Increased Serum Levels of IL-28 and IL-29 and the Protective Effect ofIL28Brs8099917 Polymorphism in Patients with Hashimoto’s Thyroiditis

Abstract

Hashimoto's thyroiditis (HT) is thought to result from decreased T helper type 2 (Th2) responses, leading to the progressive destruction of thyrocytes. IFN-λ1, -λ2, and -λ3 (also known as IL-29, IL-28A, and IL-28B, respectively) are recently described members of the IFN-λ family and have been shown to decrease the production of Th2 cytokines in vitro. However, the role and mechanism of IFN-λ1 in HT remain unknown. The purpose of this study was to examine whether IL29 and IL28B gene polymorphisms are susceptibility genes for the development of HT. Also, we investigated the effects of IL-29 and IL-28 serum levels in the pathogenesis of HT. Using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method, single-nucleotide polymorphisms (SNPs) of IL28B rs8099917 (IL28 G/T) and IL29 rs30461 (IL29 T/C) were studied in 99 patients with HT and 100 healthy controls. Considering the allelic distribution of the IL28 G/T polymorphism, a higher frequency of the G allele was observed in the control group versus the HT group. Thus, it was suggested that the G allele may be protective against HT pathogenesis (OR = 0.388, 95% CI = 0.217-0.693; p = 0.001). Our findings also demonstrated that there was a statistically significant difference in serum IL-28 and IL-29 levels between case and control groups (p < 0.001). Increased serum levels of IL-28 and IL-29 were found in patients with HT. However, we did not find a relationship between the IL29 gene polymorphism and HT. In conclusion, the IL28B gene polymorphism and serum IL-28 and IL-29 levels seem to play a role in the pathogenesis of HT.

Serum Antithyroglobulin Antibody Levels Are Associated with Diabetic Retinopathy among Euthyroid Type 2 Diabetes Patients: A Hospital-Based, Retrospective Study

“…A variety of inflammatory cytokines in serum have been confirmed to be closely related to the occurrence and development of T2D-DR [ 36 – 38 ]. At the same time, a large number of studies also showed that a variety of circulating cytokines involving in the occurrence and development of thyroid autoimmunity [ 39 – 41 ]. We speculate that the above two groups of pathological processes might overlap or promote each other, which induces a higher TgAb titer in patients with severe DR and vice versa.…”

Evaluation of IL-29 in Euthyroid Patients with Graves’ Orbitopathy: A Preliminary Study

“…In the discussion of the results of the present study, the most important is single report focused on IL-29 in HT conducted on 99 patients [ 20 ]. The cited study revealed increased IL-29 serum level in HT patients if compared with healthy controls.…”

“…They together form a large family called IL-10 family [ 17 ]. We know now that polymorphisms of the genes of IL-10, IL-22, and IL-28 are associated with a higher prevalence of autoimmune thyroid disease [ 18 – 20 ]. Until the present study was conducted, only one research aimed to evaluate the role of IL-29 in thyroid disorders.…”

“…Until the present study was conducted, only one research aimed to evaluate the role of IL-29 in thyroid disorders. In the cited study, elevated serum levels of IL-28 and IL-29 were detected in patients with Hashimoto's thyroiditis (HT) [ 20 ].…”

Low levels of serum IL‐39 are associated with autoimmune thyroid disease

“…Several cytokines, including interleukin (IL)‐17, IL‐23, IL‐28, and IL‐29, have been implicated in the pathogenesis of HT. 8 , 9 , 10 , 11 , 12 , 13 , 14 Additionally, IL‐6, IL‐21, IL‐23, and IL‐37 are all involved in the occurrence of GD. 15 , 16 , 17 , 18 , 19 IL‐12 family plays a key role in immune responses through their functional, unique structural, and immunological characteristics.…”