Osteopontin as a Biomarker in Interstitial Lung Diseases.

Osteopontin (OPN) is a glycoprotein involved in Th1 and Th17 differentiation, and inflammation and tissue remodeling. OPN is a biomarker of disease activity in patients with autoimmune inflammatory conditions. This study aimed to assess the diagnostic and prognostic value of OPN in interstitial lung diseases (ILDs). Between May 2016 and October 2019, 344 patients with ILD were recruited at the Hospital Universitario Marqués de Valdecilla (Spain) and were prospectively followed-up. This study involved the determination of OPN serum levels by ELISA and OPN RNA expression quantified using qPCR. Six genetic polymorphisms in OPN (rs28357094, rs2853749, rs2853750, rs11728697, rs7695531, and rs1126616) were genotyped using TaqMan assays. OPN serum levels were also assessed in 140 healthy controls. OPN serum levels (median [interquartile range]) were significantly higher in ILD patients than in controls (1.05 [0.75-1.51] ng/mL versus 0.81 [0.65-0.98] ng/mL in healthy controls; p < 0.01). OPN serum levels were inversely correlated with the forced vital capacity. OPN serum levels were also higher in ILD patients who died or underwent lung transplantation when compared with the remaining ILD patients (1.15 [0.80-1.72] ng/mL versus 0.99 [0.66-1.32] ng/mL; p = 0.05). Survival worsened in ILD patients with OPN > 1.03 ng/mL at 1, 3, and 5 years. No statistically significant differences in the genetic frequencies of OPN polymorphisms or the RNA expression were found among the different ILD groups. Elevated levels of OPN in the serum may be a useful indicator in identifying patients with ILD who are more likely to experience poor outcomes.

Inflammasome-Related Genetic Polymorphisms as Severity Biomarkers of COVID-19.

The most critical forms of coronavirus disease 2019 (COVID-19) are associated with excessive activation of the inflammasome. Despite the COVID-19 impact on public health, we still do not fully understand the mechanisms by which the inflammatory response influences disease prognosis. Accordingly, we aimed to elucidate the role of polymorphisms in the key genes of the formation and signaling of the inflammasome as biomarkers of COVID-19 severity. For this purpose, a large and well-defined cohort of 377 COVID-19 patients with mild (n = 72), moderate (n = 84), severe (n = 100), and critical (n = 121) infections were included. A total of 24 polymorphisms located in inflammasome-related genes (NLRP3, NLRC4, NLRP1, CARD8, CASP1, IL1B, IL18, NFKB1, ATG16L1, and MIF) were genotyped in all of the patients and in the 192 healthy controls (HCs) (who were without COVID-19 at the time of and before the study) by RT-qPCR. Our results showed that patients with mild, moderate, severe, and critical COVID-19 presented similar allelic and genotypic distribution in all the variants studied. No statistically significant differences in the haplotypic distribution of NLRP3, NLRC4, NLRP1, CARD8, CASP1, IL1B, and ATG16L1 were observed between COVID-19 patients, who were stratified by disease severity. Each stratified group of patients presented a similar genetic distribution to the HCs. In conclusion, our results suggest that the inflammasome polymorphisms studied are not associated with the worsening of COVID-19.

Personalized cardiovascular risk assessment in Rheumatoid Arthritis patients using circulating molecular profiles and their modulation by TNFi, IL6Ri, and JAKinibs.

BACKGROUND & OBJECTIVES: This study aimed to: 1) analyze the inflammatory profile of Rheumatoid Arthritis (RA) patients, identifying clinical phenotypes associated with cardiovascular (CV) risk; 2) evaluate biologic and targeted-synthetic disease-modifying antirheumatic drugs (b-DMARDs and ts-DMARDs': TNFi, IL6Ri, JAKinibs) effects; and 3) characterize molecular mechanisms in immune-cell activation and endothelial dysfunction. PATIENTS & METHODS: A total of 387 RA patients and 45 healthy donors were recruited, forming three cohorts: i) 208 RA patients with established disease but without previous CV events; ii) RA-CVD: 96 RA patients with CV events, and iii) 83 RA patients treated with b-DMARDs/ts-DMARDs for 6 months. Serum inflammatory profiles (cytokines/chemokines/growth factors) and NETosis/oxidative stress-linked biomolecules were evaluated. Mechanistic in vitro studies were performed on monocytes, neutrophils and endothelial cells (EC). RESULTS: In the first RA-cohort, unsupervised clustering unveiled three distinct groups: cluster 3 (C3) displayed the highest inflammatory profile, significant CV-risk score, and greater atheroma plaques prevalence. In contrast, cluster 1 (C1) exhibited the lowest inflammatory profile and CV risk score, while cluster 2 (C2) displayed an intermediate phenotype. Notably, 2nd cohort RA-CVD patients mirrored C3's inflammation. Treatment with b-DMARDs or ts-DMARDs effectively reduced disease-activity scores (DAS28) and restored normal biomolecules levels, controlling CV risk. In vitro, serum from C3-RA or RA-CVD patients increased neutrophils activity and CV-related protein levels in cultured monocytes and EC, which were partially prevented by pre-incubation with TNFi, IL6Ri, and JAKinibs. CONCLUSIONS: Overall, analyzing circulating molecular profiles in RA patients holds potential for personalized clinical management, addressing CV risk and assisting healthcare professionals in tailoring treatment, ultimately improving outcomes.

The complement system is linked to insulin resistance in patients with systemic lupus erythematosus.

OBJECTIVES: Systemic lupus erythematosus (SLE) patients more commonly have insulin resistance (IR) than control subjects. Recent studies have revealed that the complement (C) system is not only a mediator of the immune system but is also related to the pathogenesis of atherosclerosis in the general population. Given that the C alteration is a characteristic of SLE, in the present work we set out to analyse if there is a relationship between the C system and IR in patients with SLE. METHODS: New generation functional assays of the three pathways of the C system were performed in 225 non-diabetic patients with SLE. In addition, the serum levels of inactive (C1q, C2, C3, C4, factor D), activated (C3a) and regulators (C1 inhibitor and factor H) molecules of the C system were evaluated. Insulin and C-peptide serum levels were measured, and insulin resistance and indices of beta cell function were calculated using the homeostatic model assessment (HOMA). Metabolic syndrome criteria fulfillments were applied. Multivariable linear regression analysis was performed to assess the relationship between C system and IR indices and the presence of metabolic syndrome. RESULTS: After adjusting for covariates that included traditional cardiovascular risk factors associated with IR and prednisone, serum C3a and factor H levels were positively related to higher levels of the HOMA2-IR index. Besides, in the multivariable analysis, after adjustment for covariates, serum levels of C1q and C3 associated with a higher odds ratio for the presence of metabolic syndrome. CONCLUSIONS: IR and metabolic syndrome are positively and independently related to higher serum levels of some serum C elements in patients with SLE with a predominant role of the alternative pathway elements.

Interleukin-6 serum levels are associated with disease features and cardiovascular risk in patients with systemic sclerosis.

OBJECTIVES: Systemic sclerosis (SSc) is a chronic multisystem disease characterised by microcirculatory vascular dysfunction and progressive fibrosis of the skin and internal organs. Interleukin-6 (IL-6) is a proinflammatory cytokine that has been implicated in the pathogenesis of several autoimmune diseases and in the initiation and progression of the cardiovascular disease. In the present work we aimed to study the relationship of IL-6 with clinical manifestations and the cardiovascular risk in patients with SSc. METHODS: Cross-sectional study that included 53 individuals with SSc. A multivariate analysis was performed to study the relationship between IL-6 and disease characteristics and cardiovascular risk assessed by Systematic Coronary Risk Estimation (SCORE2) in SSc. RESULTS: The presence of digital ulcers, calcinosis, and anti-Scl70 antibody was associated with higher levels of IL-6. This was also the case for functional respiratory parameters where this association was found to be significant and negative after correction for covariates. In addition, the SCORE2 cardiovascular risk algorithm showed a positive and significant association with circulating IL-6. CONCLUSIONS: IL-6 levels are associated with disease manifestations and cardiovascular risk in patients with SSc.

Red Cell Distribution Width Association with Subclinical Cardiovascular Disease in Patients with Rheumatoid Arthritis.

Red cell distribution width (RDW) is a measure of the variation in mean corpuscular volume that reflects the degree of anisocytosis on the peripheral blood smear. RDW value variation has been implicated in several disorders including chronic inflammatory processes and cardiovascular (CV) diseases. In the present work, our objective was to study the relationship that RDW has with the characteristics of the disease in patients with rheumatoid arthritis (RA), focusing on CV risk factors and subclinical atherosclerosis. A cross-sectional study was conducted that included 430 patients with RA and 208 controls matched by sex and age. Complete blood count, including RDW, was assessed. Multivariable analysis was performed to analyze the relationship of RDW with RA disease characteristics, subclinical carotid atherosclerosis, and traditional CV factors, including a comprehensive profile of lipid molecules and insulin resistance and beta cell function indices. After multivariable adjustment, the RDW was significantly higher in RA patients compared with controls (beta coefficient 1.0 [95% confidence interval 0.2 to 1.8] %, p = 0.020). Furthermore, although the erythrocyte sedimentation rate showed a positive and significant relationship with RDW, this association was not found with C-reactive protein and interleukin-6. A positive and independent relationship was observed between DAS28-ESR disease activity score and RDW. However, no association was found between the RDW and other disease activity scores that do not include erythrocyte sedimentation rate in their formula. The SCORE2 CV risk algorithm was positively and significantly associated with higher RDW values. Likewise, a negative relationship was found between RDW with total cholesterol and low-density lipoprotein cholesterol, and a positive relationship was found between RDW and insulin resistance indices. In conclusion, RDW values are higher in RA patients compared to matched controls. Although the relationship of RDW with disease activity was not consistent, RDW shows associations with subclinical CV disease risk factors, including dyslipidemia and insulin resistance, and with the SCORE2 CV disease-risk prediction algorithm.

Blood Composite Scores in Patients with Systemic Lupus Erythematosus.

Complete blood count-derived ratios have been described as inflammatory biomarkers in several diseases. These hematological scores include the neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammatory index ([SIRI]; neutrophils × monocytes/lymphocytes). Our aim was to study how these biomarkers are related to disease expression in a large and well-characterized series of patients with systemic lupus erythematosus (SLE). A total of 284 SLE patients and 181 age- and sex-matched healthy controls were recruited. The NLR, MLR, PLR, and SIRI were calculated, and activity (SLEDAI-2K), severity (Katz), and damage index (SLICC-DI) scores were assessed in patients with SLE. Multivariable linear regression analysis was performed to study whether these scores differ between patients and controls and how they are related to clinical and laboratory features of the disease. Crude cell counts of neutrophils, monocytes, lymphocytes, and platelets were lower in SLE patients compared to controls. Despite this, NLR, MLR, and PRL, but not SIRI, were higher in SLE patients than in controls after multivariable analysis. However, the relationship between the different scores and disease characteristics was limited. Only the Katz severity index revealed a significant positive relationship with SIRI, NLR, and MLR after adjustment for covariates. Similarly, alternative complement cascade activation and low C3 were significantly associated with higher NLR, MLR, and PLR. In conclusion, although cytopenias are a common feature of patients with SLE, hematologic composite scores are independently higher in this population compared to controls. However, the relationship of these scores with the characteristics of the disease is scarce, with the relationship with the complement system being the most consistent.

The Ratio of Monocytes to HDL-Cholesterol Is Associated with Cardiovascular Risk and Insulin Resistance in Patients with Rheumatoid Arthritis.

The monocytes to high-density lipoprotein (HDL)-cholesterol ratio (MHR) indicates inflammation based on the anti-inflammatory properties of HDL-cholesterol as well as the pro-inflammatory effect of monocytes. Several studies have investigated MHR in various disorders, specifically in cardiovascular diseases. Consequently, MHR has been significantly associated with cardiovascular and all-cause mortality in the general population, regardless of established risk factors. However, its role in the augmented risk of cardiovascular disease found in rheumatoid arthritis (RA) has not been studied to date. This is a cross-sectional study that encompassed 430 patients with RA and 208 controls matched by sex and age. Complete blood cell count and complete lipid profile were evaluated. Multivariable analysis was made to analyze the relationship between MHR and RA disease and features subclinical carotid atherosclerosis, and traditional CV factors including insulin resistance and beta cell function indices. MHR values did not differ between controls and patients after multivariable adjustment (12 ± 6 vs. 11 ± 6, p = 0.18). No relationship between this ratio and the characteristics of the disease was found excluding ESR, which showed a significant and positive association with MHR after adjustment for covariates. MHR significantly correlated with Systematic Coronary Risk Evaluation-2 (SCORE2) cardiovascular risk algorithm, and insulin resistance and beta cell function parameters after adjustment. In conclusion, MHR does not differ between patients with RA and controls. The relationship of this biomarker with disease-related data is poor. However, MHR is highly and positively related to cardiovascular risk and insulin resistance in RA.

Mean Platelet Volume in a Series of 315 Patients with Rheumatoid Arthritis: Relationship with Disease Characteristics, including Subclinical Atherosclerosis and Cardiovascular Comorbidity.

Mean platelet volume (MPV) refers to the average platelet size in femtoliters. Increased or decreased MPV has been associated with several disorders, including inflammatory and cardiovascular diseases. In the present study, our objective was to analyze the relationship of MPV with disease activity in a large and well-characterized series of patients with rheumatoid arthritis (RA). This is a cross-sectional study that included 315 patients with RA and 208 controls matched by sex and age. Complete blood count, including MPV, was assessed. Multivariable analysis was performed to examine the relationship of MPV with RA disease characteristics, carotid atherosclerosis, and traditional cardiovascular factors, including a comprehensive profile of lipid molecules and insulin resistance or beta cell function indices. The multivariable analysis, which includes other hematological modifications produced by the disease and platelet values, showed that MPV levels were significantly lower in RA patients than in controls. Erythrocyte sedimentation rate and interleukin-6, but not C-reactive protein, were negatively correlated with MPV after adjustment for covariates. Similarly, disease activity and MPV had a significant and independent negative correlation. No relationships were found between MPV and cardiovascular risk factors, lipid profile or insulin resistance indices or subclinical atherosclerosis. In conclusion, patients with RA have lower levels of MPV than controls. MPV is negatively related to acute phase reactants and disease activity in RA.

Mucosal Immune Defence Gene Polymorphisms as Relevant Players in the Pathogenesis of IgA Vasculitis?

ITGAM-ITGAX (rs11150612, rs11574637), VAV3 rs17019602, CARD9 rs4077515, DEFA (rs2738048, rs10086568), and HORMAD2 rs2412971 are mucosal immune defence polymorphisms, that have an impact on IgA production, described as risk loci for IgA nephropathy (IgAN). Since IgAN and Immunoglobulin-A vasculitis (IgAV) share molecular mechanisms, with the aberrant deposit of IgA1 being the main pathophysiologic feature of both entities, we assessed the potential influence of the seven abovementioned polymorphisms on IgAV pathogenesis. These seven variants were genotyped in 381 Caucasian IgAV patients and 997 matched healthy controls. No statistically significant differences were observed in the genotype and allele frequencies of these seven polymorphisms when the whole cohort of IgAV patients and those with nephritis were compared to controls. Similar genotype and allele frequencies of all polymorphisms were disclosed when IgAV patients were stratified according to the age at disease onset or the presence/absence of gastrointestinal or renal manifestations. Likewise, no ITGAM-ITGAX and DEFA haplotype differences were observed when the whole cohort of IgAV patients, along with those with nephritis and controls, as well as IgAV patients, stratified according to the abovementioned clinical characteristics, were compared. Our results suggest that mucosal immune defence polymorphisms do not represent novel genetic risk factors for IgAV pathogenesis.

Malondialdehyde Serum Levels in Patients with Systemic Sclerosis Relate to Dyslipidemia and Low Ventricular Ejection Fraction.

Systemic sclerosis (SSc) is a chronic disease characterized by vasculopathy with the involvement of dysfunctional microcirculatory vessels. Features of the disease include progressive fibrosis of the skin and internal organs and systemic inflammation characterized by the presence of circulating autoantibodies and proinflammatory cytokines. Furthermore, macrovascular disease and atherosclerosis are more common in patients with SSc than in the general population. Oxidative stress plays a crucial role in the development of several processes, including endothelial dysfunction, cancer, inflammation, and atherogenesis. Malondialdehyde (MDA) is a well-established marker of oxidative stress. In this work, we have analyzed the relationship between serum MDA levels and clinical, laboratory, and vascular characteristics in a well-characterized cohort of 53 patients with SSc. A multivariable analysis was performed to study the relationship between circulating MDA and disease characteristics in patients with SSc. Cardiovascular assessment was also performed, including ultrasonography of the carotid and aorta, and echocardiography. MDA showed a significant and positive relationship with the serum levels of lipid profile molecules such as total cholesterol (ß coefficient = 0.006 (95% CI: 0.0004 to 0.01), nmol/mL, p = 0.037) and LDL cholesterol (ß coefficient = 0.008 (95% CI: 0.001 to 0.01) nmol/mL, p = 0.017). On the contrary, most manifestations of the disease, including skin, lung, and joint involvement, as well as the presence of digital ulcers, were not related to MDA. However, high MDA levels were significantly and independently associated with lower ventricular ejection fraction after adjustment for covariates (ß coefficient = -0.04 (95% CI: -0.06 to -0.02), nmol/mL, p = 0.001). In conclusion, serum MDA levels were related to higher levels of total and LDL cholesterol and a lower left ventricular ejection fraction in patients with SSc. MDA could serve as a potential biomarker of dyslipidemia and heart failure in SSc.

Relationship between Disease Characteristics and Circulating Interleukin 6 in a Well-Characterized Cohort of Patients with Systemic Lupus Erythematosus.

Interleukin-6 (IL-6) is a proinflammatory cytokine that mediates pleiotropic functions in immune responses and inflammatory diseases. The literature lacks studies, with a clinical perspective, on the relationship between IL-6 serum levels and the characteristics of the disease in patients with systemic lupus erythematosus (SLE). In the present work, we aimed to analyze the association between circulating IL-6 and disease manifestations in a well-characterized series of patients with SLE. Serum IL-6 levels and disease activity (SLEDAI-2K), severity (Katz) and damage index (SLICC-DI), complete lipid profile, and subclinical carotid atherosclerosis were evaluated in 284 patients with SLE. In addition, a complete characterization of the complement system was performed in samples from patients with SLE. A multivariate linear regression analysis was carried out to study the relationship between clinical and laboratory characteristics of the disease and IL-6 levels. Age (beta coef. 0.07 [95%CI 0.01-0.1] pg/mL, p = 0.014), C-reactive protein (beta coef. 0.21 [95%CI 0.16-0.25] pg/mL, p < 0.01), and male gender (beta coef. 2 [95%CI 0.3-0.5] pg/mL, p = 0.024), were positively associated with higher IL-6 levels in SLE patients. Most disease characteristics and damage and activity indices did not show significant relationships with IL-6. However, after multivariate analysis, IL-6 was associated with lower serum levels of HDL cholesterol (beta coef. -0.04 [95%CI -0.08-(-0.1)] pg/mL, p = 0.011), and apolipoprotein A1 (beta coef. -0.02 [95%CI -0.04-(-0.001)] pg/mL, p = 0.035). In contrast, the alternative complement cascade, C1inh, and C3a were all positively and independently associated with higher serum levels of IL-6. Moreover, stratification of the Systematic Coronary Risk Assessment 2 (SCORE2) results according to different categories of cardiovascular risk was associated with higher circulating serum IL-6 levels (beta coef. 0.2 [95%CI 0.02-0.4], pg/mL, p = 0.028). In conclusion, in a large series of SLE patients, IL-6 was not associated with disease-related features of SLE, including damage, severity, or activity indices. However, an association was found between serum IL-6 levels and circulating C3a and cardiovascular risk. Our study emphasizes the importance that IL-6 could have in cardiovascular disease and complement system disruption of SLE patients. Therapies targeting IL-6 could have a role in these two clinical manifestations of patients with SLE.

E-Selectin, ICAM-1, and ET-1 Biomarkers Address the Concern of the Challenging Diagnosis of Interstitial Lung Disease in Patients with Autoimmune Diseases.

Interstitial lung disease (ILD) constitutes the most critical comorbidity in autoimmune diseases (ADs) and its early diagnosis remains a challenge for clinicians. Accordingly, we evaluated whether E-selectin, ICAM-1, and ET-1, key molecules in endothelial damage, could be useful biomarkers for the detection of AD-ILD+. We recruited patients with rheumatoid arthritis (RA)-ILD+ (n = 21) and systemic sclerosis (SSc)-ILD+ (n = 21). We included comparison groups of patients: RA-ILD- (n = 25), SSc-ILD- (n = 20), and idiopathic pulmonary fibrosis (IPF) (n = 21). Serum levels of these proteins were determined by ELISA. E-selectin, ICAM-1, and ET-1 serum levels were increased in RA-ILD+ and IPF patients in comparison to RA-ILD- patients. Additionally, SSc-ILD+ and IPF patients exhibited higher ICAM-1 levels than those with SSc-ILD-. The ability of E-selectin, ICAM-1, and ET-1 to discriminate RA-ILD+ from RA-ILD- patients, and ICAM-1 to distinguish SSc-ILD+ from SSc-ILD- patients was confirmed using ROC curve analysis. Furthermore, elevated levels of ET-1 and E-selectin correlated with lung function decline in RA-ILD+ and SSc-ILD+ patients, respectively. In conclusion, our findings support the relevant role of E-selectin, ICAM-1, and ET-1 in RA-ILD+ patients as well as of ICAM-1 in SSc-ILD+ patients, constituting potential screening blood biomarkers of ILD in AD. Moreover, this study suggests ET-1 and E-selectin as possible indicators of worsening lung function in RA-ILD+ and SSc-ILD+ patients, respectively.

Relationship of Fibroblast Growth Factor 23 Serum Levels with Disease Characteristics in Systemic Lupus Erythematosus Patients.

Fibroblast growth factor 23 (FGF23), a hormone secreted by osteocytes and osteoblasts, is a major regulator of vitamin D and phosphate homeostasis. FGF23 has been associated with the disturbance of mineral homeostasis, and with kidney and cardiovascular diseases. Systemic lupus erythematosus (SLE) is an autoimmune disorder that can affect virtually any organ. In the present work, we set out to analyze the relationship of FGF23 with the expression of SLE, including patterns of activity, damage, and severity. A total of 284 well-characterized patients with SLE were recruited. Activity (SLEDAI), severity (Katz), and damage index (SLICC-DI) scores were determined. The serum levels of FGF23 were also assessed. Multivariable linear regression analysis was performed to study the relationship between disease characteristics and FGF23. FGF23 and 25(OH) vitamin D were negatively correlated. Furthermore, prednisone use was associated with higher circulating FGF23 after an adjustment for confounding factors. SLICC-DI was related to higher serum levels of FGF23 after a multivariable analysis. However, when the SLICC-DI index items and domains were analyzed separately, apart from proteinuria ≥3.5 gm/24 h, only the musculoskeletal domain, encompassing arthritis and osteoporosis, was significantly associated with higher serum levels of FGF23. In conclusion, an association is observed between elevated serum FGF23 levels and disease damage, particularly related to musculoskeletal complications and proteinuria, in patients with SLE.

Relationship between Malondialdehyde Serum Levels and Disease Features in a Full Characterized Series of 284 Patients with Systemic Lupus Erythematosus.

Malondialdehyde (MDA) is a marker of oxidative stress and antioxidant status. Oxidative stress has been observed to be increased in systemic lupus erythematosus (SLE). Some studies have shown that MDA is upregulated in SLE compared to controls. However, the literature lacks reports regarding the relationship of MDA to disease manifestations. This is relevant since SLE is a multisystemic disease which may affect virtually any organ in the body. In this study, we set out to analyze how MDA serum levels are associated with disease expression in a large series of SLE patients who were fully characterized in clinical and laboratory terms. A total of 284 patients with SLE were recruited. Serum levels of MDA, and the activity (SLEDAI), severity (Katz) and damage index (SLICC-DI) scores, full lipid profile, and carotid subclinical atherosclerosis were assessed. In addition, a full characterization of the complement system was performed in SLE patients' samples. Multivariable linear regression analysis was executed to study the relationship between clinical and laboratory disease characteristics and MDA. A statistically significant negative relationship was found between disease duration and MDA. In contrast, the presence of anti-nucleosome antibodies was positively associated with MDA. Regarding the SLICC-DI areas, both the musculoskeletal domain and the cutaneous domain were significantly related to higher serum MDA values. Furthermore, after adjustment for confounding factors, lower levels of the classical complement pathway, which denotes activation, were associated with higher serum levels of MDA. In conclusion, cumulative musculoskeletal and skin damage in SLE patients is associated with superior serum levels of MDA. In addition, activation of the complement system is also related to higher circulating MDA levels.

HDL Cholesterol Efflux and the Complement System Are Linked in Systemic Lupus Erythematosus.

Cholesterol efflux capacity (CEC), the ability of high-density lipoprotein (HDL) cholesterol to accept cholesterol from macrophages, has been linked to cardiovascular events. Systemic lupus erythematosus (SLE) is characterized by the consumption of complement (C) proteins and has been associated with an increased risk of cardiovascular disease. CEC is reduced in SLE patients compared to controls. In the present work, our objective was to analyze whether the disruption of C influences CEC in patients with SLE. New-generation functional assays of the three pathways of the C system were performed in 207 patients with SLE. Additionally, serum levels of inactive (C1q, C2, C3, C4, and factor D) and activated (C3a) molecules, and regulators (C1-inhibitor and factor H) of C system were measured. CEC, using an in vitro assay, and lipoprotein serum concentrations were assessed. Multivariable linear regression analysis was performed to assess the relationship between C system and CEC. After full multivariable analysis, the alternative C cascade functional test showed a significant and negative relationship with CEC. This was also the case for C2 and C3, in which the associations were found to be positive and statistically significant, after adjustment for covariates. In conclusion, C system and CEC are interconnected in patients with SLE.

Full characterization of the three pathways of the complement system in patients with systemic lupus erythematosus.

Background: To date a complete characterization of the components of the complement (C) pathways (CLassical, LEctin and ALternative) in patients with systemic lupus erythematosus (SLE) has not been performed. We aimed to assess the function of these three C cascades through functional assays and the measurement of individual C proteins. We then studied how they relate to clinical characteristics. Methods: New generation functional assays of the three pathways of the C system were assessed in 284 patients with SLE. Linear regression analysis was performed to study the relationship between the activity, severity, and damage of the disease and C system. Results: Lower values of the functional tests AL and LE were more frequent than those of the CL pathway. Clinical activity was not related to inferior values of C routes functional assays. The presence of increased DNA binding was negatively linked to all three C pathways and products, except for C1-inh and C3a which were positively related. Disease damage revealed a consistent positive, rather than a negative, relationship with pathways and C elements. Anti-ribosomes and anti-nucleosomes were the autoantibodies that showed a greater relationship with C activation, mainly due to the LE and CL pathways. Regarding antiphospholipid antibodies, the most related with C activation were IgG anti-ß2GP, predominantly involving the AL pathway. Conclusion: Not only the CL route, but also the AL and LE are related to SLE features. C expression patterns are linked to disease profiles. While accrual damage was associated with higher functional tests of C pathways, anti-DNA, anti-ribosomes and anti-nucleosomes antibodies, were the ones that showed a higher relationship with C activation, mainly due to the LE and CL pathways.

Serum and genetic markers related to rapid clinical progression of coronary artery disease.

INTRODUCTION AND OBJECTIVES: Patients with clinically evident coronary artery disease differ in their rate of progression, which impacts prognosis. We aimed to characterize serum and genetic markers in patients with rapid clinical progression (RCP) of coronary artery disease vs those with long standing stable (LSS) disease. METHODS: Retrospective study of cases (RCP) and controls (LSS) (1:2). Patients requiring ≥ 2 revascularizations due to atherosclerotic progression in the 10 years after a first angioplasty were considered to be RCP and those without events during the same period after the first angioplasty were considered to have LSS disease. After patient selection, we analyzed serum values, mRNA expression and genetic polymorphisms of inflammatory markers, including interleukin-6, C-reactive protein, and tumor necrosis factor (TNF)-a, and atherogenic markers consisted of proprotein convertase subtilisin/kexin type 9 (PCSK9), low-density lipoprotein receptor, sterol regulatory element binding transcription factor 2, and apolipoprotein-B. RESULTS: The study included 180 patients (58 RCP and 122 LSS). Demographic characteristics, classic risk factors and the extent of coronary disease were similar in the 2 groups. Patients with RCP showed higher serum levels of interleukin-6 and PCSK9 and higher TNF mRNA expression. Interleukin-6 rs180075C, TNF rs3093664 non-G and PCSK9 rs2483205 T alleles conferred a risk of RCP (P<.05 in all cases). Among patients with RCP, 51.7% had all 3 risk alleles vs 18% of those with LSS (P<.001). CONCLUSIONS: We suggest the existence of specific phenotypic and genotypic markers associated with RCP of coronary artery disease that could help to individualize the type and intensity of treatment.

Cranial and extracranial giant cell arteritis do not exhibit differences in the IL6 -174 G/C gene polymorphism.

OBJECTIVES: Since interleukin-6 (IL-6) is a pivotal proinflammatory cytokine implicated in the pathogenesis of giant cell arteritis (GCA), we aimed to determine the potential association of the functional IL6 -174 G/C polymorphism with GCA as well as if the single base change variation at the promoter region in the human IL-6 gene may account for differences in the clinical spectrum of GCA between cranial and extracranial large vessel vasculitis (LVV)-GCA. METHODS: The IL6 -174 G/C polymorphism (rs1800795) was genotyped in 191 patients with biopsy-proven GCA who had typical cranial manifestations of the disease, 109 patients with extracranial LVV-GCA, without cranial ischaemic manifestations of GCA, and 877 ethnically matched unaffected controls. A comparative study was carried out between patients with cranial and extracranial LVV-GCA and controls. RESULTS: No significant differences in genotype and allele frequencies of IL6 -174 G/C polymorphism were found between the whole cohort of GCA patients and healthy controls. It was also the case when cranial and extracranial LVV-GCA were compared or when each of these subgroups was compared to controls. Moreover, no significant results in genotype and allele frequencies of IL6 -174 G/C polymorphism were disclosed when the whole cohort of GCA patients were stratified according to the presence of polymyalgia rheumatica, severe ischaemic manifestations, including permanent visual loss and peripheral arteriopathy, and HLA-DRB1*04:01 status. CONCLUSIONS: Our results show that the IL6 -174 G/C polymorphism does not influence the phenotypic expression of GCA.

Serum Levels of Lipoprotein Lipase Are Increased in Patients with Inflammatory Bowel Disease.

Disruption of the lipid profile is commonly found in patients with inflammatory bowel disease (IBD). Lipoprotein lipase (LPL) is a key molecule involved in triglyceride metabolism that plays a significant role in the progression of atherosclerosis. In this study, our aim was to study whether serum LPL levels are different in IBD patients and controls and whether IBD features are related to LPL. This was a cross-sectional study that encompassed 405 individuals; 197 IBD patients with a median disease duration of 12 years and 208 age- and sex-matched controls. LPL levels and a complete lipid profile were assessed in all individuals. A multivariable analysis was performed to determine whether LPL serum levels were altered in IBD and to study their relationship with IBD characteristics. After the fully multivariable analysis, including cardiovascular risk factors and the changes in lipid profile that the disease causes itself, patients with IBD showed significantly higher levels of circulating LPL (beta coefficient 196 (95% confidence interval from 113 to 259) ng/mL, p < 0.001). LPL serum levels did not differ between Crohn's disease and ulcerative colitis. However, serum C-reactive protein levels, disease duration, and the presence of an ileocolonic Crohn's disease phenotype were found to be significantly and independently positively related to LPL. In contrast, LPL was not associated with subclinical carotid atherosclerosis. In conclusion, serum LPL levels were independently upregulated in patients with IBD. Inflammatory markers, disease duration and disease phenotype were responsible for this upregulation.