Thyroid disorders in patients with myasthenia gravis: A systematic review and meta-analysis.

BACKGROUND: Our purpose was to determine the prevalence of thyroid disorders in myasthenia gravis (MG) or whether MG was associated with an increased risk of thyroid disorders. METHODS: Pubmed, Embase, Web of Science, Cochrane database, Google Scholar and the Chinese Biomedical Databases were searched about the relationship between thyroid disorders and myasthenia gravis up to November 30, 2018, without language restrictions. The prevalence and relative risk (RR) for thyroid disorders were pooled by the R and STATA software. RESULTS: 39 papers with 24,927 MG patients were ultimately included for analysis in this meta-analysis. The pooled estimate of thyroid autoimmunity prevalence in MG patients was 10.1% (95%CI 6.7%-15.1%). Subgroups in patients with thyroid autoimmunity showed the prevalence of positive TGAb was the highest in MG patients (12.6%, 95%CI 8.1%-19.1%), followed by GD (6.0%, 95%CI 4.2%-8.5%), HT (4.6%, 95%CI 1.9%-10.5%). Moreover, the pooled estimated prevalence of thyroid dysfunction in MG patients was 6.8% (95%CI 4.6%-9.8%). After stratification, the results showed the prevalence of hyperthyroidism and hypothyroidism in MG cases were 5.6% (95%CI 3.9%-8.0%) and 2.6% (95%CI 1.7%-4.1%), respectively. In addition, meta-analysis of 2 studies showed that MG was significantly associated with the increased risk of thyroid autoimmunity (OR = 2.86; 95%CI 1.54-5.28, P = .001). CONCLUSIONS: This systemic review and meta-analysis provides reliable evidence that thyroid disorders are prevalent in MG, especially TGAb positivity, GD, hyperthyroidism, and HT, and MG is associated with increased risk for thyroid autoimmunity.

Associations of TNFRSF1A Polymorphisms with Autoimmune Thyroid Diseases: A Case-Control Study.

Previous studies have shown associations of polymorphisms in the tumor necrosis factor (TNF) receptor super family member 1A (TNFRSF1A) gene with several groups of inflammatory and autoimmune related diseases, but associations of TNFRSF1A polymorphisms with autoimmune thyroid diseases (AITD), mainly including two sub-types of Hashimoto's thyroiditis (HT) and Graves' disease (GD), in the Chinese Han population is unclear. A case-control study of 1812 subjects (965 AITD patients and 847 unrelated healthy controls) was conducted to assess AITD associations with five single nucleotide polymorphisms (SNPs), including rs4149576, rs4149577, rs4149570, rs1800693, and rs767455 in the TNFRSF1A gene locus. Genotyping was performed and evaluated using the platform of ligase detection reaction. No significant difference was observed in the allele and genotype frequencies between HT or GD patients and controls in any of the five SNPs in the TNFRSF1A gene (all p values >0.05). However, a moderate association of rs4149570 with HT was found after adjusting for age and gender [odds ratio (OR)=1.40, p=0.03]. No obvious difference was found in the haplotype distribution of any of the five SNPs in the TNFRSF1A gene between the AITD patients and controls. These data suggest that these five SNPs in the TNFRSF1A gene are not associated with AITD in the Chinese Han population, but rs4149570 shows a weak association with HT after adjusting for gender and age.

TNFSF4 Gene Variations Are Related to Early-Onset Autoimmune Thyroid Diseases and Hypothyroidism of Hashimoto's Thyroiditis.

The aim of the current study was to examine whether the polymorphism loci of the tumor necrosis factor superfamily member 4 (TNFSF4) gene increase the risk of susceptibility to autoimmune thyroid diseases (AITDs) in the Han Chinese population, and a case-control study was performed in a set of 1,048 AITDs patients and 909 normal healthy controls in the study. A total of four tagging single nucleotide polymorphisms (SNPs) in the TNFSF4 region, including rs7514229, rs1234313, rs16845607 and rs3850641, were genotyped using the method of ligase detection reaction. An association between GG genotype of rs3850641 in TNFSF4 gene and AITDs was found (p = 0.046). Additionally, the clinical sub-phenotype analysis revealed a significant association between GG genotype in rs7514229 and AITDs patients who were ≤18 years of age. Furthermore, rs3850641 variant allele G was in strong association with hypothyroidism in Hashimoto's thyroiditis (HT) (p = 0.018). The polymorphisms of the TNFSF4 gene may contribute to the susceptibility to AITDs pathogenesis.