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OBJECTIVE: The objective of this study is to determine the associations of protein-specific anti-malondialdehyde-acetaldehyde (MAA) antibodies with prevalent and incident rheumatoid arthritis-interstitial lung disease (RA-ILD). METHODS: Within a multicenter, prospective cohort of US veterans with RA, RA-ILD was validated by medical record review of clinical diagnoses, chest imaging, and pathology. Serum antibodies to MAA-albumin, MAA-collagen, MAA-fibrinogen, and MAA-vimentin (IgA, IgM, and IgG) were measured by a standardized enzyme-linked immunosorbent assay. Associations of anti-MAA antibodies with prevalent and incident RA-ILD were assessed using multivariable regression models adjusting for established RA-ILD risk factors. RESULTS: Among 2,739 participants with RA (88% male, mean age of 64 years), there were 114 with prevalent and 136 with incident RA-ILD (average time to diagnosis: 6.6 years). Higher IgM anti-MAA-collagen (per 1 SD: adjusted odds ratio [aOR] 1.28, 95% confidence interval [CI] 1.02-1.61), IgA anti-MAA-fibrinogen (aOR 1.48, 95% CI 1.14-1.92), and IgA (aOR 1.78, 95% CI 1.34-2.37) and IgG (aOR 1.48, 95% CI 1.14-1.92) anti-MAA-vimentin antibodies were associated with prevalent RA-ILD. In incident analyses, higher IgA (per one SD: adjusted hazards ratio [aHR] 1.40, 95% CI 1.11-1.76) and IgM (aHR 1.29, 95% CI 1.04-1.60) anti-MAA-albumin antibody concentrations were associated with increased ILD risk. Participants with IgA (aHR 2.13, 95% CI 1.16-3.90) or IgM (aHR 1.98, 95% CI 1.08-3.64) anti-MAA-albumin antibody concentrations in the highest quartile had an approximately two-fold increased risk of incident RA-ILD. Across all isotypes, anti-MAA-fibrinogen, anti-MAA-collagen, and anti-MAA-vimentin antibodies were not significantly associated with incident RA-ILD. CONCLUSION: Protein-specific anti-MAA antibodies to collagen, fibrinogen, and vimentin were associated with prevalent RA-ILD. IgA and IgM anti-MAA-albumin antibodies were associated with a higher risk of incident RA-ILD. These findings suggest that MAA modifications and resultant immune responses may contribute to RA-ILD pathogenesis.
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Acetaldehído , Artritis Reumatoide , Autoanticuerpos , Enfermedades Pulmonares Intersticiales , Veteranos , Humanos , Enfermedades Pulmonares Intersticiales/inmunología , Enfermedades Pulmonares Intersticiales/epidemiología , Masculino , Persona de Mediana Edad , Femenino , Artritis Reumatoide/inmunología , Artritis Reumatoide/epidemiología , Anciano , Estados Unidos/epidemiología , Estudios Prospectivos , Acetaldehído/inmunología , Autoanticuerpos/inmunología , Autoanticuerpos/sangre , Incidencia , Prevalencia , Fibrinógeno/inmunología , Inmunoglobulina M/inmunología , Vimentina/inmunología , Inmunoglobulina A/inmunología , Inmunoglobulina A/sangre , Inmunoglobulina G/inmunología , Inmunoglobulina G/sangre , Colágeno/inmunología , Albúmina Sérica/inmunologíaRESUMEN
Respiratory-related diseases are a leading cause of death in rheumatoid arthritis (RA) and are disproportionately higher in men, which may be attributable to environmental risk factors. Animal studies have demonstrated potentiated autoimmunity, arthritis, and profibrotic/inflammatory lung disease with a combination of airborne exposures and collagen-induced arthritis (CIA). This study aimed to determine whether hormone-dependent differences explained these observations. Arthritis-prone male intact and castrated DBA/1J mice received intranasal inhalation of lipopolysaccharide (LPS) daily for 5 wk and CIA induction. Arthritis scores and serum pentraxin-2 levels were increased in castrated versus intact mice. In contrast, airway cell influx, lung tissue infiltrates, and lung levels of proinflammatory and profibrotic markers (C5a, IL-33, and matrix metalloproteinases) were reduced in castrated versus intact mice. CIA + LPS-induced lung histopathology changes and the expression of lung autoantigens including malondialdehyde acetaldehyde (MAA)- and citrulline (CIT)-modified proteins and vimentin were reduced in castrated animals. There were no differences in serum anti-MAA or anti-CIT protein antibody (ACPA) levels or serum pentraxin levels between groups. Testosterone replacement led to a reversal of several lung inflammatory/profibrotic endpoints noted earlier in castrated male CIA + LPS-treated mice with testosterone supplementation promoting neutrophil influx, MAA expression, and TNF-α, IL-6, and MMP-9. These findings imply that testosterone contributes to lung and arthritis inflammatory responses following CIA + LPS coexposure, but not to systemic autoantibody responses. The CIA + LPS model provides a paradigm for investigations focused on the mechanistic underpinnings for epidemiologic and phenotypic sex differences in RA-related lung disease.NEW & NOTEWORTHY Our study shows that testosterone acts as a key immunomodulatory hormone contributing to critical features of rheumatoid arthritis (RA)-associated lung disease in the setting of airborne endotoxin (lipopolysaccharide; LPS) exposures and concomitant arthritis induction in mice. The exaggerated airway inflammation observed following combined exposures in male mice was accompanied by increases in profibrotic mediators, netosis, and increased expression of lung autoantigens, all relevant to the pathogenesis of lung disease in arthritis.
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Artritis Experimental , Artritis Reumatoide , Enfermedades Pulmonares , Humanos , Masculino , Femenino , Animales , Ratones , Lipopolisacáridos/farmacología , Endotoxinas , Testosterona/farmacología , Ratones Endogámicos DBA , AutoantígenosRESUMEN
OBJECTIVES: To quantify associations of serum alarmins with risk of rheumatoid arthritis-associated interstitial lung disease (RA-ILD). METHODS: Using serum collected at enrolment, three alarmins (interleukin [IL]-33, thymic stromal lymphopoietin [TSLP], and IL-25) were measured in a multicentre prospective RA cohort. ILD was classified using systematic medical record review. Cross-sectional associations of log-transformed (IL-33, TSLP) or quartile (IL-25) values with RA-ILD at enrolment (prevalent RA-ILD) were examined using logistic regression, while associations with incident RA-ILD developing after enrolment were examined using Cox proportional hazards. Covariates in multivariate models included age, sex, race, smoking status, RA disease activity score, and anti-cyclic citrullinated antibody positivity. RESULTS: Of 2,835 study participants, 115 participants (4.1%) had prevalent RA-ILD at baseline and an additional 146 (5.1%) developed incident ILD. There were no associations between serum alarmin concentrations and prevalent ILD in unadjusted or adjusted logistic regression models. In contrast, there was a significant inverse association between IL-33 concentration and the risk of developing incident RA-ILD in unadjusted (HR 0.73 per log-fold increase; 95% CI 0.57-0.95; p= 0.018) and adjusted (HR 0.77; 95% CI 0.59-1.00, p= 0.047) models. No significant associations of TSLP or IL-25 with incident ILD were observed. CONCLUSIONS: In this study, we observed a significant inverse association between serum IL-33 concentration and the risk of developing incident RA-ILD, but no associations with prevalent ILD. Additional investigation is required to better understand the mechanisms driving this relationship and how serum alarmin IL-33 assessment might contribute to clinical risk stratification in patients with RA.
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Objective: Post-translational protein modifications with malondialdehyde-acetaldehyde (MAA) and citrulline (CIT) are implicated in the pathogenesis of rheumatoid arthritis (RA). Although precise mechanisms have not been elucidated, macrophage-fibroblast interactions have been proposed to play a central role in the development and progression of RA. The purpose of our study was to evaluate the downstream effects of macrophage released soluble mediators, following stimulation with fibrinogen (FIB) modified antigens, on human fibroblast-like synoviocytes (HFLS). Methods: PMA-treated U-937 monocytes (MÏ) and macrophage-differentiated peripheral blood mononuclear cells (MP) were stimulated with FIB, FIB-MAA, FIB-CIT, or FIB-MAA-CIT. HFLS-RA cells were stimulated directly with FIB antigens or with supernatants (SN) from macrophages (MÏ-SN or MP-SN) stimulated with FIB antigens. Genes associated with an aggressive HFLS phenotype, extracellular matrix proteins, and activated signaling pathways were evaluated. Results: HFLS-RA cells treated with MÏ-SNFIB-CIT and MÏ-SNFIB-MAA-CIT demonstrated significant increases in mRNA expression of genes associated with an aggressive phenotype at 24-h as compared to direct stimulation with the same antigens. Similar results were obtained using MP-SN. Cellular morphology was altered and protein expression of vimentin (p<0.0001 vs. MÏ-SNFIB) and type II collagen (p<0.0001) were significantly increased in HFLS-RA cells treated with any of the MÏ-SN generated following stimulation with modified antigens. Phosphorylation of JNK, Erk1/2, and Akt were increased most substantially in HFLS-RA treated with MÏ-SNFIB-MAA-CIT (p<0.05 vs MÏ-SNFIB). These and other data suggested the presence of PDGF-BB in MÏ-SN. MÏ-SNFIB-MAA-CIT contained the highest concentration of PDGF-BB (p<0.0001 vs. MÏ-SNFIB) followed by MÏ-SNFIB-CIT then MÏ-SNFIB-MAA. HFLS-RA cells treated with PDGF-BB showed similar cellular morphology to the MÏ-SN generated following stimulation with modified FIB, as well as the increased expression of vimentin, type II collagen, and the phosphorylation of JNK, Erk1/2 and Akt signaling molecules. Conclusion: Together, these findings support the hypothesis that in response to MAA-modified and/or citrullinated fibrinogen, macrophages release soluble factors including PDGF-BB that induce fibroblast activation and promote an aggressive fibroblast phenotype. These cellular responses were most robust following macrophage activation with dually modified fibrinogen, compared to single modification alone, providing novel insights into the combined role of multiple post-translational protein modifications in the development of RA.
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Artritis Reumatoide , Hemostáticos , Humanos , Fibrinógeno , Vimentina , Becaplermina , Colágeno Tipo II , Leucocitos Mononucleares , Proteínas Proto-Oncogénicas c-akt , Macrófagos , Fibroblastos , AcetaldehídoRESUMEN
OBJECTIVE: To assess whether circulating levels of adiponectin, leptin, and fibroblast growth factor 21 (FGF-21) are associated with incident cardiovascular disease (CVD) in rheumatoid arthritis (RA). METHODS: Adipokines were measured using banked enrollment serum from patients with RA and dichotomized above/below the median value. Incident CVD events (coronary artery disease [CAD], stroke, heart failure [HF] hospitalization, venous thromboembolism, CVD-related deaths) were identified using administrative data and the National Death Index. Covariates were derived from medical record, biorepository, and registry databases. Multivariable Cox models were generated to quantify associations between adipokine concentrations and CVD incidence. Five-year incidence rates were predicted. RESULTS: Among 2,598 participants, 639 (25%) had at least 1 CVD event over 19,585 patient-years of follow-up. High adiponectin levels were independently associated with HF hospitalization (hazard ratio [HR] 1.39 [95% confidence interval (95% CI) 1.07-1.79], P = 0.01) and CVD-related death (HR 1.49 [95% CI 1.16-1.92], P = 0.002) but not with other CVD events. High leptin was independently associated with CVD-related death (HR 1.44 [95% CI 1.05-1.97], P = 0.02). High FGF-21 levels were independently associated with lower rates of CAD (HR 0.75 [95% CI 0.58-0.97], P = 0.03). In subgroup analyses, associations between high adiponectin and leptin levels with CVD-related death were driven by strong associations in nonobese patients. CONCLUSION: Adipokines are associated with HF hospitalization and CVD-related death in patients with RA, with stronger associations in nonobese participants. These findings suggest that adipokines effectively predict clinically important outcomes in RA perhaps through an association with body composition and metabolic health. Further study is needed to determine whether adipokine measures might augment existing tools to identify RA patients at increased risk of CVD.
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Adipoquinas , Artritis Reumatoide , Enfermedades Cardiovasculares , Humanos , Adipoquinas/sangre , Adiponectina , Artritis Reumatoide/sangre , Artritis Reumatoide/diagnóstico , Artritis Reumatoide/epidemiología , Enfermedades Cardiovasculares/sangre , Enfermedades Cardiovasculares/diagnóstico , Enfermedades Cardiovasculares/epidemiología , Enfermedad de la Arteria Coronaria , Leptina , Factores de RiesgoRESUMEN
BACKGROUND AND AIMS: Current treatment strategies for alcoholic liver disease (ALD) are limited by the lack of agents specifically targeting the metabolic breakdown products of ethanol. Reactive aldehyde species (RASP) inhibitors have been developed that have the capability to sequester these aldehyde byproducts, potentially limiting toxicity. The purpose of this study was to determine if the RASP inhibitor ADX-629 could target these metabolic breakdown products in a mouse model of ALD. METHODS AND RESULTS: A chronic/binge mouse model of ALD was used to determine the efficacy of ADX-629 treatment. Mice were fed an alcohol-containing (5 %) liquid or control diet for 10 days and treated by oral gavage with ADX-629 30 min prior to administering a bolus gavage of 31.5 % ethanol. Test groups included: Control - no ADX, Control + ADX, Ethanol - no ADX and Ethanol + ADX. Compared to ethanol-fed mice receiving sham treatment, ethanol mice treated with ADX-629 demonstrated significant decreases (p < 0.05) in liver acetaldehyde (AA), liver malondialdehyde-acetaldehyde (MAA), circulating anti-MAA antibody, liver/serum triglycerides (p < 0.01) levels, and overall fat accumulation in the liver as determined by Oil Red O and bodipy staining (p < 0.0001). Serum levels of pro-inflammatory cytokines IFN-γ and MCP-1 levels were decreased following ADX-629 treatment (p < 0.01). CONCLUSIONS: These findings demonstrate that the use of this unique RASP inhibitor (ADX-629) is effective in the treatment of ALD. Given the ubiquitous nature of aldehydes in the context of tissue inflammation and damage, ADX-629 and other RASP inhibitors may have additional applications in disease states.
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Etanol , Hepatopatías Alcohólicas , Ratones , Animales , Aldehídos , Hepatopatías Alcohólicas/tratamiento farmacológico , Modelos Animales de Enfermedad , Acetaldehído , MalondialdehídoRESUMEN
OBJECTIVE: Post-translational modifications of extracellular matrix proteins such as fibrinogen may lead to tolerance loss and have been implicated in rheumatoid arthritis (RA) pathogenesis. The purpose of this study was to determine whether fibrinogen (FIB) modified with citrulline (CIT), malondialdehyde-acetaldehyde (MAA) or both leads to altered macrophage polarization, peptidyl arginine deiminase (PAD) expression, or production of citrullinated proteins. METHODS: PMA-treated U-937 cells (M0 cells) were stimulated with MAA, CIT or MAA-CIT modified FIB. Macrophage (M1/M2) phenotypes were evaluated by flow cytometry, RT-PCR, and ELISA. PAD enzyme expression and protein citrullination was evaluated using RT-PCR and Western Blot. RESULTS: Flow cytometry revealed that M0 macrophages stimulated with FIB-MAA-CIT resulted in mixed M1/M2 phenotypes as demonstrated by cell surface expression and mRNA levels of CD14, CD192, CD163, and CD206 (p < 0.001 vs. others), and the release of IL-18, IP-10, CCL22, and IL-13 (p < 0.001 vs. others). While FIB-MAA treated M0 cells demonstrated a mixed M1/M2 phenotype, cytokine and cell surface markers differed from FIB-MAA-CIT. Finally, M0 cells treated with FIB-CIT demonstrated markers and cytokines consistent with only the M1-like phenotype. Exposure of M0 cells to FIB-MAA-CIT (at 48 h) and FIB-MAA (at 24 h) led to increased mRNA expression and protein expression of PAD2 (p < 0.001) with increased protein citrullination. CONCLUSION: These findings suggest that MAA-modification and citrullination of FIB, in isolation or combination, yield specific effects on macrophage polarization, PAD expression and citrullination that ultimately may induce inflammatory and fibrotic responses associated with RA.
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Artritis Reumatoide , Fibrinógeno , Acetaldehído , Citrulina/metabolismo , Fibrinógeno/metabolismo , Humanos , Hidrolasas , Macrófagos/metabolismo , Malondialdehído , Desiminasas de la Arginina Proteica/metabolismo , ARN MensajeroRESUMEN
OBJECTIVES: This study assessed whether circulating levels of adiponectin and leptin are associated with higher mortality in patients with RA. METHODS: Participants were adults from the Veterans Affairs RA Registry. Adipokines and inflammatory cytokines were measured as part of a multi-analyte panel on banked serum at enrolment. Dates and causes of death were derived from the Corporate Data Warehouse and the National Death Index. Covariates were derived from medical record, biorepository and registry databases. Multivariable Cox proportional hazard models evaluated associations between biomarkers and all-cause and cause-specific mortality. RESULTS: A total of 2583 participants were included. Higher adiponectin levels were associated with older age, male sex, white race, lower BMI, autoantibody seropositivity, radiographic damage, longer disease duration, prednisone use and osteoporosis. Higher adiponectin concentrations were also associated with higher levels of inflammatory cytokines but not higher disease activity at enrolment. Leptin was primarily associated with greater BMI and comorbidity. The highest quartile of adiponectin (vs lowest quartile) was associated with higher all-cause mortality [hazard ratio (HR): 1.46 (95% CI: 1.11, 1.93), P = 0.009] and higher cardiovascular mortality [HR: 1.85 (95% CI: 1.24, 2.75), P = 0.003], after accounting for covariates. Higher leptin levels were also associated with greater all-cause and cancer mortality. CONCLUSIONS: Elevations in adipokines are associated with age, BMI, comorbidity and severe disease features in RA and independently predict early death. Associations between adiponectin and inflammatory cytokines support the hypothesis that chronic subclinical inflammation promotes metabolic changes that drive elevations in adipokines and yield adverse health outcomes.
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Adipoquinas , Artritis Reumatoide , Adulto , Humanos , Masculino , Adipoquinas/sangre , Adiponectina , Artritis Reumatoide/mortalidad , Citocinas , Inflamación , Leptina , FemeninoRESUMEN
INTRODUCTION: Inflammatory bowel disease (IBD) is associated with immune responses with oxidative stress wherein high levels of malondialdehyde result in the formation of a highly stable and immunogenic malondialdehyde-acetaldehyde adduct (MAA). Thus, this study evaluated the status of MAA and anti-MAA antibody isotypes in IBD and their potential as novel serological biomarkers for differentiating ulcerative colitis (UC) from Crohn's disease (CD). METHODS: Levels of MAA and anti-MAA antibodies were examined in patients with IBD (171), non-IBD gastrointestinal diseases (77), and controls (83) from 2 independent cohorts using immunohistochemistry and enzyme-linked immunosorbent assay. Receiver operating characteristic curves and Youden cutoff index from logistic regression were used to determine the sensitivity and specificity. RESULTS: The MAA and blood immunoglobulin G (IgG) anti-MAA antibody levels were significantly elevated in IBD compared with non-IBD patients (P = 0.0008) or controls (P = 0.02). Interestingly, patients with UC showed higher levels of IgG anti-MAA (P < 0.0001) than patients with CD including those with colonic CD (P = 0.0067). The odds ratio by logistic regression analysis predicted stronger association of IgG anti-MAA antibody with UC than CD. Subsequent analysis showed that IgG anti-MAA antibody levels could accurately identify (P = 0.0004) UC in the adult cohort with a sensitivity of 75.3% and a specificity of 71.4% and an area under the curve of 0.8072 (0.7121-0.9024). The pediatric cohort also showed an area under the curve of 0.8801 (0.7988-0.9614) and precisely distinguished (P < 0.0001) UC with sensitivity (95.8%) and specificity (72.3%). DISCUSSION: Circulating IgG anti-MAA antibody levels can serve as a novel, noninvasive, and highly sensitive test to identify patients with UC and possibly differentiate them from patients with CD.
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Colitis Ulcerosa , Enfermedad de Crohn , Enfermedades Inflamatorias del Intestino , Acetaldehído , Adulto , Autoanticuerpos , Biomarcadores , Niño , Humanos , Inmunoglobulina G , MalondialdehídoRESUMEN
Airborne biohazards are risk factors in the development and severity of rheumatoid arthritis (RA) and RA-associated lung disease, yet the mechanisms explaining this relationship remain unclear. Lipopolysaccharide (LPS, endotoxin) is a ubiquitous inflammatory agent in numerous environmental and occupational air pollutant settings recognized to induce airway inflammation. Combining repetitive LPS inhalation exposures with the collagen induced arthritis (CIA) model, DBA1/J mice were assigned to either: sham (saline injection/saline inhalation), CIA (CIA/saline), LPS (saline/LPS 100 ng inhalation), or CIA + LPS for 5 weeks. Serum anti-citrullinated (CIT) protein antibody (ACPA) and anti-malondialdehyde-acetaldehyde (MAA) antibodies were strikingly potentiated with co-exposure (CIA + LPS). CIT- and MAA-modified lung proteins were increased with co-exposure and co-localized across treatment groups. Inhaled LPS exacerbated arthritis with CIA + LPS > LPS > CIA versus sham. Periarticular bone loss was demonstrated in CIA and CIA + LPS but not in LPS alone. LPS induced airway inflammation and neutrophil infiltrates were reduced with co-exposure (CIA + LPS). Potentially signaling transition to pro-fibrotic processes, there were increased infiltrates of activated CD11c+CD11b+ macrophages and transitioning CD11c+CD11bint monocyte-macrophage populations with CIA + LPS. Moreover, several lung remodeling proteins including fibronectin and matrix metalloproteinases as well as complement C5a were potentiated with CIA + LPS compared to other treatment groups. IL-33 concentrations in lung homogenates were enhanced with CIA + LPS with IL-33 lung staining driven by LPS. IL-33 expression was also significantly increased in lung tissues from patients with RA-associated lung disease (N = 8) versus controls (N = 7). These findings suggest that patients with RA may be more susceptible to developing interstitial lung disease following airborne biohazard exposures enriched in LPS.
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Contaminantes Atmosféricos/efectos adversos , Artritis Experimental/complicaciones , Artritis Reumatoide/complicaciones , Lipopolisacáridos/efectos adversos , Enfermedades Pulmonares Intersticiales/inmunología , Animales , Artritis Experimental/diagnóstico , Artritis Experimental/inmunología , Artritis Experimental/patología , Artritis Reumatoide/diagnóstico , Artritis Reumatoide/inmunología , Artritis Reumatoide/patología , Autoanticuerpos/inmunología , Autoantígenos/inmunología , Estudios de Casos y Controles , Polvo , Voluntarios Sanos , Humanos , Exposición por Inhalación/efectos adversos , Interleucina-33/análisis , Interleucina-33/metabolismo , Pulmón/inmunología , Pulmón/patología , Enfermedades Pulmonares Intersticiales/patología , Masculino , Ratones , Índice de Severidad de la EnfermedadRESUMEN
BACKGROUND/OBJECTIVE: Cytokines and chemokines (cytokines) are central to rheumatoid arthritis (RA) pathogenesis, with increasing use of multiplex immunoassays in clinical/research settings. Rheumatoid factor (RF) may interfere with assay outcomes by nonspecifically binding detection analytes. We evaluated the performance of a commercially available multiplex platform, including assessment of the impact of RF depletion. METHODS: Forty-five cytokines were tested using Meso Scale Discovery V-PLEX™ and samples from 40 RA and 40 osteoarthritis (OA) patients. Select samples were depleted of RF using a commercial binder. Performance was assessed using intra-assay coefficients of variation (CV), intraclass correlation coefficients (ICC), percent change following RF depletion, and disease discrimination. Values above or below quantification thresholds were imputed. RESULTS: Of the 45 cytokines analyzed, 31 yielded CVs <10%; none demonstrated CVs >30%. ICCs universally exceeded 0.85 with the exception of eight analytes. RF depletion altered cytokine values by <15% for 40 analytes with larger changes (>30%) only seen for one analyte. Twenty-three cytokines differed significantly based on measurement in plasma vs. serum. Three analytes were higher in the serum of RA vs. OA (IL-10, IP-10, TNFα), and none were significantly greater in OA vs. RA. Seventeen analytes required imputation for >50% of the samples tested, primarily related to concentrations below the lower limit of quantification threshold. CONCLUSION: The results from this commercially available multiplex assay were generally highly reproducible and interference induced by RF only meaningfully impacted the quantification of five of the analytes examined.
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Artritis Reumatoide/sangre , Quimiocinas/sangre , Citocinas/sangre , Inmunoensayo , Osteoartritis/sangre , Anciano , Artritis Reumatoide/diagnóstico , Biomarcadores/sangre , Femenino , Humanos , Masculino , Persona de Mediana Edad , Osteoartritis/diagnóstico , Valor Predictivo de las Pruebas , Reproducibilidad de los Resultados , Factor Reumatoide/sangre , Estados UnidosRESUMEN
BACKGROUND: Although biologics represent a major advance in rheumatoid arthritis (RA), many patients fail to achieve adequate responses to these agents. We examined whether combined positivity to three well-characterized autoantibodies predicts treatment response among RA patients initiating biologics. METHODS: The study included biologic-naïve patients initiating anti-TNF treatment, biologic-exposed patients switching to rituximab or tocilizumab, and patients (biologic naïve or exposed) initiating abatacept. Rheumatoid factor (RF), anti-cyclic citrullinated peptide (CCP) antibody, and IgG antibodies to malondialdehyde-acetaldehyde (MAA) were measured using banked enrollment serum. The relationship between the number of autoantibodies positive (0-3) and treatment response (absolute improvement in 28-joint Disease Activity Score [DAS28-CRP] or improvement > 1.2) at 6 months was examined using multivariable linear and logistic regression. RESULTS: Of 1,229 patients initiating biologics, 79% were women; 89% were Caucasian. The number of baseline RA-related autoantibodies positive was associated with improved treatment response in a dose-dependent fashion. Compared to patients seronegative for all autoantibodies, adjusting for covariates, those positive for all three were more than twice (OR 2.35; 95% CI 1.57-3.51) as likely to achieve DAS28 improvement > 1.2 units. Associations of autoantibody positivity with biologic treatment response were strongest for anti-CCP antibody, persisted in analyses limited to biologic naïve patients, and did not appear to differ markedly among different agents examined. CONCLUSION: An expanded autoantibody profile appears to significantly predict RA treatment response to biologic treatment in a dose-dependent fashion. Incorporating these serologic profiles with additional biomarkers or other informative patient characteristics could provide an opportunity to personalize RA management.
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Antirreumáticos/uso terapéutico , Artritis Reumatoide/tratamiento farmacológico , Autoanticuerpos/sangre , Productos Biológicos/uso terapéutico , Inhibidores del Factor de Necrosis Tumoral/uso terapéutico , Acetaldehído/inmunología , Adulto , Anciano , Anticuerpos Antiproteína Citrulinada/sangre , Antirreumáticos/efectos adversos , Artritis Reumatoide/sangre , Artritis Reumatoide/diagnóstico , Artritis Reumatoide/inmunología , Productos Biológicos/efectos adversos , Biomarcadores/sangre , Investigación sobre la Eficacia Comparativa , Sustitución de Medicamentos , Femenino , Humanos , Masculino , Malondialdehído/inmunología , Persona de Mediana Edad , Estudios Prospectivos , Sistema de Registros , Inducción de Remisión , Factor Reumatoide/sangre , Resultado del Tratamiento , Inhibidores del Factor de Necrosis Tumoral/efectos adversosRESUMEN
OBJECTIVE: To examine serum autoantibodies to malondialdehyde-acetaldehyde (MAA) prior to rheumatoid arthritis (RA) diagnosis. METHODS: Concentrations of anti-MAA antibody isotypes, anti-cyclic citrullinated peptide 2 (anti-CCP-2), and IgM rheumatoid factor (IgM-RF) were evaluated before and after RA diagnosis in samples from cases (n = 214) and controls (n = 210). The timing of elevations in autoantibody concentrations relative to RA diagnosis was explored using separate mixed models for each antibody and/or isotype. Associations between prediagnosis autoantibody concentrations in RA patients were examined using mixed effects linear regression models. RESULTS: Concentrations of IgG (log2 difference 0.34) and IgA (log2 difference 0.43) anti-MAA antibodies in RA patients diverged from controls at 3.0 years and 2.3 years prior to diagnosis, respectively (P < 0.05 for both). There was no evidence of case-control divergence for IgM anti-MAA antibody concentration. Anti-CCP-2 and IgM-RF concentrations diverged between RA patients and controls beginning at 17.6 years and 7.2 years prior to RA diagnosis, respectively. All 3 anti-MAA antibody isotypes (IgA, IgM, and IgG) were significantly associated with anti-CCP-2 antibody and RF concentrations prior to diagnosis (ß = 0.22-0.27 for IgM-RF; ß = 0.44-0.93 for anti-CCP-2) (P < 0.001). CONCLUSION: IgG and IgA anti-MAA autoantibodies are elevated prior to RA diagnosis but appear later in the preclinical course than anti-CCP-2 or RF. These findings suggest that MAA formation and anti-MAA immune responses could play a role in the transition from subclinical autoimmunity to clinically apparent arthritis.
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Acetaldehído/inmunología , Artritis Reumatoide/diagnóstico , Autoanticuerpos/sangre , Malondialdehído/inmunología , Adulto , Anticuerpos Antiproteína Citrulinada/sangre , Artritis Reumatoide/sangre , Artritis Reumatoide/inmunología , Estudios de Casos y Controles , Femenino , Humanos , Inmunoglobulina M/inmunología , Masculino , Persona de Mediana Edad , Factor Reumatoide/sangreRESUMEN
BACKGROUND/OBJECTIVE: Malondialdehyde-acetaldehyde adducts (MAA) act as potent immune adjuvants and co-localize with citrullinated antigens in tissues effected by rheumatoid arthritis (RA). We sought to examine the role of MAA-adducts in promoting RA-related autoimmunity and inflammation. METHODS: DBA/J1 mice were immunized with human serum albumin (HSA), HSA-MAA, citrullinated HSA (HSA-Cit), or HSA-MAA-Cit with subsequent measurement of serum anti-citrullinated protein antibody (ACPA) and anti-Cit T cell responses. Cellular binding of the same antigens was examined using THP-1 monocytes and Chinese Hamster Ovary (CHO) cells transfected with specific scavenger receptors (SRs: TLR4, SR-B2, SREC-1). The effects of these antigens on THP-1 activation were then examined by quantifying plate adherence, pro-inflammatory (TNFα, IL-1ß, IL-10) cytokine release, and SR (CD14, SR-B2)/co-stimulatory molecule (CD80, HLA-DR) expression. Comparisons were completed using one-way ANOVA with Tukey's post-hoc test. RESULTS: Mice immunized with co-modified HSA produced significantly higher ACPA concentrations than all other groups whereas T cell responses to citrullinated proteins were highest following immunization with HSA-MAA. Both transfected CHO and THP-1 cells demonstrated significantly higher binding of HSA-MAA-Cit vs. HSA or HSA-Cit. THP-1 cells exposed to HSA-MAA-Cit expressed significantly higher concentrations of TNFα, IL-1ß, and IL-10 vs. all other groups. Furthermore, THP-1 cells demonstrated significantly increased plate adherence and higher expression of CD14, SR-B2, and HLA-DR following incubation with HSA-MAA-Cit vs. HSA or HSA-Cit. CONCLUSION: These studies demonstrate that MAA-adduction of citrullinated antigen greatly enhances immune and cellular responses, potentially acting as a key co-factor in RA pathogenesis.
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Acetaldehído/inmunología , Anticuerpos Antiproteína Citrulinada/sangre , Citrulinación/inmunología , Malondialdehído/inmunología , Acetaldehído/química , Adyuvantes Inmunológicos/química , Animales , Anticuerpos Antiproteína Citrulinada/inmunología , Artritis Reumatoide/inmunología , Células CHO , Cricetulus , Citocinas/metabolismo , Humanos , Inmunogenicidad Vacunal , Inflamación/metabolismo , Masculino , Malondialdehído/química , Ratones Endogámicos DBA , Monocitos/metabolismo , Receptores Depuradores/metabolismo , Albúmina Sérica Humana/química , Albúmina Sérica Humana/inmunología , Linfocitos T/inmunología , Linfocitos T/metabolismo , Células THP-1RESUMEN
Biomaterials with enhanced biocompatibility are favored in implant studies to improve the outcomes of total joint replacement surgeries. This study tested the hypothesis that nano-structured surfaces for orthopedic applications, produced by the ion beam-assisted deposition method, would enhance osteointegration by altering the expression of bone-associated genes in osteoblasts. The ion beam-assisted deposition technique was employed to deposit nano-films on glass or titanium substrates. The effects of the ion beam-assisted deposition produced surfaces on the human osteosarcoma cell line SAOS-2 at the molecular level were investigated by assays of adhesion, proliferation, differentiation, and apoptosis on coated surfaces versus uncoated cobalt-chrome, as the control. Ion beam-assisted deposition nano-coatings enhanced bone-associated gene expression at initial cell adhesion, proliferation, and differentiation compared to cobalt-chrome surfaces as assessed by polymerase chain reaction techniques. Increased cell proliferation was observed using a nuclear cell proliferation-associated antigen. Moreover, enhanced cell differentiation was determined by alkaline phosphatase activity, an indicator of bone formation. In addition, programmed cell death assessed by annexin V staining and flow cytometry was lower on nano-surfaces compared to cobalt-chrome surfaces. Overall, the results indicate that nano-coated surfaces produced by the ion beam-assisted deposition technique for use on implants were superior to orthopedic grade cobalt-chrome in supporting bone cell adhesion, proliferation, and differentiation and reducing apoptosis. Thus, surface properties altered by the ion beam-assisted deposition technique should enhance bone formation and increase the biocompatibility of bone cell-associated surfaces.
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Materiales Biocompatibles Revestidos/química , Materiales Biocompatibles Revestidos/farmacología , Regulación de la Expresión Génica/efectos de los fármacos , Nanoestructuras/química , Osteoblastos/efectos de los fármacos , Osteoblastos/metabolismo , Osteogénesis/genética , Apoptosis/efectos de los fármacos , Adhesión Celular/efectos de los fármacos , Diferenciación Celular/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Vidrio/química , Humanos , Osteoblastos/citología , Osteogénesis/efectos de los fármacos , Propiedades de Superficie , Titanio/químicaRESUMEN
BACKGROUND: Circulating uric acid (UA) is an important biomarker, not only in the detection and management of gout, but also in assessing the risk of related comorbidity. The impact of collection methods on clinical UA measurements has been the subject of limited study. After observing significant differences between UA concentrations of blood samples obtained by different collection tubes, we began examining the effects of exogenous tube components on measured UA concentrations. We aimed to: (1) demonstrate the variability in uricase-based UA measurements attributable to different collection methods and (2) identify factors influencing this variability. METHODS: Blood samples from human subjects were collected using Serum Separator Tubes (SST tubes), Acid Citrate Dextrose (ACD) tubes, and Sodium Citrate (SC) tubes. Circulating UA concentrations were measured by chemistry analyzers utilizing the uricase method. Absorbance assays were run in order to determine the effects of citric acid, sodium citrate, and dextrose on measured absorbance in the presence of leuco crystal violet dye, hydrogen peroxide, and peroxidase. Statistical analyses-including Student's T tests and ANOVA-were used to compare results. RESULTS: UA concentrations of blood samples collected in ACD tubes were significantly lower than those collected in SST tubes (P < 0.01). Samples collected in SC tubes trended towards lower UA measurements than samples collected in SST tubes, although this difference did not reach statistical significance (P = 0.06). Blood samples spiked with separate concentrations of sodium citrate (3.2 and 22.0 g/L), citric acid (8.0 g/L), and dextrose (24.5 g/L) demonstrated significantly lower UA measurements compared to controls (P < 0.01). Absorbance assays demonstrated that increasing concentrations of citric acid and sodium citrate-in the presence of leuco crystal violet, hydrogen peroxide, and peroxidase-decreased the amount of oxidized dye in the uricase method of UA measurement in a dose-dependent manner (P < 0.01). In contrast, dextrose did not significantly alter the amount of oxidized dye available. DISCUSSION: Our results indicate that citric acid obstructs accurate uricase-based UA measurement, providing falsely low values. Citric acid, a known antioxidant, scavenges hydrogen peroxide, a key intermediate using the uricase method. By scavenging hydrogen peroxide, citric acid decreases the amount of oxidized leuco dye leading to falsely low UA measurements. Therefore, collection tubes, like ACD and SC tubes, which contain concentrations of citric acid or its conjugate base sodium citrate should not be used to measure circulating UA levels when utilizing uricase-based measurement methods.
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Antioxidantes/química , Recolección de Muestras de Sangre/métodos , Ácido Cítrico/química , Urato Oxidasa/química , Ácido Úrico/sangre , Anciano , Anticoagulantes/química , Biomarcadores/sangre , Estudios de Cohortes , Glucosa/análogos & derivados , Glucosa/química , Gota/sangre , Gota/diagnóstico , Voluntarios Sanos , Humanos , Masculino , Persona de Mediana Edad , Citrato de Sodio/químicaRESUMEN
Doxycycline (DOX), a derivative of tetracycline, is a broad-spectrum antibiotic that exhibits a number of therapeutic activities in addition to its antibacterial properties. For example, DOX has been used in the management of a number of diseases characterized by chronic inflammation. One potential mechanism by which DOX inhibits the progression of these diseases is by reducing oxidative stress, thereby inhibiting subsequent lipid peroxidation and inflammatory responses. Herein, we tested the hypothesis that DOX directly scavenges reactive oxygen species (ROS) and inhibits the formation of redox-mediated malondialdehyde-acetaldehyde (MAA) protein adducts. Using a cell-free system, we demonstrated that DOX scavenged reactive oxygen species (ROS) produced during the formation of MAA-adducts and inhibits the formation of MAA-protein adducts. To determine whether DOX scavenges specific ROS, we examined the ability of DOX to directly scavenge superoxide and hydrogen peroxide. Using electron paramagnetic resonance (EPR) spectroscopy, we found that DOX directly scavenged superoxide, but not hydrogen peroxide. Additionally, we found that DOX inhibits MAA-induced activation of Nrf2, a redox-sensitive transcription factor. Together, these findings demonstrate the under-recognized direct antioxidant property of DOX that may help to explain its therapeutic potential in the treatment of conditions characterized by chronic inflammation and increased oxidative stress.
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Doxiciclina/química , Depuradores de Radicales Libres/química , Sistema Libre de Células , Doxiciclina/farmacología , Depuradores de Radicales Libres/farmacología , Células HEK293 , Humanos , Peróxido de Hidrógeno/química , Peróxido de Hidrógeno/metabolismo , Inflamación/tratamiento farmacológico , Inflamación/metabolismo , Malondialdehído/química , Malondialdehído/metabolismo , Factor 2 Relacionado con NF-E2/metabolismo , Estrés Oxidativo/efectos de los fármacos , Superóxidos/química , Superóxidos/metabolismoRESUMEN
BACKGROUND: Fracture healing in alcoholics is delayed and often associated with infections resulting in prolonged rehabilitation. It has been reported that binge drinking of alcohol increases oxidative stress and delays fracture healing in rats, which is prevented by treatment with the antioxidant n-acetyl cysteine (NAC). Oxidative stress is a significant factor in pathologies of various organs resulting from chronic alcoholism. Therefore, we hypothesize that treatment with NAC reduces oxidative stress and restores fracture healing in chronic alcoholics. METHODS: Rats (10 months old) were pair-fed the Lieber-DeCarli ethanol (EtOH) diet or control diet for 16 weeks. A closed fracture was performed and rats allowed to recover for 72 hours. Rats were divided into 4 groups-control, control + NAC, EtOH, and EtOH + NAC-and injected intraperitoneally with 200 mg/kg of NAC daily for 3 days. Serum and bone fracture callus homogenates were collected and assayed for traditional markers of inflammation, oxidative stress, and bone regeneration. RESULTS: The oxidative stress marker malondialdehyde (MDA) was increased in both serum and bone tissue in EtOH-fed animals compared to controls. NAC treatment significantly (p < 0.01) reduced MDA to near normal levels and dramatically increased the index of antioxidant efficacy (catalase/MDA ratio) (p < 0.01). Inflammatory markers tumor necrosis factor-α, interferon-γ, and interleukin-6 were significantly decreased in serum and callus following NAC treatment. NAC treatment reduced EtOH-induced bone resorption as evidenced by significant decreases in C-telopeptide of type-I-collagen levels (p < 0.05) and band-5 tartrate-resistant acid phosphatase levels in the tissue (p < 0.001). CONCLUSIONS: Oxidative stress and excessive inflammation are involved in the inhibition of fracture healing by EtOH. In this study, early short-term treatment of EtOH-fed animals with the antioxidant NAC reduced oxidative stress and normalized the innate immune response to fracture in the early phase of fracture healing, thereby restoring the normal onset of bone regeneration.
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Acetilcisteína/farmacología , Etanol/toxicidad , Fémur/efectos de los fármacos , Fémur/lesiones , Curación de Fractura/efectos de los fármacos , Animales , Relación Dosis-Respuesta a Droga , Etanol/administración & dosificación , Fémur/metabolismo , Curación de Fractura/fisiología , Mediadores de Inflamación/antagonistas & inhibidores , Mediadores de Inflamación/metabolismo , Masculino , Ratas , Ratas Wistar , Resultado del TratamientoRESUMEN
Precision-cut liver slices (PCLSs) provide a novel model for studies of alcoholic liver disease (ALD). This is relevant, as in vivo ethanol exposure does not appear to generate significant liver damage in ethanol-fed mice, except in the National Institute on Alcohol Abuse and Alcoholism binge model of ALD. Previous studies have shown that the two metabolites of ethanol consumption, malondialdhyde (MDA) and acetaldehyde (AA), combine to form MDA-AA (MAA) adducts, which have been correlated with the development and progression of ALD. In this study, murine PCLSs were incubated with ethanol and examined for the production of MAA adducts. PCLSs were homogenized, and homogenates were injected into C57BL/6 mice. PCLSs from control-, pair-, and ethanol-fed animals served as targets in in situ cytotoxic assays using primed T cells from mice hyperimmunized with control or ethanol-exposed PCLS homogenates. A CD45.1/CD45.2 passive-transfer model was used to determine whether T cells from the spleens of mice hyperimmunized with PCLS ethanol-exposed homogenates trafficked to the liver. PCLSs incubated with ethanol generated MAA-modified proteins in situ. Cytotoxic (CD8+) T cells from immunized mice killed naïve PCLSs from control- and pair-fed mice in vitro, a response that was blunted in PCLSs from ethanol-fed mice. Furthermore, CD45.1 CD8+ T cells from hyperimmunized mice trafficked to the liver but did not initiate liver damage. This study demonstrates that exposure to liver tissue damaged by ethanol mediates robust immune responses to well-characterized alcohol metabolites and native liver proteins in vitro. Moreover, although these proinflammatory T cells traffic to the liver, these responses appear to be dampened in vivo by locally acting pathways. NEW & NOTEWORTHY This study shows that the metabolites of ethanol and lipid breakdown produce malondialdehyde-acetaldehyde adducts in the precision-cut liver slice model system. Additionally, precision-cut liver slices exposed to ethanol and harboring malondialdehyde-acetaldehyde adducts generate liver-specific antibody and T cell responses in the spleens of naïve mice that could traffic to the liver.
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Acetaldehído/inmunología , Autoinmunidad , Hígado Graso Alcohólico/inmunología , Hepatopatías Alcohólicas/inmunología , Hígado/inmunología , Malondialdehído/inmunología , Linfocitos T Citotóxicos/inmunología , Acetaldehído/metabolismo , Traslado Adoptivo , Animales , Movimiento Celular , Células Cultivadas , Modelos Animales de Enfermedad , Hígado Graso Alcohólico/metabolismo , Femenino , Humanos , Técnicas In Vitro , Interleucina-6/inmunología , Interleucina-6/metabolismo , Antígenos Comunes de Leucocito/inmunología , Antígenos Comunes de Leucocito/metabolismo , Hígado/metabolismo , Hepatopatías Alcohólicas/metabolismo , Activación de Linfocitos , Malondialdehído/metabolismo , Ratones Endogámicos C57BL , Fenotipo , Bazo/inmunología , Bazo/metabolismo , Linfocitos T Citotóxicos/metabolismo , Linfocitos T Citotóxicos/trasplanteRESUMEN
BACKGROUND: Malondialdehyde (MDA) and acetaldehyde (AA) exist following ethanol metabolism and tobacco pyrolysis. As such, lungs of individuals with alcohol use disorders (AUDs) are a target for the effects of combined alcohol and cigarette smoke metabolites. MDA and AA form a stable protein adduct, malondialdehyde-acetaldehyde (MAA) adduct, known to be immunogenic, profibrotic, and proinflammatory. MAA adduct is the dominant epitope in anti-MAA antibody formation. We hypothesized that MAA-adducted protein forms in lungs of those who both abuse alcohol and smoke cigarettes, and that this would be associated with systemically elevated anti-MAA antibodies. METHODS: Four groups were established: AUD subjects who smoked cigarettes (+AUD/+smoke), smokers without AUD (-AUD/+smoke), AUD without smoke (+AUD/-smoke), and non-AUD/nonsmokers (-AUD/-smoke). RESULTS: We observed a significant increase in MAA adducts in lung cells of +AUD/+smoke versus -AUD/-smoke. No significant increase in MAA adducts was observed in -AUD/+smoke or in +AUD/-smoke compared to -AUD/-smoke. Serum from +AUD/+smoke had significantly increased levels of circulating anti-MAA IgA antibodies. After 1 week of alcohol that MAA-adducted protein is formed in the lungs of those who smoke cigarettes and abuse alcohol, leading to a subsequent increase in serum IgA antibodies. CONCLUSIONS: MAA-adducted proteins could play a role in pneumonia and other diseases of the lung in the setting of AUD and smoking.