Autoantibodies in the pathogenesis of idiopathic inflammatory myopathies: Does the endoplasmic reticulum stress response have a role?

Idiopathic inflammatory myopathies (IIMs) are a group of rare, acquired autoimmune diseases characterized by profound muscle weakness and immune cell invasion into non-necrotic muscle. They are related to the presence of antibodies known as myositis-specific antibodies and myositis-associated antibodies, which are associated with various IIM phenotypes and the clinical prognosis. The possibility of the participation of other pathological mechanisms involved in the inflammatory response in IIM has been proposed. Such mechanisms include the overexpression of major histocompatibility complex class I in myofibers, which correlates with the activation of stress responses of the endoplasmic reticulum (ER). Taking into account the importance of the ER for the maintenance of homeostasis of the musculoskeletal system in the regulation of proteins, there is probably a relationship between immunological and non-immunological processes and autoimmunity, and an example of this might be IIM. We propose that ER stress and its relief mechanisms could be related to inflammatory mechanisms triggering a humoral response in IIM, suggesting that ER stress might be related to the triggering of IIMs and their auto-antibodies' production.

Suicide Risk in Rheumatoid Arthritis Patients is Associated With Suboptimal Vitamin D Levels.

BACKGROUND/OBJECTIVE: Rheumatoid arthritis (RA) patients might experience anxiety and depressive symptoms. Deficient vitamin D levels may be a trigger for these conditions. The aim of this study was to determine the frequency of depression, anxiety symptoms, and suicidal risk or ideation in patients with RA associated with vitamin D serum levels. METHODS: In this cross-sectional study, we recruited RA patients older than 18 years, classified into 3 groups according to serum vitamin D levels: sufficient, ≥30 ng/mL; insufficient, 20-29 ng/mL; and deficient, <20 ng/mL. Based on the self-reported Plutchik and the Hospital Anxiety and Depression Scale, we evaluated the association of suicidal risk, depression, and anxiety with the vitamin D levels in RA and the Rheumatoid Arthritis Quality-of-Life Questionnaire. RESULTS: We studied 72 patients with RA between January and October 2019. We found an inverse correlation between Plutchik score and suicidal risk with inadequate vitamin D levels, but not with the Hospital Anxiety and Depression Scale. Suicidal ideation was associated with a higher score on the Rheumatoid Arthritis Quality-of-Life Questionnaire. CONCLUSIONS: Despite the high prevalence of depressive and anxiety symptoms in RA patients, a Plutchik low correlation coefficient with inadequate serum levels of vitamin D was found. However, in the analysis of covariance, we were able to find that vitamin D levels remain associated with a reduction of suicide ideation. Further studies are needed to identify a risk profile for early psychological interventions to improve the quality of life in RA patients.

Therapeutic response to leflunomide in combo therapy and monotherapy is associated to serum teriflunomide (A77 1726) levels.

There is a significant rate of therapeutic failure in rheumatoid arthritis (RA) patients treated with leflunomide (LEF). This study investigates the utility values of teriflunomide levels (A77 1726) in identifying RA patients who remained with moderate or severe disease activity after the treatment with LEF. In this cross-sectional study, we compared: (a) RA patients who achieved a DAS28-ESR ≤ 3.2, and (b) RA patients who maintained a DAS28-ESR > 3.2 after treatment. ROC curves determined the cut-off of A77 1726 with the better performance to identify patients achieving a DAS28-ESR ≤ 3.2. Of the 115 patients treated with LEF, 69 (60%) remained with moderate/severe disease activity and 46 (40%) achieved low disease activity/remission. Higher A77 1726 levels showed a negative correlation with DAS28-ESR (r = - 0.42, p < 0.001) and other parameters of disease activity. We obtained the following utility values with the cut-off of A77 1726 > 10 µg/mL to identify RA patients who achieved a DAS28-ESR ≤ 3.2: sensitivity of 91.31%; specificity of 73.91%; positive predictive value of 70.00%; and negative predictive value of 92.73%. Serum A77 1726 discriminated between RA patients who remained with moderate/severe disease activity despite the treatment with LEF both as monotherapy and LEF as combo therapy.

Presence of anti-TIF-1γ, anti-Ro52, anti-SSA/Ro60 and anti-Su/Ago2 antibodies in breast cancer: a cross-sectional study.

OBJECTIVES: The presence of myositis-specific antibodies (MSA), was recently reported in healthy individuals, cancer patients without myopathy and paraneoplastic rheumatic syndromes. We sought to analyze the frequency of MSA, myositis-associated antibodies (MAA) and autoantibodies related to systemic autoimmune rheumatic diseases (SARD) in breast cancer patients. METHODS: One hundred fifty-two breast cancer patients were enrolled in a cross-sectional study. Clinical information was collected, and autoantibodies tested by immunoprecipitation of an 35S-methionine-labeled K562 cell extract, enzyme-linked immunosorbent assay (ELISA) and Western blot when indicated. All statistical tests were performed using the software statistical package for the social science (SPSS) ver. 19.0 (IBM Inc., NYSE, USA). RESULTS: Autoantibodies associated with SARD: anti-52 kD ribonucleoprotein/tripartite motif-containing 21 (anti-Ro52/TRIM21) was found in 5.9% (9/152), anti-Sjögren syndrome-related antigen A/60 kD ribonucleoprotein antibody (anti-SSA/Ro60) in 3.9% (6/152) and anti-Su antigen/Argonaute 2 antibody (anti-Su/Ago2) in 2.6% (4/152). Meanwhile, anti-transcription intermediary factor-1γ (anti-TIF-1γ, p155/140) antibody was positive in 2 cases and anti-polymyositis/scleroderma antibody was detected in one case. As a whole, 14.47% (22/152) of breast cancer patients showed autoantibodies associated with SARD. These specific autoantibodies were not associated with the presence of rheumatic diseases except one rheumatoid arthritis patient positive for anti-Ro52/TRIM21. CONCLUSIONS: Autoantibodies to TIF-1γ were found in two patients with breast cancer without dermatomyositis (DM). More common specificities were autoantibodies anti-SSA/Ro60, anti-Ro52/TRIM21 and anti-Su/Ago2. More studies are needed in order to establish the biological meaning of the presence of SARD-associated autoantibodies in breast cancer.

Anti-Cyclic Citrullinated Peptide Antibodies and Severity of Interstitial Lung Disease in Women with Rheumatoid Arthritis.

OBJECTIVE: To evaluate whether serum titers of second-generation anticyclic citrullinated peptide antibodies (anti-CCP2) are associated with the severity and extent of interstitial lung disease in rheumatoid arthritis (RA-ILD). METHODS: In across-sectional study, 39 RA-ILD patients confirmed by high-resolution computed tomography (HRCT) were compared with 42 RA without lung involvement (RA only). Characteristics related to RA-ILD were assessed in all of the patients and serum anti-CCP2 titers quantified. RESULTS: Higher anti-CCP2 titers were found in RA-ILD compared with RA only (medians 77.9 versus 30.2 U/mL, P < 0.001). In the logistic regression analysis after adjustment for age, disease duration (DD), smoke exposure, disease activity, functioning, erythrocyte sedimentation rate, and methotrexate (MTX) treatment duration, the characteristics associated with RA-ILD were higher anti-CCP2 titers (P = 0.003) and + RF (P = 0.002). In multivariate linear regression, the variables associated with severity of ground-glass score were anti-CCP2 titers (P = 0.02) and with fibrosis score DD (P = 0.01), anti-CCP2 titers (P < 0.001), and MTX treatment duration (P < 0.001). CONCLUSIONS: Anti-CCP2 antibodies are markers of severity and extent of RA-ILD in HRCT. Further longitudinal studies are required to identify if higher anti-CCP2 titers are associated with worst prognosis in RA-ILD.

Serum levels of anticyclic citrullinated peptide antibodies, interleukin-6, tumor necrosis factor-α, and C-reactive protein are associated with increased carotid intima-media thickness: a cross-sectional analysis of a cohort of rheumatoid arthritis patients without cardiovascular risk factors.

UNLABELLED: The main cause of death in rheumatoid arthritis (RA) is cardiovascular events. We evaluated the relationship of anticyclic citrullinated peptide (anti-CCP) antibody levels with increased carotid intima-media thickness (cIMT) in RA patients. METHODS: Forty-five anti-CCP positive and 37 anti-CCP negative RA patients, and 62 healthy controls (HC) were studied. All groups were assessed for atherogenic index of plasma (AIP) and cIMT. Anti-CCP, C-reactive protein (CRP), and levels of tumor necrosis factor alpha (TNFα) and interleukin-6 (IL-6) were measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: The anti-CCP positive RA patients showed increased cIMT compared to HC and anti-CCP negative (P < 0.001). Anti-CCP positive versus anti-CCP negative RA patients, had increased AIP, TNFα and IL-6 (P < 0.01), and lower levels of high density lipoprotein cholesterol (HDL-c) (P = 0.02). The cIMT correlated with levels of anti-CCP (r = 0.513, P = 0.001), CRP (r = 0.799, P < 0.001), TNFα (r = 0.642, P = 0.001), and IL-6 (r = 0.751, P < 0.001). In multiple regression analysis, cIMT was associated with CRP (P < 0.001) and anti-CCP levels (P = 0.03). CONCLUSIONS: Levels of anti-CCP and CRP are associated with increased cIMT and cardiovascular risk supporting a clinical role of the measurement of cIMT in RA in predicting and preventing cardiovascular events.

Modifications in lipid levels are independent of serum TNF-α in rheumatoid arthritis: results of an observational 24-week cohort study comparing patients receiving etanercept plus methotrexate or methotrexate as monotherapy.

OBJECTIVE: To compare the modifications in lipids between patients with rheumatoid arthritis (RA) receiving etanercept plus methotrexate (ETA + MTX) versus methotrexate (MTX) and their relationship with serum levels of tumor necrosis factor-alpha (TNF-α). METHODS: In an observational cohort study, we compared changes in lipid levels in patients receiving ETA + MTX versus MTX in RA. These groups were assessed at baseline and at 4 and 24 weeks, measuring clinical outcomes, total cholesterol, triglycerides, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol, and TNF-α. RESULTS: Baseline values for lipid levels were similar in both groups. HDL-C levels increased significantly only in the ETA + MTX group (from 45.5 to 50.0 mg/dL at 4 weeks, a 10.2% increase, P < 0.001, and to 56.0 mg/dL at 24 weeks, a 25.1% increase, P < 0.001), while other lipids underwent no significant changes. ETA + MTX also exhibited a significant increase in TNF-α (44.8 pg/mL at baseline versus 281.4 pg/mL at 24 weeks, P < 0.001). The MTX group had no significant changes in lipids or TNF-α. Significant differences in HDL-C between groups were observed at 24 weeks (P = 0.04) and also in TNF-α (P = 0.01). CONCLUSION: HDL-C levels increased significantly following treatment with ETA + MTX, without a relationship with decrease of TNF-α.

Comparison of two assays to determine anti-citrullinated peptide antibodies in rheumatoid arthritis in relation to other chronic inflammatory rheumatic diseases: assaying anti-modified citrullinated vimentin antibodies adds value to second-generation anti-citrullinated cyclic peptides testing.

Determination of anti-citrullinated peptide antibodies (ACPA) plays a relevant role in the diagnosis of rheumatoid arthritis (RA). To date, it is still unclear if the use of several tests for these autoantibodies in the same patient offers additional value as compared to performing only one test. Therefore, we evaluated the performance of using two assays for ACPA: second-generation anti-citrullinated cyclic peptides antibodies (anti-CCP2) and anti-mutated citrullinated vimentin (anti-MCV) antibodies for the diagnosis of RA. We compared three groups: RA (n = 142), chronic inflammatory disease (CIRD, n = 86), and clinically healthy subjects (CHS, n = 56) to evaluate sensitivity, specificity, predictive values, and likelihood ratios (LR) of these two assays for the presence of RA. A lower frequency of positivity for anti-CCP2 was found in RA (66.2%) as compared with anti-MCV (81.0%). When comparing RA versus other CIRD, sensitivity increased when both assays were performed. This strategy of testing both assays had high specificity and LR+. We conclude that adding the assay of anti-MCV antibodies to the determination of anti-CCP2 increases the sensitivity for detecting seropositive RA. Therefore, we propose the use of both assays in the initial screening of RA in longitudinal studies, including early onset of undifferentiated arthritis.

-383 A/C tumor necrosis factor receptor 1 polymorphism and ankylosing spondylitis in Mexicans: a preliminary study.

The objective of this study was to evaluate the differences in allele and genotype frequencies of -383 tumor necrosis factor receptor 1 (TNFR1) polymorphism between ankylosing spondylitis (AS) and controls. Mexican Mestizos with AS were matched by gender, age, and ethnicity with healthy controls and compared in allele and genotype frequencies of the -383 TNFR1 polymorphism. Polymorphisms were genotyped using PCR-RFLP. The AA genotype occurred at a higher frequency in the AS group (92%) compared with controls (79%, P = 0.03). A allele was increased in AS (96% vs. 88%, P = 0.015) and was associated with genetic susceptibility for AS (odds ratio = 3.48, 95% CI = 1.23-10.61). This preliminary study is the first assessing the association of the -383 A/C TNFR1 polymorphism with AS, although it has the limitation of a small sample size. These data are of interest for the genetic epidemiology of AS in the Mexican population, requiring further investigation in other countries.

[Assessment of serum IgG activity correlation against cyclic citrullinated peptide antibodies, topoisomerase I and centromere proteins in Mexican patients with progressive systemic sclerosis]. / Evaluación de la correlación de la actividad de IgG sérica contra péptido citrulinado cíclico, topoisomerasa I y proteínas de centrómero en pacientes mexicanos con esclerosis sistémica progresiva.

OBJECTIVE: To evaluate sera titers for antibodies anti-cyclic citrullinated peptide and their correlation against sera levels of anti-topoisomerase I and anti-centromere antibodies in Mexican patients with systemic sclerosis. PATIENTS AND METHODS: Consecutive outpatients with systemic sclerosis who attending to rheumatology clinic at a second level hospital facility. The antibodies anti-cyclic citrullinated peptide, anti-topoisomerase I and anti-centromere were determined by enzymatic immunoassay (ELISA). STATISTICAL ANALYSIS: Spearman for correlation between numerical variables with nonparametric distribution. Fisher exact test or chi2 to compare proportions and Student t test for dimensional variables. RESULTS: Thirty female patients were included; aged 53 +/- 13, the disease duration at the time of the study was 10 +/- 9. Twenty-three patients (77%) exhibited diffuse disease. Anti-centromere, anti-topoisomerase I, and anti-cyclic citrullinated peptide were detected in nine, nine and three patients respectively. The correlation analysis showed the independence of autoantibodies anti-centromere and anti-topoisomerase I with respect to the levels of anti-cyclic citrullinated peptide. CONCLUSIONS: This study confirms the low frequency of anti-cyclic citrullinated peptide antibodies in patients with systemic sclerosis. A lack of correlation between autoantibodies considered as "mutually excluded" anti-topoisomerase I and anti-centromere, indicating that the analysis of the relevance for anti-cyclic citrullinated peptide in systemic sclerosis must include other clinical and serological variables.

Circulating leptin and bone mineral density in rheumatoid arthritis.

OBJECTIVE: To evaluate the association between circulating leptin and bone mineral density (BMD) in patients with rheumatoid arthritis (RA). METHODS: One-hundred thirty postmenopausal women with RA were assessed for body mass index (BMI), disease characteristics, history of drug use, rheumatoid factor, and erythrocyte sedimentation rate (ESR). BMD (g/cm(2)) was determined in the hip and spine by DEXA. Serum leptin concentrations were measured by ELISA. Spearman's correlation coefficients (rho) were determined between BMD and leptin and other variables. A multiple regression analysis was used to adjust for confounders. RESULTS: Patients' serum leptin levels varied widely (range 2-128 ng/ml). Thirty-three patients (25%) had osteoporosis. Higher levels of leptin correlated significantly with BMD in the lumbar spine (rho = 0.17, p = 0.04) and total hip (rho = 0.21, p = 0.01). The variables that were negatively correlated with BMD were age, duration of menopause, and ESR. After adjustment for confounders, leptin was no longer associated with BMD. In the multivariate model, factors that remained associated with BMD in the total hip were age (p = 0.021) and BMI (p = 0.003); and the factors that remained associated with BMD in the lumbar spine were BMI (p = 0.03) and ESR (p = 0.01). CONCLUSION: No relevant association was found between circulating leptin levels and BMD in patients with RA in this cross-sectional study. Followup studies are needed to evaluate whether abnormal leptin levels confer a risk for fractures due to osteoporosis.

Circulating E-selectin and tumor necrosis factor-alpha in extraarticular involvement and joint disease activity in rheumatoid arthritis.

In this cross-sectional study, we assessed the relationship between circulating TNF-alpha and E-selectin (sE-selectin) with extraarticular involvement and severity of joint disease in RA. We compared 56 patients who had RA and extraarticular involvement (ExRA) with a group of 84 patients with only articular involvement (non-ExRA). ExRA had higher circulating TNF-alpha than non-ExRA (32 +/- 9 vs. 28 +/- 6 pg/mL, P = 0.002). sE-selectin levels did not differ between both groups. sE-selectin correlated with tender joint count (rho = 0.19, P = 0.03), morning stiffness (rho = 0.19, P = 0.03), severity of pain (rho = 0.21, P = 0.02), disease activity (assessed by the patient) (rho = 0.21, P = 0.02), HAQ-DI (rho = 0.29, P = 0.004), and rheumatoid factor titers (rho = 0.31, P = <0.001). Circulating TNF-alpha had no correlation with sE-selectin or disease activity. We concluded that sE-selectin correlated with severity of joint disease, further follow-up studies should evaluate if sE-selectin is useful as prognosis marker for progression of articular damage.