STAT4 plays an important role in disease activity in SLE patients. STAT4 particles have the capacity to activate the transcription of genes associated with the production of TH1 and Th17 lymphocytes, with a greater predominance on the production of IFN-γ and IL-17A. The presence of variants in STAT4 genes has a major impact on the generation of autoimmunity. However, there are few studies evaluating the impact of these variants on the production of proinflammatory cytokines such as IFN-γ and IL-17A. Methods—A case–control study was carried out with 206 Mexican mestizo patients residing in Western Mexico with a diagnosis of SLE and a group of 80 patients without autoimmune diseases was captured to determine the cut-off point for high IFN-γ levels. In this study, SLE patients with high IFN-γ levels were considered as cases (cut-off > 15.6 pg/mL), and SLE patients with normal IFN-γ levels were considered as controls (cut-off ≤ 15.6 pg/mL). Disease activity was identified from the systemic lupus erythematosus disease activity index (SLEDAI). For the determination of levels of cytokines IFN-γ, IL-12, and IL17A, commercial ELISA kits were used. Genotyping of STAT4 rs7574865 (G > T) was performed by quantitative polymerase chain reaction (qPCR) using TaqMan probes. Results—The patients with SLE had a median age of 45 years with a range of disease duration from 4 years to 18 years; 45.6% were identified as having disease activity. In this sample, we identified a high IFN-γ prevalence of 35.4%. The levels of IFN-γ were higher in the patients with genotype TT than GG. We found that TT genotype conferred a higher risk of high IFN-γ when compared to the GG and GT genotypes. Conclusions—In this study, we identified that the polymorphic genotype TT of the STAT4 gene rs7574865 polymorphism is associated with increased levels of IFN-γ. However, its strength of association was weak, so complementary studies are needed to evaluate its impact on SLE patients.

Background. Multiple sclerosis (MS) is a chronic autoimmune inflammatory disease. Low vitamin D levels have been reported to be a risk factor for MS, and genetic variances could be implicated. The aim of this study was to evaluate the association of MS with rs10766197 polymorphism of CYP2R1 gene and rs10877012 polymorphism of CYP27B1 gene. The second aim was to analyse whether these polymorphisms are associated with the severity of the progression of MS. Material and Methods. In a case-control study, we included 116 MS patients and 226 controls, all of whom were Mexican Mestizo. MS was diagnosed by McDonald criteria (2017). A complete neurological evaluation was performed to evaluate the severity of disease progression. Serum 25-hydroxyvitamin D [25(OH) vitamin D] levels were measured by ELISA. Single nucleotide polymorphisms rs10766197 of CYP2R1 gene and rs10877012 SNP of CYP27B1 gene were genotyped by real-time PCR. Results. Serum 25(OH) vitamin D levels were lower in MS patients than in controls ( ). No differences were observed between serum 25(OH) vitamin D levels of MS patients with severe progression compared to low progression ( ). A higher frequency of the A allele of CYP2R1 rs10766197 was observed between MS patients and controls ( ). No differences were observed in the frequency of T allele of CYP27B1 rs10877012 ( ). In subanalysis, patients with genotypes of CYP2R1 rs10766197 had an increased risk of MS compared to controls ( ). No increased risk was observed in genotypes of CYP27B1 rs10877012 ( ). No differences were observed in allele frequencies of either polymorphism between patients with severe vs. low disease progression. Conclusion. Lower serum 25(OH) vitamin D levels were observed in MS patients than in controls, although these levels were not associated with disease progression. Carriers of genotypes of CYP2R1 rs10766197 had an increased risk of MS. None of these polymorphisms was associated with severe progression of MS.

Background. Myostatin is a regulator of muscle size. To date, there have been no published studies focusing on the relation between myostin levels and myopenia in rheumatoid arthritis (RA). Objective. Evaluate the value of serum myostatin as a biomarker of cachexia and low skeletal muscle mass (LSMM) in RA patients, along with whether high serum myostatin is associated to these conditions after adjusting for potential confounders. Methods. This cross-sectional study included 161 female RA patients and 72 female controls. In the RA group, we assessed several potential risk factors for LSMM and rheumatoid cachexia. Dual-energy X-ray absorptiometry was used to quantify the skeletal muscle mass index (SMMI) (considering kg/m²) and the presence of rheumatoid cachexia (a fat-free mass percentile and fat mass percentile of the reference population). Serum myostatin concentrations were determined by ELISA. To identify a cut-off for high serum myostatin levels, we performed ROC curve analysis. Multivariable logistic regression analysis was used to identify the risk factors for LSMM and rheumatoid cachexia. The risk was expressed as odds ratios (ORs) and their 95% confidence intervals (95% CIs). Results. Compared to the controls, the RA group had a higher proportion of LSMM and exhibited high serum myostatin levels ( ). ROC curve analysis showed that a myostatin ng/mL was the most efficient cut-off for identifying rheumatoid cachexia (sensitivity: 53%, specificity: 71%) and LSMM (sensitivity: 43%, specificity: 77%). In the multivariable logistic regression, RA with high myostatin levels (≥17 ng/mL) was found to increase the risk of cachexia ( , 95% CI: 1.24-6.29; ) and LSMM ( , 95% CI: 1.17-7.89; ). Conclusions. High serum myostatin levels increase the risk of LSMM and rheumatoid cachexia. We propose that high myostatin levels are useful biomarkers for the identification of patients in risk of rheumatoid cachexia and myopenia.

The objective of the study is to determine the personal, behavioral and psychological variables associated with somatization and the number of diseases in each gender from a sample of Mexican general population. They answered a questionnaire of behavioral and psychological variables including somatization and the sum of 16 different diseases and any additional one, finally the body mass index (BMI) was measured. A total of 164 participants (women = 90, men = 74) were included. We observed that women had more somatization and number of diseases than men and that more variables (mainly psychological) were associated with somatization and with the number of diseases in women than in men. Among the variables most negatively correlated in women with both variables were sleep quality (r = −0.525 and r = −0.536, p < 0.001), self-acceptance (r = −0.460 and r = −0.501, p < 0.001), positive relations with others (r = −0.447 and r = −0.441 p < 0.001), environmental mastery (r = −0.414, p < 0.001, for both variables), purpose in life and optimism; while men only showed a low negative correlation between emotion regulation and the number of diseases (r = −0.289, p < 0.05). The positive associated variables in women were anxiety, negative emotions and depression; while men showed a lower correlation between these three variables only with somatization. The somatization and age were positively related to the number of diseases in both genders and the BMI was significantly associated with the number of diseases only in men. In conclusion, women had more somatization and number of diseases than men and also had more relation between psychological variables and the two dependent variables than men, which could in part explains the higher values of somatization and the number of diseases in women, considering that they usually present higher values of psychopathological variables.