Interleukin (IL)-23 Receptor, IL-17A and IL-17F Gene Polymorphisms in Brazilian Patients with Rheumatoid Arthritis.

Rheumatoid arthritis (RA) is a progressive, autoimmune disease for which the previous studies have shown that some functional polymorphisms can influence its etiology. Knowing this, the aim of this study was to investigate the association of +2199 A/C IL-23R (rs10889677), -197 G/A IL-17A (rs2275913), and +7488 A/G IL-17F (rs763780) gene polymorphisms with RA susceptibility and clinical features in a Brazilian population. A total of 127 RA patients and 134 healthy controls were recruited for the analyses of polymorphic variants. Genotyping was performed using RFLP-PCR. Logistic regression was used to analyze the genotype distribution of the polymorphisms. Individuals carrying the homozygous CC genotype for the IL-23R polymorphism seem to be at lower risk for RA development (OR 0.22; p = 0.004), as well as those carrying the variant C allele (OR 0.56; p = 0.002). For the -197 G/A IL-17A polymorphism, the wild-type genotype (GG) was significantly associated with a 3.18-fold (OR 3.18; p = 0.033) increased risk for RA. In relation to the +7488 A/G IL-17F polymorphism, no significant difference was found between RA cases and control subjects (p > 0.05). Moreover, when investigating the relationship between polymorphisms and clinical features, no evidence of an association was found. Our findings suggest that the variants +2199 A/C IL-23R and -197 G/A IL-17A could contribute to RA development in the studied population. However, larger studies are needed to fully understand this genetic predisposition.

Investigation of H19/RsaI Polymorphism in Children With Low Birth Weight in Pernambuco, Brazil.

BACKGROUND: H19 is a strong candidate gene for influencing birth weight variation and is exclusively imprinted maternally. In an attempt to understand the relationship of this gene polymorphism with low birth weight children, we investigated association of H19/RsaI polymorphism with low birth weight and normal birth weight in children and their mothers. OBJECTIVES: The aim of our study was to establish the association between H19 gene polymorphism and LW in children born in Pernambuco, state of Brazil. PATIENTS AND METHODS: It were selected 89 children, 40 low birth weight (LW) and 49 normal birth weight (NW) and 71 mothers (40 mothers of newborns NW and 31 mothers of newborns LW) attended at Dom Malan Hospital, Petrolina, Pernambuco - Brazil. Peripheral blood samples were collected from patients and genomic DNA was extracted and detected by electrophoresis agarose gel, stained by Blue Green Loading Dye. DNA PCR amplification was done using the primers H1 (sense) and H3 (antisense). PCR products were digested with RsaI and electrophoresed on agarose gel stained by ethidium bromide. Statistical analyses were performed using the program BioEstat version 5.0. RESULTS: The RsaI polymorphism in the H19 gene showed that genotype frequencies did not differ statistically between low birth weight (AA = 12.5%, AB = 45%, BB = 42.5%) and control (AA = 8.6% AB = 36.73%, BB= 55.10% groups) and the allele frequencies were not significantly different (P = 0.2897). We also did not observe any association between maternal H19 allele polymorphism and low birth weight newborns (P =0.7799) or normal birth weight children (P = 0.8976). CONCLUSIONS: The small size of sample may be the explanation for these results; future studies with more patients are needed to confirm the effect of H19/RsaI polymorphism on birth weight of LW newborns.

Interleukin-6 promoter polymorphisms -174 G/C in Brazilian patients with systemic lupus erythematosus.

To investigate the association of the IL-6 gene promoter polymorphism (-174 G/C) with SLE susceptibility and disease features in Brazilian patients, a case-control study of 80 lupus cases and 60 volunteer healthy women was performed. Genotyping was carried out by polymerase chain reaction and PCR product was digested by HSP92II restriction enzyme, being after visualized in polyacrylamide gel. There were significant differences in the distribution of the IL-6 gene C/C polymorphism between the SLE and control groups (χ(2) = 8.668; P = 0.0032). Individual carriers of the variant allele G had a 1.98 (95% CI: 1.0844-3.6353)-fold increased risk for SLE. Besides, association was observed in frequency of C allele (P = 0.0247; OR = 0.5036) between SLE patients and control groups. This study presents preliminary evidence for association between IL-6 polymorphism and SLE susceptibility in a Northeast population from Brazil.

Tumor necrosis factor alpha promoter polymorphism -308 G/A in Brazilian patients with systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the production of antibodies to components of the cell nucleus in association with a diverse array of clinical manifestations. Polymorphisms in cytokines genes may play an important role in the development and clinical manifestation. Due to this, there is a great interest in the identification of biomarkers that which could quantify the susceptibility and disease activity. A case-control study of 98 lupus cases and 76 lupus-free adults controls, was performed to analyze whether or not the polymorphism of the TNF-α gene promoter at positions -308 G/A would alter the risk for SLE and clinical manifestations. Genotyping was carried out by polymerase chain reaction, PCR products were digested by NcoI restriction enzyme and fractionated after on 2% Agarose gel and visualized posteriorly staining by ethidium bromide. There were significant differences in the distribution of the TNF-α gene polymorphism between the SLE and control groups. Individual carriers of the variant allele A had a 3.29 (95% CI: 1.7738-6.1325)-fold increased risk for SLE. Moreover, association was observed between SLE patients and serositis (P=0.0228). This study presents a preliminary evidence of association between TNF-α polymorphism and SLE susceptibility in the Northeast population from Brazil.