Francisco J. Ballina-García

Cytokines and regulatory T cells in rheumatoid arthritis and their relationship with response to corticosteroids.

Objective. To analyze circulating cytokines and regulatory T cells (Treg) in patients with rheumatoid arthritis (RA) of different durations, and their association with functional interleukin 10 (IL-10) and tumor necrosis factor-α (TNF-α) genotypes in patients treated with corticosteroids. Methods. Serum levels of IL-6, IL-10, IL-17, IL-18, TNF-α, and transforming growth factor-ß (TGF-ß) were quantified in 196 patients and 61 healthy controls. Percentage of CD4+CD25high cells was determined by flow cytometry and Foxp3 expression by real-time reverse-transcription polymerase chain reaction. Data were related to clinical measurements and presence of the genotype −1082GG IL-10/−308GG TNF-α, previously associated with good response to corticosteroids. Results. Levels of TNF-α, IL-6, and IL-18 were significantly higher in patients compared to controls, while TGF-ß and IL-10 were lower. Serum samples of patients at disease onset (n = 32) had increased IL-6 and decreased TGF-ß, but there were no differences in other cytokines. These patients also presented a higher percentage of CD4+CD25high cells than those with established disease, although no significant differences were detected in Foxp3. Patients under corticosteroid treatment who were carriers of the good responder genotype had higher levels of TGF-ß, Foxp3, and Treg compared to patients with other genotypes, while relatively lower levels of TNF-α and IL-17 were observed. Conclusion. Patients at onset of RA present fewer alterations in cytokine levels and Treg than those with longer disease duration, supporting the role of disease progression in subsequent changes. The antiinflammatory balance observed in high IL-10/low TNF-α patients treated with prednisone supports the use of these genetic polymorphisms as predictors of response to corticosteroid therapy.

Interleukin 10 and Tumor Necrosis Factor-α Genotypes in Rheumatoid Arthritis — Association with Clinical Response to Glucocorticoids

Objective. There are dysregulated levels of interleukin 10 (IL-10) and tumor necrosis factor-α (TNF-α) in rheumatoid arthritis (RA), and their role in the disease is controversial. We analyzed the association of functional polymorphisms of IL-10 and TNF-α with susceptibility and disease characteristics at the time of diagnosis, and we also evaluated their possible use as predictors of clinical response to treatments. Methods. Patients with recent-onset RA (n = 162) and healthy controls (n = 373) were genotyped for −1082 IL-10 and −308 TNF-α polymorphisms and data were related to clinical and immunological measurements of patients at the time of diagnosis. Response to treatment after 6 months was determined in 125 patients by the absolute change in Disease Activity Score (DAS28) and the American College of Rheumatology criteria for improvement. Results. We found a reduced frequency of the low IL-10 producer genotype (−1082AA) in patients with RA compared to controls (26.5% vs 38.9%; p = 0.006), while it is a risk factor for anticyclic citrullinated peptide antibodies (anti-CCP) positivity (p = 0.028). Evaluation of clinical response to treatments indicated that carriage of the high IL-10 genotype was associated with a favorable outcome (p = 0.009), specifically to prednisone therapy (p = 0.0003). No significant effects were observed with TNF-α polymorphism alone; however, in combination with the IL-10 genotype, it increased the strength of these associations. Conclusion. Results show an association between the low IL-10 producer genotype and protection from RA; nevertheless, when other specific genetic and/or environmental factors trigger onset of RA, this genotype may predispose to development of anti-CCP+ RA disease with reduced response to prednisone treatment.

Effects of glucocorticoid treatment on CD25−FOXP3+ population and cytokine-producing cells in rheumatoid arthritis

OBJECTIVES To investigate CD25(-)FOXP3(+) cells in RA patients and their possible relationship with disease features and response to glucocorticoids (GCs). METHODS Peripheral blood mononuclear cells were collected from 147 RA patients, 29 healthy controls and 75 SLE patients as disease controls. The proportion of CD4(+)FOXP3(+) cells with negative, low or high CD25 expression and the levels of IL-10-, TNF-α-, IL-17- and IFNγ-producing cells were assessed by flow cytometry. The presence of the high IL-10 genotype (-1082GG), associated with good response to GC, was determined by PCR amplification and hybridization with allele-specific fluorescently labelled probes. Data were related to treatment and clinical parameters. RESULTS The CD25(-)FOXP3(+) population was significantly increased in RA patients and negatively correlated with DAS-28 and other disease parameters. The IL-10 genotype did not influence the frequency of these cells in controls or the entire RA group; however, GC-treated patient carriers of the high IL-10 genotype presented significantly higher levels of this population in addition to an increased percentage of IL-10-secreting cells and relatively low amounts of TNF-α-, IFN-γ- and IL-17-positive cells. Finally, a prospective study confirmed that genetically high IL-10 producers significantly increase CD25(-)FOXP3(+) cells after 6 months of GC treatment. CONCLUSION The present study provides the first evidence of increased CD25(-)FOXP3(+) cells in RA patients, which were associated with disease activity and with GC treatment in carriers of the high IL-10 genotype, suggesting that this population plays a role in the clinical response to prednisone in RA.

IFNα Serum Levels Are Associated with Endothelial Progenitor Cells Imbalance and Disease Features in Rheumatoid Arthritis Patients

Introduction IFNα has been largely implicated in the ethiopathogenesis of autoimmune diseases but only recently it has been linked to endothelial damage and accelerated atherosclerosis in autoimmunity. In addition, proinflammatory conditions are supposed to be implicated in the cardiovascular status of these patients. Since a role for IFNα in endothelial damage and impaired Endothelial Progenitor Cell (EPC) number and function has been reported in other diseases, we aimed to evaluate the potential associations of IFNα serum levels on EPC populations and cytokine profiles in Rheumatoid Arthritis (RA) patients. Methods pre-EPC, EPC and mature EPC (mEPC) populations were quantified by flow cytometry analyzing their differential CD34, CD133 and VEGFR2 expression in blood samples from 120 RA patients, 52 healthy controls (HC), and 83 systemic lupus erythematosus (SLE) patients as disease control. Cytokine serum levels were measured by immunoassays and clinical and immunological data, including cardiovascular (CV) events and CV risk factors, were retrospectively obtained by reviewing clinical records. Results Long-standing, but not recent onset RA patients displayed a significant depletion of all endothelial progenitor populations, unless high IFNα levels were present. In fact, the IFNhigh RA patient group (n = 40, 33%), showed increased EPC levels, comparable to SLE patients. In addition, high IFNα serum levels were associated with higher disease activity (DAS28), presence of autoantibodies, higher levels of IL-1β, IL-6, IL-10 and MIP-1α, lower amounts of TGF-β, and increased mEPC/EPC ratio, thus suggesting higher rates of endothelial damage and an endothelial repair failure. Finally, the relationship between high IFNα levels and occurrence of CV events observed in RA patients seems to support this hypothesis. Conclusions IFNα serum marker could be used to identify a group of RA patients with increased disease activity, EPC imbalance, enhanced proinflammatory profile and higher cardiovascular risk, probably due, at least in part, to an impaired endothelial repair.

Red cell distribution width is associated with cardiovascular risk and disease parameters in rheumatoid arthritis

OBJECTIVE Since red cell distribution width (RDW) has been associated with cardiovascular (CV) disease and inflammation in several conditions, the main aim of this study was to evaluate its prognostic value in RA patients and its potential associations with clinical features. METHODS The history of CV events was retrospectively reviewed in 160 RA patients and RDW was recorded at disease onset and 6 and 12 months after diagnosis to calculate the accumulated value [area under the curve (AUC) RDW] and change during the first year (ΔRDW). In addition, RDW was analysed in 110 patients with established disease in relation to clinical features. RESULTS Increased RDW at diagnosis and AUC RDW were able to predict the occurrence of CV events in RA patients [hazard ratio (HR) 1.247 (95% CI 1.079, 1.441), P = 0.003 and HR 1.038 (95% CI 1.018, 1.059), P = 0.0001, respectively] after adjusting by potential confounding factors. Receiver operating characteristic curve analyses revealed a better power of discrimination for the AUC RDW (P = 3.394 × 10(-5)). In addition, an increase in RDW during the first year was associated with poor CV outcome (P = 0.010). On the other hand, RDW in patients with established RA was significantly associated with disease activity, acute phase reactants and severity. CONCLUSION RDW at disease onset may be used as an early marker of CV risk in RA, whereas in patients with established disease it was related to the activity of the disease. These findings suggest that RDW can be considered as a surrogate marker of inflammation and, consequently, CV risk in RA patients.

Red cell distribution width is associated with endothelial progenitor cell depletion and vascular-related mediators in rheumatoid arthritis.

OBJECTIVES The role of Red Cell Distribution Width (RDW) as a predictor of cardiovascular (CV) events has been proposed in a variety of conditions, including Rheumatoid Arthritis (RA). However, the mechanisms underlying this effect are still unknown. Since inflammation and Endothelial Progenitor Cells (EPCs) imbalance have been reported in RA patients to be related to CV disease, we wondered whether RDW could be linked to endothelial repair failure in RA. METHODS EPCs (CD34+VEGFR2+CD133+) were quantified by flow cytometry in peripheral blood samples from 194 RA patients. IFNα, TNFα, IFNγ, IL-8, VEGF, GM-CSF, MCP-1, ICAM-1, EGF, Leptin and Resistin serum levels were quantified by immunoassays. Clinical and immunological parameters as well as history of traditional CV risk factors and CV events were registered from medical records. RDW was measured in complete blood cell count analyses. RESULTS RDW was negatively related to EPC counts in patients with established disease (>1 year, n=125) (r=-0.306, p<0.001). Moreover, RDW was independently associated to an EPC depletion in the whole group (β [95% CI]: -3.537 [-6.162, -0.911], p=0.009) after adjusting for clinical parameters, disease duration, treatments and traditional CV risk factors. Additionally, RDW was positively correlated with IFNα serum levels, a cytokine related to endothelial damage, and with IL-8, VEGF and neutrophil to lymphocyte ratio, thus supporting the association with inflammation and vascular remodelling. CONCLUSIONS RDW was associated to EPC depletion and increased levels of different mediators linked to endothelial damage and vascular repair failure, thereby shedding new light on the nature of RDW as CV-predictor.

Altered profile of circulating microparticles in rheumatoid arthritis patients

Microparticles (MPs) could be considered biomarkers of cell damage and activation as well as novel signalling structures. Since rheumatoid arthritis (RA) is characterized by immune and endothelial activation, the main aim of the present study was to analyse MP counts in RA patients. Citrated-blood samples were obtained from 114 RA patients, 33 healthy controls (HC) and 72 individuals with marked cardiovascular (CV) risk without autoimmune manifestations (CVR). MPs were analysed in platelet-poor plasma (PPP) and different subsets were identified by their surface markers: platelet- (CD41+), endothelial- (CD146+), granulocyte- (CD66+), monocyte- (CD14+) and Tang- (CD3+CD31+) derived. Disease activity score (DAS28), clinical and immunological parameters as well as traditional CV risk factors (diabetes, hypertension, dyslipidaemia and obesity) were registered from clinical records and all data were integrated using Principal Component Analysis (PCA). Absolute MP number was increased in RA patients compared with HC and positively correlated with traditional CV risk factors, similar to that of CVR subjects. In addition, frequency of the different MP subsets was different in RA patients and significantly associated with disease features. Moreover, in vitro assays revealed that MPs isolated from RA patients were able to promote endothelial activation and exhibited detrimental effects on human microvascular endothelial cells (HMEC-I) endothelial cell functionality. Circulating MPs from RA patients displayed quantitative and qualitative alterations that are the result of both disease-specific and traditional CV risk factors. Accordingly, this MP pool exhibited in vitro detrimental effects on endothelial cells, thus supporting their role as biomarkers of vascular damage.

Angiogenic T cells are decreased in rheumatoid arthritis patients

Objective The mechanisms underlying the increased cardiovascular risk (CVR) of rheumatoid arthritis (RA) patients remain unclear. Since the recently discovered angiogenic T cells (Tang) could have a role in endothelial repair through cooperating with endothelial progenitor cells (EPC), the main aim of this study was to analyse the Tang and EPC populations in relation to disease-specific features and traditional CVR factors. Methods Tang (CD3+CD31+CXCR4+) and EPC (CD34+VEGFR2+CD133+) populations were quantified by flow cytometry in peripheral blood samples from 103 RA patients and 18 matched healthy controls (HC). Clinical features and traditional CVR factors were obtained from clinical records, and 28-joint Disease Activity Score was used for measuring disease activity. Interferon (IFN) α serum levels were measured by immunoassays. Results Tang and EPC were strongly decreased in RA patients. In HC, but not in patients, both populations were positively correlated and inversely related to low density lipoprotein- and total-cholesterol levels. Sex, diabetes, dyslipidaemia, hypertension or obesity did not significantly influence Tang in patients, although detected in smokers. However, Tang were closely related to disease activity, autoantibody positivity and IFNα levels. Multiple regression analysis adjusted for traditional CVR factors confirmed that only disease activity, age at diagnosis, antinuclear antibody positivity and smoking habit could predict Tang frequency. Finally, patients who had suffered a CV event since their RA diagnosis presented higher Tang decrease and IFNα levels than those who were CV event-free. Conclusions Disease-specific parameters, including disease activity, autoantibody profiles and IFNα levels, are associated with Tang decrease in RA, thus probably accounting for CVR.

Paraoxonase 1 Activity Is Modulated by the rs662 Polymorphism and IgG Anti-High-Density Lipoprotein Antibodies in Patients With Rheumatoid Arthritis: Potential Implications for Cardiovascular Disease.

Paraoxonase 1 (PON‐1) is a high‐density lipoprotein (HDL)–associated antioxidant enzyme that plays an important role in HDL‐mediated cardioprotection. Although genetic polymorphisms are known to modulate PON-1 activity, its involvement in cardiovascular disease (CVD) in rheumatoid arthritis (RA) is controversial, suggesting that other factors may modulate its function. Since anti‐HDL antibodies have been found to be related to an impaired lipid profile and occurrence of CVD in RA, this study was undertaken to examine the associations between PON-1 activity, anti‐HDL antibodies, and CVD according to PON1 genetic variants in patients with RA.

Non-Esterified Fatty Acids Profiling in Rheumatoid Arthritis: Associations with Clinical Features and Th1 Response.

Objectives Since lipid compounds are known to modulate the function of CD4+ T-cells and macrophages, we hypothesize that altered levels of serum non-esterified fatty acids (NEFA) may underlie rheumatoid arthritis (RA) pathogenesis. Methods Serum levels of NEFA (palmitic, stearic, palmitoleic, oleic, linoleic, γ-linoleic, arachidonic –AA–, linolenic, eicosapentaenoic –EPA– and docosahexaenoic –DHA–) were quantified by LC-MS/MS after methyl-tert-butylether (MTBE)-extraction in 124 RA patients and 56 healthy controls (HC). CD4+ phenotype was studied by flow cytometry. TNFα, IL-8, VEGF, GM-CSF, IFNγ, IL-17, CCL2, CXCL10, leptin and resistin serum levels were quantified by immunoassays. The effect of FA on IFNγ production by PBMC was evaluated in vitro. Results Lower levels of palmitic (p<0.0001), palmitoleic (p = 0.002), oleic (p = 0.010), arachidonic (p = 0.027), EPA (p<0.0001) and DHA (p<0.0001) were found in RA patients, some NEFA being altered at onset. Cluster analysis identified a NEFA profile (hallmarked by increased stearic and decreased EPA and DHA) overrepresented in RA patients compared to HC (p = 0.002), being associated with clinical features (RF, shared epitope and erosions), increased IFNγ expression in CD4+ T-cells (p = 0.002) and a Th1-enriched serum milieu (IFNγ, CCL2 and CXCL10, all p<0.005). In vitro assays demonstrated that imbalanced FA could underlie IFNγ production by CD4+ T-cells. Finally, changes on NEFA levels were associated with clinical response upon TNFα-blockade. Conclusion An altered NEFA profile can be found in RA patients associated with clinical characteristics of aggressive disease and enhanced Th1 response. These results support the relevance of lipidomic studies in RA and provide a rationale for new therapeutic targets.