Variants of Interleukin-22 Gene Confer Predisposition to Autoimmune Thyroid Disease

MBL2 polymorphism may be a protective factor of autoimmune thyroid disease susceptibility

Genetic susceptibility is an essential pathogenetic mechanism in autoimmune thyroid disease (AITD). MBL2 gene polymorphisms have been shown to play a vital role in the pathogenesis of multiple autoimmune disorders, but its contribution to AITD is unclear. The aim of this study was to assess the linkage between MBL2 gene polymorphisms and AITD susceptibility in a Chinese Han population. One thousand seven hundred sixty seven subjects consisting of 965 AITD patients and 802 controls from a Chinese Han population were enrolled in the case-control study. Four common single-nucleotide polymorphisms (SNPs) in the MBL2 gene were tested using high-throughput sequencing technology for sequence-based SNP genotyping. The allele and genotype distribution results showed that the minor alleles of rs198266, rs10824793, and rs4935046 were significantly lower in Hashimoto's thyroiditis (HT) patients than in healthy controls. In further genetic model analysis, the dominant models of rs1982266, rs10824793, and rs4935046 for MBL2 in the AITD group exhibited a lower risk of morbidity. Finally, we discovered that haplotype AAGC was associated with Graves' disease (GD), while AGC was associated with HT. Our study provides strong evidence for a genetic correlation between MBL2 and AITD, and the polymorphism of the MBL2 gene may be a protective factor for AITD, especially for HT. These findings can advance our understanding of the etiology of AITD, as well as provide guidance for prevention and intervention toward AITD.

Identification of genetic variants of the IL-22 gene in association with an altered risk of COPD susceptibility

The incidence of chronic obstructive pulmonary disease (COPD) is related to the interaction between environmental exposure and genetic factors. Far more than 15% of smokers eventually develop COPD. In addition to smoking, genetic susceptibility may be another factor in the development of COPD. IL-22 and its receptors are increased in human and experimental COPD and contribute to pathogenesis. Here, we conducted a case-control study to evaluate the association between IL-22 tag-single nucleotide polymorphisms (SNPs) and COPD risk. Four tag-SNPs (rs2227478, rs2227481, rs2227484 and rs2227485) were identified according to linkage disequilibrium (LD) analysis in 30 healthy controls. A total of 513 COPD cases and 504 controls were recruited to perform an association study between these four tag-SNPs and COPD risk. We found that the "C" allele of rs2227478T>C and the "T" allele of rs2227481C>T were obviously related to decreased COPD susceptibility. Genetic model analysis showed that rs2227478T>C and rs2227481C>T were significantly associated with a decreased risk of COPD under dominant models after adjusting for the above factors. In the recessive model, rs2227485T>C was obviously associated with decreased COPD risk. Our data showed that only rs2227485T>C was associated with a decreased COPD risk after Bonferroni correction. The eQTL analysis showed that rs2227485T>C was significantly associated with IL-22 expression. The pGL4-rs2227485-C gene reporter had a higher promoter activity than pGL4-rs2227485-T. In our study, rs2227485T>C, located in the promoter region of IL-22, was associated with a decreased risk of COPD and increased IL-22 promoter activity, suggesting that this variant might modulate COPD susceptibility.

Interleukine-22 gene variants are associated with susceptibility to visceral leishmaniasis

Visceral leishmaniasis (VL) is an infectious disease caused by an intracellular protozoan belonging to Leishmania species. Interleukin (IL)-22 plays an important role in inflammatory response, chemotaxis, regulation of cellular proliferation and tissue repair. Considering the role of IL-22 in control of leishmaniasis and the effect of its single nucleotide polymorphisms (SNPs) on respective function and production, this study aimed to investigate the probable association of IL-22 SNPs with VL. The study was carried out on 110 patients with VL, 102 healthy individuals with negative leishmanin skin test (negative control group (NCG)), and 144 healthy individuals with positive leishmanin skin test (LSTPG). Four SNPs in IL-22 including rs2227501, rs2227503, rs2227513 and rs1026786 were analyzed by polymerase chain reaction-restricted fragment length polymorphism (PCR- RFLP) in the study groups. The frequency of A allele and AA genotype at rs1026786 were significantly higher in the LSTPG group than in the patients (P = 0.013 and P = 0.001, respectively). Conversely, the frequency of AG genotype was significantly higher in the patients and the NCG than in the LSTPG group (P = 0.0001 and P = 0.002, respectively). For rs2227503, the frequency of AG genotype was significantly higher in the LSTPG group than in the NCG (P = 0.025). The haplotype TGAA frequency was significantly higher in the NCG, compared to patients and LSTPG group (P = 0.004 and P = 0.023, respectively). The frequencies of haplotypes TAAG and TGAG were significantly higher in the patients than in the LSTPG group (P = 0.046 and P = 0.014, respectively). The TAAA/TAAG frequency was significantly higher in the patients than in the LSTPG group (P = 0.013). Inheritance of rs1026786 A allele and AA genotype of IL-22 could be a possible protective factor against VL, whereas the inheritance of the haplotypes TAAG and TGAG may predispose Iranian population to the disease.

Evaluation of interleukin-29 in autoimmune and inflammatory thyroid diseases

OBJECTIVE

Interleukins play an important role in the development of autoimmune disorders. The aim of this study was to compare the concentration of interleukin-29 (IL-29) between healthy controls (CS) and patients with selected thyroid disorders: Graves' disease (GD), Hashimoto's thyroiditis (HT) and subacute thyroiditis (SAT).

DESIGN AND METHODS

The following parameters were examined in the group of 95 individuals (45 with GD, 22 with HT, 28 with SAT) and 72 CS: thyroid hormones and autoantibodies, inflammatory markers and the concentration of IL-29 in serum.

RESULTS

The concentration of IL-29 in the GD subgroup was higher than that in the CS subgroup [264.0 (62.5-1018.0) vs. 62.5 (62.5-217.0) pg/mL, P = .001]. We found no differences in IL-29 concentrations between the CS and HT or SAT subgroups. Multivariable linear regression analysis indicated that IL-29 was a statistically significant independent predictor of GD presence (r = 0.24; P = .003) after adjustment for TRAb (R2  = 0.45; P < .001). The ROC analysis of IL-29 at GD diagnosis revealed an IL-29 cut-off of 123 pg/mL (sensitivity: 0.689 and specificity: 0.625) as the best value, which significantly indicated the presence of GD [area under the ROC curve (AUC): 0.676; 95% confidence interval (CI): 0.574-0.778, P < .001].

CONCLUSION

This is the first study to demonstrate elevated IL-29 serum levels in patients with GD. Our results suggest that IL-29 might be engaged in one of the pathogenetic pathways of GD, but no HT and SAT. Future studies are required to evaluate the potential of the protein as a therapeutic target in GD.

Innate and Adaptive Gene Single Nucleotide Polymorphisms Associated With Susceptibility of Severe Inflammatory Complications in Acanthamoeba Keratitis

Purpose

Over a third of patients with Acanthamoeba keratitis (AK) experience severe inflammatory complications (SICs). This study aimed to determine if some contact lens (CL) wearers with AK were predisposed to SICs due to variations in key immune genes.

Methods

CL wearers with AK who attended Moorfields Eye Hospital were recruited prospectively between April 2013 and October 2014. SICs were defined as scleritis and/or stromal ring infiltrate. Genomic DNA was processed with an Illumina Low Input Custom Amplicon assay of 58 single nucleotide polymorphism (SNP) targets across 18 genes and tested for association in PLINK.

Results

Genomic DNA was obtained and analyzed for 105 cases of AK, 40 (38%) of whom experienced SICs. SNPs in the CXCL8 gene encoding IL-8 was significantly associated with protection from SICs (chr4: rs1126647, odds ratio [OR] = 0.3, P = 0.005, rs2227543, OR = 0.4, P = 0.007, and rs2227307, OR = 0.4, P = 0.02) after adjusting for age, sex, steroids prediagnosis, and herpes simplex keratitis (HSK) misdiagnosis. Two TLR-4 SNPs were associated with increased risk of SICs (chr9: rs4986791 and rs4986790, both OR = 6.9, P = 0.01). Th-17 associated SNPs (chr1: IL-23R rs11209026, chr2: IL-1β rs16944, and chr12: IL-22 rs1179251) were also associated with SICs.

Conclusions

The current study identifies biologically relevant genetic variants in patients with AK with SICs; IL-8 is associated with a strong neutrophil response in the cornea in AK, TLR-4 is important in early AK disease, and Th-17 genes are associated with adaptive immune responses to AK in animal models. Genetic screening of patients with AK to predict severity is viable and this would be expected to assist disease management.

METTL3 Is Involved in the Development of Graves' Disease by Inducing SOCS mRNA m6A Modification

OBJECTIVE

Epigenetic modifications in RNA are known to play critical roles in cell differentiation through regulating expressions of some key genes including members of the suppressor of cytokine signaling (SOCS) family. The present study aimed to unveil the relationship of SOCS mRNA methylation induced by methyltransferase like 3 (METTL3) with Graves' disease (GD).

METHODS

Differently expressed genes (DEG) in GD tissues were identified using microarray analysis and further validated using CD4⁺ T cell microarray of GD tissues and isolated peripheral blood mononuclear cells (PBMCs). Furthermore, expressions of METTL3 targeted genes were detected using METTL3 knock-down experiment in RAW264.7 cells.

RESULTS

High throughput microarrays revealed that METTL3 and SOCS molecules were aberrantly expressed in thyroid tissues and CD4⁺T cells of GD compared to the controls. Bioinformatic analysis was undertaken by searching databases of found genes of the SOCS family that possessed many mRNA m6A modification loci. METTL3 knock-down experiment revealed that expressions of SOCS family members SOCS1, SOCS2, SOCS4, SOCS5, and SOCS6 were increased after METTL3 knock-down.

CONCLUSIONS

For the first time, the present study revealed the relationship between m6A modification and GD and indicated that METTL3 may be involved in the development of GD by inducing mRNA m6A methylation modification of SOCS family members.

Proteomics Screening of Differentially Expressed Cytokines in Tears of Patients with Graves' Ophthalmopathy

BACKGROUND

The current study aimed at exploring the cytokine profile in the tears of patients with Graves' ophthalmopathy (GO).

METHODS

Tears were sampled from the eyes of 7 patients with active GO and 7 healthy volunteers using filter paper. Then the levels of up to 34 cytokines in the tears of each subject were detected using high-throughput protein microarray technology in line with the introduction.

RESULTS

The results of cytokine protein microarray screening showed that 10 proteins, namely, CD40, CD40 Ligand, GITR, IL-12p70, IL-1 beta, IL-2, IL-21, IL-6, MIP-3 alpha and TRANCE, were overexpressed (with fold change >1.20) and 3 proteins, namely, GM-CSF, IL-1 sRI and IL-13 were downregulated (with fold change < 0.83) in GO patients. In addition, the protein levels of CD40 and CD40 ligand (CD40L) were significantly different between GO patients and healthy controls (P=0.028 and 0.011, respectively). Further Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses of differently expressed proteins showed that these proteins were involved in biological functions including biological processes (positive regulation of cytokine production, JAK-STAT cascade and leukocyte proliferation), molecular functions (cytokine and growth factor receptors binding and cytokine activity), and other important pathways (cytokine-cytokine receptor interaction, JAK-STAT signaling pathway, IL-17 signaling pathway, NF-kappa B signaling pathway, Th17 cell differentiation, and intestinal immune network for IgA production), all of which might be involved in the pathology of GO.

CONCLUSION

Our cytokine protein microarray analysis indicated that several proteins were differentially expressed in GO patients, which provides potential targets for GO prevention.

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

BACKGROUND

The most frequent cause of hyperthyroidism is Graves' disease (GD). Orbitopathy is the most prevalent and recognizable extrathyroidal manifestation of Graves' disease with unrevealed pathogenesis. Interleukin 29 (IL-29) is a relatively newly discovered inflammatory cytokine. Thus, the aim of this study was to evaluate the relationship between IL-29 and Graves' orbitopathy (GO) in euthyroid patients.

METHODS

Thirty-one euthyroid patients with Graves' disease and with active GO [clinical activity score (CAS) ≥ 3/7], seventeen euthyroid patients with GD but without GO, and seventy-two healthy control subjects (CS) matched for age and gender were enrolled in the study. The following parameters were evaluated in every participant: thyroid-related hormones and autoantibodies and inflammatory markers (white blood cells, hsCRP). ELISA assay was applied to measure the concentration of IL-29.

RESULTS

We found higher level of IL-29 in GO group in comparison with CS [165 (133-747) vs. 62 (62-217) pg/mL, p < 0.001]. Furthermore, participants in the subgroup with GD with GO as compared with GD without GO had higher concentration of IL-29 [165 (133-747) vs. 62 (62-558) pg/mL, p = 0.031]. The ROC analysis for IL-29 revealed IL-29 cut-off of 105 pg/mL (sensitivity 1.000 and specificity 0.597) as the best value significantly indicating the presence of GO in GD [area under the ROC curve (AUC): 0.739, 95% confidence interval (CI): 0.646-0.833, p < 0.001].

CONCLUSIONS

The present study revealed for the first time an elevated level of IL-29 in the serum of patients with GD and GO that might suggest its involvement in the pathogenesis of GD ocular complications.

Interleukin-22 Polymorphisms in Plasmodium falciparum-Infected Malaria Patients

Background and Objectives. Malaria infection, caused by Plasmodium falciparum, is the most lethal and frequently culminates in severe clinical complications. Interleukin-22 (IL-22) has been implicated in several diseases including malaria. The objective of this study was to investigate the role of IL-22 gene polymorphisms in P. falciparum infection. Material and Methods. Ten single-nucleotide polymorphisms (SNPs), rs976748, rs1179246, rs2046068, rs1182844, rs2227508, rs2227513, rs2227478, rs2227481, rs2227491, and rs2227483, of IL-22 gene were genotyped through PCR-based assays of 250 P. falciparum infection. IL-22 gene promoter activity.

RESULTS

We found that the rs2227481 TT genotype (odds ratio 0.254, confidence interval = 0.097-0.663, P. P. falciparum infection. P. P. P. P.

CONCLUSION

The study suggests that IL-22 polymorphisms in rs2227481 and rs2227483 could contribute to protection against P. falciparum infection. IL-22 gene promoter activity.

Metabolic Imbalance and Vitamin D Deficiency in Type 1 Diabetes in the Algerian Population

BACKGROUND

We aimed to assess Vitamin D levels in patients with Type 1 Diabetes (T1D) and to investigate the correlation between vitamin D and metabolic imbalance.

MATERIAL AND METHODS

For our study, we selected thirty-one patients with T1D without complications and fifty-seven healthy controls. Diabetic patients were diagnosed using the criteria of the World Health Organization/American Diabetes Association. Vitamin D, Parathyroid Hormone (PTH), insulin and C peptide assay were performed using chimilunescence. Glucose level, lipid profile, glycated haemoglobin (HbA1c) and ionogram were also analysed.

RESULTS

Vitamin D, HbA1c and Gly levels were found to be significant in T1D patients than in controls (P<0.5). However, for PTH, no significant difference was observed (P > 0. 05) and the results show a non-significant difference of total cholesterol potassium, sodium, phosphor and calcium concentration averages.

CONCLUSION

Our results indicate that the deficiency of VD is associated with an increased risk of T1DM in Algerian population.