Vitamin D Receptor Gene Polymorphisms and Autoimmune Thyroiditis: Are They Associated with Disease Occurrence and Its Features?

Adam Maciejewski,Adam Czyżyk,Michał J Kowalczyk,Ryszard Żaba,Marta Kowalska,Katarzyna Łącka,Waldemar Herman

doi:10.1155/2019/8197580

Adam Maciejewski, Adam Czyżyk + Show 5 more

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https://doi.org/10.1155/2019/8197580

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Abstract

Purpose Vitamin D, besides its role in calcium-phosphorus metabolism, turned out to play a significant immunomodulating function. Until now four single nucleotide polymorphisms of vitamin D receptor gene (VDR), rs2228570 (FokI), rs1544410 (BsmI), rs7975232 (ApaI), and rs731236 (TaqI), have been studied in autoimmune thyroid disorders, with conflicting results. Another functional polymorphism of the VDR gene, rs11568820 (Cdx2), has been shown to influence the immune system, although it has not been studied for its association with autoimmune thyroiditis to date. Therefore, the study aimed to evaluate the association of these five VDR gene polymorphisms with susceptibility to autoimmune thyroiditis among Caucasian Polish population. A relationship between the studied polymorphisms and selected clinical features of the disease was additionally assessed. Methods 223 patients with autoimmune thyroiditis and 130 control subjects were enrolled in the study. VDR polymorphisms were studied by PCR-RFLP or TaqMan real-time PCR. Results Allele and genotype distributions of any of the studied polymorphisms did not differ significantly between patients and controls. Similarly, frequencies of haplotypes derived from rs1544410-rs7975232-rs731236 (BsmI-ApaI-TaqI) polymorphisms were not significantly different in the two studied groups. However, a weak association between rs1544410 (BsmI) or rs7975232 (ApaI) VDR polymorphisms and thyroid volume was found (p = 0.03 and p = 0.04, resp.). Conclusions Our results suggest that VDR gene is not a major susceptibility factor for autoimmune thyroiditis development, at least in Caucasian Polish population.

Highlights

Autoimmune thyroid diseases (AITDs) are common pathologies that affect up to 5% of the population and their incidence is still increasing [1]
Genotype distributions were consistent with Hardy-Weinberg equilibrium (HWE) for the studied vitamin D receptor gene (VDR) polymorphisms in both groups (p > 0.05)
VDR gene polymorphisms have been extensively studied for their potential association with susceptibility to different autoimmune and inflammatory disorders, for example, multiple sclerosis (MS), type 1 diabetes (T1D), rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), inflammatory bowel diseases, or tuberculosis [12]

Summary

Introduction

Autoimmune thyroid diseases (AITDs) are common pathologies that affect up to 5% of the population and their incidence is still increasing [1]. Autoimmune thyroiditis (AIT), known as Hashimoto’s thyroiditis, is the most frequent manifestation of AITDs. The etiology of the disease is complex. The etiology of the disease is complex It develops as a result of an interaction between predisposing gene variants and environmental triggers. Genetic factors in general predominate and contribute 70-80 % to the development of AIT. These already proven genetic agents are responsible for less than 20% of the genetic susceptibility to the disease [3]

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