Longitudinal analysis of blood DNA methylation identifies mechanisms of response to tumor necrosis factor inhibitor therapy in rheumatoid arthritis.

BACKGROUND: Rheumatoid arthritis (RA) is a chronic, immune-mediated inflammatory disease of the joints that has been associated with variation in the peripheral blood methylome. In this study, we aim to identify epigenetic variation that is associated with the response to tumor necrosis factor inhibitor (TNFi) therapy. METHODS: Peripheral blood genome-wide DNA methylation profiles were analyzed in a discovery cohort of 62 RA patients at baseline and at week 12 of TNFi therapy. DNA methylation of individual CpG sites and enrichment of biological pathways were evaluated for their association with drug response. Using a novel cell deconvolution approach, altered DNA methylation associated with TNFi response was also tested in the six main immune cell types in blood. Validation of the results was performed in an independent longitudinal cohort of 60 RA patients. FINDINGS: Treatment with TNFi was associated with significant longitudinal peripheral blood methylation changes in biological pathways related to RA (FDR<0.05). 139 biological functions were modified by therapy, with methylation levels changing systematically towards a signature similar to that of healthy controls. Differences in the methylation profile of T cell activation and differentiation, GTPase-mediated signaling, and actin filament organization pathways were associated with the clinical response to therapy. Cell type deconvolution analysis identified CpG sites in CD4+T, NK, neutrophils and monocytes that were significantly associated with the response to TNFi. INTERPRETATION: Our results show that treatment with TNFi restores homeostatic blood methylation in RA. The clinical response to TNFi is associated to methylation variation in specific biological pathways, and it involves cells from both the innate and adaptive immune systems. FUNDING: The Instituto de Salud Carlos III.

Influence of the EULAR recommendations for the use of imaging in large vessel vasculitis in the diagnosis of giant cell arteritis: results of the ARTESER register.

OBJECTIVE: The main study objective was to determine how giant cell arteritis (GCA) is diagnosed in our clinical practice and whether the EULAR recommendations have influenced the diagnostic procedures used. METHODS: ARTEritis of the Rheumatology Spanish Society -Sociedad Española de Reumatología (ARTESER) is a multicentre observational retrospective study conducted in 26 hospitals with support from the Spanish Society of Rheumatology. All patients diagnosed with GCA between 1 June 2013 and 29 March 2019 were included. The gold standard for the diagnosis of GCA was the judgement of the physician in charge, according to clinical criteria, supported by data available from laboratory tests, imaging studies (ultrasound, positron emission tomography (PET) and MRI/CT angiography) and temporal artery biopsy (TAB) when available. RESULTS: We included 1675 patients with GCA (mean age±SD (76.9±8.1) years, 1178 women (70.3%)). Of these, 776 patients had a positive TAB (46.3%), 503 (30.0%) positive ultrasound, 245 positive PET (14.6%) and 64 positive MRI/CT angiography (3.8%). These percentages changed substantially over the study. From 2013 to 2019, the use of ultrasound in diagnosis grew from 25.8% to 52.9% and PET from 12.3% to 19.6%, while use of TAB decreased from 50.3% to 33.3%. CONCLUSIONS: Biopsy was the most widely used diagnostic test for confirming GCA, but use of imaging as a diagnostic tool has grown in recent years. Following publication of the 2018 EULAR recommendations, ultrasound has displaced biopsy as the first-line diagnostic test; TAB was performed in a third and PET in a fifth of cases.

Interactions between rheumatoid arthritis antibodies are associated with the response to anti-tumor necrosis factor therapy.

BACKGROUND: Blocking of the Tumor Necrosis Factor (TNF) activity is a successful therapeutic approach for 50-60% of rheumatoid arthritis (RA) patients. However, there are yet no biomarkers to stratify patients for anti-TNF therapy. Rheumatoid factor (RF) and anti-cyclic-citrullinated antibodies (anti-CCP) have been evaluated as biomarkers of response but the results have shown limited consistency. Anti-carbamylated protein (anti-CarP) and anti-peptidylarginine deiminase type 4 (anti-PAD4) antibodies have been much less studied. Despite being linked to common immune processes, the interaction between these markers has not been evaluated yet. Our aim was to analyze the interaction between these four antibodies in relation to the response to anti-TNF therapy. METHODS: For this objective, a prospective cohort of n = 80 RA patients starting anti-TNF therapy was recruited. Serum determinations at baseline were performed for RF, anti-CCP, anti-CarP and anti-PAD4 antibodies using enzyme-linked immunosorbent assays (ELISA). The clinical response to anti-TNF therapy was determined at week 12 using the change in DAS28 score. Association was performed using multivariate linear regression adjusting for baseline DAS28, sex and age. RESULTS: The interaction between pairs of antibodies was tested by the addition of an interaction term. We found two highly significant antibody interactions associated with treatment response: anti-CarP with anti-PAD4 (p = 0.0062), and anti-CCP with RF (p = 0.00068). The latter antibody interaction was replicated in an independent retrospective cohort of RA patients (n = 199, p = 0.04). CONCLUSIONS: The results of this study suggest that antibody interaction effects are important factors in the response to anti-TNF therapy in RA.

Different clinical expression of patients with ankylosing spondylitis according to gender in relation to time since onset of disease. Data from REGISPONSER.

OBJECTIVE: To describe the differential characteristics by gender and time since disease onset in patients diagnosed with ankylosing spondylitis (AS) attending the Spanish rheumatology clinics, including those on the "Spanish Registry of spondyloarthritis" (REGISPONSER), as well as the diagnostic and therapeutic implications that this entails. PATIENTS AND METHODS: This is a transversal and observational study of 1514 patients with AS selected from 2367 spondyloarthritis cases included in REGISPONSER. For each patient, the demographics, epidemiology, geriatric, clinical, laboratory, radiological, and therapeutic aspects were were evaluated and comprehensively recorded under the aegis of REGISPONSER, constituting the Minimum Basic identifying data for the disease. Physical function was assessed by Bath Ankylosing Spondylitis Functional Index (BASFI). Clinical activity was evaluated using erythrocyte sedimentation rate, C reactive protein and Bath Ankylosing Spondylitis Disease Activity Index (BASDAI). Each patient underwent pelvic anteroposterior, anteroposterior and lateral lumbar spine as well as lateral cervical spine x rays; they were scored according to the Bath Ankylosing Spondylitis Spine Radiographic Index, which measures structural damage. RESULTS: Of the 1514 patients screened, 1131 (74.7%) were men. We found significant differences in age at onset of symptoms as well as in the day of inclusion, between the two groups, being lower in men. We also obtained differences in the duration of the disease, which was lower in women. As for the existence of a history of AS among first-degree relatives, family forms were more common among women. The mean BASDAI score was also higher in women, regardless of time since onset of disease. In contrast, the improvement of pain with the use of NSAID's and radiological severity were higher in men, both reaching statistical significance. CONCLUSIONS: Among the Spanish AS patients, there are some differences in the clinical manifestations, even when the time since onset of disease was controlled; we also found radiological differences by gender; men showing more structural damage, while women were more active. These data suggest that the phenotype of AS differs between genders. This can influence the subsequent diagnostic approach and therapeutic decisions.

Erosive osteoarthritis of the feet: description of two patients.

Erosive osteoarthritis is considered an unusual disease, mostly developing among women. The typical locations are the interphalangeal joints of the hands. However, on a few occasions it has also been found in hips, shoulders and feet. We describe two patients (one woman and one man) who have this disease in their feet.