele frequency of HLA-DRB1*04 was 32% for TAB-positive GCA, 29% for GCA without TAB result, 27% for TAB-negative GCA and 20% in population controls. Making several strong assumptions, we estimated that around two-thirds of TAB-negative cases and one-third of cases without TAB result may have been overdiagnosed. From these data, TAB sensitivity is estimated as 88%.

CONCLUSIONS

Conservatively assuming 95% specificity, TAB has a negative likelihood ratio of around 0.12. Our method for utilising standard genotyping data as an "unbiased umpire" might be used as a way of comparing the accuracy of different diagnostic pathways.

Common co-morbidities in polymyalgia rheumatica and giant cell arteritis: cross-sectional study in UK Biobank

Objective

The aim was to determine prevalent co-morbidities in cases with PMR or GCA compared with matched controls.

Methods

This was a nested, cross-sectional case-control study within the UK Biobank, which recruited participants aged 40-69 years. Case status was defined as self-reported prior diagnosis of PMR or GCA. Ten controls per case were matched for age, sex, ethnicity and assessment centre. Associations with selected self-reported co-morbidities were studied using conditional logistic regression.

Results

Of PMR (n = 1036) or GCA (n = 102) cases, 72% were female, 98% White, and 58% reported current use of glucocorticoids. Mean age was 63 years. At the time of the assessment visit, compared with controls, PMR/GCA cases were more likely to report poor general health and at least several days of low mood in the past 2 weeks. PMR was associated with hypothyroidism [odds ratio (OR) = 1.34; 95% CI = 1.07, 1.67] and ever-use of HRT (OR = 1.26; 95% CI = 1.07, 1.47). Regarding common co-morbidities, PMR and GCA were both associated with hypertension (PMR: OR = 1.21; 95% CI = 1.06, 1.39; GCA: OR = 1.86; 95% CI = 1.23, 2.81) and cataract (PMR: OR = 1.51; 95% CI = 1.19, 1.93; GCA: OR = 3.84; 95% CI = 2.23, 6.60). Additionally, GCA was associated with depression (OR = 3.05; 95% CI = 1.59, 5.85). Neither condition was associated with diabetes.

Conclusion

Participants with a history of PMR/GCA, including those not currently taking glucocorticoids, rated their health as poorer than matched controls. Some previously described disease associations (hypothyroidism and early menopause) were replicated. Hypertension and cataract, both of which can be exacerbated by long-term glucocorticoid therapy, were over-represented in both diseases, particularly GCA.

Micro-RNA content of circulating extracellular vesicles in early rheumatoid arthritis as biomarkers and mediators of methotrexate efficacy

OBJECTIVES

Extracellular vesicles (EVs) are abundant in body fluids, contributing to intercellular signalling by transferring cargo that includes microRNAs (miRs) - themselves implicated in pathobiology. For the first time we evaluated the potential of EV miRs to contribute diagnostic information in early RA, predict methotrexate (MTX) efficacy or shed light on the drug's mechanism of action.

METHODS

798 miRs isolated from serum-derived EVs of 46 patients with untreated RA, 23 with untreated polymyalgia rheumatica (PMR; inflammatory disease control group) and 12 in whom significant inflammatory disease had been excluded (non-inflammatory controls; NICs) were profiled (Nanostring); the same measurements were made for RA patients after 6 months' MTX treatment. Analyses took multiple testing into account.

RESULTS

28 EV miRs were robustly differentially expressed between early RA (but not PMR) patients and NICs after correction for age and sex, suggesting discriminatory value. Cross-validated partial least squared-discriminant analysis also indicated the predictive potential of a distinct baseline EV miR signature with respect to MTX-induced remission at 6 months. The change in expression of 13 miRs over the course of MTX treatment differed significantly between responders and non-responders, and four of those exhibiting increased relative abundance amongst responders have known roles in regulating the pathogenic potential of synovial fibroblasts, namely miR-212-3p, miR-338-5p, miR-410-3p, and miR-537.

CONCLUSION

Our data highlight the potential of serum EV miRs as diagnostic and therapeutic biomarkers, highlighting a novel potential mechanism via which MTX may exert its therapeutic effect in early RA that warrants further investigation.

Identification of new risk loci shared across systemic vasculitides points towards potential target genes for drug repurposing

OBJECTIVES

The number of susceptibility loci currently associated with vasculitis is lower than in other immune-mediated diseases due in part to small cohort sizes, a consequence of the low prevalence of vasculitides. This study aimed to identify new genetic risk loci for the main systemic vasculitides through a comprehensive analysis of their genetic overlap.

METHODS

Genome-wide data from 8467 patients with any of the main forms of vasculitis and 29 795 healthy controls were meta-analysed using ASSET. Pleiotropic variants were functionally annotated and linked to their target genes. Prioritised genes were queried in DrugBank to identify potentially repositionable drugs for the treatment of vasculitis.

RESULTS

Sixteen variants were independently associated with two or more vasculitides, 15 of them representing new shared risk loci. Two of these pleiotropic signals, located close to CTLA4 and CPLX1, emerged as novel genetic risk loci in vasculitis. Most of these polymorphisms appeared to affect vasculitis by regulating gene expression. In this regard, for some of these common signals, potential causal genes were prioritised based on functional annotation, including CTLA4, RNF145, IL12B, IL5, IRF1, IFNGR1, PTK2B, TRIM35, EGR2 and ETS2, each of which has key roles in inflammation. In addition, drug repositioning analysis showed that several drugs, including abatacept and ustekinumab, could be potentially repurposed in the management of the analysed vasculitides.

CONCLUSIONS

We identified new shared risk loci with functional impact in vasculitis and pinpointed potential causal genes, some of which could represent promising targets for the treatment of vasculitis.

Pre-treatment calprotectin (MRP8/14) provides no added value to testing CRP alone in terms of predicting response to TNF inhibitors in rheumatoid arthritis in a post hoc analysis

OBJECTIVES

The inflammatory protein calprotectin (MRP8/14) has been identified as a promising biomarker of treatment response in rheumatoid arthritis (RA). Our aim was to test MRP8/14 as a biomarker of response to tumour necrosis factor (TNF)-inhibitors in the largest RA cohort to date and to compare with C-reactive protein (CRP).

METHODS

Serum MRP8/14 was measured in 470 patients with RA about to commence treatment with adalimumab (n=196) or etanercept (n=274). Additionally, MRP8/14 was measured in the 3-month sera of 179 adalimumab-treated patients. Response was determined using European League against Rheumatism (EULAR) response criteria calculated using the traditional 4-component (4C) DAS28-CRP and alternate validated versions using 3-component (3C) and 2-component (2C), clinical disease activity index (CDAI) improvement criteria and change in individual outcome measures. Logistic/linear regression models were fitted for response outcome.

RESULTS

In the 3C and 2C models, patients with RA were 1.92 (CI: 1.04 to 3.54) and 2.03 (CI: 1.09 to 3.78) times more likely to be classified as EULAR responders if they had high (75th quartile) pre-treatment levels of MRP8/14 compared with low (25th quartile). No significant associations were observed for the 4C model. When only using CRP as a predictor, in the 3C and 2C analyses, patients above the 75th quartile were 3.79 (CI: 1.81 to 7.93) and 3.58 (CI: 1.74 to 7.35) times more likely to be EULAR responders and addition of MRP8/14 did not significantly improve model fit (p values=0.62 and 0.80, respectively). No significant associations were observed in the 4C analysis. Exclusion of CRP from the outcome measure (CDAI) did not result in any significant associations with MRP8/14 (OR 1.00 (CI: 0.99 to 1.01), suggesting that the associations were due to the correlation with CRP and that there is no additional utility of MRP8/14 beyond use of CRP in patients with RA starting TNFi therapy.

CONCLUSION

Beyond correlation with CRP, we found no evidence to suggest that MRP8/14 explains additional variability in response to TNFi in patients with RA over and above CRP alone.

An Automated Method for Artifical Intelligence Assisted Diagnosis of Active Aortitis Using Radiomic Analysis of FDG PET-CT Images

The aim of this study was to develop and validate an automated pipeline that could assist the diagnosis of active aortitis using radiomic imaging biomarkers derived from [18F]-Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography (FDG PET-CT) images. The aorta was automatically segmented by convolutional neural network (CNN) on FDG PET-CT of aortitis and control patients. The FDG PET-CT dataset was split into training (43 aortitis:21 control), test (12 aortitis:5 control) and validation (24 aortitis:14 control) cohorts. Radiomic features (RF), including SUV metrics, were extracted from the segmented data and harmonized. Three radiomic fingerprints were constructed: A-RFs with high diagnostic utility removing highly correlated RFs; B used principal component analysis (PCA); C-Random Forest intrinsic feature selection. The diagnostic utility was evaluated with accuracy and area under the receiver operating characteristic curve (AUC). Several RFs and Fingerprints had high AUC values (AUC > 0.8), confirmed by balanced accuracy, across training, test and external validation datasets. Good diagnostic performance achieved across several multi-centre datasets suggests that a radiomic pipeline can be generalizable. These findings could be used to build an automated clinical decision tool to facilitate objective and standardized assessment regardless of observer experience.

Somatostatin Receptor PET/MR Imaging of Inflammation in Patients With Large Vessel Vasculitis and Atherosclerosis

BACKGROUND

Assessing inflammatory disease activity in large vessel vasculitis (LVV) can be challenging by conventional measures.

OBJECTIVES

We aimed to investigate somatostatin receptor 2 (SST2) as a novel inflammation-specific molecular imaging target in LVV.

METHODS

In a prospective, observational cohort study, in vivo arterial SST2 expression was assessed by positron emission tomography/magnetic resonance imaging (PET/MRI) using 68Ga-DOTATATE and 18F-FET-βAG-TOCA. Ex vivo mapping of the imaging target was performed using immunofluorescence microscopy; imaging mass cytometry; and bulk, single-cell, and single-nucleus RNA sequencing.

RESULTS

Sixty-one participants (LVV: n = 27; recent atherosclerotic myocardial infarction of ≤2 weeks: n = 25; control subjects with an oncologic indication for imaging: n = 9) were included. Index vessel SST2 maximum tissue-to-blood ratio was 61.8% (P < 0.0001) higher in active/grumbling LVV than inactive LVV and 34.6% (P = 0.0002) higher than myocardial infarction, with good diagnostic accuracy (area under the curve: ≥0.86; P < 0.001 for both). Arterial SST2 signal was not elevated in any of the control subjects. SST2 PET/MRI was generally consistent with 18F-fluorodeoxyglucose PET/computed tomography imaging in LVV patients with contemporaneous clinical scans but with very low background signal in the brain and heart, allowing for unimpeded assessment of nearby coronary, myocardial, and intracranial artery involvement. Clinically effective treatment for LVV was associated with a 0.49 ± 0.24 (standard error of the mean [SEM]) (P = 0.04; 22.3%) reduction in the SST2 maximum tissue-to-blood ratio after 9.3 ± 3.2 months. SST2 expression was localized to macrophages, pericytes, and perivascular adipocytes in vasculitis specimens, with specific receptor binding confirmed by autoradiography. SSTR2-expressing macrophages coexpressed proinflammatory markers.

CONCLUSIONS

SST2 PET/MRI holds major promise for diagnosis and therapeutic monitoring in LVV. (PET Imaging of Giant Cell and Takayasu Arteritis [PITA], NCT04071691; Residual Inflammation and Plaque Progression Long-Term Evaluation [RIPPLE], NCT04073810).

A methodological framework for AI-assisted diagnosis of active aortitis using radiomic analysis of FDG PET-CT images: Initial analysis

BACKGROUND

The aim of this study was to explore the feasibility of assisted diagnosis of active (peri-)aortitis using radiomic imaging biomarkers derived from [18F]-Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography (FDG PET-CT) images.

METHODS

The aorta was manually segmented on FDG PET-CT in 50 patients with aortitis and 25 controls. Radiomic features (RF) (n = 107), including SUV (Standardized Uptake Value) metrics, were extracted from the segmented data and harmonized using the ComBat technique. Individual RFs and groups of RFs (i.e., signatures) were used as input in Machine Learning classifiers. The diagnostic utility of these classifiers was evaluated with area under the receiver operating characteristic curve (AUC) and accuracy using the clinical diagnosis as the ground truth.

RESULTS

Several RFs had high accuracy, 84% to 86%, and AUC scores 0.83 to 0.97 when used individually. Radiomic signatures performed similarly, AUC 0.80 to 1.00.

CONCLUSION

A methodological framework for a radiomic-based approach to support diagnosis of aortitis was outlined. Selected RFs, individually or in combination, showed similar performance to the current standard of qualitative assessment in terms of AUC for identifying active aortitis. This framework could support development of a clinical decision-making tool for a more objective and standardized assessment of aortitis.

Comprehensive genetic and functional analyses of Fc gamma receptors influence on response to rituximab therapy for autoimmunity

BACKGROUND

Rituximab is widely used to treat autoimmunity but clinical response varies. Efficacy is determined by the efficiency of B-cell depletion, which may depend on various Fc gamma receptor (FcγR)-dependent mechanisms. Study of FcγR is challenging due to the complexity of the FCGR genetic locus. We sought to assess the effect of FCGR variants on clinical response, B-cell depletion and NK-cell-mediated killing in rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE).

METHODS

A longitudinal cohort study was conducted in 835 patients [RA = 573; SLE = 262]. Clinical outcome measures were two-component disease activity score in 28-joints (2C-DAS28CRP) for RA and British Isles Lupus Assessment Group (BILAG)-2004 major clinical response (MCR) for SLE at 6 months. B-cells were evaluated by highly-sensitive flow cytometry. Single nucleotide polymorphism and copy number variation for genes encoding five FcγRs were measured using multiplex ligation-dependent probe amplification. Ex vivo studies assessed NK-cell antibody-dependent cellular cytotoxicity (ADCC) and FcγR expression.

FINDINGS

In RA, carriage of FCGR3A-158V and increased FCGR3A-158V copies were associated with greater 2C-DAS28CRP response (adjusted for baseline 2C-DAS28CRP). In SLE, MCR was associated with increased FCGR3A-158V, OR 1.64 (95% CI 1.12-2.41) and FCGR2C-ORF OR 1.93 (95% CI 1.09-3.40) copies. 236/413 (57%) patients with B-cell data achieved complete depletion. Homozygosity for FCGR3A-158V and increased FCGR3A-158V copies were associated with complete depletion in combined analyses. FCGR3A genotype was associated with rituximab-induced ADCC, and increased NK-cell FcγRIIIa expression was associated with improved clinical response and depletion in vivo. Furthermore, disease status and concomitant therapies impacted both NK-cell FcγRIIIa expression and ADCC.

INTERPRETATION

FcγRIIIa is the major low affinity FcγR associated with rituximab response. Increased copies of the FCGR3A-158V allele (higher affinity for IgG1), influences clinical and biological responses to rituximab in autoimmunity. Enhancing FcγR-effector functions could improve the next generation of CD20-depleting therapies and genotyping may stratify patients for optimal treatment protocols.

FUNDING

Medical Research Council, National Institute for Health and Care Research, Versus Arthritis.

Pre-defined gene co-expression modules in rheumatoid arthritis transition towards molecular health following anti-TNF therapy

BACKGROUND

No reliable biomarkers to predict response to TNF inhibitors (TNFi) in RA patients currently exist. The aims of this study were to replicate changes in gene co-expression modules that were previously reported in response to TNFi therapy in RA; to test if changes in module expression are specific to TNFi therapy; and to determine whether module expression transitions towards a disease-free state in responding patients.

METHOD

Published transcriptomic data from the whole blood of disease-free controls (n = 10) and RA patients, treated with the TNFi adalimumab (n = 70) or methotrexate (n = 85), were studied. Treatment response was assessed using the EULAR response criteria following 3 or 6 months of treatment. Change in transcript expression between pre- and post-treatment was recorded for previously defined modules. Linear mixed models tested whether modular expression after treatment transitioned towards a disease-free state.

RESULTS

For 25 of the 27 modules, change in expression between pre- and post-treatment in the adalimumab cohort replicated published findings. Of these 25 modules, six transitioned towards a disease-free state by 3 months (P < 0.05), irrespective of clinical response. One module (M3.2), related to inflammation and TNF biology, significantly correlated with response to adalimumab. Similar patterns of modular expression, with reduced magnitude, were observed in the methotrexate cohort.

CONCLUSION

This study provides independent validation of changes in module expression in response to therapy in RA. However, these effects are not specific to TNFi. Further studies are required to determine whether specific modules could assist molecular classification of therapeutic response.

Interplay between demographic, clinical and polygenic risk factors for severe COVID-19

BACKGROUND

We aimed to identify clinical, socio-demographic and genetic risk factors for severe COVID-19 (hospitalization, critical care admission or death) in the general population.

METHODS

In this observational study, we identified 9560 UK Biobank participants diagnosed with COVID-19 during 2020. A polygenic risk score (PRS) for severe COVID-19 was derived and optimized using publicly available European and trans-ethnic COVID-19 genome-wide summary statistics. We estimated the risk of hospital or critical care admission within 28 days or death within 100 days following COVID-19 diagnosis, and assessed associations with socio-demographic factors, immunosuppressant use and morbidities reported at UK Biobank enrolment (2006-2010) and the PRS. To improve biological understanding, pathway analysis was performed using genetic variants comprising the PRS.

RESULTS

We included 9560 patients followed for a median of 61 (interquartile range = 34-88) days since COVID-19 diagnosis. The risk of severe COVID-19 increased with age and obesity, and was higher in men, current smokers, those living in socio-economically deprived areas, those with historic immunosuppressant use and individuals with morbidities and higher co-morbidity count. An optimized PRS, enriched for single-nucleotide polymorphisms in multiple immune-related pathways, including the 'oligoadenylate synthetase antiviral response' and 'interleukin-10 signalling' pathways, was associated with severe COVID-19 (adjusted odds ratio 1.32, 95% CI 1.11-1.58 for the highest compared with the lowest PRS quintile).

CONCLUSION

This study conducted in the pre-SARS-CoV-2-vaccination era, emphasizes the novel insights to be gained from using genetic data alongside commonly considered clinical and socio-demographic factors to develop greater biological understanding of severe COVID-19 outcomes.

Somatostatin receptor PET/MR imaging of large vessel inflammation in active compared with inactive vasculitis and atherosclerosis

Background

Use of 18F-FDG PET in large vessel vasculitis (LVV) is limited by non-specific uptake due to arterial remodelling and/or atherosclerosis leading to diagnostic uncertainty.

Purpose

To investigate somatostatin receptor 2 (SST2) as a novel inflammation-specific PET imaging target in LVV.

Methods

In a prospective observational cohort study, we tested the ability of PET/MRI using two somatostatin receptor tracers (68Ga-DOTATATE and 18F-FET-βAG-TOCA) to differentiate active from inactive LVV, and aortic atherosclerosis in patients with recent myocardial infarction. Ex vivo mapping of the imaging target was performed using immunofluorescence microscopy, imaging mass cytometry, and bulk, single-cell and single-nuclei RNA sequencing of temporal artery biopsies from LVV patients.

Results

Sixty-one participants were included (LVV, n=27; myocardial infarction ≤2 weeks, n=25; control subjects with an oncological indication for imaging, n=9). LVV patients (mean age 58 [SD 16] years; 78% female; 63% active or grumbling disease) had giant cell arteritis (n=13), Takayasu arteritis (n=13), or unspecified LVV (n=1). Baseline index vessel SST2 PET maximum tissue-to-blood ratio (TBRmax) was 61.8% (95% CI 31.5–99.0%, p&lt;0.0001) higher in patients with active/grumbling LVV than inactive LVV, and 34.6% (95% CI 15.1–57.6%, p=0.0002) higher than recent myocardial infarction (Fig. 1a–c; arrow: PET signal; arrowhead: aortic thickening; asterisk: aortic atherosclerosis), with good diagnostic accuracy (AUC ≥0.86, p&lt;0.001 for both). None of the control subjects without LVV or MI had increased arterial SST2 PET signal (Fig. 1d).

Mean aortic TBRmax was strongly correlated with Indian Takayasu Clinical Activity Score (r=0.82 [95% CI 0.46–0.95], p=0.001) and maximum wall thickness on MRI (r=0.68 [95% CI 0.31–0.87], p=0.002). SST2 PET/MRI was generally consistent with 18F-FDG PET/CT in LVV patients with contemporaneous scans (Fig. 1a, b), but with very low background signal in the brain and heart allowing for unimpeded assessment of nearby coronary, myocardial, and intracranial artery involvement. On follow-up imaging after a mean 9.3 (SD 3.2) months, clinically effective treatment for LVV was associated with a 0.49 ±SEM 0.24 (p=0.04; 22.3%) reduction in SST2 PET TBRmax, with good scan-scan repeatability in inactive LVV patients with no change in treatment (ICC 0.86, 95% CI 0.04–0.99).

SST2 localised to macrophages, pericytes, and perivascular adipocytes in inflamed arterial specimens (Fig. 2; a: H&E; b: imaging mass cytometry; arrow: SST2/CD68 co-staining). SSTR2-expressing macrophages co-expressed pro-inflammatory markers (S100A8, S100A9). Specific SST2 radioligand binding was confirmed by autoradiography in LVV specimens.

Conclusion

This is the first study to examine SST2 PET/MRI in LVV and to provide histological and gene expression data for validation. Here we show this novel approach holds major promise for diagnosis and therapeutic monitoring in LVV.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Wellcome Trust; Imperial NIHR Biomedical Research Centre

Non-Trough adalimumab and certolizumab drug levels associated with a therapeutic EULAR response in adherent patients with rheumatoid arthritis

OBJECTIVES

Interventions aimed at increasing tumour-necrosis factor-alpha inhibitor serum drug levels (SDLs) may improve treatment response; however, previous studies suggesting SDL cut-offs have not accounted for treatment adherence. The aim of this study was to establish the relationship between Adalimumab/Certolizumab SDLs and EULAR good vs non/moderate response, and to define SDL cut-offs associated with good response in fully adherent patients.

METHODS

In a prospective observational study, 475 patients with RA were treated with Certolizumab (n = 192) or Adalimumab (n = 283). At baseline, 3/6/12-months patients had DAS28, self-reported treatment adherence, and SDLs measured. Fully adherent patients were analysed as a subgroup. Follow-up data at 3/6/12-months was analysed separately. Median SDLs were compared in good vs non/moderate response, and receiver-operator characteristics curves (ROC) were used to establish cut-off SDLs.

RESULTS

Fully adherent good responders had significantly higher median Adalimumab/Certolizumab SDLs compared with non/moderate responders (p= 0·04 and p= 0·0005, respectively). ROC analysis reported 3-month non-trough Adalimumab SDLs discriminated good vs non/moderate response with an AUC of 0·63 (95% CI 0·52-0·75), with a cut-off of 7·5mg/l being 39·1% specific, and 80·9% sensitive. Similarly, 3-month non-trough Certolizumab SDLs discriminated good vs non/moderate response with an AUC of 0·65 (95% CI 0·51-0·78), with a cut-off of 26·0mg/l being 43·9% specific, and 77·8% sensitive.

CONCLUSION

In fully adherent patients, higher SDLs are detected in good responders suggesting that interventions to improve SDLs such as encouraging adherence could improve treatment response. 3-month non-trough SDL cut-offs of 7·5mg/l for Adalimumab and 26·0mg/l for Certolizumab may be useful in clinical practice.

Systemic Inflammation Is Associated With Future Risk of Fatal Infection: An Observational Cohort Study

BACKGROUND

Many diseases are associated with chronic inflammation, resulting in widening application of anti-inflammatory therapies. Although they are effective as disease-modifying agents, these anti-inflammatory therapies increase the risk of serious infection; however, it remains unknown whether chronic systemic inflammation per se is also associated with fatal infection.

METHODS

Using serum C-reactive protein (CRP) data from 461 052 UK Biobank participants, we defined incidence rate ratios (IRRs) for death from infection, cardiovascular disease, or other causes and adjusted for comorbidities and the use of anti-inflammatory therapies.

RESULTS

Systemic inflammation, defined as CRP ≥2 mg/L, was common in all comorbidities considered. After adjusting for confounding factors, systemic inflammation was associated with a higher IRR point estimate for infection death (1.70; 95% confidence interval [CI], 1.51-1.92) than cardiovascular (1.48; CI, 1.40-1.57) or other death (1.41; CI, 1.37-1.45), although CIs overlapped. C-reactive protein thresholds of ≥5 and ≥10 mg/L yielded similar findings, as did analyses in people with ≥2, but not <2, comorbidities.

CONCLUSIONS

Systemic inflammation per se identifies people at increased risk of infection death, potentially contributing to the observed risks of anti-inflammatory therapies in clinical trials. In future clinical trials of anti-inflammatory therapies, researchers should carefully consider risks and benefits in target populations, guided by research into mechanisms of infection risk.

Developing consensus in Histopathology: the role of the Delphi method

The Delphi method is a well-established research tool, used for consensus building across a number of fields. Despite its widespread use, and popularity in many medical specialities, there is a paucity of literature on the use of the Delphi method in Histopathology. This literature review seeks to critique the Delphi methodology and explore its potential applications to histopathology-based clinical and research questions. We review those published studies that have utilized the Delphi methodology in Histopathology settings and specifically outline the advantages and limitations of this technique, highlighting situations where its application can be most effective.

The Effect of Endogenous Cushing Syndrome on All-cause and Cause-specific Mortality

OBJECTIVE

We aimed to perform a systematic review and meta-analysis of all-cause and cause-specific mortality of patients with benign endogenous Cushing syndrome (CS).

METHODS

The protocol was registered in PROSPERO (CRD42017067530). PubMed, EMBASE, CINHAL, Web of Science, and Cochrane Central searches were undertaken from inception to January 2021. Outcomes were the standardized mortality ratio (SMR), proportion, and cause of deaths. The I2 test, subgroup analysis, and meta-regression were used to assess heterogeneity across studies.

RESULTS

SMR was reported in 14 articles including 3691 patients (13 Cushing disease [CD] and 7 adrenal CS [ACS] cohorts). Overall SMR was 3.0 (95% CI, 2.3-3.9; I2 = 80.5%) for all CS, 2.8 (95% CI, 2.1-3.7; I2 = 81.2%) for CD and 3.3 (95% CI, 0.5-6.6; I2 = 77.9%) for ACS. Proportion of deaths, reported in 87 articles including 19 181 CS patients (53 CD, 24 ACS, and 20 combined CS cohorts), was 0.05 (95% CI, 0.03-0.06) for all CS subtypes with meta-regression analysis revealing no differences between CS subtypes (P = .052). The proportion of deaths was 0.1 (10%) in articles published before 2000 and 0.03 (3%) in 2000 until the last search for CS (P < .001), CD (P < .001), and ACS (P = .01). The causes of death were atherosclerotic diseases and thromboembolism (43.4%), infection (12.7%), malignancy (10.6%), active disease (3.5%), adrenal insufficiency (3.0%), and suicide (2.2%). Despite improved outcomes in recent years, increased mortality from CS persists. The causes of death highlight the need to prevent and manage comorbidities in addition to treating hypercortisolism.

OA13 Comprehensive genetic and functional analyses of Fc gamma receptors explain response to rituximab therapy for autoimmune rheumatic diseases

Background/Aims

Rituximab is widely used to treat rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) but clinical response varies. Efficacy is determined by the efficiency of depletion, which may depend on a variety of Fc gamma receptor (FcγR)-dependent mechanisms. Previous research was limited by complexity of the FCGR locus, not integrating copy number variation with functional SNP, and small sample size. Here, we aimed to assess the effect of the full range of FcγRs variants on depletion, clinical response and functional effect on NK-cell-mediated killing in two rheumatic diseases with a view to personalised B-cell depleting therapies.

Methods

A prospective longitudinal study was conducted in 873 patients (RA = 611; SLE=262) from four cohorts (BSRBR-RA, BILAG-BR, Leeds RA and Leeds SLE Biologics). For RA, the outcome measures were 3C-DAS28CRP and 2C-DAS28CRP at 6 (+/-3) months post-rituximab (adjusted for baseline DAS28). For SLE, major clinical response (MCR) was defined as improvement of active BILAG-2004 domains to grade C/better at 6 months. B-cell depletion was evaluated by highly-sensitive flow cytometry. Qualitative and quantitative polymorphisms for five major FcγRs were measured using a commercial multiplex ligation-dependent probe amplification. Median NK cell FcγRIIIa expression (CD3-CD56+CD16+) and NK-cell degranulation (CD107a) in the presence of rituximab-coated Daudi/Raji B-cell lines were assessed using flow cytometry.

Results

In RA, for FCGR3A, carriage of V allele (coefficient -0.25 [SE 0.11]; p = 0.02) and increased copies of V allele (-0.20 [0.09]; p = 0.02) were associated with better 2C-DAS28 response. Irrespective of FCGR3A genotype, increased gene copies were associated with a better response. In SLE, 177/262 (67.6%) achieved BILAG response (MCR=34.4%; Partial=33.2%). MCR was associated with increased copies of FCGR3A-158V allele, OR 1.64 (95% CI 1.12-2.41) and FCGR2C-ORF allele 1.93 (1.09-3.40). Of patients with B-cells data in the combined cohort, 236/413 (57%) achieved complete depletion post-rituximab. Only homozygosity for V allele and higher copies of FCGR3A V allele were associated with increased odds of depletion. Patients with complete depletion had higher NK cell FcγRIIIa expression at rituximab initiation than those with incomplete depletion (p = 0.04) and this higher expression was associated with improved EULAR response in RA. Moreover, for FCGR3A, degranulation activity was increased in V allele carriers vs FF genotype in the combined cohort; p = 0.02.

Conclusion

FcγRIIIa is the major low affinity FcγR and increased copies of the FCGR3A-158V allele, encoding the allotype with a higher affinity for IgG1, was associated with clinical and biological responses to rituximab in two autoimmune diseases. This was supported by functional data on NK cell-mediated cytotoxicity. In SLE, increased copies of the FCGR2C-ORF allele was also associated with improved response. Our findings indicate that enhancing FcγR-effector functions could improve the next generation of CD20-depleting therapies and genotyping could stratify patients for optimal treatment protocols.

Disclosure

M. Md Yusof: None. J. Robinson: None. V. Davies: None. D. Wild: None. M. Morgan: None. J. Taylor: None. Y. El-Sherbiny: None. D. Morris: None. L. Liu: None. A. Rawstron: None. M. Buch: None. D. Plant: None. H. Cordell: None. J. Isaacs: None. I. Bruce: None. P. Emery: Grants/research support; PE has received consultancy fees and funding for research from Roche within the last 3 years. A. Barton: None. T. Vyse: None. J. Barrett: None. E. Vital: Grants/research support; EMV has received consultancy fees and funding for research from Roche within the last 3 years. A. Morgan: None.

OA24 Predicting drug immunogenicity to tumour necrosis factor inhibitors in patients with rheumatoid arthritis

Background/Aims

Rheumatoid arthritis (RA) is a chronic immune-mediated inflammatory disease that irreversibly damages synovial joints. Tumour necrosis factor inhibitors (TNFi) may be prescribed for patients with moderate to severe RA. However, approximately 40% of patients do not respond well to TNFi, with a lack of effectiveness underpinned by immunogenicity (development of anti-drug antibodies) in some patients. A recent well-powered study by Sazonovs et al. (2020) reported a strong genetic association between the HLA-DQA1 locus and immunogenicity to TNFi in a cohort of Crohn's disease patients treated with either infliximab or adalimumab. The current study aimed to investigate the association between HLA alleles, primarily HLA-DQA1, and immunogenicity to adalimumab in RA patients.

Methods

Anti-adalimumab antibody titres were measured using radioimmunoassay in serum samples from RA patients following six months of treatment. Genetic datasets were generated using the Illumina OmniExpress genotyping array and, following standard quality control filtering, variants were imputed using SNP2HLA statistical software. Following imputation, filtering was performed to exclude variants in linkage disequilibrium or with low minor allele frequency. Logistic regression models were developed to explore the association between HLA alleles and amino acids and immunogenicity (all models were adjusted for sex). Amino acid positions of interest were annotated using P2Rank; a ligand binding site prediction tool.

Results

A total of 171 HLA alleles and 339 amino acid positions were analysed in 226 RA patients. The strongest association observed between HLA alleles and immunogenicity was for HLA-DQB1*02 (coefficient = 0.87; 95% CI, 0.31-1.43; p value = 2.10E-3), followed by HLA-DQA1*05 (coefficient = 0.91; 95% CI, 0.29-1.53; p value = 3.95E-3). The strongest associated amino acid positions were amino acids 66 and 67 within the ligand binding domain of the HLA-DQB1 protein.

Conclusion

In keeping with previous findings in Crohn's disease, variants within HLA-DQ molecules confer the strongest evidence for immunogenicity risk in RA patients receiving adalimumab. RA patients carrying these variants could be redirected to receive etanercept, an effective alternative to monoclonal antibodies that is not immunogenic. Further well-powered studies in RA are now warranted to replicate these findings.

Disclosure

M. Alshehri: None. N. Nair: None. C. Yap: None. J.D. Isaacs: None. K. Hyrich: Honoraria; Abbvie. A.W. Morgan: None. A.G. Wilson: None. A. Barton: None. D. Plant: None.

OA26 Erythrocyte mean corpuscular volume as a surrogate marker for methotrexate polyglutamation during early treatment in rheumatoid arthritis

Background/Aims

The long-term outcomes for patients with rheumatoid arthritis (RA) depend on early and effective disease control. Methotrexate remains the key first-line disease-modifying therapy for the majority of patients. The gradual onset of action of methotrexate has been proposed to be linked to the build-up of intracellular stores of the drug, achieved through the process of polyglutamation. This is a complex and expensive assay. Recent work has shown an association between the increase in mean corpuscular volume (MCV) of erythrocytes and improvements in disease activity. This study seeks to relate intracellular methotrexate and 5-methyl-tetrahydrofolate polyglutamate concentrations with changes in MCV and their association with early ‘steroid free’ remission in RA patients.

Methods

68 drug-naïve, newly diagnosed RA patients were recruited form the Newcastle Early Arthritis Clinic (NEAC). These patients were followed up for 6 months with serial blood sampling and quantification of the erythrocyte methotrexate and 5-methyl-tetrahydrofolate polyglutamate levels by liquid chromatography-mass spectrometry (LC-MS). This was then related to the contemporaneous erythrocyte MCV values from the clinical monitoring bloods on those occasions and the treatment outcome at 6 months. The outcome measure used was 4 component DAS28CRP remission (&lt;2.4) with only the baseline intramuscular steroid permitted for the definition of remission.

Results

The majority of patients displayed a gradual increase in MCV over the first 6 months of treatment (MCV change from patient baseline used to normalise the data). When grouped by the ‘steroid free’ remission outcome, there was a divergence in MCV change with greater MCV increases observed in those achieving remission from 4 months of treatment onward (p &lt; 0.05). In the same patient group, the accumulation of longer chain methotrexate polyglutamates (chain length 3 to 5) was observed to follow a similar trend to MCV with higher polyglutamate concentrations in those achieving the remission outcome from 2 months of treatment (P &lt; 0.05). When the contemporaneous MCV and MTX polyglutamate samples were compared, an association was observed between the longer chain MTX polyglutamates and the change in MCV values (R2 = 0.39, p &lt; 0.001), but not between intracellular 5-methyl-tetrahydrofolate and MCV (R2 = 0.01, p = NS).

Conclusion

Change in MCV shows an association with early remission induction with MTX therapy in treatment-naïve RA patients. This change in MCV appears to be associated with the accumulation of intracellular MTX metabolites, rather than via depletion of intracellular folates. MCV may therefore represent a tractable proxy measure of methotrexate polyglutamation for application in larger studies or for the purpose of drug monitoring.

Disclosure

P.M. Brown: None. A.G. Pratt: None. A.E. Anderson: None. A.W. Morgan: None. J.D. Isaacs: None.

P189 A longitudinal study of psychological predictors of response to adalimumab in patients with rheumatoid arthritis

Background/Aims

The treatment of rheumatoid arthritis (RA) has improved since the introduction of targeted biological disease-modifying antirheumatic drugs (bDMARDs), such as adalimumab. However, no treatment options for RA are universally effective. Psychological factors may have an important role in treatment response. Published data reported that pre-treatment psychological variables such as an increased treatment necessity belief correlated with better adherence to adalimumab in RA patients. This current study aimed to investigate whether psychological factors correlate with change in 4V-DAS28-CRP as well as subcomponents of the score in adalimumab-treated RA patients.

Methods

Psychological, clinical and demographic data and DAS28 scores were collected pre-treatment, and at 3,6, and 12-months post-treatment, as part of a prospective national study, BRAGGSS. Sixteen pre-treatment clinical and psychological variables were tested for association with treatment response at 3 and 12 months. Multiple linear regression models were analysed and a Bonferroni corrected p-value of &lt; 0.003 was applied at each interval to assess significance.

Results

Data was available for 501 patients at 3 months follow up. Pre-treatment Beliefs about Medicine Questionnaire (BMQ) scores with regards to treatment necessity (P = 0.001), and two domains of the Illness Perception Questionnaire (IPQ), which were treatment belief and treatment control (P = 0.0001), correlated with the change in DAS28 by 3 months (Table 1). At 12 months, data were available for 362 patients. The treatment belief domain of the pre-treatment Illness Perception Questionnaire correlated with the change in tender joint count (P = 0.001) (Table 1). At 12 months no other sub-components correlated with the psychological variables.

Conclusion

Pre-treatment scores with regards to Illness Perception and Beliefs about Medicine correlated with 4V-DAS28-CRP response at 3 months. Of the subcomponents of DAS28, the psychological variables showed the highest correlation with tender joint count; as the tender joint count receives the highest weighting in the 4 variable DAS28 score, this may confound the assessment of treatment response. It will be necessary to undertake further analyses to assess the predictive value of these potentially modifiable psychological variables identified, but to also understand factors contributing to these psychological scores, such as the role of severe disease itself on psychological beliefs.

Disclosure

N. Raza: None. N. Nair: None. D. Plant: None. K. Hyrich: None. A.W. Morgan: None. J. Isaacs: None. A.G. Wilson: None. A. Barton: None.

P200 Combining protein quantitative trait and genetic risk score analysis to identify biomarkers of treatment response to TNFi in patients with rheumatoid arthritis

Background/Aims

Rheumatoid arthritis (RA) is an inflammatory joint disease that can lead to disability if inflammation is not controlled. Biologic disease modifying anti-rheumatic drugs (bDMARDs), including tumour necrosis factor inhibitors (TNFi), are an effective line of therapy for moderate to severe RA. However, treatment response to TNFi is not universal and cannot be predicted from clinical factors. In this study, a protein quantitative trait loci (pQTL) study and genetic risk score (GRS) analysis were combined to identify protein-based biomarkers that are predictive of TNFi treatment response.

Methods

Protein expression data were generated using Sequential Window Acquisition of All Theoretical Mass Spectra (SWATH-MS) in serum samples taken from 80 RA patients about to commence therapy with etanercept. Protein expression was log2 transformed and the k-nearest neighbour model was used to impute missing values. A pQTL study was performed in patients with available imputed genome-wide genetic variation data to detect cis-acting genetic markers (p &lt; 1E-05). GRS for pQTLs were subsequently tested in 1,430 RA patients with available genome-wide genetic and TNFi treatment response data (improvement in DAS28 between pre-treatment and 3/6 months on drug). The GRS analysis was adjusted for baseline disease activity, sex, conventional synthetic DMARD co-therapy and the first 10 principal components, calculated from the genetic datasets.

Results

Following imputation, expression levels for 271 proteins were analysed in 69 RA patients with available genotype data. 514 cis-pQTLs were found for 16 proteins. GRS for the proteins Apolipoprotein(a) (UniProt ID P08519, p = 0.017) and Carboxypeptidase N subunit 2 (P22792, p = 0.027) were found to be modestly associated with treatment response; however, scores for both proteins explained less than 1% of the variance in DAS28 difference between time-points.

Conclusion

This study identified two protein-based genetic biomarkers of treatment response to TNFi. However, genetic scores based on these proteins are unlikely to be useful predictors, explaining little variance in on-treatment disease activity.

Disclosure

Z. Li: None. S.F. Ling: None. N. Nair: None. J.D. Isaacs: None. K.L. Hyrich: Honoraria; Abbvie. A.W. Morgan: None. A.G. Wilson: None. A. Barton: None. D. Plant: None.

OA16 Therapeutic certolizumab pegol drug levels to achieve good EULAR response in patients with rheumatoid arthritis: results from the Biologics in Rheumatoid Arthritis Genetics and Genomics Study Syndicate (BRAGGSS) cohort

Background/Aims

Rheumatoid arthritis (RA) is a systemic inflammatory disease which is often treated with biologic disease-modifying anti-rheumatic drugs (bDMARDs) like tumour-necrosis factor inhibitors (TNFi) including certolizumab pegol (CTZ). A proportion of patients (approximately 30%) do not respond to treatment, and previous studies have shown that low drug levels and poor adherence are associated with poor response; however, an optimal drug level has not been defined or applied in clinical practice.

The aim of this analysis is to determine an optimal CTZ drug level associated with a “good” European Alliance of Associations for Rheumatology (EULAR) response in fully adherent and non-adherent patients with RA.

Methods

In a prospective observational cohort study, patients with RA were treated with CTZ. At baseline, and at 6 months, 4-component DAS28 scores, as well as self-reported treatment adherence data were collected. Drug levels were measured using ELISA during follow-up at 6 months from treatment initiation. Patients were considered fully adherent if they self-reported never having altered, forgotten or omitted any dose of their biologic drug at follow-up. Patients without drug levels were excluded.

In fully adherent patients, the relationship between random CTZ levels and clinical efficacy after 6 months was determined using a concentration-effect curve, and a receiver-operator characteristics (ROC) curve established a therapeutic cut-off concentration using the EULAR response classification.

Median drug levels in “good” EULAR responders were compared between adherent and non-adherent patients to provide an estimated therapeutic range.

Results

Of 347 RA patients taking CTZ recruited, 111 (32.0%) had drug levels and EULAR response measured at 6 months, of which 42 (37.8%) also provided self-reported treatment adherence data. Of those, 37 (88.1%) reported being fully adherent.

In 37 fully adherent RA patients taking CTZ, clinical efficacy was positively correlated with increasing CTZ concentration reaching a maximum median DAS28CRP improvement of 2.99 (IQR 2.67-3.40) with levels above 30mg/L. Levels exceeding 30mg/L showed no significant additional benefit. The ROC curve showed an area under the curve (AUC) of 0.714 (95% CI 0.526-0.901) for random CTZ levels with EULAR good response versus non/moderate responders. A cut-off of 30mg/L had a sensitivity and specificity of 86.4% and 60.0%, respectively, to classify good responders in fully adherent patients.

Fully adherent good responders (n = 37) had a median drug level of 34.5mg/L (IQR 31-38), whereas good responders in the remaining cohort (n = 76) had a median drug level of 23.5 (IQR 15-30).

Conclusion

In RA patients taking CTZ, random drug levels were higher in EULAR good responders, and in fully adherent patients. A target lower threshold drug level cut-off of 30mg/L or a target range from 23.5mg/L to 34.5mg/L may be useful in clinical practice.

Disclosure

R.M. Hum: None. P. Ho: None. N. Nair: None. D. Plant: None. A.W. Morgan: None. J.D. Isaacs: None. A.G. Wilson: None. K.L. Hyrich: None. A. Barton: None.

Oral 11β-HSD1 inhibitor AZD4017 improves wound healing and skin integrity in adults with type 2 diabetes mellitus: a pilot randomized controlled trial

BACKGROUND

Chronic wounds (e.g. diabetic foot ulcers) reduce the quality of life, yet treatments remain limited. Glucocorticoids (activated by the enzyme 11β-hydroxysteroid dehydrogenase type 1, 11β-HSD1) impair wound healing.

OBJECTIVES

Efficacy, safety, and feasibility of 11β-HSD1 inhibition for skin function and wound healing.

DESIGN

Investigator-initiated, double-blind, randomized, placebo-controlled, parallel-group phase 2b pilot trial.

METHODS

Single-center secondary care setting. Adults with type 2 diabetes mellitus without foot ulcers were administered 400 mg oral 11β-HSD1 inhibitor AZD4017 (n = 14) or placebo (n = 14) bi-daily for 35 days. Participants underwent 3-mm full-thickness punch skin biopsies at baseline and on day 28; wound healing was monitored after 2 and 7 days. Computer-generated 1:1 randomization was pharmacy-administered. Analysis was descriptive and focused on CI estimation. Of the 36 participants screened, 28 were randomized.

RESULTS

Exploratory proof-of-concept efficacy analysis suggested AZD4017 did not inhibit 24-h ex vivoskin 11β-HSD1 activity (primary outcome; difference in percentage conversion per 24 h 1.1% (90% CI: -3.4 to 5.5) but reduced systemic 11β-HSD1 activity by 87% (69-104%). Wound diameter was 34% (7-63%) smaller with AZD4017 at day 2, and 48% (12-85%) smaller after repeat wounding at day 30. AZD4017 improved epidermal integrity but modestly impaired barrier function. Minimal adverse events were comparable to placebo. Recruitment rate, retention, and data completeness were 2.9/month, 27/28, and 95.3%, respectively.

CONCLUSION

A phase 2 trial is feasible, and preliminary proof-of-concept data suggests AZD4017 warrants further investigation in conditions of delayed healing, for example in diabetic foot ulcers.

SIGNIFICANCE STATEMENT

Stress hormone activation by the enzyme 11β-HSD type 1 impairs skin function (e.g. integrity) and delays wound healing in animal models of diabetes, but effects in human skin were previously unknown. Skin function was evaluated in response to treatment with a 11β-HSD type 1 inhibitor (AZD4017), or placebo, in people with type 2 diabetes. Importantly, AZD4017 was safe and well tolerated. This first-in-human randomized, controlled, clinical trial found novel evidence that 11β-HSD type 1 regulates skin function in humans, including improved wound healing, epidermal integrity, and increased water loss. Results warrant further studies in conditions of impaired wound healing, for example, diabetic foot ulcers to evaluate 11β-HSD type 1 as a novel therapeutic target forchronic wounds.

Non-communicable disease, sociodemographic factors, and risk of death from infection: a UK Biobank observational cohort study

BACKGROUND

Non-communicable diseases (NCDs) have been highlighted as important risk factors for COVID-19 mortality. However, insufficient data exist on the wider context of infectious diseases in people with NCDs. We aimed to investigate the association between NCDs and the risk of death from any infection before the COVID-19 pandemic (up to Dec 31, 2019).

METHODS

For this observational study, we used data from the UK Biobank observational cohort study to explore factors associated with infection death. We excluded participants if data were missing for comorbidities, body-mass index, smoking status, ethnicity, and socioeconomic deprivation, and if they were lost to follow-up or withdrew consent. Deaths were censored up to Dec 31, 2019. We used Poisson regression models including NCDs present at recruitment to the UK Biobank (obesity [defined by use of body-mass index] and self-reported hypertension, chronic heart disease, chronic respiratory disease, diabetes, cancer, chronic liver disease, chronic kidney disease, previous stroke or transient ischaemic attack, other neurological disease, psychiatric disorder, and chronic inflammatory and autoimmune rheumatological disease), age, sex, ethnicity, smoking status, and socioeconomic deprivation. Separate models were constructed with individual NCDs replaced by the total number of prevalent NCDs to define associations with multimorbidity. All analyses were repeated with non-infection-related death as an alternate outcome measure to establish differential associations of infection death and non-infection death. Associations are reported as incidence rate ratios (IRR) accompanied by 95% CIs.

FINDINGS

After exclusion of 9210 (1·8%) of the 502 505 participants in the UK Biobank cohort, our study sample comprised 493 295 individuals. During 5 273 731 person-years of follow-up (median 10·9 years [IQR 10·1-11·6] per participant), 27 729 deaths occurred, of which 1385 (5%) were related to infection. Advancing age, male sex, smoking, socioeconomic deprivation, and all studied NCDs were independently associated with the rate of both infection death and non-infection death. Compared with White ethnicity, a pooled Black, Asian, and minority ethnicity group was associated with a reduced risk of infection death (IRR 0·64, 95% CI 0·46-0·87) and non-infection death (0·80, 0·75-0·86). Stronger associations with infection death than with non-infection death were observed for advancing age (age 65 years vs 45 years: 7·59, 95% CI 5·92-9·73, for infection death vs 5·21, 4·97-5·48, for non-infection death), current smoking (vs never smoking: 3·69, 3·19-4·26, vs 2·52, 2·44-2·61), socioeconomic deprivation (most vs least deprived quintile: 2·13, 1·78-2·56, vs 1·38, 1·33-1·43), class 3 obesity (vs non-obese: 2·21, 1·74-2·82, vs 1·55, 1·44-1·66), hypertension (1·36, 1·22-1·53, vs 1·15, 1·12-1·18), respiratory disease (2·21, 1·96-2·50, vs 1·28, 1·24-1·32), chronic kidney disease (5·04, 4·28-7·31, vs 2·50, 2·20-2·84), psychiatric disease (1·56, 1·30-1·86, vs 1·23, 1·18-1·29), and chronic inflammatory and autoimmune rheumatological disease (2·45, 1·99-3·02, vs 1·41, 1·32-1·51). Accrual of multimorbidity was also more strongly associated with risk of infection death (five or more comorbidities vs none: 9·53, 6·97-13·03) than of non-infection death (5·26, 4·84-5·72).

INTERPRETATION

Several NCDs are associated with an increased risk of infection death, suggesting that some of the reported associations with COVID-19 mortality might be non-specific. Only a subset of NCDs, together with the accrual of multimorbidity, advancing age, smoking, and socioeconomic deprivation, were associated with a greater IRR for infection death than for other causes of death. Further research is needed to define why these risk factors are more strongly associated with infection death, so that more effective preventive strategies can be targeted to high-risk groups.

FUNDING

British Heart Foundation.

Mortality and Specific Causes of Death in Endogenous Cushing’s Syndrome: A Systematic Review, Meta-Analysis and Meta-Regression

Background: Endogenous Cushing’s syndrome (CS) refers to an inappropriate hypercortisolism usually caused by either Cushing’s disease (CD) or adrenal CS (ACS). CS results in significant morbidity and excess mortality if untreated. Even in treated cases there is often a significant health burden. Due to the rarity of CS (incidence ~ 1/1M population), single cohort studies have insufficient power for reporting accurate mortality data. Only one previous systematic review and meta-analysis for CS has been reported that limited its scope to the inclusion of specific CD subgroup. Aims: To perform a meta-analysis and meta-regression analysis of all-cause and specific cause -mortality amongst patients with benign endogenous CS. Methods: The protocol was registered in PROSPERO (CRD42017067530). Searches were undertaken of PubMed, EMBASE, CINHAL, web of science and Cochrane Central from start until April 2019. The primary outcomes were proportion of mortality and SMR. The meta-analysis was done with STATA version 16.1 software. The I2 test, subgroup analysis and meta-regression statistics were used to assess heterogeneity among included studies. Results: A total of 11,527 articles, were retrieved. 87 articles with 100 study cohorts containing 17,276 CS patients reporting mortality were included. Fifty-three study cohorts reported Cushing’s disease (CD) patients, 27 study cohorts reported for adrenal CS patients and 20 studies cohorts reported on both types of CS. The overall SMR of all type CS was 2.91 (95% CI 2.41–3.68) with I2 =40.3%. The SMR for CD was 3.27 (95% CI 2.33–4.21) with I2 = 55.6%. The SMR in ACS was 1.62 (95% CI 0.08–3.16) with I2 =0.0%. The overall proportion of death in CS was 0.05 (95% CI 0.03–0.06) with I2 =51.86%; in CD was 0.04 (95% CI 0.03–0.06) with I2 = 62.7% and in ACS 0.06 (95% CI 0.04–0.11) with I2 = 40.3 %. The proportion of death during the 30-day operative period was highest before 1991 at 0.07 and decreased to 0.03 in 1991–2000 to 0.01 in 2001–2010 and zero after 2011. The causes of death reported across 64 studies were cardiac causes (24.7%), infection (14.4%), cerebrovascular diseases (9.4%), malignancy (9.0%), thromboembolism (4.2%), active disease (2.9%), and adrenal insufficiency (2.7%). Conclusion: CS is associated with increase in overall mortality. Advances in operative techniques and care have decreased peri-operative mortality over a 20 year period. The causes of death highlight the need for aggressive management of cardiovascular risk, prevention of thrombo-embolism, infection control and a normalised cortisol level.

Real World Mortality and Specific Causes of Death in Chronic Oral Glucocorticoid Use: A Systematic Review, Meta-Analysis and Meta-Regression

Background: Glucocorticoids (GCs) are widely used as therapeutic agents with prevalence 0.9–3.7%, but they are associated with significant side effects. Understanding of mortality ratios and causes of death from GC use is poorly appreciated and likely to help shape future stratification of clinical practice. Aims: To perform a meta-analysis of all-cause and specific cause -mortality amongst chronic GC users. Methods: The protocol was registered in PROSPERO (CRD42017067530). Searches were undertaken of PubMed, EMBASE, CINHAL, web of science and Cochrane Central from 1966 to April 2019. The primary outcomes were proportion of death and SMR in chronic GC use patients. The meta-analysis was performed with STATA version 16.1. The I2, subgroup analysis and meta-regression were used to assess heterogeneity among included studies. Results: A total of 109,511 articles, were screened. One hundred eighteen articles with 128 patient cohorts containing 51,374 patients reporting mortality fulfilled the eligibility criteria and were included in the meta-analysis. SMR from seven autoimmune/inflammatory disease studies was 1.84 (95%CI 1.27,2.41) with I2 70.2 6%. The proportion of overall death was 0.12 (95% CI 0.1, .014) with I2 89.3%. The proportion of death was 0.18 (95% CI 0.13,0.24) with I2 92.0% in vasculitis diseases (40 studies), 0.10 (95% CI 0.08, 0.13) with I2 86.2% in connective tissue diseases (67 studies), 0.07 (95% CI 0.03, 0.13) with I2 88.7% in inflammatory diseases (15 studies), 0.28 (95% CI 0.21–0.37) with I2 0.0% in haematologic diseases (2 studies), and 0.06 (95% CI 0.05, 0.09) with I2 0.0% in respiratory diseases (3 studies). GC prescription reports were different across studies and led to different prediction of mortality with high heterogeneity. Proportion of death amongst a GC cumulative dose of 0.3 to 3.9 gram, 4.0 to 7.3 gram and 7.4 to 36.7 gram were 0.11 (95% CI 0.06, 0.20), 0.04 (95% CI 0.02, 0.08) and 0.16 (95% CI 0.08, 0.28), respectively. The proportion of deaths predicted by average mean dose of ≥ 5mg/d, &gt;5–7.5 mg/d, &gt;7.5–10 mg/d and &gt;10–30 mg/d were 0.02 (95% CI 0.01, 0.10), 0.15 (95% CI 0.15, 0.16), 0.08 (95% CI 0.03, 0.19) and 0.14 (95% CI 0.11, 0.19), respectively. The proportion of death predicted by a maintenance dose of ≥5mg/d, &gt;5–7.5 mg/d, &gt;7.5–10 mg/d and &gt;10–30 mg/d were 0.08 (95% CI 0.05, 0.13), 0.12(95% CI 0.05, 0.23), 0.11(95% CI 0.06, 0.210) and 0.12(95% CI 0.05, 0.24) respectively. The causes of death (77 studies) were cardiac (25.3%), infection (13.2%), malignancy (15.6%), respiratory failure (10.6%), active underlying disease (4.4%), cerebrovascular disease (1.1%) and thromboembolism (0.9%). Conclusion: This is the first meta-analysis of oral GC use and mortality from real-world clinical practice publications. Multiple factors contribute to mortality, including GC dose, duration of exposure, route, preparation, together with patient and disease-specific factors.

Evaluating tertiary adrenal insufficiency in rheumatology patients on long-term systemic glucocorticoid treatment

OBJECTIVE

Patients with rheumatic diseases are often treated with prolonged, high-dose systemic glucocorticoids which can cause hypothalamic-pituitary-adrenal (HPA) axis suppression and development of tertiary adrenal insufficiency. Adrenal insufficiency carries the risk of serious, potentially life-threatening adrenal crisis. Our study evaluated the prevalence, characteristics and recovery of patients with underlying rheumatology conditions who had received prolonged glucocorticoid treatment.

DESIGN AND PATIENTS

Retrospective, cross-sectional study. We evaluated 238 patients seen in outpatient rheumatology clinic, managed in accordance with current nationally and internationally accepted clinical guidelines.

MEASUREMENTS

Data collected included patient demographics, historical steroid data, 09.00 h cortisol/short synacthen test (SST) results and follow-up data on those with repeat assessments.

RESULTS

Overall, 65% of our cohort had a 09.00 h cortisol <350 nmol/L. On SST, 43% of patients demonstrated evidence of possible tertiary adrenal insufficiency. Prednisolone equivalent dose at time of SST was significantly higher in the group who failed SST vs. those who passed; mean of 5.57 mg vs. 3.59mg (p = .005). 09.00 h cortisol result correlated with 30-min cortisol on SST (R²  = .20, p = .002). 0-min cortisol on SST correlated more strongly with 30-min cortisol than 09.00 h cortisol (R²  = .59, p-value < .001). Patients with 0-min cortisol >350 nmol/L, all passed their SST. Patients who remained on prednisolone were more likely to recover (71%) vs. those switched to hydrocortisone (27%), P = .02. Peak steroid dose was predictive of recovery; significantly lower in those who recovered (mean of 22.3 mg vs. 33.8 mg, P = .03). Steroid duration was not found to be a predictor of recovery [recovery (64.2 months) vs. non-recovery (55.6 months), P = .58]. There was no correlation found to outcome on SST with age, sex, peak steroid dose, steroid duration, underlying rheumatological condition, additional exogenous steroid use or serum sodium.

CONCLUSIONS

Forty three percent of our patients demonstrated sub-optimal adrenal function on SST. Steroid dose at the time of SST was the only significant predictive risk factor for tertiary adrenal insufficiency. 09.00 h cortisol demonstrated good correlation with outcome on SST and could represent a valid screening test to reduce need for SST if 09.00 h >350 nmol/L. Further prospective data are required to further characterize risk factors, predictive features of recovery and establish optimal management strategy of steroids (prednisolone vs hydrocortisone) to encourage adrenal recovery.

Dose-dependent oral glucocorticoid cardiovascular risks in people with immune-mediated inflammatory diseases: A population-based cohort study

BACKGROUND

Glucocorticoids are widely used to reduce disease activity and inflammation in patients with a range of immune-mediated inflammatory diseases. It is uncertain whether or not low to moderate glucocorticoid dose increases cardiovascular risk. We aimed to quantify glucocorticoid dose-dependent cardiovascular risk in people with 6 immune-mediated inflammatory diseases.

METHODS AND FINDINGS

We conducted a population-based cohort analysis of medical records from 389 primary care practices contributing data to the United Kingdom Clinical Practice Research Datalink (CPRD), linked to hospital admissions and deaths in 1998-2017. We estimated time-variant daily and cumulative glucocorticoid prednisolone-equivalent dose-related risks and hazard ratios (HRs) of first all-cause and type-specific cardiovascular diseases (CVDs). There were 87,794 patients with giant cell arteritis and/or polymyalgia rheumatica (n = 25,581), inflammatory bowel disease (n = 27,739), rheumatoid arthritis (n = 25,324), systemic lupus erythematosus (n = 3,951), and/or vasculitis (n = 5,199), and no prior CVD. Mean age was 56 years and 34.1% were men. The median follow-up time was 5.0 years, and the proportions of person-years spent at each level of glucocorticoid daily exposure were 80% for non-use, 6.0% for <5 mg, 11.2% for 5.0-14.9 mg, 1.6% for 15.0-24.9 mg, and 1.2% for ≥25.0 mg. Incident CVD occurred in 13,426 (15.3%) people, including 6,013 atrial fibrillation, 7,727 heart failure, and 2,809 acute myocardial infarction events. One-year cumulative risks of all-cause CVD increased from 1.4% in periods of non-use to 8.9% for a daily prednisolone-equivalent dose of ≥25.0 mg. Five-year cumulative risks increased from 7.1% to 28.0%, respectively. Compared to periods of non-glucocorticoid use, those with <5.0 mg daily prednisolone-equivalent dose had increased all-cause CVD risk (HR = 1.74; 95% confidence interval [CI] 1.64-1.84; range 1.52 for polymyalgia rheumatica and/or giant cell arteritis to 2.82 for systemic lupus erythematosus). Increased dose-dependent risk ratios were found regardless of disease activity level and for all type-specific CVDs. HRs for type-specific CVDs and <5.0-mg daily dose use were: 1.69 (95% CI 1.54-1.85) for atrial fibrillation, 1.75 (95% CI 1.56-1.97) for heart failure, 1.76 (95% CI 1.51-2.05) for acute myocardial infarction, 1.78 (95% CI 1.53-2.07) for peripheral arterial disease, 1.32 (95% CI 1.15-1.50) for cerebrovascular disease, and 1.93 (95% CI 1.47-2.53) for abdominal aortic aneurysm. The lack of hospital medication records and drug adherence data might have led to underestimation of the dose prescribed when specialists provided care and overestimation of the dose taken during periods of low disease activity. The resulting dose misclassification in some patients is likely to have reduced the size of dose-response estimates.

CONCLUSIONS

In this study, we observed an increased risk of CVDs associated with glucocorticoid dose intake even at lower doses (<5 mg) in 6 immune-mediated diseases. These results highlight the importance of prompt and regular monitoring of cardiovascular risk and use of primary prevention treatment at all glucocorticoid doses.

Pharmacogenetics of TNF inhibitor response in rheumatoid arthritis utilizing the two-component disease activity score

Aim:

TNF inhibitor drugs are a treatment option for rheumatoid arthritis, but response is not universal. Response is typically measured using the composite 4-component (4C) disease activity score 28 (DAS28) which contains more subjective measures. This study used a validated 2-component (2C) DAS28 score to determine whether SNPs associated with response were replicated in the UK population.

Materials & methods:

A literature review identified TNF inhibitor response SNPs. Linear regression was conducted to replicate associations with 4C or 2C-DAS28 response.

Results:

Eighteen independent SNPs were analyzed in 1828 patients. One and four associations with 4C and 2C-DAS28 response respectively were identified (p ≤ 0.05).

Conclusion:

Further genetic associations were replicated using the 2C-DAS28 which may reflect the objective nature of 2C-AS28.

Latent Class Trajectory Modeling of 2-Component Disease Activity Score in 28 Joints Identifies Multiple Rheumatoid Arthritis Phenotypes of Response to Biologic Disease-Modifying Antirheumatic Drugs

OBJECTIVE

To determine whether using a reweighted disease activity score that better reflects joint synovitis, i.e., the 2-component Disease Activity Score in 28 joints (DAS28) (based on swollen joint count and C-reactive protein level), produces more clinically relevant treatment outcome trajectories compared to the standard 4-component DAS28.

METHODS

Latent class mixed modeling of response to biologic treatment was applied to 2,991 rheumatoid arthritis (RA) patients in whom treatment with a biologic disease-modifying antirheumatic drug was being initiated within the Biologics in Rheumatoid Arthritis Genetics and Genomics Study Syndicate cohort, using both 4-component and 2-component DAS28 scores as outcome measures. Patient groups with similar trajectories were compared in terms of pretreatment baseline characteristics (including disability and comorbidities) and follow-up characteristics (including antidrug antibody events, adherence to treatments, and blood drug levels). We compared the trajectories obtained using the 4- and 2-component scores to determine which characteristics were better captured by each.

RESULTS

Using the 4-component DAS28, we identified 3 trajectory groups, which is consistent with previous findings. We showed that the 4-component DAS28 captures information relating to depression. Using the 2-component DAS28, 7 trajectory groups were identified; among them, distinct groups of nonresponders had a higher incidence of respiratory comorbidities and a higher proportion of antidrug antibody events. We also identified a group of patients for whom the 2-component DAS28 scores remained relatively low; this group included a high percentage of patients who were nonadherent to treatment. This highlights the utility of both the 4- and 2-component DAS28 for monitoring different components of disease activity.

CONCLUSION

Here we show that the 2-component modified DAS28 defines important biologic and clinical phenotypes associated with treatment outcome in RA and characterizes important underlying response mechanisms to biologic drugs.

Differential DNA methylation correlates with response to methotrexate in rheumatoid arthritis

OBJECTIVES

Identifying blood-based biomarkers that predict treatment response in RA is a clinical priority. We investigated differential DNA methylation as a candidate biomarker of response for the first-line drug used in RA, MTX.

METHODS

DNA methylation was measured in DNA samples from individuals recruited to the Rheumatoid Arthritis Medication Study. Differentially methylated positions were compared between whole blood samples collected at baseline and at 4 weeks from patients who, by 6 months, had a good (n = 34) or poor response (n = 34) to MTX using linear modelling, adjusting for gender, age, cell composition, baseline 28-joint disease activity score (DAS28) and smoking status. Analyses also compared methylation with changes in DAS28 and changes in swollen joint count and tender joint count, and changes in CRP over the initial 6 months after MTX commencement. Differentially methylated positions showing significant differences with any response parameter were tested using pyrosequencing in an independent group of 100 patients from the Rheumatoid Arthritis Medication Study.

RESULTS

In the discovery group, two CpG sites showed methylation changes at 4 weeks associated with clinical EULAR response by 6 months. Significant changes in methylation for three differentially methylated positions associated with change in tender joint counts, three with change in swollen joint count and a further four with change in CRP. Of the 12 CpGs, four showed replicated association in an independent dataset of samples from the Rheumatoid Arthritis Medication Study.

CONCLUSION

These data represent an advance on current practice by contributing to a personalized medicine strategy allowing an escalation or change in therapy as early as 4 weeks.

MON-157 The Effect of Exogenous Cushing’s Syndrome on All-Cause and Cause-Specific Mortality: A Systematic Review

Chronic oral glucocorticoid (GC) exposure from therapeutic anti-inflammatory or immunosuppressive use is the most common cause of Cushing’s syndrome (CS). Previous studies of glucocorticoid therapy and mortality have produced inconsistent results and systematic reviews have only focused on endogenous CS. This is the first study that aimed to investigate all-cause and cause-specific mortality in association with exogenous CS from chronic oral GC therapy. The protocol was designed according to the principles of the PRISMA statement and registered in PROSPERO reference CRD42017067530. A literature review was performed in PubMed/MEDLINE (1966 to 31 Mar 2019), EMBASE (1974 to 31 Mar 2019), web of science (1900 to 31 Mar 2019), CINAHL (1981 to 31 Mar 2019) and reference lists within selected articles. Of 104,064 studies, 127 met the inclusion criteria, encompassing 51,380 patients. The Risk Of Bias In Non-randomized Studies of Interventions (ROBIN-I) tool was chosen and modified for evaluation of quality. The weighted percentage mortality by 5 groups of diseases including vasculitis, connective tissue diseases, inflammatory diseases, haematologic diseases and respiratory tract diseases, was 18.1, 12.7, 16.1, 28.2 and 5.7, respectively. The leading causes of death were cardiovascular disease (25.6%), malignancy (15.6 %), infection (13.4) and respiratory failure (10.8%). Although these studies showed high mortality in patients exposed to GC, estimates were not adjusted for known confounders and available data do not allow disentangling the relative contribution of CS vs. the underlying disease or non-GC immunosuppressive therapies. More extensive, high quality, prospective studies are needed to evaluate these associations and to identify modifiable risk factors.

Oral glucocorticoids and incidence of hypertension in people with chronic inflammatory diseases: a population-based cohort study

BACKGROUND

Only a few population-based studies have examined the association between glucocorticoids and hypertension, with inconsistent results. We aimed to investigate the effect of oral glucocorticoids on incidence of hypertension in adults with chronic inflammatory diseases.

METHODS

We analyzed electronic health records from 389 practices in England during 1998-2017 of adults diagnosed with any of 6 chronic inflammatory diseases but with no previous diagnosis of hypertension. We used glucocorticoid prescription data to construct time-variant daily and cumulative variables of prednisolone-equivalent dose (cumulated from 1 year before the start of follow-up) and estimated incidence rates and adjusted hazard ratios (HRs) for hypertension using Cox regression analysis.

RESULTS

Among 71 642 patients in the cohort, 24 896 (34.8%) developed hypertension during a median follow-up of 6.6 years. The incidence rate of hypertension was 46.7 (95% confidence interval [CI] 46.0-47.3) per 1000 person-years. Incidence rates increased with higher cumulative glucocorticoid prednisolone-equivalent dose, from 44.4 per 1000 person-years in periods of nonuse to 45.3 per 1000 person-years for periods with between > 0.0 and 959.9 mg (HR 1.14, 95% CI 1.09-1.19), to 49.3 per 1000 person-years for periods with 960-3054.9 mg (HR 1.20, 95% CI 1.14-1.27), and to 55.6 per 1000 person-years for periods with ≥ 3055 mg (HR 1.30, 95% CI 1.25-1.35). Cumulative effects were seen for the 6 diseases studied, but dose-response effects were not found for daily dose.

INTERPRETATION

Cumulative dose of oral glucocorticoids was associated with increased incidence of hypertension, suggesting that blood pressure should be monitored closely in patients routinely treated with these drugs. Given that glucocorticoids are widely prescribed, the associated health burden could be high. Trial registration: ClinicalTrials. gov, no. NCT03760562.

Incidence of infections associated with oral glucocorticoid dose in people diagnosed with polymyalgia rheumatica or giant cell arteritis: a cohort study in England

BACKGROUND

Most patients with polymyalgia rheumatica or giant cell arteritis are treated with glucocorticoid therapy in primary care. We estimated dose-response risks of infection for this population in England.

METHODS

We conducted a retrospective record-linkage study involving a cohort of people with polymyalgia rheumatica or giant cell arteritis registered in family practices across England (1998-2017). Estimates of first occurring infection per level of time-variant current and cumulative dose were obtained using Kaplan-Meier methods and multilevel proportional-hazards Cox models.

RESULTS

Of 39 938 patients attending 389 family practices, 22 234 (55.7%) had at least 1 infection over a median follow-up period of 4.8 years, with 5937 (26.7%) requiring hospital admission and 1616 (7.3%) dying within 7 days of diagnosis. Cumulative risks of all-cause infection were 18.3% (95% confidence interval [CI] 17.9%-18.7%) at 1 year, 54.7% (95% CI 54.1%-55.2%) at 5 years and 76.9% (95% CI 76.2%-77.5%) at 10 years. Lower respiratory tract infections, conjunctivitis and herpes zoster were the most commonly diagnosed infections. The increases in adjusted hazard ratios (HRs) for all-cause infection per 5 mg prednisolone-equivalent daily dose increase and per 1000 mg cumulative dose increase in the last year from the patient's end date of follow-up were 1.13 (95% CI 1.12-1.14) and 1.50 (95% CI 1.49-1.52), respectively. Adjusted HRs associated with periods of current glucocorticoid versus no glucocorticoid use ranged from 1.48 (95% CI 1.39-1.57) for fungal to 1.70 (95% CI 1.60-1.80) for bacterial infection. Stepwise dose-related associations were found for bacterial, viral, parasitic and fungal infections, irrespective of patient age, duration of underlying chronic disease and baseline vaccination status.

INTERPRETATION

We quantified the excess risk of all-cause, bacterial, viral, parasitic and fungal infection conferred by oral glucocorticoids in people with polymyalgia rheumatica or giant cell arteritis and found strong dose responses for all types, even at daily doses of less than 5 mg prednisolone.

Standardized protocols for differentiation of THP-1 cells to macrophages with distinct M(IFNγ+LPS), M(IL-4) and M(IL-10) phenotypes

In vitro models of differing macrophage functions are useful since human monocyte-derived macrophages are short-lived, finite and vary from donor to donor. Published protocols using the promonocytic cell line THP-1 have tended to result in cells that closely resemble classically-activated macrophages, differentiated in IFNγ and LPS. However, no protocol, to date, has fully recapitulated polarization of THP-1 to the M(IL-4) or M(IL-10) macrophage phenotypes seen when human monocyte-derived macrophages are exposed to each cytokine. Here we present protocols that can be used to prepare M(IL-4) polarized THP-1 that transcribe CCL17, CCL26, CD200R and MRC1 and M(IL-10) cells which transcribe CD163, C1QA and SEPP1. We show that the inhibitory Fcγ Receptor IIb is preferentially expressed on the surface of M(IL-4) cells, altering the balance of activating to inhibitory Fcγ Receptors. Adoption of standardized experimental conditions for macrophage polarization will make it easier to compare downstream effector functions of different macrophage polarization states, where the impact of PMA exposure is minimized and rest periods and cytokine exposure have been optimized.

Genetic associations with radiological damage in rheumatoid arthritis: Meta-analysis of seven genome-wide association studies of 2,775 cases

BACKGROUND

Previous studies of radiological damage in rheumatoid arthritis (RA) have used candidate-gene approaches, or evaluated single genome-wide association studies (GWAS). We undertook the first meta-analysis of GWAS of RA radiological damage to: (1) identify novel genetic loci for this trait; and (2) test previously validated variants.

METHODS

Seven GWAS (2,775 RA cases, of a range of ancestries) were combined in a meta-analysis. Radiological damage was assessed using modified Larsen scores, Sharp van Der Heijde scores, and erosive status. Single nucleotide polymophsim (SNP) associations with radiological damage were tested at a single time-point using regression models. Primary analyses included age and disease duration as covariates. Secondary analyses also included rheumatoid factor (RF). Meta-analyses were undertaken in trans-ethnic and European-only cases.

RESULTS

In the trans-ethnic primary meta-analysis, one SNP (rs112112734) in close proximity to HLA-DRB1, and strong linkage disequilibrium with the shared-epitope, attained genome-wide significance (P = 4.2x10-8). In the secondary analysis (adjusting for RF) the association was less significant (P = 1.7x10-6). In both trans-ethnic primary and secondary meta-analyses 14 regions contained SNPs with associations reaching P<5x10-6; in the European primary and secondary analyses 13 and 10 regions contained SNPs reaching P<5x10-6, respectively. Of the previously validated SNPs for radiological progression, only rs660895 (tagging HLA-DRB1*04:01) attained significance (P = 1.6x10-5) and had a consistent direction of effect across GWAS.

CONCLUSIONS

Our meta-analysis confirms the known association between the HLA-DRB1 shared epitope and RA radiological damage. The lack of replication of previously validated non-HLA markers highlights a requirement for further research to deliver clinically-useful prognostic genetic markers.

Rapid visual recovery following intravenous tocilizumab in glucocorticoid resistant refractory giant cell arteritis

A 72-year-old man presented with a short history of headache, jaw claudication, double vision, amaurosis fugax and distended temporal arteries. A diagnosis of giant cell arteritis (GCA) was confirmed on temporal artery ultrasound and temporal artery biopsy. Despite treatment with high-dose oral glucocorticoid (GC) and multiple pulses of intravenous methylprednisolone, his vision deteriorated to hand movements in one eye. 8 mg/kg intravenous tocilizumab, a humanised, recombinant anti-IL-6 receptor antibody, was administered within 48 hours of vision loss and continued monthly, resulting in marked visual improvement within days, as well as sustained remission of GCA. This case suggests a possible role for tocilizumab as a rescue therapy to prevent or recover visual loss in patients with GCA resistant to GC treatment, termed refractory GCA. Further research is required to elucidate the role of intravenous administration of tocilizumab in this setting.

Association of response to TNF inhibitors in rheumatoid arthritis with quantitative trait loci for CD40 and CD39

OBJECTIVES

We sought to investigate whether genetic effects on response to TNF inhibitors (TNFi) in rheumatoid arthritis (RA) could be localised by considering known genetic susceptibility loci for relevant traits and to evaluate the usefulness of these genetic loci for stratifying drug response.

METHODS

We studied the relation of TNFi response, quantified by change in swollen joint counts ( Δ SJC) and erythrocyte sedimentation rate ( Δ ESR) with locus-specific scores constructed from genome-wide assocation study summary statistics in 2938 genotyped individuals: 37 scores for RA; scores for 19 immune cell traits; scores for expression or methylation of 93 genes with previously reported associations between transcript level and drug response. Multivariate associations were evaluated in penalised regression models by cross-validation.

RESULTS

We detected a statistically significant association between Δ SJC and the RA score at the CD40 locus (p=0.0004) and an inverse association between Δ SJC and the score for expression of CD39 on CD4 T cells (p=0.00005). A previously reported association between CD39 expression on regulatory T cells and response to methotrexate was in the opposite direction. In stratified analysis by concomitant methotrexate treatment, the inverse association was stronger in the combination therapy group and dissipated in the TNFi monotherapy group. Overall, ability to predict TNFi response from genotypic scores was limited, with models explaining less than 1% of phenotypic variance.

CONCLUSIONS

The association with the CD39 trait is difficult to interpret because patients with RA are often prescribed TNFi after failing to respond to methotrexate. The CD39 and CD40 pathways could be relevant for targeting drug therapy.

Dose dependency of iatrogenic glucocorticoid excess and adrenal insufficiency and mortality: a cohort study in England

CONTEXT

Adrenal insufficiency and Cushing's syndrome are known adverse events of glucocorticoids. However, no population estimates of dose-related risks are available.

OBJECTIVE

To investigate dose-related risks of adrenal dysfunction and death in adults with six chronic inflammatory diseases treated with oral glucocorticoids.

DESIGN AND SETTING

Retrospective record-linkage open-cohort study spanning primary and hospital care in England.

PATIENTS

70,638 people oral glucocorticoid-users and 41,166 non-users aged ≥18 years registered in 389 practices in 1998-2017.

MAIN OUTCOME MEASURES

Incidence rates and hazard ratios (HRs) of diagnosed adrenal dysfunction and death.

RESULTS

During a median follow-up of 5.5 years, 183 patients had glucocorticoid-induced adrenal insufficiency and 248 glucocorticoid-induced Cushing's syndrome. A total of 22,317 (31.6%) and 7,544 (18.3%) deaths occurred amongst glucocorticoid users and non-users, respectively. Incidence of all outcomes increased with higher current daily and cumulative doses. For adrenal insufficiency, the increases in HRs were of 1.07 (95% CI 1.04-1.09) for every increase of 5mg per day and of 2.25 (95% CI 2.15-2.35) per 1000mg of cumulative prednisolone-equivalent dose over the past year. The respective increases in HRs for Cushing's syndrome were of 1.09 (95% CI 1.08-1.11) and 2.31 (95% CI 2.23-2.40) and for mortality of 1.26 (95% CI 2.24-1.28) and 2.05 (95% CI 2.04-2.06).

CONCLUSION

We report a high glucocorticoid dose-dependent increased risk of adrenal adverse events and death. The low observed absolute risk of adrenal insufficiency highlights a potential lack of awareness, and a need for increased physician and patient education about the risks of adrenal dysfunction induced by glucocorticoids.