Polymorphisms of interleukin-21 and interleukin-21-receptor genes confer risk for autoimmune thyroid diseases

IL-21 (rs2055979 and rs2221903)/IL-21R (rs3093301) Polymorphism and High Levels of IL-21 Are Associated with Rheumatoid Arthritis in Mexican Patients

Rheumatoid Arthritis (RA) is characterized by joint destruction, chronic inflammation, and autoantibody production. IL-21/IL-21R plays an essential role in the immunopathology of RA. Elevated IL-21 serum levels have been associated with RA and disease activity. Here, we evaluated the association of IL-21/IL-21R polymorphisms and IL-21 serum levels with RA. The study included 275 RA patients and 280 Control subjects (CSs). Single nucleotide polymorphisms IL-21 (rs2055979 and rs2221903) and IL-21R (rs3093301) were genotyped using PCR-RFLP. Clinical activity was evaluated by DAS28-ESR; IL-21 and anti-CCP serum levels were quantified by ELISA. The IL-21 rs2055979 AA genotype was higher in RA patients than in the CS group (p = 0.0216, OR = 1.761, 95% CI = 1.085-2.859); furthermore, RA patients showed anti-CCP elevated levels compared to the CA genotype (p = 0.0296). The IL21R rs3093301 AA genotype was also higher in RA patients than in the CS group (p = 0.0122, OR = 1.965, 95% CI = 1.153-3.348). The AT haplotypes of IL-21 rs2055979 and rs2221903 were more frequent (49%) in the RA group (p = 0.006). IL-21 serum levels were significantly elevated in the RA group, but without an association with IL-21 polymorphisms. In conclusion, IL-21 rs2255979 and IL-21R rs3093301 are associated with a higher risk of RA, and could be a genetic marker. Moreover, the elevated IL-21 levels in RA suggest that IL-21/IL-21R could be a therapeutic target in RA.

Interleukins 4 and 21 Protect Anti-IgM Induced Cell Death in Ramos B Cells: Implication for Autoimmune Diseases

Interleukins 4 (IL-4) and 21 (IL-21) belong to the common gamma chain cytokine family which are highly involved in the progression of autoimmune diseases. While IL-4 is well known to be involved in the suppression of apoptosis of autoreactive B cells, the role played by IL-21 remains unclear. In the current study, we activated the human Burkitt’s lymphoma Ramos B cells with anti-IgM to mimic B cell hyperactivation observed in patients of autoimmune diseases. Consistent with other reported findings, anti-IgM led to the downregulation of proteins involved in B cell survival and proliferation, as well as the activation of caspase 3 activity and DNA damage, resulting in apoptotic cell death after 48-hour treatment. Although both IL-4 and IL-21 reversed anti-IgM-induced apoptosis and cell cycle arrest, they did so via different mechanisms: while IL-4 could directly suppress anti-IgM-induced caspase 3 activation and marker indicative of DNA damage, IL-21 could induce B cell proliferation in the presence of anti-IgM. Importantly, IL-21 also suppressed activation induced cell death in human primary B cells. Pre-treatment with clinically validated JAK inhibitors completely reversed the effects of IL-4 and IL-21 to rescue anti-IgM induced cell death and DNA damage. The results indicate the underlying mechanisms of how IL-4 and IL-21 differentially promote survival of hyperactivated B cells and provide hints to treat autoimmune diseases.

Leptin receptor is a key gene involved in the immunopathogenesis of thyroid-associated ophthalmopathy

Thyroid‐associated ophthalmopathy (TAO), the most common and severe manifestation of Graves' disease (GD), is a disfiguring and potentially blinding autoimmune disease. The high relapse rate (up to 20%) and substantial side effects of glucocorticoid treatment further decrease the life quality of TAO patients. To develop novel therapies, we amid to explore the immunopathogenesis of TAO. To identify the key immune‐related genes (IRGs) in TAO, we integrated the IRG expression profiles in thyrocytes from a GD patient set (GD vs healthy control) and a TAO patient set (TAO vs GD). Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), protein‐protein interaction (PPI) and receiver operating characteristic (ROC) curve analyses identified the leptin receptor (LEPR) gene as the key IRG in TAO immunopathogenesis. Gene set enrichment analysis (GSEA) suggested enrichment of the antigen presentation pathway in TAO patients with higher LEPR. Increased LEPR expression was validated in TAO orbital tissues, and weighted gene co‐expression network analysis (WGCNA) showed that cell adhesion processes were positively correlated with LEPR. Our study revealed that LEPR is a key gene in TAO immunopathogenesis and plays different roles in thyrocytes and orbital tissues. Our findings provide new insights into diagnostic and therapeutic biomarkers for TAO.

Interleukin-21 receptor gene polymorphism is associated with hepatitis B virus-related hepatocellular carcinoma in Chinese patients

Background

We investigated the relationship between hepatitis B virus (HBV)‐related pathogenesis and single nucleotide polymorphisms (SNPs) in interleukin‐21 (IL‐21)‐JAK‐STAT signaling pathway genes.

Methods

We used the high‐resolution melting (HRM) method to genotype five SNPs (IL‐21 rs2221903, IL‐21 rs4833837, IL‐21 receptor (IL‐21R) rs2285452, JAK3 rs3008, and STAT3 rs1053023) in 546 HBV‐infected patients and 353 healthy Chinese subjects. The HBV‐infected patients were further divided into subgroups based on the HBV‐related pathologies: chronic hepatitis B (CHB), HBV‐related liver cirrhosis (LC), and HBV‐related hepatocellular carcinoma (HCC).

Results

There were no significant differences in the genotype and allele distributions of the five SNPs between the HBV‐infected patients and healthy subjects. The genotype and allele frequencies were similar in the two groups for IL‐21 rs2221903 (A>G, P = 0.83 and 0.67), rs4833837 (A>G, P = 0.80 and 0.49), IL‐21R rs2285452 (G>A, P = 0.25 and 0.68), STAT3 rs1053023 (A>G, P = 1.00 and 0.96), and JAK3 rs3008 (C>T, P = 0.32 and 0.54). However, patients with the IL‐21R rs2285452 AA genotype were more susceptible to HBV‐related HCC than those with the IL‐21R rs2285452 GA/GG genotype (P = 0.03, OR = 3.27, 95% CI = 1.16‐9.20). The serological marker model of “HBsAg+, HBeAg+, HBcAb+” was predominant among patients with HBV infection. However, there was no association between the genotype's distribution of the five SNPs and the serological marker models (P > 0.05).

Conclusions

These findings demonstrate that the IL‐21R rs2285452 AA genotype increases the risk of HBV‐related HCC in Chinese patients.

Variations in CD14 Gene Are Associated With Autoimmune Thyroid Diseases in the Chinese Population

Autoimmune thyroid diseases (AITDs) are chronic organ-specific autoimmune diseases and mainly include Graves' disease (GD) and Hashimoto's thyroiditis (HT). CD14 is an important component of the immune system as a receptor for gram-negative lipopolysaccharide (LPS). The genetic polymorphisms of CD14 have been confirmed to be associated with a variety of autoimmune diseases. However, its relationship with AITDs is still unclear. The study was aimed to determine whether four single nucleotide polymorphisms (rs2915863, rs2569190, rs2569192, and rs2563298) of CD14 are associated with AITDs and its subgroups of GD and HT. The results showed significant association of rs2915863 and rs2569190 with GD. The frequencies of rs2915863 genotypes and T allele in patients with GD differed significantly from their controls (P = 0.007 and P = 0.021, respectively). For rs2569190, frequencies of genotypes and G allele in GD patients also showed positive P-values (P = 0.038 and P = 0.027, respectively). The correlations between these two loci and GD are more pronounced in female GD patients and patients with a family history. In genetic model analysis, the allele model, recessive model, and homozygous model of rs2569190 and rs2915863 embodied strong correlations with GD after the adjusting of age and gender (P = 0.014, P = 0.015, P = 0.009, and P = 0.014, P = 0.001, P = 0.006, respectively). However, these four sites are not related to HT. We firstly discovered the relationship between CD14 gene polymorphism and GD, and the results indicate that CD14 is an important risk locus for AITD and its SNPs may contribute to host's genetic predisposition to GD.

Thyroid-associated Ophthalmopathy

Thyroid-associated ophthalmopathy is the most frequent extrathyroidal involvement of Graves’ disease but it sometimes occurs in euthyroid or hypothyroid patients. Thyroid-associated ophthalmopathy is an autoimmune disorder, but its pathogenesis is not completely understood. Autoimmunity against putative antigens shared by the thyroid and the orbit plays a role in the pathogenesis of disease. There is an increased volume of extraocular muscles, orbital connective and adipose tissues. Clinical findings of thyroid-associated ophthalmopathy are soft tissue involvement, eyelid retraction, proptosis, compressive optic neuropathy, and restrictive myopathy. To assess the activity of the ophthalmopathy and response to treatment, clinical activity score, which includes manifestations reflecting inflammatory changes, can be used. Supportive approaches can control symptoms and signs in mild cases. In severe active disease, systemic steroid and/or orbital radiotherapy are the main treatments. In inactive disease with proptosis, orbital decompression can be preferred. Miscellaneous treatments such as immunosuppressive drugs, somatostatin analogs, plasmapheresis, intravenous immunoglobulins and anticytokine therapies have been used in patients who are resistant to conventional treatments. Rehabilitative surgeries are often needed after treatment.

Copy number variations exploration of multiple genes in Graves' disease

BACKGROUND

Few previous published papers reported copy number variations of genes could affect the predisposition of Graves' disease (GD). Herein, the aim of this study was to explore the association between copy number variations (CNV) profile and GD.

METHODS

The preliminary copy number microarray used to screen copy number variant genes was performed in 6 GD patients. Five CNV candidate genes (CFH, CFHR1, KIAA0125, UGT2B15, and UGT2B17) were then validated in an independent set of samples (50 GD patients and 50 matched healthy ones) by the Accucopy assay method. The CNV of the other 2 genes TRY6 and CCL3L1 was investigated in 144 GD patients and 144 healthy volunteers by the definitive genotyping technique using the Taqman quantitative polymerase-chain-reaction (Taqman qPCR). TRY6 gene-associated single nucleotide polymorphism (SNP), rs13230029, was genotyped by the PCR-ligase detection reaction (LDR) in 675 GD patients and 898 healthy controls.

RESULTS

There were no correlation of the gene copy number (GCN) of CFH, CFHR1, KIAA0125, UGT2B15, and UGT2B17 with GD. In comparison with that of controls, the GCN distribution of TRY6 and CCL3L1 in GD patients did not show significantly differ (P > 0.05). Furthermore, TRY6-related polymorphism (rs13230029) showed no difference between GD patients and controls. No correlation was found between CNV or SNP genotype and clinical phenotypes. Generally, there were no link of the copy numbers of several genes, including CFH, CFHR1, KIAA0125, UGT2B15, UGT2B17, TRY6, and CCL3L1 to GD.

CONCLUSION

Our results clearly indicated that the copy number variations of multiple genes, namely CFH, CFHR1, KIAA0125, UGT2B15, UGT2B17, TRY6, and CCL3L1, were not associated with the development of GD.

Comprehensive analysis of cytokine gene polymorphisms defines the association of IL-12 gene with ophthalmopthy in Korean children with autoimmune thyroid disease

In early onset autoimmune thyroid disease (AITD) showing a strong genetic tendency, cytokines have been suggested to play a critical role in the development of AITD. To directly compare the influences of several cytokine gene polymorphisms, 25 single nucleotide polymorphisms (SNPs) in 17 cytokine genes were analyzed on 104 Korean children with AITD [Hashimoto's disease (HD) = 44, Graves' disease (GD) = 60 (thyroid-associated ophthalmopathy (TAO) = 29, non-TAO = 31)] and 192 controls. Compared with healthy controls, any significant association with polymorphisms of cytokine genes was not found in HD and GD. Among GD patients, non-TAO group only showed significant associations with IL-12 C allele (rs3212227: A > C) (76.6% vs. 51.6%, OR = 0.3 [0.15-0.71], Pc = 0.007). Particularly, the frequency of IL-12C allele was significantly lower in the non-TAO group than in the TAO group (82.8% vs. 51.6%, Pc = 0.018). Our comprehensive analysis of cytokine gene polymorphisms suggests that IL-12 gene may play impact on specific pathogenesis of ophthalmopathy in Korean children with AITD.

Elevated follicular helper T cells and expression of IL-21 in thyroid tissues are involved in the pathogenesis of Graves' disease

The follicular helper T cell (Tfh) and IL-21 have been shown to play an important role in many autoimmune diseases. However, less is known about their role in Graves' disease (GD). This study aimed to investigate the expression of Tfhs and related factors (IL-21, IL-21R, CXCR5, and CXCL13) in GD thyroid tissues and to explore the effect of IL-21 on thyroid follicular cells (TFCs). The expression of Tfh-related factors in GD and normal thyroid tissues was validated using immunohistochemistry, real-time polymerase chain reaction and Western blotting. Confocal microscopy confirmed the presence of Tfh and IL-21R on CD4(+)T-/CD19(+)B cell in GD thyroid tissues. Furthermore, the effect of IL-21 on cAMP production in TFCs upon thyroid-stimulating antibody (TSAb) stimulation was also examined by an in vitro bioassay. The increased expression of Tfh-related factors was observed in GD thyroid tissues compared to control subjects. Confocal microscopy further confirmed the presence of Tfhs and the expression of IL-21R on CD4(+)T cells and CD19(+)B cells in GD thyroid tissues. Moreover, the expression of IL-21mRNA in GD thyroid tissues was correlated with the levels of thyroid autoantibodies. Additionally, IL-21 could indirectly promote cAMP production upon TSAb stimulation in TFCs when cooperating with lymphocytes, and GD TFCs were more sensitive to IL-21 stimulation than normal TFCs. There is increased expression of Tfhs and related factors (IL-21, IL-21R, CXCR5, and CXCL13) in GD thyroid tissues, and the expression of IL-21mRNA in GD thyroid tissues was found to correlate with the serum levels of thyroid autoantibodies and thyroid hormones. Moreover, IL-21 could indirectly enhance the biological activity of TFCs upon TSAb stimulation when cooperating with lymphocytes in vitro, particularly in GD TFCs, suggesting that Tfh and IL-21 might be involved in the pathogenesis of GD.

Tumor necrosis factor receptor-associated factor 1 (TRAF1) polymorphisms and susceptibility to autoimmune thyroid disease

Former studies have revealed the link between the tumor necrosis factor (TNF) receptor-associated factor 1 (TRAF1) polymorphisms and autoimmunity. In the present study, we took an opportunity to investigate the association between TRAF1 and autoimmune thyroid disease (AITD) in order to find a new susceptibility gene. A total of 1029 AITD patients [677 Graves' disease (GD) patients and 352 Hashimoto thyroiditis (HT) patients] and 899 controls were enrolled. We used matrix-assisted laser desorption ionization-time of flight mass spectrometer (MALDI-TOF-MS) to detect the polymorphisms of rs4836834, rs10760130, rs10818488, rs2239658, rs2900180. We also explored the association between polymorphisms and clinical subphenotypes. Genotype frequencies of the five loci in all AITD patients were significantly different from those of controls. Genotype frequencies of rs10760130, rs2239658 and rs2900180 in GD patients were significantly different from controls. Allele analysis found that T allele of rs4836834, G allele of rs10760130, A allele of rs10818488, T allele of rs2239658 and T allele of rs2900180 were significantly higher in GD and AITD patients. No significant differences were found between HT patients and controls. Haplotype analysis found three haplotypes including ACAGC, TTGAT and TCGAC. ACAGC frequencies were significantly lower in GD and HT patients. However, TTGAT frequency was only significantly higher in GD patients. No significant results were found between polymorphisms and clinical subphenotypes. Our study reveals TRAF1 as a susceptibility gene of AITD in Chinese Han population.

IL-21 polymorphisms rs907715 and rs2221903 are associated with decreased non-small cell lung cancer susceptibility

The etiology of lung cancer is still incompletely understood. Previous studies have suggested the association between IL-21 polymorphisms and autoimmune diseases, however, little is known about its role in lung cancer susceptibility. Here, we investigated the role of two SNPs of IL-21 gene in a cohort of non-small cell lung cancer (NSCLC) patients. A total of 128 NSCLC patients and 156 healthy controls were genotyped. Multivariate logistic regression was used to analyze the association between IL-21 polymorphisms and NSCLC risk. Our data showed that both rs907715 and rs2221903 were significantly associated with lung cancer susceptibility, and patients carrying rs907715A (P = 0.007, adjusted OR = 0.60, 95% CI = 0.42-0.87) or rs2221903G (P = 0.020, adjusted OR = 0.52, 95% CI = 0.30-0.90) allele had a decreased risk of NSCLC. Further study identified that the association between IL-21 polymorphisms and NSCLC risk was limited to lung adenocarcinoma. Haplotype analysis revealed that the AG (P = 0.006, OR = 0.072 95% CI = 0.011-0.451) and AA (P = 0.022, OR = 0.657, 95% CI = 0.458-0.941) haplotypes of rs907715/rs2221903 were associated with a decreased risk of NSCLC, whereas the GA (P = 0.0001, OR = 1.932, 95% CI = 1.378-2.710) haplotype was associated with an increased risk. In conclusion, our study demonstrates the association between IL-21 polymorphisms (rs907715 and rs2221903) and NSCLC risk in a Chinese Han population, indicating their potential role in lung cancer detection and treatment.

Investigation of IL-21 gene polymorphisms (rs2221903, rs2055979) in cases with multiple sclerosis of Azerbaijan, Northwest Iran

BACKGROUND

Multiple Sclerosis (MS) is a chronic inflammatory demyelinating disease of the Central Nervous System that is immunologically mediated in genetically susceptible individuals. IL-21, a cytokine produced by TCD4(+) cells, particularly by Th-17 cells, is believed to play an important role in the MS pathogenesis.

OBJECTIVE

This study was performed to investigate the impact of genetic polymorphisms in IL-21 gene on MS susceptibility and clinical profiles.

METHODS

Seventy Iranian patients with clinically definite relapsing-remitting MS and 110 age, sex and ethic matched controls were genotyped for IL-21 gene polymorphisms using PCR-RFLP method.

RESULTS

Our results showed that the IL-21 rs2221903 SNP is not polymorphic in our population. Also, the allelic and genotypic frequencies of the IL-21 rs2055979 did not differ significantly between the MS patients and controls (P = 0.413 and P = 0.565 respectively, and OR = 1.122, 95% CI = 0.79-1.87 for T allele). However, our results showed that IL-21 rs2055979 (G/T) T allele positive (TT+GT) MS patients had lower (PI ≤ 1.5) disease progression compared to rs2055979 T allele negative (GG) patients (P = 0.009).

CONCLUSION

Our results showed that no outstanding association exists between IL-21 alleles and susceptibility to MS. However, our clinical analysis showed significant association of IL-21 gene polymorphism with the progression of multiple sclerosis disease. Our results indicate that the G allele promotes, or the T allele protects against disease progression. To clarify the role of IL-21 rs2055979 in MS pathogenesis, further comprehensive studies with larger sample sizes among different ethnicity populations are recommended.

TSHR intronic polymorphisms (rs179247 and rs12885526) and their role in the susceptibility of the Brazilian population to Graves' disease and Graves' ophthalmopathy

PURPOSE

Intronic thyroid-stimulating hormone receptor polymorphisms have been associated with the risk for both Graves' disease and Graves' ophthalmopathy, but results have been inconsistent among different populations. We aimed to investigate the influence of thyroid-stimulating hormone receptor intronic polymorphisms in a large well-characterized population of GD patients.

METHODS

We studied 279 Graves' disease patients (231 females and 48 males, 39.80 ± 11.69 years old), including 144 with Graves' ophthalmopathy, matched to 296 healthy control individuals. Thyroid-stimulating hormone receptor genotypes of rs179247 and rs12885526 were determined by Real Time PCR TaqMan(®) SNP Genotyping.

RESULTS

A multivariate analysis showed that the inheritance of the thyroid-stimulating hormone receptor AA genotype for rs179247 increased the risk for Graves' disease (OR = 2.821; 95 % CI 1.595-4.990; p = 0.0004), whereas the thyroid-stimulating hormone receptor GG genotype for rs12885526 increased the risk for Graves' ophthalmopathy (OR = 2.940; 95 % CI 1.320-6.548; p = 0.0083). Individuals with Graves' ophthalmopathy also presented lower mean thyrotropin receptor antibodies levels (96.3 ± 143.9 U/L) than individuals without Graves' ophthalmopathy (98.3 ± 201.9 U/L). We did not find any association between the investigated polymorphisms and patients clinical features or outcome.

CONCLUSION

We demonstrate that thyroid-stimulating hormone receptor intronic polymorphisms are associated with the susceptibility to Graves' disease and Graves' ophthalmopathy in the Brazilian population, but do not appear to influence the disease course.

RNASET2 tag SNP but not CCR6 polymorphisms is associated with autoimmune thyroid diseases in the Chinese Han population

Background

Polymorphisms of the CC chemokine receptor 6 (CCR6) and RNASET2 tag SNP have been shown to be associated with the susceptibility to several immune-related diseases. This study was conducted to identify the association of CCR6 and RNASET2 tag SNP with autoimmune thyroid diseases (AITDs) in the Chinese Han population.

Methods

We enrolled 1061 patients with AITDs, including 701 patients with Graves’ disease (GD) and 360 patients with Hashimoto’s thyroiditis (HT), and 938 healthy individuals for a case–control genetic association study. Three CCR6 single nucleotides polymorphisms (SNPs) (rs3093023/rs3093024/rs6902119) and one tagging SNP (rs9355610) within RNASET2 gene were selected for genotyping by multiplex polymerase chain reaction (PCR) and ligase detection reaction (LDR).

Results

The frequency of rs9355610 genotypes in the patients with GD differed significantly from that in the controls (p = 0.017). The frequency of the minor G allele of rs9355610 was significantly higher in the GD patients than in the healthy controls (p = 0.005, OR = 1.225, 95% CI:1.063-1.412). However, we could not find significant differences in the genotype or allele frequencies of HT patients compared with healthy controls. After gender stratification, the frequency of the minor G allele in both male and female GD patients was significantly higher than that in the healthy controls (p = 0.036, OR = 1.308, 95% CI:1.017-1.684 ; p = 0.048, OR = 1.19, 95% CI:1.001-1.413; respectively);. Furthermore, the frequency of haplotype AT in GD patients was significantly lower than that in their control groups (p = 0.003) and showed a protective effect against GD (OR = 0.806, 95% CI: 0.699-0.929). The frequency of haplotype GT in GD patients was significantly higher than that in their control groups (p = 0.048), indicating that GT was the risk haplotype to GD (OR = 1.267, 95% CI: 1.001-1.603). There were no significant differences in the allele or genotype frequencies of three SNPs of CCR6 (rs3093023/rs3093024/ rs6902119) gene between GD patients, HT patients and controls.

Conclusions

Our results suggest that the rs9355610 tag SNP of RNASET2 gene is positively associated with susceptibility to GD in the Chinese Han population. No association was found for the tested CCR6 SNPs.

Expression levels and genetic polymorphisms of interleukin-2 and interleukin-10 as biomarkers of Graves' disease

The aim of the present study was to determine whether the expression levels of interleukin (IL)-2 and IL-10 may be used as biological markers in Graves’ disease (GD) patients. A total of 256 individuals, including 118 GD patients and 138 healthy individuals, were enrolled into the study. Blood samples were collected from each patient and healthy individual, which were then subjected to enzyme-linked immunosorbent assay (ELISA). Total RNA and total proteins were determined using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot analysis, respectively. In addition, restriction fragment length polymorphism (RFLP) analysis was performed to detect the presence of genetic polymorphisms. The ELISA results indicated that the IL-2 and IL-10 serum levels in the GD patients were increased by ~5.2 and ~7-fold when compared with the levels in the healthy controls. The results of RT-qPCR indicated that the mRNA expression levels of IL-2 and IL-10 were upregulated in the GD patients when compared with the healthy controls. Furthermore, the western blot analysis results revealed that the protein expression levels of IL-2 and IL-10 were significantly increased in the GD patients. RFLP analysis indicated that the increased number of GG single nucleotide polymorphisms (SNPs) in the GD group were detected in the −330 locus of the IL-2 promoter and the −1082 locus of the IL-10 promoter. In addition, the results indicated that the relatively high rates of homozygous GG SNPs (IL-2 −330T/G and IL-10 −1082A/G polymorphisms) on the alleles may be associated with the incidence of GD. The serum, mRNA and protein expression levels of IL-2 and IL-10 were significantly increased in GD patients when compared with the levels in the healthy controls. In conclusion, the expression levels and genetic polymorphisms of IL-2 and IL-10 may be potential biomarkers for the incidence of Graves’ disease in the population studied.

Functional interleukin-21 polymorphism is a protective factor of diffuse large B-cell lymphoma

Interleukin-21 (IL-21) is a recently discovered cytokine and plays critical roles in antitumor immune responses. Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma. In this study, we investigated the association between IL-21 genetic polymorphisms and the susceptibility to DLBCL, and the possible functions of these polymorphisms. Two IL-21 polymorphisms, rs907715G/A and rs2221903A/G, were examined in 212 DLBCL patients and 232 healthy controls. Data showed that percentages of rs907715GA and AA genotypes were significantly lower in patients than in controls (odds ratio [OR]=0.60, 95% confidence interval [CI]: 0.40-0.90, p=0.014; OR=0.31, 95% CI: 0.17-0.56, p<0.001, respectively). Frequency of the rs2221903A/G polymorphism did not reveal any significant differences between patients and healthy donors. Further analyses demonstrated a significantly decreased number of rs907715AA genotype in patients with advanced Ann Arbor stages (III+IV). Moreover, we investigated the correlation between IL-21 polymorphisms and serum level of IL-21. Results showed that subjects carrying rs907715AA had significantly increased level of IL-21 than those with GG genotype or GA genotype. These data suggest that rs907715G/A polymorphism may act as a protective factor of DLBCL and might affect the serum level of IL-21.

Polymorphism in interleukin 21 gene is associated with decreased susceptibility to diffuse large B cell lymphoma

Interleukin 21 (IL-21) plays a key role in innate and adaptive immunity. Polymorphisms in IL-21 gene may be greatly involved in various diseases. The aim of the study was to investigate the association between IL-21 genetic polymorphisms and the susceptibility to diffuse large B cell lymphoma (DLBCL). IL-21 -2498G/A and +78A/G polymorphisms were examined in 221 DLBCL patients and 243 healthy controls. We found that distributions of -2498GA genotype and -2498AA genotype were clearly decreased in DLBCL cases compared to healthy donors (odds ratio [OR] = 0.71, 95% confidence interval [CI] = 0.43-0.92, P = 0.021; OR = 0.36, 95 % CI = 0.15-0.48, P < 0.001; data were adjusted for age and sex). Stratification analyses revealed that patients with advanced Ann Arbor stages (III+IV) had further decreased percentage of -2498AA genotype than those with primary stages (OR = 0.31, 95% CI = 0.13-0.87, P = 0.023; data were adjusted for age and sex). In addition, we evaluated the possible effect of IL-21 polymorphisms on gene expression by examining serum level of IL-21 in patients and controls. Data revealed that subjects carrying -2498AA genotype had significantly higher serum level of IL-21 than those with GG genotype or GA genotype. These data suggest that IL-21 -2498G/A polymorphism is associated with decreased susceptibility to DLBCL and may increase serum level of IL-21.

Association of IL-21 polymorphisms (rs907715, rs2221903) with susceptibility to multiple autoimmune diseases: a meta-analysis

OBJECTIVES

Previous published data indicated that interleukin-21 (IL-21) gene polymorphisms were shown to associate with multiple autoimmune diseases (ADs), but the results remain inconclusive. The aim of this study was to perform a meta-analysis to assess the overall association between IL-21 gene polymorphisms (rs907715, rs2221903) and multiple ADs.

METHODS

All eligible case-control studies were searched in the PubMed and Embase database. A meta-analysis was conducted on the association between the IL-21 gene variants and ADs using: (1) allelic contrast, (2) homozygote contrast, (3) the recessive model, and (4) the dominant model.

RESULTS

A total of 12 relevant studies including 10,535 cases and 19,356 controls were enrolled in this meta-analysis. A significant association between IL-21 rs907715 gene polymorphism and AD was found under the allelic (OR: 1.102, 95% CI: 1.057-1.149, p = 0.000), homozygous (OR: 1.220, 95% CI: 1.089-1.368, p = 0.001), dominant (OR: 1.160, 95% CI: 1.027-1.309, p = 0.017), and recessive genetic model (OR: 1.119, 95% CI: 1.055-1.187, p = 0.000) among Caucasian populations. However, there was no significant association between IL-21 rs2221903 polymorphism and AD in different genetic models.

CONCLUSIONS

Data from the present study suggest that the IL-21 rs907715 polymorphism might be associated with multiple ADs susceptibility in Caucasians. Especially, the allele G of intronic rs907715 in IL-21 confers increased risk of ADs.

Association between STAT4 gene polymorphisms and autoimmune thyroid diseases in a Chinese population

The STAT4 gene encodes a transcriptional factor that transmits signals induced by several key cytokines which play important roles in the development of autoimmune diseases. The aim of this study was to explore the association of STAT4 polymorphism with Graves’ disease (GD) and Hashimoto’s thyroiditis (HT). A total of 1048 autoimmune thyroid diseases (AITDs) patients (693 with GD and 355 with HT) and 909 age- and gender-matched controls were examined. STAT4 polymorphisms (rs7574865/rs10181656/rs7572482) were genotyped by multiplex polymerase chain reaction (PCR) and ligase detection reaction (LDR). The results indicated that the frequencies of rs7574865 genotypes in patients with GD differed significantly from the controls (p = 0.028), the T allele frequency of GD patients was also significantly higher than the controls (p = 0.020). The genotypes of rs10181656 differed significantly in GD patients from controls (p = 0.012); G allele frequencies were significantly higher in AITD patients than the controls (p = 0.014 and 0.031, respectively). The frequencies of haplotype GC with GD and HT patients were significantly lower than their controls (p = 0.015 and 0.030, respectively). In contrast, the frequencies of haplotype TG with GD and HT patients were significantly higher than their controls (p = 0.016 and 0.048, respectively). These findings strongly suggest that STAT4 rs7574865/rs10181656 polymorphisms increase the risk of AITD in a Chinese population.

Current concepts in the molecular pathogenesis of thyroid-associated ophthalmopathy

Graves' disease (GD) is a common autoimmune condition. At its core, stimulatory autoantibodies are directed at the thyroid-stimulating hormone receptor (TSHR), resulting in dysregulated thyroid gland activity and growth. Closely associated with GD is the ocular condition known as thyroid-associated ophthalmopathy (TAO). The pathogenesis of TAO remains enigmatic as do the connections between the thyroid and orbit. This review highlights the putative molecular mechanisms involved in TAO and suggests how these insights provide future directions for identifying therapeutic targets. Genetic, epigenetic, and environmental factors have been suggested as contributory to the development of GD and TAO. Thyroid-stimulating hormone receptor and insulin-like growth factor receptor (IGF-1R) are expressed at higher levels in the orbital connective tissue from individuals with TAO than in healthy tissues. Together, they form a functional complex and appear to promote signaling relevant to GD and TAO. Orbital fibroblasts display an array of cell surface receptors and generate a host of inflammatory molecules that may participate in T and B cell infiltration. Recently, a population of orbital fibroblasts has been putatively traced to bone marrow-derived progenitor cells, known as fibrocytes, as they express CD45, CD34, CXCR4, collagen I, functional TSHR, and thyroglobulin (Tg). Fibrocytes become more numerous in GD and we believe traffic to the orbit in TAO. Numerous attempts at developing complete animal models of GD have been largely unsuccessful, because they lack fidelity with the ocular manifestations seen in TAO. Better understanding of the pathogenesis of TAO and development of improved animal models should greatly accelerate the identification of medical therapy for this vexing medical problem.