Maria Elizabeth Rossi da Silva

Adipose tissue at the crossroads in the development of the metabolic syndrome, inflammation and atherosclerosis

The authors analyze insulin resistance, the metabolic syndrome and endothelial dysfunction as consequence of a common antecedent, a low grade inflammation, indicating that in obesity there is a chronically activated inflammatory state of the adipose tissue. Furthermore, the inflammatory signaling is discussed according to the adipose tissue depot, visceral or subcutaneous.

Unregulated IL-23/IL-17 immune response in autoimmune diseases

INTRODUCTION Type 1A diabetes (T1D) is an autoimmune disease resulting from the selective destruction of pancreatic beta cells by T cells most likely due to interaction of environmental and genetic factors. The CD4(+) T cells, largely implicated in this disease, comprise different subsets; based on the cytokines they produce. These subsets include Th1, Th2, regulatory T cells and another population of recently described T cells called Th17 cells. Increased expression of interleukin 17 (IL-17) has been detected in sera and in target tissues of patients with various autoimmune diseases. The differentiation of Th17 cells from naïve T cells appears to involve signals from TGF-beta, IL-6, IL-21, IL-1beta and IL-23. IL-23, a member of the IL-12 family, which activate the effector function of Th17 cells to promote inflammatory responses. In animal models, IL-23 is involved in the development of autoimmune diabetes. In humans, it seems to cause multi-organ inflammation, contributing to rheumatoid arthritis, inflammatory bowel disease and celiac disease manifestations. CONCLUSIONS The discovery that certain autoimmune disorders might be largely mediated by an unregulated IL-23/IL-17 response has important implications for the development of novel therapies for these diseases.

Creatine in Type 2 Diabetes: A Randomized, Double-Blind, Placebo-Controlled Trial

UNLABELLED Creatine supplementation improves glucose tolerance in healthy subjects. PURPOSES The aim was to investigate whether creatine supplementation has a beneficial effect on glycemic control of type 2 diabetic patients undergoing exercise training. METHODS A 12-wk randomized, double-blind, placebo-controlled trial was performed. The patients were allocated to receive either creatine (CR) (5 g·d) or placebo (PL) and were enrolled in an exercise training program. The primary outcome was glycosylated hemoglobin (HbA1c). Secondary outcomes included the area under the curve of glucose, insulin, and C-peptide and insulin sensitivity indexes. Physical capacity, lipid profile, and GLUT-4 protein expression and translocation were also assessed. RESULTS Twenty-five subjects were analyzed (CR: n=13; PL: n=12). HbA1c was significantly reduced in the creatine group when compared with the placebo group (CR: PRE=7.4 ± 0.7, POST=6.4 ± 0.4; PL: PRE=7.5 ± 0.6, POST=7.6 ± 0.7; P=0.004; difference=-1.1%, 95% confidence interval=-1.9% to -0.4%). The delta area under the curve of glucose concentration was significantly lower in the CR group than in the PL group (CR=-7790 ± 4600, PL=2008 ± 7614; P=0.05). The CR group also presented decreased glycemia at times 0, 30, and 60 min during a meal tolerance test and increased GLUT-4 translocation. Insulin and C-peptide concentrations, surrogates of insulin sensitivity, physical capacity, lipid profile, and adverse effects were comparable between the groups. CONCLUSIONS Creatine supplementation combined with an exercise program improves glycemic control in type 2 diabetic patients. The underlying mechanism seems to be related to an increase in GLUT-4 recruitment to the sarcolemma.

Family-based association of HLA class II alleles and haplotypes with type I diabetes in Brazilians reveals some characteristics of a highly diversified population.

The association of HLA class II haplotypes with type I diabetes was analyzed in 56 Southeastern Brazilian families using affected family-based controls (AFBAC) method. DRB1-DQA1-DQB1 alleles were determined by polymerase chain reaction/sequence-specific primer genotyping. This study first revealed the great haplotype diversity of Brazilians (65 different haplotypes even with incomplete DRB1 subtyping), probably due to the admixture of Africans genes with European and Amerindian genes in this population. The results revealed increased frequencies of the DRB1*03-DQA1*0501-DQB1*02 and DRB1*0401-DQA1*03-DQB1*0302 haplotypes in the patient group The highest risk for type I diabetes was associated with the heterozygote DRB1*03/*04 genotype as largely reported, and DRB1*03/X and DRB1*04/Y genotypes conferred a significant, but much lower disease risk. Protection from type I diabetes revealed some peculiarities in Southeastern Brazilians: a lack of significant protecting effect of the DRB1*1501-DQA1*0102-DQB1*0602 haplotype, and an apparent protection conferred by the DRB1*13-DQB1*0301, DRB1*11-DQB1*0301, and DRB1*01-DQB1*0501 two-locus haplotypes. The risk to type I diabetes in the highly diversified Southeastern Brazilians evidenced specific information to the prediction of the disease in this region of the country.

Prevalence of celiac disease among blood donors in São Paulo: the most populated city in Brazil

OBJECTIVE: Celiac disease is a permanent enteropathy caused by the ingestion of gluten, which leads to an immune-mediated inflammation of the small intestine mucosa. The prevalence of celiac disease varies among different nations and ethnic backgrounds, and its diversity is determined by genetic and environmental factors. São Paulo city is one of the largest cities in the world, with a vast population and an important history of internal migratory flow from other Brazilian regions, as well as immigration from other, primarily European, countries, resulting in significant miscegenation. The aim of the present study was to estimate the prevalence of adults with undiagnosed celiac disease among blood donors of São Paulo by collecting information on the ancestry of the population studied. METHODS: The prevalence of celiac disease was assessed by screening for positive IgA transglutaminase and IgA endomysium antibodies in 4,000 donors (volunteers) in the Fundação Pró-Sangue Blood Center of São Paulo, São Paulo, Brazil. The antibody-positive subjects were asked to undergo a small bowel biopsy. RESULTS: Of the 4,000 subjects, twenty-four had positive tests, although both antibody tests were not always concordant. For example, ten subjects were positive for IgA tissue transglutaminase only. In twenty-one positive patients, duodenal biopsies were performed, and the diagnosis of celiac disease was confirmed in fourteen patients (Marsh criteria modified by Oberhuber). In this group, 67% claimed to have European ancestry, mainly from Italy, Portugal and Spain. CONCLUSION: The prevalence of celiac disease is at least 1:286 among supposedly healthy blood bank volunteers in São Paulo, Brazil.

Marcadores genéticos e auto-imunes do diabetes melito tipo 1: da teoria para a prática

Type 1 A diabetes mellitus (T1AD) results from the autoimmune destruction of the insulin producing pancreatic beta-cells. The largest contribution to genetic susceptibility comes from several genes located in the major histocompatibility complex on chromosome 6p21.3 (IDDM1 locus), accounting for at least 40% of the family aggregation of this disease. The highest-risk human leukocyte antigen HLA genotype for T1AD is DR3-DQA1*0501-DQB1*0201/DR4-DQA1*0301-DQB1*0302, whereas -DR15-DQA1*0102-DQB1*0602 haplotype is associated with dominant protection. Three other T1D loci associated with predisposition are the Variable Number for Tandem Repeats (VNTR) near the insulin gene (IDDM2), which accounts to 10% of genetic susceptibility, the Cytotoxic T-Lymphocyte-associated Antigen (CTLA-4)(IDDM 12) and the Protein Tyrosine Phosphatasis Nonreceptor-type 22 (PTPN22). Many other gene suspected to predispose to autoimmunity have been investigated. T1AD is frequently associated with autoimmune thyroid disease, celiac disase, Addison´s disease and many other autoimmune diseases, characterized by organ-specific autoantibodies and related to the same genetic background. Using these autoantibodies, organ specific autoimmunity may be detected before the development of clinical disease preventing significant morbidity.

hCG-secreting pineal teratoma causing precocious puberty: Report of two patients and review of the literature

Two boys are described with precocious puberty (PP) due to pineal immature teratoma associated with choriocarcinoma. Patient 1 was a 7 year-old boy with a 2-year history of PP. He had elevated CSF and plasma beta-hCG levels. Magnetic resonance imaging (MRI) showed a 3.0 cm pineal mass. He was initially submitted to a trial with radiotherapy, followed by radical surgical resection, stereotactic radiotherapy and chemotherapy. Long-term follow up included the appearance of acute hydrocephalus requiring CSF shunting, local hemorrhage and extensive radionecrosis. Death occurred 1.5 years after diagnosis. Patient 2 was a 7 year-old boy with an 8-month history of PP. He had elevated CSF and plasma beta-hCG and alpha-fetoprotein levels. MRI showed a 1.0 cm pineal mass. He was submitted to radical surgical resection (which caused normalization of levels of markers) and prophylactic chemotherapy. The boy is doing well 1.5 years after diagnosis. An extensive review of the literature corroborates the idea that this last treatment paradigm (surgery and chemotherapy) probably represents the best treatment regimen for these patients.

The PTPN22 1858T allele but not variants in the proximal promoter region of IL-21 gene is associated with the susceptibility to type 1 diabetes and the presence of autoantibodies in a Brazilian cohort

Interleukin (IL)‐21 and protein tyrosine phosphatase non‐receptor 22 (PTPN22) regulate lymphocyte function and have been implicated in the pathogenesis of autoimmune diabetes. We sequenced the proximal promoter of the IL‐21 gene for the first time and analysed the PTPN22 1858T polymorphism in type 1A diabetes (T1AD) patients and healthy controls (HC). We correlated the frequencies of islet and extra‐pancreatic autoantibodies with genotypes from both loci. The case series comprised 612 T1AD patients and 792 HC. Genotyping of PTPN22 C1858T was performed on 434 T1AD patients and 689 HC. The −448 to +83 base pairs (bp) region of the IL‐21 gene was sequenced in 309 Brazilian T1AD and 189 HC subjects. We also evaluated human leucocyte antigen (HLA) DR3/DR4 alleles. The frequencies of glutamic acid decarboxylase (GAD65), tyrosine phosphatase‐like protein (IA)‐2, anti‐nuclear antibody (ANA), thyroid peroxidase (TPO), thyroglobulin (TG), thyrotrophin receptor autoantibody (TRAb), anti‐smooth muscle (ASM) and 21‐hydroxylase (21‐OH) autoantibodies were higher in T1AD patients than in HC. The PTPN22 1858T allele was associated with an increased risk for developing T1AD [odds ratio (OR) = 1·94; P < 0·001], particularly in patients of European ancestry, and with a higher frequency of GAD65 and TG autoantibodies. HLA‐DR3/DR4 alleles predominated in T1AD patients. A heterozygous allelic IL‐21 gene variant (g.‐241 T > A) was found in only one patient. In conclusion, only PTPN22 C1858T polymorphism and HLA‐DR3 and/or DR4 alleles, but not allelic variants in the 5′‐proximal region of the IL‐21 gene were associated with T1AD risk. Patients with T1AD had increased frequencies of anti‐islet‐cell, anti‐thyroid, anti‐nuclear, anti‐smooth muscle and anti‐21‐OH autoantibodies. The C1858T PTPN22 polymorphism was also associated with a higher frequency of GAD65 and TG autoantibodies.

Cardiovascular, metabolic and hormonal responses to the progressive exercise performed to exhaustion in patients with type 2 diabetes treated with metformin or glyburide.

Objectives:  To evaluate the effects of Metformin and Glyburide on cardiovascular, metabolic and hormonal parameters during progressive exercise performed to exhaustion in the post‐prandial state in women with type 2 diabetes (T2DM).

Autoantibodies and High-Risk HLA Susceptibility Markers in First-Degree Relatives of Brazilian Patients with Type 1 Diabetes Mellitus: A Progression to Disease Based Study

PurposeThe objective of this study was to determine the frequencies of autoantibodies to heterogeneous islet-cell cytoplasmic antigens (ICA), glutamic acid decarboxylase65 (GAD65A), insulinoma-associated antigen-2 (IA-2A) and insulin (IAA)–and human leukocyte antigen (HLA) class II markers (HLA-DR and -DQ) in first degree relatives of heterogeneous Brazilian patients with type I diabetes(T1DM). A major focus of this study was to determine the influence of age, gender, proband characteristics and ancestry on the prevalence of autoantibodies and HLA-DR and -DQ alleles on disease progression and genetic predisposition to T1DM among the first-degree relatives.MethodsIAA, ICA, GAD65A, IA-2A and HLA- class II alleles were determined in 546 first-degree-relatives, 244 siblings, 55 offspring and 233 parents of 178 Brazilian patients with T1DM.ResultsOverall, 8.9% of the relatives were positive for one or more autoantibodies. IAA was the only antibody detected in parents. GAD65 was the most prevalent antibody in offspring and siblings as compared to parents and it was the sole antibody detected in offspring. Five siblings were positive for the IA-2 antibody. A significant number (62.1%) of siblings had 1 or 2 high risk HLA haplotypes. During a 4-year follow-up study, 5 siblings (expressing HLA-DR3 or –DR4 alleles) and 1 offspring positive for GAD65A progressed to diabetes.ConclusionsThe data indicated that the GAD65 and IA-2 antibodies were the strongest predictors of T1DM in our study population. The high risk HLA haplotypes alone were not predictive of progression to overt diabetes.