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Genetic susceptibility has been described in insulin resistance (IR). Chemokine (C-C motif) ligand-2 (CCL2) is overexpressed in white adipose tissue and is the ligand of C-C motif receptor-2 (CCR2). The CCL2 G-2518A polymorphism is known to regulate gene expression, whereas the physiological effects of the CCR2Val64Ile polymorphism are unknown. The aim of the study is to investigate the relationship between these polymorphisms with soluble CCL2 levels (sCCL2), metabolic markers, and adiposity. In a cross-sectional study we included 380 Mexican-Mestizo individuals, classified with IR according to Stern criteria. Polymorphism was identified using PCR-RFLP/sequence-specific primers. Anthropometrics and metabolic markers were measured by routine methods and adipokines and sCCL2 by ELISA. The CCL2 polymorphism was associated with IR (polymorphic A+ phenotype frequencies were 70.9%, 82.6%, in individuals with and without IR, resp.). Phenotype carriers CCL2 (A+) displayed lower body mass and fat indexes, insulin and HOMA-IR, and higher adiponectin levels. Individuals with IR presented higher sCCL2 compared to individuals without IR and was associated with CCR2 (Ile+) phenotype. The double-polymorphic phenotype carriers (A+/Ile+) exhibited higher sCCL2 than double-wild-type phenotype carriers (A-/Ile-). The present findings suggest that sCCL2 production possibly will be associated with the adiposity and polymorphic phenotypes of CCL2 and CCR2, in Mexican-Mestizos with IR.

Primary Sjögren's syndrome (pSS) is a chronic systemic autoimmune disease characterized by lymphocytic infiltration of exocrine glands. Soluble Fas receptor (sFas) has been suggested as a Fas-mediated apoptosis blocker that could impair clonal deletion in infiltrated autoreactive cells. The FAS -670A>G promoter polymorphism has been studied in pSS. However, a relationship between FAS -670A>G promoter polymorphism and sFas levels in pSS had not been found. We examined this relationship in 77 Mexican pSS patients and 84 healthy subjects were included. Genotypes were identified by PCR-RFLP, and Fas soluble levels were quantified by ELISA. No significant differences between allele and genotype frequencies were found between these two groups. The sFas levels in the serum of pSS patients were significantly higher than in controls (9961 vs 8840 pg/mL, respectively). In addition, AA genotype carriers had significantly higher levels of sFas than GG carriers (pSS: 10,763 and 9422 pg/mL; controls: 9712 and 8305 pg/mL, respectively). An additive model analysis between genotypes (AG+GG vs AA) in both groups, demonstrated a significant association between carriers of the A allele and high sFas levels. In conclusion, carrying the double dose of A allele of FAS -670A>G polymorphism is associated with high levels of sFas in pSS, but it is not a susceptibility marker for pSS.

To investigate the association of sICAM-1 and sVCAM-1 with ICAM1 721G>A and VCAM1 1238G>C polymorphisms and rheumatoid arthritis (RA) clinical activity, sixty RA patients and 60 healthy non-related subjects (HS) matched for age and sex were recruited. Soluble adhesion molecules were determined by ELISA technique. Rheumatoid factor (RF), C reactive protein (CRP) and the erythrocyte sedimentation rate (ESR) were measured by routine methods. Disability and clinical activity was measured with Spanish-HAQ-DI and DAS28 scores, respectively. The ICAM1 and VCAM1 polymorphism were identified using the PCR-RFLP procedure. Inter-group comparison showed increased levels of sICAM-1 and sVCAM-1 in RA patients (284 and 481 ng/mL) versus HS (132 and 280 ng/mL); in the RA group, significant correlations between sVCAM-1 and RF (r = 0.402), ESR (r = 0.426), Spanish-HAQ-DI (r = 0.276), and DAS28 (r = 0.342) were found, whereas sICAM-1 only correlated with RF (r = 0.445). In RA patients, a significant association with the 721A allele of ICAM1 polymorphism (p = 0.04), was found. In addition, the allele impact (G/A+A/A) of this polymorphism was confirmed, (p = 0.038, OR = 2.3, C.I. 1.1-5.0). sVCAM-1 and sICAM-1 serum levels reflected the clinical status in RA, independently of the ICAM1 and VCAM1 polymorphism. However, the ICAM1 721A allele could be a genetic marker to RA susceptibility.

Background: Rheumatoid arthritis (RA) is characterized by a progressive joint damage mediated mainly by tumor necrosis factor alpha (TNFalpha). We investigated the relationship of TNFalpha-308 and -238 polymorphisms with messenger RNA (mRNA) expression and soluble TNFalpha (sTNFalpha) in 50 RA and 100 healthy subjects (HS)., Methods: Clinical and laboratory assessments were performed. Spanish Health Assessment Questionnaire Disability Index, Spanish version of Arthritis Impact Measurement Scales and Disease Activity Score using 28 joint count indices were applied to RA patients. The TNFalpha-308 and -238 polymorphisms were performed by polymerase chain reaction and restriction fragment length polymorphism techniques. The mRNA expression of TNFalpha was quantified by real-time polymerase chain reaction. The sTNFalpha levels were measured by enzyme-linked immunosorbent assay., Results: The TNFalpha-308 polymorphism showed an increased frequency of guanine (G)/adenine (A) genotype in RA versus HS (P = 0.03; 95% confidence interval, 1.05-8.08; odds ratio, 2.9) and also the A allele was more frequent in RA patients versus HS (P = 0.04; 95% confidence interval, 1.01-7.29; odds ratio, 2.7). The G/G genotype and also the G allele were more frequent in HS. No significant difference was observed in TNFalpha-238 polymorphism. Rheumatoid arthritis patients showed high TNFalpha mRNA expression (1.33-fold). The G/G genotype was associated with high mRNA and sTNFalpha levels in both TNFalpha polymorphisms. The correlation of sTNFalpha levels with C-reactive protein, erythrocyte sedimentation rate, rheumatoid factor, Spanish Health Assessment Questionnaire Disability Index, and Spanish version of Arthritis Impact Measurement Scales, was observed., Conclusion: The TNFalpha-308 polymorphism is a susceptibility marker to RA. The G/G genotype is associated with a high mRNA and soluble TNFalpha expression.

We investigate the clinical association of tumor necrosis factor receptor 2 (TNFR2) M196R polymorphism with rheumatoid arthritis (RA) and knee osteoarthritis (OA). Acute phase reactants, lipid profile, sTNFR2 levels, disease activity-disability indexes, and TNFR2 M196R polymorphism were analyzed in 50 RA, 50 knee OA patients, and 120 healthy subjects (HS). The M/M genotype frequency was 0.74 (RA), 0.80 (OA), and 0.64 (HS). The M/R genotype frequency was RA (0.26), OA (0.20), and HS (0.29). The R/R genotype was observed only in HS (0.07). The M allele was associated with OA (P = 0.0137, OR = 2.43). Total cholesterol, triglyceride levels, apolipoprotein A-I and B showed significant differences (P < 0.05). The highest sTNFR2 levels were observed in RA and OA (P = 0.001), however M/M and M/R carriers do not correlate with sTNFR2 production. Our findings suggest an association of the M allele with knee OA. In addition, high sTNFR2 levels in RA and OA were found.