Mannose binding lectin gene polymorphisms and associated auto-immune diseases in type 1 diabetes Brazilian patients.

In our study we investigated the possible role of MBL2 functional single nucleotide polymorphisms (SNPs) in the augmented susceptibility to develop other autoimmune diseases in presence of type 1 diabetes (T1D) in a group of Brazilian patients. Patients were stratified for the presence of autoimmune diseases known to be associated with T1D, such as autoimmune thyroid disease (AITD) and celiac disease (CD), and compared with healthy controls (HC). Our findings suggest that MBL2 functional SNPs are more closely related to AITD than to T1D, being MBL2 SNPs frequencies in T1D patients not affected by AITD comparable to the HC ones, while significantly different between AITD patients and patients not affected by the disease. Thus, the association between MBL2 polymorphisms and T1D that we previously reported, seems to result from the stronger association of MBL2 SNPs with another autoimmune disease, the AITD, frequently associated with T1D.

Prevalence of autoimmune thyroid disease and thyroid dysfunction in young Brazilian patients with type 1 diabetes.

Patients with an autoimmune condition are known to be at higher risk of developing other autoimmune disorders. Type 1 diabetes may be associated with additional autoimmune disorders including autoimmune thyroid disease. The aim of this study was to investigate the prevalence of thyroid autoantibodies in a group of children, adolescents, and young adults with type 1 diabetes from northeastern Brazil as well as their significance for the development of thyroid disorders. The study design was cross-sectional and descriptive, analyzing young people with a previous type 1 diabetes diagnosis. Two hundred and fourteen children and adolescents with prior diagnosis of type 1 diabetes were evaluated. Antibodies to thyroperoxidase (anti-TPO) were determined in all patients and thyroid-stimulating hormone (TSH) levels. The anti-TPO antibody test was positive in 54 out of the 214 patients studied, resulting in an overall prevalence of 25.2%. Among the anti-TPO-positive subjects, females were predominant (72%) over males (28%) (p < 0.001). A total of 55.5% patients with positive anti-TPO antibodies had abnormal TSH levels. Clinically significant hypothyroidism was found in 29.6% and subclinical hypothyroidism in 22.2% of patients with positive anti-TPO. Hyperthyroidism was present in only 3% of them. Our results demonstrate the high prevalence of autoimmune thyroiditis in patients with type 1 diabetes and the need for these patients of regular screening to make a precocious diagnosis of thyroid dysfunction.

Mannose binding lectin gene polymorphisms are associated with type 1 diabetes in Brazilian children and adolescents.

Mannose-binding lectin is an important constituent of the innate immune system, the serum levels of which are greatly affected by polymorphisms of the MBL2 gene: three polymorphisms in exon 1, as well as nucleotide variations in the promoter region of the gene, have been associated with protein deficiency and some infectious and autoimmune disease. The aim of this study was to investigate a possible association between MBL2 gene polymorphisms in patients who have developed type 1 diabetes during childhood and adolescence. We evaluated MBL2 gene polymorphisms in 214 children and adolescents with type 1 diabetes and compared them with a healthy control group, finding significant differences in genotypic and allelic frequencies (p = 0.004 and p = 0.0008, respectively). Our results suggest that patients with type 1 diabetes possessing the 0 allele have a higher risk for developing type 1 diabetes during childhood and adolescence, and that this risk factor is not related to age at diagnosis.