Biomarkers in Systemic Lupus Erythematosus along with Metabolic Syndrome.

Metabolic syndrome (MetS) is a group of physiological abnormalities characterized by obesity, insulin resistance (IR), and hypertriglyceridemia, which carry the risk of developing cardiovascular disease (CVD) and type 2 diabetes (T2D). Immune and metabolic alterations have been observed in MetS and are associated with autoimmune development. Systemic lupus erythematosus (SLE) is an autoimmune disease caused by a complex interaction of environmental, hormonal, and genetic factors and hyperactivation of immune cells. Patients with SLE have a high prevalence of MetS, in which elevated CVD is observed. Among the efforts of multidisciplinary healthcare teams to make an early diagnosis, a wide variety of factors have been considered and associated with the generation of biomarkers. This review aimed to elucidate some primary biomarkers and propose a set of assessments to improve the projection of the diagnosis and evolution of patients. These biomarkers include metabolic profiles, cytokines, cardiovascular tests, and microRNAs (miRs), which have been observed to be dysregulated in these patients and associated with outcomes.

YKL-40 serum levels are predicted by inflammatory state, age and diagnosis of idiopathic inflammatory myopathies.

YKL-40 increase according to the aging process, and its functions have been associated with tissue remodeling and systemic inflammation. In Rheumatoid Arthritis (RA) it has been proposed as a possible biomarker of activity and severity, however; in the field of idiopathic inflammatory myopathies (IIM) the role of YKL-40 in IIM is not clear. Thus, we aimed to evaluate if there is an association between the serum levels and muscle tissue expression of YKL-40 with age, IIM phenotype, muscle strength and myositis disease activity. The main finding was that age is the most important variable that affects the YKL-40 serum levels. In muscle biopsy, we observed that YKL-40 is mainly expressed in infiltrating lymphoid cells than in muscle tissue. Using ANCOVA according to the b-coefficients, YKL-40 serum levels are predicted by inflammatory state, age, and IIM diagnosis.

Osteopontin: A Bone-Derived Protein Involved in Rheumatoid Arthritis and Osteoarthritis Immunopathology.

Osteopontin (OPN) is a bone-derived phosphoglycoprotein related to physiological and pathological mechanisms that nowadays has gained relevance due to its role in the immune system response to chronic degenerative diseases, including rheumatoid arthritis (RA) and osteoarthritis (OA). OPN is an extracellular matrix (ECM) glycoprotein that plays a critical role in bone remodeling. Therefore, it is an effector molecule that promotes joint and cartilage destruction observed in clinical studies, in vitro assays, and animal models of RA and OA. Since OPN undergoes multiple modifications, including posttranslational changes, proteolytic cleavage, and binding to a wide range of receptors, the mechanisms by which it produces its effects, in some cases, remain unclear. Although there is strong evidence that OPN contributes significantly to the immunopathology of RA and OA when considering it as a common denominator molecule, some experimental trial results argue for its protective role in rheumatic diseases. Elucidating in detail OPN involvement in bone and cartilage degeneration is of interest to the field of rheumatology. This review aims to provide evidence of the OPN's multifaceted role in promoting joint and cartilage destruction and propose it as a common denominator of AR and OA immunopathology.

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

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

Impaired muscle strength is associated with ultrastructure damage in myositis.

The muscle fiber ultrastructure in Idiopathic Inflammatory Myopathies (IIM) has been scarcely explored, especially in Inclusion Body Myositis. The aim of this study was to implement the Scanning Electron Microscopy (SEM) in a small cohort of IIM patients, together with the characterization of immunological profile for a better understanding of the pathophysiology. For immunological profile characterization, we identified the presence of autoantibodies (Ro-52, OJ, EJ, PL7, PL12, SRP, Jo-1, PMScl75, PMScl100, Ku, SAE1, NXP2, MDA5, TIF1γ, Mi-2α, Mi-2ß) and quantified cytokines (IL-1ß, IFN-α2, IFN-γ, TNF-α, IL-6, IL-10, IL-12p70, IL-17A, IL-18, IL-23, IL-33) and chemokines (CCL2, CXCL8). The histological analysis was made by hematoxylin-eosin staining while the muscle fiber ultrastructure was characterized by SEM. We observed changes in the morphology and structure of the muscle fiber according to muscle strength and muscle enzymes. We were able to find and describe muscle fiber ultrastructure with marked irregularities, porosities, disruption in the linearity and integrity of the fascicle, more evident in patients with increased serum levels of muscle enzymes and diminished muscle strength. Despite the scarce reports about the use of SEM as a tool in all clinical phenotypes of IIM, our work provides an excellent opportunity to discuss and reframe the clinical usefulness of SEM in the diagnostic approach of IIM.

Osteopontin: another piece in the systemic lupus erythematosus immunopathology puzzle.

Osteopontin (OPN) is a phosphoglycoprotein involved in bone remodelling, wound healing, cell adhesion, tissue remodelling, and immune response that is distributed widely in normal adult tissues. OPN biological activity is regulated by thrombin and matrix metalloproteinases (MMPs) cleavage, where the full-length (OPN-FL) protein and the cleaved OPN-N are associated with autoimmune diseases such as systemic lupus erythematosus (SLE). OPN overexpression has been associated with a predisposition to SLE and bad prognosis since OPN could mediate a sustained polyclonal B cell activation that besides to intracellular OPN (iOPN) form, promote the T follicular helper (TFH) cells and enhance anti-nuclear antibody production. Currently, the role of OPN in lupus nephritis (LN) has been reported and extensively studied; however, no data are available about the potential mechanism of OPN in neuropsychiatric SLE (NPSLE). In this review, we highlighted the contribution of OPN and iOPN in LN and NPSLE immunopathology.

The DNA co-vaccination using Sm antigen and IL-10 as prophylactic experimental therapy ameliorates nephritis in a model of lupus induced by pristane.

INTRODUCTION: Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the production of autoantibodies such as anti-Sm. Studies in patients with SLE and murine models of lupus reveal that the most critical anti-Sm autoantibodies are predominantly direct against D1(83-119), D2, and B´/B epitopes. OBJECTIVES: The present study aimed to analyze the induction of antigen-specific tolerance after prophylactic immunization with a DNA vaccine encoding the epitopes: D183-119, D2, B´/B, and B´/BCOOH in co-vaccination with IFN-γ or IL-10 in a murine model of lupus induced by pristane. MATERIAL AND METHODS: To obtain endotoxin-free DNA vaccines, direct cloning techniques using pcDNA were performed: D183-119, D2, B´/B, B´/BCOOH, IFN-γ, or IL-10. Lupus was induced by 0.5 mL of pristane via intraperitoneal in BALB/c female mice. Immunoprecipitation with K562 cells was metabolically labeled with 35S and ELISA to detect serum antibodies or mice IgG1, IgG2a isotypes. ELISA determined IL-10 and IFN-γ from splenocytes supernatants. Proteinuria was assessed monthly, and lupus nephritis was evaluated by immunofluorescence, and electron microscopy. RESULTS: The prophylactic co-vaccination with D2/IL-10 reduced the expression of kidney damage observed by electron microscopy, direct immunofluorescence, and H & E, along with reduced level of anti-nRNP/Sm antibodies (P = 0.048). CONCLUSION: The prophylactic co-vaccination of IL-10 with D2 in pristane-induced lupus ameliorates the renal damage maybe by acting as prophylactic DNA tolerizing therapy.

Contribution of rs3211938 polymorphism at CD36 to glucose levels, oxidized low-density lipoproteins, insulin resistance, and body mass index in Mexican mestizos with type-2 diabetes from western Mexico / Contribución del polimorfismo rs3211938 de CD36 a los niveles de glucosa, las lipoproteínas de baja densidad oxidadas, la resistencia a la insulina y el índice de masa corporal en mestizos mexicanos con diabetes de tipo 2 del occidente de México

Background: type-2 diabetes mellitus (T2DM) is a chronic metabolic disorder characterized by hyperglycemia, insulin resistance (IR), and abnormal fatty acid metabolism in which the CD36 receptor has been implicated in glucose and lipid dysregulation. Objective: to evaluate the contribution of polymorphism CD36 rs3211938 to metabolic profile in T2DM Mexican mestizos from western Mexico. Methods: we included 115 individuals classified as non-T2DM (NT2DM) adults and T2DM patients. Polymorphism CD36 rs3211938 was assessed by PCR-RFLP. Anthropometric and metabolic markers were measured by routine methods, and insulin and oxidized LDL (ox-LDL) were measured by ELISA. Results: the distribution of genotypes between NT2DM and T2DM patients was different (p < 0.001), as was the allele frequency (p = 0.002). NT2DM TG carriers showed the lowest levels of basal insulin and HOMA-IR index in comparison with TT carriers (p < 0.05 and p < 0.05, respectively). In the T2DM group TG carriers showed high BMI, WHR, and weight values (p = 0.001; p ≤ 0.05 and p < 0.05, respectively), and the highest levels of basal glucose, HDL-cholesterol, ox-LDL, and HOMA-IR (p < 0.001; p < 0.001; p < 0.001, and p = 0.001, respectively) in comparison with diabetic TT carriers. Conclusion: the CD36 rs3211938 TG genotype is associated with high levels of glucose, ox-LDL, HDL-cholesterol, and IR, and with increased BMI in Mexican mestizo T2DM patients from western Mexico. (AU)

Antecedentes: la diabetes mellitus de tipo 2 (DMT2) es un trastorno metabólico crónico caracterizado por hiperglucemia, resistencia a la insulina (RI) y metabolismo anormal de ácidos grasos en el que se ha implicado el receptor CD36 en la disregulación de la glucosa y los lípidos. Objetivo: evaluar la contribución del polimorfismo CD36 rs3211938 al perfil metabólico en individuos mestizos mexicanos con DMT2 del occidente de México. Métodos: se incluyeron 115 individuos clasificados en adultos sin DMT2 (NDMT2) y pacientes con DMT2. El polimorfismo CD36 rs3211938 se identificó mediante PCR-RFLP. Las mediciones antropométricas y metabólicas se realizaron mediante métodos de rutina y la insulina y las LDL-oxidadas (LDL-ox) se midieron por ELISA. Resultados: las distribuciones de los genotipos entre los pacientes NDMT2 y DMT2 fueron diferentes (p < 0,001), así como la frecuencia alélica (p = 0,002). Los individuos NDMT2 portadores del genotipo TG mostraron niveles más bajos de insulina basal e índice HOMA-IR en comparación con los portadores del genotipo TT (p < 0,05 y p < 0,05, respectivamente). En el grupo DMT2, los portadores del genotipo TG presentaron valores elevados de índice de masa corporal (IMC), índice cintura-cadera (ICC) y peso (p = 0,001; p < 0,05 y p < 0,05, respectivamente) y niveles más altos de glucosa basal, HDL-colesterol, LDL-ox y HOMA-IR (p < 0,001; p < 0,001; p < 0,001 y p = 0,001, respectivamente) en comparación con los portadores del genotipo TT. Conclusión: el genotipo TG del polimorfismo CD36 rs3211938 se asocia a altos niveles de glucosa, ox-LDL, HDL-colesterol y RI, y a aumentos del IMC en los pacientes mestizos mexicanos con DMT2 del occidente de México. (AU)

Contribution of rs3211938 polymorphism at CD36 to glucose levels, oxidized low-density lipoproteins, insulin resistance, and body mass index in Mexican mestizos with type-2 diabetes from western Mexico.

INTRODUCTION: Background: type-2 diabetes mellitus (T2DM) is a chronic metabolic disorder characterized by hyperglycemia, insulin resistance (IR), and abnormal fatty acid metabolism in which the CD36 receptor has been implicated in glucose and lipid dysregulation. Objective: to evaluate the contribution of polymorphism CD36 rs3211938 to metabolic profile in T2DM Mexican mestizos from western Mexico. Methods: we included 115 individuals classified as non-T2DM (NT2DM) adults and T2DM patients. Polymorphism CD36 rs3211938 was assessed by PCR-RFLP. Anthropometric and metabolic markers were measured by routine methods, and insulin and oxidized LDL (ox-LDL) were measured by ELISA. Results: the distribution of genotypes between NT2DM and T2DM patients was different (p < 0.001), as was the allele frequency (p = 0.002). NT2DM TG carriers showed the lowest levels of basal insulin and HOMA-IR index in comparison with TT carriers (p < 0.05 and p < 0.05, respectively). In the T2DM group TG carriers showed high BMI, WHR, and weight values (p = 0.001; p ≤ 0.05 and p < 0.05, respectively), and the highest levels of basal glucose, HDL-cholesterol, ox-LDL, and HOMA-IR (p < 0.001; p < 0.001; p < 0.001, and p = 0.001, respectively) in comparison with diabetic TT carriers. Conclusion: the CD36 rs3211938 TG genotype is associated with high levels of glucose, ox-LDL, HDL-cholesterol, and IR, and with increased BMI in Mexican mestizo T2DM patients from western Mexico.

INTRODUCCIÓN: Antecedentes: la diabetes mellitus de tipo 2 (DMT2) es un trastorno metabólico crónico caracterizado por hiperglucemia, resistencia a la insulina (RI) y metabolismo anormal de ácidos grasos en el que se ha implicado el receptor CD36 en la disregulación de la glucosa y los lípidos. Objetivo: evaluar la contribución del polimorfismo CD36 rs3211938 al perfil metabólico en individuos mestizos mexicanos con DMT2 del occidente de México. Métodos: se incluyeron 115 individuos clasificados en adultos sin DMT2 (NDMT2) y pacientes con DMT2. El polimorfismo CD36 rs3211938 se identificó mediante PCR-RFLP. Las mediciones antropométricas y metabólicas se realizaron mediante métodos de rutina y la insulina y las LDL-oxidadas (LDL-ox) se midieron por ELISA. Resultados: las distribuciones de los genotipos entre los pacientes NDMT2 y DMT2 fueron diferentes (p < 0,001), así como la frecuencia alélica (p = 0,002). Los individuos NDMT2 portadores del genotipo TG mostraron niveles más bajos de insulina basal e índice HOMA-IR en comparación con los portadores del genotipo TT (p < 0,05 y p < 0,05, respectivamente). En el grupo DMT2, los portadores del genotipo TG presentaron valores elevados de índice de masa corporal (IMC), índice cintura-cadera (ICC) y peso (p = 0,001; p < 0,05 y p < 0,05, respectivamente) y niveles más altos de glucosa basal, HDL-colesterol, LDL-ox y HOMA-IR (p < 0,001; p < 0,001; p < 0,001 y p = 0,001, respectivamente) en comparación con los portadores del genotipo TT. Conclusión: el genotipo TG del polimorfismo CD36 rs3211938 se asocia a altos niveles de glucosa, ox-LDL, HDL-colesterol y RI, y a aumentos del IMC en los pacientes mestizos mexicanos con DMT2 del occidente de México.

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

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

Downregulation of hippocampal NR2A/2B subunits related to cognitive impairment in a pristane-induced lupus BALB/c mice.

Neuropsychiatric systemic lupus erythematosus (NPSLE) is associated with learning and memory deficit. Murine model of lupus induced by pristane in BALB/c mice is an experimental model that resembles some clinical and immunological SLE pathogenesis. Nevertheless, there is no experimental evidence that relates this model to cognitive dysfunction associated with NR2A/2B relative expression. To evaluate cognitive impairment related to memory deficits in a murine model of lupus induced by pristane in BALB/c mice related to mRNA relative expression levels of NR2A/2B hippocampal subunits in short and long-term memory task at 7 and 12 weeks after LPS exposition in a behavioral test with the use of Barnes maze. A total of 54 female BALB/c mice 8-12 weeks old were included into 3 groups: 7 and 12 weeks using pristane alone (0.5 mL of pristane) by a single intraperitoneal (i.p.) injection. A control group (single i.p. injection of 0.5 mL NaCl 0.9%) and pristane plus LPS exposure using single i.p. pristane injection and LPS of E. coli O55:B5, in a dose of 3mg/kg diluted in NaCl 0.9% 16 weeks post-pristane administration. To determine cognitive dysfunction, mice were tested in a Barnes maze. Serum anti-Sm antibodies and relative expression of hippocampal NR2A/2B subunits (GAPDH as housekeeping gene) with SYBR green quantitative reverse transcription polymerase chain reaction and 2-ΔΔCT method were determined in the groups. Downregulation of hippocampal NR2A subunit was more evident than NR2B in pristane and pristane+LPS at 7 and 12 weeks of treatment and it is related to learning and memory disturbance assayed by Barnes maze. This is the first report using the murine model of lupus induced by pristane that analyzes the NMDA subunit receptors, finding a downregulation of NR2A subunit related to learning and memory disturbance being more evident when they were exposed to LPS.

Evaluación clínica y ultrasonográfica de la glándula tiroides en pacientes con artritis reumatoide.

Introducción: Los pacientes con artritis reumatoide pueden desarrollar enfermedad tiroidea autoinmune (ETA), cuyo diagnóstico clínico puede ser difícil debido a que ambas comparten síntomas como artralgias, mialgias, rigidez matutina o fatiga. Objetivo: Determinar la prevalencia de ETA en pacientes con artritis reumatoide. Método: Estudio transversal que incluyó 78 pacientes con artritis reumatoide y 81 controles clínicamente sanos pareados por edad y sexo. A ambos grupos se realizó cuantificación de anticuerpos antitiroideos, pruebas de función tiroidea, ultrasonido y biopsia de glándula tiroides cuando la puntuación de Thyroid Imaging Reporting and Data System (TIRADS) fue ≥ 4. Resultados: 24.4 % de los pacientes con artritis reumatoide presentó hipotiroidismo (p = 0.003) y altos títulos de anticuerpos antitiroideos versus controles clínicamente sanos; 53 % de los ultrasonidos tiroideos resultó normal en pacientes hipotiroideos; en pacientes con artritis reumatoide positivos para anticuerpos antitiroideos se encontró perfusión incrementada en 40 %. Los casos clasificados como TIRADS 4 fueron enviados a aspiración, con resultado histopatológico benigno. Conclusiones: Se demostró el valor clínico agregado de la evaluación tiroidea en pacientes con artritis reumatoide, conforme a la prevalencia de hipotiroidismo subclínico, positividad de anticuerpos antitiroideos y anomalías en el ultrasonido independientes de la función tiroidea normal o alterada. Introduction: Patients with rheumatoid arthritis can develop autoimmune thyroid disease (ATD), the clinical diagnosis of which can be difficult because both entities share symptoms such as arthralgia, myalgia, morning stiffness or fatigue. Objective: To determine the prevalence of ATD in patients with rheumatoid arthritis. Method: Cross-sectional study that included 78 patients with rheumatoid arthritis and 81 clinically healthy controls matched by age and gender. Both groups underwent anti-thyroid antibodies quantification, thyroid function tests, thyroid ultrasound and thyroid gland biopsy when the Thyroid Imaging Reporting and Data System (TIRADS) score was ≥ 4. Results: Hypothyroidism was found in 24.4% of patients with rheumatoid arthritis (p = 0.003), as well as high titers of anti-thyroid antibodies versus clinically healthy controls; 53% of thyroid ultrasounds were normal in hypothyroid patients, and increased perfusion was found in 40% of rheumatoid arthritis patients who tested positive for anti-thyroid antibodies. Cases classified as TIRADS 4 underwent aspiration with benign histopathological results. Conclusions: Thyroid assessment added clinical value was demonstrated in patients with rheumatoid arthritis, according to the prevalence of subclinical hypothyroidism, anti-thyroid antibodies positivity and ultrasound abnormalities, regardless of normal or altered thyroid function.

Potential Chronotherapeutic Optimization of Antimalarials in Systemic Lupus Erythematosus: Is Toll-Like Receptor 9 Expression Dependent on the Circadian Cycle in Humans?

Toll-like receptor 9 (TLR9) belongs to the group of endosomal receptors of the innate immune system with the ability to recognize hypomethylated CpG sequences from DNA. There is scarce information about TLR9 expression and its association with the circadian cycle (CC). Different patterns of TLR9 expression are regulated by the CC in mice, with an elevated expression at Zeitgeber time 19 (1:00 a.m.); nevertheless, we still need to corroborate this in humans. In systemic lupus erythematosus (SLE), the inhibitory effect of chloroquine (CQ) on TLR9 is limited. TLR9 activation has been associated with the presence of some autoantibodies: anti-Sm/RNP, anti-histone, anti-Ro, anti-La, and anti-double-stranded DNA. Treatment with CQ for SLE has been proven to be useful, in part by interfering with HLA-antigen coupling and with TLR9 ligand recognition. Studies have shown that TLR9 inhibitors such as antimalarial drugs are able to mask TLR9-binding sites on nucleic acids. The data presented here provide the basic information that could be useful for other clinical researchers to design studies that will have an impact in achieving a chronotherapeutic effect by defining the ideal time for CQ administration in SLE patients, consequently reducing the pathological effects that follow the activation of TLR9.

Low CD36 and LOX-1 Levels and CD36 Gene Subexpression Are Associated with Metabolic Dysregulation in Older Individuals with Abdominal Obesity.

Background. Obesity study in the context of scavenger receptors has been linked to atherosclerosis. CD36 and LOX-1 are important, since they have been associated with atherogenic and metabolic disease but not fat redistribution. The aim of our study was to determinate the association between CD36 and LOX-1 in presence of age and abdominal obesity. Methods. This is a cross-sectional study that included 151 healthy individuals, clinically and anthropometrically classified into two groups by age (<30 and ≥30 years old) and abdominal obesity (according to World Health Organization guidelines). We excluded individuals with any chronic and metabolic illness, use of medication, or smoking. Fasting blood samples were taken to perform determination of CD36 mRNA expression by real-time PCR, lipid profile and metabolic and low grade inflammation markers by routine methods, and soluble scavenger receptors (CD36 and LOX-1) by ELISA. Results. Individuals ≥30 years old with abdominal obesity presented high atherogenic index, lower soluble scavenger receptor levels, and subexpression of CD36 mRNA (54% less). On the other hand, individuals <30 years old with abdominal adiposity presented higher levels in the same parameters, except LOX-1 soluble levels. Conclusion. In this study, individuals over 30 years of age presented low soluble scavenger receptors levels pattern and CD36 gene subexpression, which suggest the chronic metabolic dysregulation in abdominal obesity.

Serum leptin and serum leptin/serum leptin receptor ratio imbalance in obese rheumatoid arthritis patients positive for anti-cyclic citrullinated peptide antibodies.

INTRODUCTION: Leptin has a prominent role in the development and maintenance of acute and chronic inflammatory states such as rheumatoid arthritis (RA) and obesity. Nevertheless, the association of serum leptin (sLep) and soluble leptin receptor (sLepR) in RA pathogenesis has not been clarified. The purpose of this study was to evaluate the association of sLep, sLepR and leptin production indexes such as sLep/fat mass ratio with clinical activity and biomarkers and anti-cyclic citrullinated peptide (anti-CCP) antibodies in RA compared with body mass index (BMI) matched control subjects. METHODS: We included 64 RA patients and 66 controls matched for age, gender and BMI. Subjects were evaluated for BMI, fat mass distribution, sLep, sLepR, sLep/fat mass ratio and sLepR/fat mass ratio. Patients were evaluated for clinical activity and anti-CCP antibodies. RESULTS: We found two or three fold increased sLep levels, sLep/sLepR ratio and sLep/fat mass ratio in obese anti-CCP positive RA patients vs. CONTROLS: Partial correlations showed that anti-CCP antibodies were correlated with sLep/fat mass ratio (partial r = 0.347, P = 0.033) after adjustment for age, subcutaneous adipose tissue and fat mass. CONCLUSIONS: In preobese and obese RA patients there is and increased production of sLep according to anti-CCP positivity. This phenomenon suggests there is an additive effect of chronic inflammation resulting from RA and obesity in which leptin favors the humoral response against citrullinated proteins. In summary, the data observed in our study suggests sLep could be a surrogate marker of chronicity and humoral immunity in RA in the presence of obesity.

The Impact of LEP G-2548A and LEPR Gln223Arg Polymorphisms on Adiposity, Leptin, and Leptin-Receptor Serum Levels in a Mexican Mestizo Population.

The polymorphisms in leptin (LEP G-2548A) and leptin-receptor (LEPR Gln223Arg) seem to influence obesity and lipid metabolism among others. The aim of this study was to investigate the effect of these polymorphisms on adiposity, leptin (sLeptin), and leptin-receptor (sLeptin-receptor) serum concentrations as well as inflammation markers. We included 382 adults originally from Western Mexico. They were genotyped by PCR-RFLP. Obese individuals showed higher sLeptin (58.2 ± 31.35 ng/mL) but lower sLeptin-receptor (12.6 ± 3.74 ng/mL) levels than normal weight ones (17.6 ± 14.62 ng/mL, 17.4 ± 4.62 ng/mL, resp.), P < 0.001. Obese subjects carriers of Arg/Arg genotype had more (P = 0.016) sLeptin-receptor (14.7 ± 4.96 ng/mL) and less (P = 0.004) sLeptin (44.0 ± 28.12 ng/mL) levels than Gln/Gln genotype (11.0 ± 2.92 ng/mL, 80.3 ± 33.24 ng/mL, resp.). Body fat mass was lower (P from 0.003 to 0.045) for A/A (36.5% ± 6.80) or Arg/Arg (36.8% ± 6.82) genotypes with respect to G/G (41.3% ± 5.52) and G/A (41.6% ± 5.61) or Gln/Gln (43.7% ± 4.74) and Gln/Arg (41.0% ± 5.52) genotypes carriers. Our results suggest that LEP -2548A and LEPR 223Arg could be genetic markers of less body fat mass accumulation in obese subjects from Western Mexico.

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

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

Low levels of CD36 in peripheral blood monocytes in subclinical atherosclerosis in rheumatoid arthritis: a cross-sectional study in a Mexican population.

UNLABELLED: Patients with rheumatoid arthritis (RA) have a higher risk for atherosclerosis. There is no clinical information about scavenger receptor CD36 and the development of subclinical atherosclerosis in patients with RA. The aim of this study was to evaluate the association between membrane expression of CD36 in peripheral blood mononuclear cells (PBMC) and carotid intima-media thickness (cIMT) in patients with RA. METHODS: We included 67 patients with RA from the Rheumatology Department of Hospital Civil "Dr. Juan I. Menchaca," Guadalajara, Jalisco, Mexico. We evaluated the cIMT, considering subclinical atherosclerosis when >0.6 mm. Since our main objective was to associate the membrane expression of CD36 with subclinical atherosclerosis, other molecules related with cardiovascular risk such as ox-LDL, IL-6, and TNFα were tested. RESULTS: We found low CD36 membrane expression in PBMC from RA patients with subclinical atherosclerosis (P < 0.001). CD36 mean fluorescence intensity had negative correlations with cIMT (r = -0.578, P < 0.001), ox-LDL (r = -0.427, P = 0.05), TNFα (r = -0.729, P < 0.001), and IL-6 (r = -0.822, P < 0.001). CONCLUSION: RA patients with subclinical atherosclerosis showed low membrane expression of CD36 in PBMC and increased serum proinflammatory cytokines. Further studies are needed to clarify the regulation of CD36 in RA.