Serum concentrations of HGF and IL-8 in patients with active Graves' orbitopathy before and after methylprednisolone therapy

Elevated expression of interleukin-27, IL-35, and decreased IL-12 in patients with thyroid-associated ophthalmopathy

PURPOSE

Thyroid-associated ophthalmopathy (TAO) is a chronic autoimmune disease. The interleukin-12 (IL-12) family includes IL-12, IL-23, IL-27, and IL-35, all of which play important roles in autoimmunity. Thus far, the relationship between IL-12, IL-27, and IL-35 and the TAO has not been evaluated.

METHODS

Seventy-five serum samples from patients with TAO were collected. Serum samples from 90 healthy controls (HC), 55 patients with Graves' disease (GD), 38 patients with uveitis (UV), 17 patients with Sjogren's syndrome (SS), and 65 patients with rheumatoid arthritis (RA) were collected as controls. The associations between IL-27, IL-35, IL-12, and other clinical parameters were analyzed.

RESULTS

Elevated serum levels of IL-27/IL-35 and decreased serum IL-12 levels were observed in TAO patients compared to those in HC (p < 0.001). For HC, we observed good diagnostic ability to predict TAO (area under the curve = 0.74, 0.78, and 0.78, for IL-27, IL-35, and IL-12, respectively). For other autoimmune diseases, IL-27, IL-35, and IL-12 had the ability to discriminate between UV, RA, and SS (area under the curve = 0.80, 0.83, and 0.85 for IL-27; 0.52, 0.69, and 0.67 for IL-35). The positive detection rates of IL-12 were significantly lower in the TAO group than in the UV and RA groups (p = 0.002, 0.01).

CONCLUSION

IL-12, IL-27, and IL-35 have the potential as biomarkers for TAO.

Novel inflammatory biomarkers in thyroid eye disease

PURPOSE

The aim of this study is to identify biochemical inflammatory markers predicting the presence or risk of developing thyroid eye disease (TED) in patients with Graves' disease (GD).

METHODS

Patients with GD (n = 100, 77 females) were included from the National Norwegian Registry of Organ-Specific Diseases. Serum samples were analysed for 92 different inflammatory biomarkers using the proximity extension assay. Biomarker levels were compared between groups of patients with and without TED and healthy subjects (HS) (n = 120).

RESULTS

TED was found in 36 of 100 GD patients. Significant (P < 0.05) differences in the levels of 52 inflammatory biomarkers were found when GD patients and HS were compared (42 elevated and 10 decreased). Out of the 42 elevated biomarkers, a significantly higher serum level of interleukin-6 (IL6) (P = 0.022) and macrophage colony-stimulating factor (CSF1) (P = 0.015) were found in patients with TED compared to patients without TED. Patients with severe TED also had significantly elevated levels of Fms-related tyrosine kinase 3 ligand (FLT3LG) (P = 0.009). Furthermore, fibroblast growth factor 21 (FGF21) was significantly increased (P = 0.008) in patients with GD who had no signs of TED at baseline but developed TED later.

CONCLUSION

We demonstrate an immunologic fingerprint of GD, as serum levels of several inflammation-related proteins were elevated, while others were decreased. Distinctly increased levels of IL6, CSF1, FLT3LG, and FGF21 were observed in TED, suggesting that these inflammatory proteins could be important in the pathogenesis, and therefore potential new biomarkers for clinical use.

The role of oxidative stress in the pathogenesis of Graves’ orbitopathy

Graves’ disease (GD) is a chronic autoimmune condition in which the anti-thyroid stimulating hormone receptor antibodies (TRAb) activate the thyrotropin receptor (TSHR) located on thyrocytes, leading to excessive thyroid hormone production. TSHR is also expressed in extrathyroidal tissues, in particular, within the orbit. The serum levels of TRAb correlate with the severity and activity of thyroid orbitopathy (TO). TO is the most common extrathyroidal manifestation of GD. It is an autoimmune inflammation of orbital tissues, that is, extraocular muscles, orbital adipose tissue or a lacrimal gland. Increased orbital fibroblast and adipocyte proliferation, overproduction of glycosaminoglycans, as well as extraocular muscle oedema, result in increased orbital tissue volume and trigger the onset of TO symptoms. The pathophysiology of TO is complex and has not been fully unexplained to date. Orbital fibroblasts show expression of the TSHR, which is the main target of autoimmunity. It has been hypothesised that T-cell activation induced by orbital receptor stimulation by the target antibody results in orbital tissue infiltration, triggering a cascade of events which leads to the production of cytokines, growth factors and reactive oxygen species (ROS). ROS cause damage to many components of the cell: the cell membrane through the peroxidation of lipids and proteins leading to a loss of their function and enzymatic activity. Oxidative stress leads to the activation of the antioxidant system, which operates through two mechanisms: enzymatic and non-enzymatic. Assessment of the concentration of oxidative stress markers and the concentration or activity of anti-oxidative system parameters enables the evaluation of oxidative stress severity, which in the future may be utilized to assess treatment efficacy and prognosis in patients with active OT.

Association between Clinical Activity Score and Serum Interleukin-6, Interleukin-8 and Interleukin-10 during Systemic Glucocorticoid Treatment for Active Moderate-to-Severe Graves' Orbitopathy

Purpose: Some interleukins (ILs) play an important role in Graves' orbitopathy (GO) pathogenesis. We aimed to compare serum IL-6, IL-8 and IL-10 in GO patients, patients with Graves' disease (GD) without GO and healthy controls (HC); to follow IL changes during glucocorticoid (GC) treatment for GO; to examine associations between ILs and Clinical Activity Score (CAS).Materials and Methods: Thirty-one patients with active moderate-to-severe GO (GO⁽⁺⁾ group), 30 patients with GD without GO (GO^(-) group) and 30 HC were enrolled. At baseline, ILs were measured in all groups, CAS was evaluated in GO⁽⁺⁾ patients, who were then treated with systemic GCs for 12 weeks. ILs and CAS were reassessed after the first week of treatment (W2) and at the end of the therapy (W12).Results: At baseline, IL-6 was significantly higher in GO⁽⁺⁾ and GO^(-) patients, IL-8 - higher in GO^(-) patients and IL-10 - lower in GO⁽⁺⁾ patients compared to HC. Baseline ILs did not correlate with CAS. At W2, all ILs and CAS decreased significantly. At W12, CAS decreased further, IL-6 remained low, IL-8 and IL-10 returned to baseline. CAS reduction correlated positively with IL-6 reduction at W12 (ρ = 0.38, p = .04).GO⁽⁺⁾ patients with overall CAS reduction≥2 had higher baseline IL-6 (3.4 vs 2.6 pg/ml, p = .15), smaller IL-10 reduction at W2 (10.5 vs 18.2%, p = .09), lower IL-6 (1.4 vs 2.4 pg/ml, p < .01) and higher IL-6 reduction at W12 (48.6 vs 21.4%, p = .01) compared to patients with CAS reduction<2. Logistic regression analysis confirmed that overall CAS reduction≥2 was associated with higher baseline IL-6, lower IL-6 at W12 and smaller IL-10 reduction at W2 (R² = 0.66).Conclusions: Higher baseline IL-6, lower IL-6 at W12 and smaller IL-10 reduction at W2 were associated with higher probability of significant overall CAS reduction. IL-6 might be a potential additional marker for assessing disease activity.

The Effect of Immunosuppression on Selected Antioxidant Parameters in Patients with Graves' Disease with Active Thyroid-Associated Orbitopathy

BACKGROUND AND STUDY AIMS

Thyroid-associated orbitopathy, the most common extrathyroidal manifestation of Graves' disease, is an autoimmune inflammation of orbital soft tissue. We report the study assessing the effect of immunosuppressive treatment with methylprednisolone on selected antioxidant parameters in patients with Graves' disease with active thyroid-associated orbitopathy.

PATIENTS AND METHODS

Activity and serum levels of selected antioxidant parameters as well as lipid peroxidation products were determined in a group of 56 patients with active thyroid-associated orbitopathy at three time-points: at baseline, after the discontinuation of intravenous methylprednisolone treatment and at 3 months after the discontinuation of additional oral methylprednisolone treatment. A control group consisted of 20 healthy age- and sex-matched volunteers.

RESULTS

We found an increased activity of superoxide dismutase and glutathione peroxidase and increased serum levels of uric acid, malondialdehyde and conjugated dienes, as well as a reduced activity of paraoxonase-1 and reduced serum vitamin C level in the study group at baseline. Systemic intravenous and oral methylprednisolone therapy led to normalization of activity and concentration of the most studied parameters.

CONCLUSION

Results of our study confirmed that oxidative stress is one of the factors involved in the pathogenesis of thyroid-associated orbitopathy and the methyloprednisolone treatment is effective in reducing both clinical symptoms and oxidative stress in patients with this disease.

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.

Integrative Analysis of Proteomics and DNA Methylation in Orbital Fibroblasts From Graves' Ophthalmopathy

BACKGROUND

Graves' ophthalmopathy (GO) is a frequent extrathyroidal complication of Graves' hyperthyroidism. Orbital fibroblasts contribute to both orbital tissue inflammation and remodeling in GO, and as such are crucial cellular elements in active GO and inactive GO. However, so far it is largely unknown whether GO disease progression is associated with functional reprogramming of the orbital fibroblast effector function. Therefore, the aim of this study was to compare both the proteome and global DNA methylation patterns between orbital fibroblasts isolated from active GO, inactive GO and healthy controls.

METHODS

Orbital fibroblasts from inactive GO (n=5), active GO (n=4) and controls (n=5) were cultured and total protein and DNA was isolated. Labelled and fractionated proteins were analyzed with a liquid chromatography tandem-mass spectrometer (LC-MS/MS). Data are available via ProteomeXchange with identifier PXD022257. Furthermore, bisulphite-treated DNA was analyzed for methylation pattern with the Illumina Infinium Human Methylation 450K beadchip. In addition, RNA was isolated from the orbital fibroblasts for real-time quantitative (RQ)-PCR. Network and pathway analyses were performed.

RESULTS

Orbital fibroblasts from active GO displayed overexpression of proteins that are typically involved in inflammation, cellular proliferation, hyaluronan synthesis and adipogenesis, while various proteins associated with extracellular matrix (ECM) biology and fibrotic disease, were typically overexpressed in orbital fibroblasts from inactive GO. Moreover, orbital fibroblasts from active GO displayed hypermethylation of genes that linked to inflammation and hypomethylated genes that linked to adipogenesis and autoimmunity. Further analysis revealed networks that contained molecules to which both hypermethylated and hypomethylated genes were linked, including NF-κB, ERK1/2, Alp, RNA polymerase II, Akt and IFNα. In addition, NF-κB, Akt and IFNα were also identified in networks that were derived from the differentially expressed proteins. Generally, poor correlation between protein expression, DNA methylation and mRNA expression was observed.

CONCLUSIONS

Both the proteomics and DNA methylation data support that orbital fibroblasts from active GO are involved in inflammation, adipogenesis, and glycosaminoglycan production, while orbital fibroblasts from inactive disease are more skewed towards an active role in extracellular matrix remodeling. This switch in orbital fibroblast effector function may have therapeutic implications and further studies into the underlying mechanism are thus warranted.

BIOINFORMATIC ANALYSIS IDENTIFIES POTENTIALLY KEY DIFFERENTIALLY EXPRESSED GENES AND PATHWAYS IN ORBITAL ADIPOSE TISSUES OF PATIENTS WITH THYROID EYE DISEASE

CONTEXT

Thyroid eye disease (TED), an orbital inflammatory status, generally occurred in Graves' disease.

OBJECTIVE

This study aimed to acquire further insight into molecular mechanisms of TED, especially several key involved genes and pathways.

DESIGN

The microarray dataset GSE58331 including expression data for orbital adipose tissue samples, isolated from TED patients and normal controls, was downloaded from a publicly accessible Gene Expression Omnibus database. Differentially expressed genes (DEGs) were identified from 23 adipose tissues of TED patients versus 20 samples from normal controls.

SUBJECTS AND METHODS

A protein-protein interaction network of DEGs was constructed by using Search Tool for the Retrieval of Interacting Genes and Cytoscape 3.6.0. Several hub genes/proteins were extracted from the protein-protein interaction network based on connectivity degree. Furthermore, we used the iRegulon plugin of Cytoscape3.6.0 to predict the transcription factors (TFs).

RESULTS

A total of 678 DEGs (538 up- and 140 down-regulated genes) were identified in TED patients. Proopiomelanocortin (POMC), interleukin 2 (IL-2), G protein subunit gamma 3 (GNG3), CXC motif chemokine receptor 4 (CXCR4), toll like receptor 4 (TLR4), colony stimulating factor 1 receptor (CSF1R), lysophosphatidic acid receptor 3 (LPAR3), CXC motif chemokine ligand-8 (CXCL8), etc., were considered as the hub genes among the DEGs. There were 6 TFs predicted to be differentially expressed in regulating the DEGs related to TED. A total of 71 DEGs had been reported to be associated with TED in the Comparative Toxicogenomics Database.

CONCLUSIONS

Through this analysis, we have identified plenty of potential biomarkers and pathways which may have an important role in the pathogenesis of TED. However, these findings require verification by more detailed future experimental studies.

Differential profiling of lacrimal cytokines in patients suffering from thyroid-associated orbitopathy

The aim was to investigate the levels of cytokines and soluble IL-6R in the tears of patients with thyroid-associated orbitopathy (TAO) disease. Schirmer’s test was adopted to collect tears from TAO patients (N = 20, 17 women, mean age (±SD): 46.0 years (±13.4)) and healthy subjects (N = 18, 10 women, 45.4 years (±18.7)). Lacrimal cytokines and soluble IL-6R (sIL-6R) were measured using a 10-plex panel (Meso Scale Discovery Company) and Invitrogen Human sIL-6R Elisa kit, respectively. Tear levels of IL-10, IL-12p70, IL-13, IL-6 and TNF-α appeared significantly higher in TAO patients than in healthy subjects. Interestingly, IL-10, IL-12p70 and IL-8 levels increased in tears whatever the form of TAO whereas IL-13, IL-6 and TNF-α levels were significantly elevated in inflammatory TAO patients, meaning with a clinical score activity (CAS) ≥ 3, compared to controls. Furthermore, only 3 cytokines were strongly positively correlated with CAS (IL-13 Spearman coeff. r: 0.703, p = 0.0005; IL-6 r: 0.553, p = 0.011; IL-8 r: 0.618, p = 0.004, respectively). Finally, tobacco use disturbed the levels of several cytokines, especially in patient suffering of TAO. The differential profile of lacrimal cytokines could be useful for the diagnosis of TAO patients. Nevertheless, the tobacco use of these patients should be taken into account in the interpretation of the cytokine levels.

Thyroid-Associated Orbitopathy and Biomarkers: Where We Are and What We Can Hope for the Future

Background

Thyroid-associated orbitopathy (TAO) is the most common autoimmune disease of the orbit. It occurs more often in patients presenting with hyperthyroidism, characteristic of Graves' disease, but may be associated with hypothyroidism or euthyroidism. The diagnosis of TAO is based on clinical orbital features, radiological criteria, and the potential association with thyroid disease. To date, there is no specific marker of the orbital disease, making the early diagnosis difficult, especially if the orbital involvement precedes the thyroid dysfunction.

Summary

The goal of this review is to present the disease and combine the available data in the literature concerning investigation of TAO biomarkers.

Conclusions

Despite the progress done in the understanding of TAO disease, some important pieces are still missing. Typically, for the future, major efforts have to be done in the discovery of new biomarkers, validation of the suspected candidates on multicenter cohorts with standardized methodologies, and establishment of their clinical performances on the specific clinical application fields in order to improve not only the management of the TAO patients but also the therapeutic options and follow-up.

Changes of Nicotinamide Phosphoribosyltransferase Expressions in Thyroid Glands of Patients with Different Thyroid Pathologies

Purpose

Our aim was to analyze NAMPT expression in thyroid tissue derived from patients with Graves' disease with (GD) and without (GO) orbitopathy, patients with toxic nodular goiters (TNG) and thyroid cancers (TC), and healthy controls.

Methods

153 thyroid tissue samples of consecutive patients who underwent thyroidectomy were collected. Previous therapy with steroids was an exclusion criterion. We collected clinicopathological data of all subjects and we assessed NAMPT expression using qPCR.

Results

We found the highest NAMPT expression in the thyroids of patients with GO (n = 20) and cancers (n = 40). Also, there was statistically significant NAMPT overexpression in patients with TNG (n = 30). Relatively low NAMPT expression was found in GD patients (n = 21) and in the control group (n = 39). In one-way ANCOVA, we confirmed that NAMPT expression differs between subgroups and that it is not influenced by age, BMI, or sex of patients.

Conclusions

Reported alteration of NAMPT expression might suggest its involvement in thyroid pathologies. Observed NAMPT overexpression in patients with GO and its relatively low levels in thyroids of patients with GD without eye changes do not confirm causal relationship between NAMPT level and orbitopathy, but this needs further investigation.

Nicotinamide phosphoribosyltransferase leukocyte overexpression in Graves' opthalmopathy

To investigate the role of NAMPT/visfatin in euthyroid patients with Graves' disease without (GD) and with Graves' ophthalmopathy (GO), we analyzed NAMPT leukocyte expression and its serum concentration. This was a single-center, cross-sectional study with consecutive enrollment. In total, 149 patients diagnosed with Graves' disease were enrolled in the study. We excluded subjects with hyper- or hypothyroidism, diabetes mellitus, other autoimmune disorders, active neoplastic disease, and infection. The control group was recruited among healthy volunteers adjusted for age, sex, and BMI with normal thyroid function and negative thyroid antibodies. Serum levels of visfatin, TSH, FT4, FT3, antibodies against TSH receptor (TRAb), antithyroperoxidase antibodies, antithyroglobulin antibodies, fasting glucose, and insulin were measured. NAMPT mRNA leukocyte expression was assessed using RT-qPCR. NAMPT/visfatin serum concentration was higher in GD (n = 44) and GO (n = 49) patients than in the control group (n = 40) (p = 0.0275). NAMPT leukocyte expression was higher in patients with GO (n = 30) than in GD patients (n = 27) and the control group (n = 29) (p < 0.0001). Simple linear regression analysis revealed that NAMPT/visfatin serum concentration was significantly associated with GD (β = 1.5723; p = 0.021). When NAMPT leukocyte expression was used as a dependent variable, simple regression analysis found association with TRAb, fasting insulin level, HOMA-IR, GD, and GO. In the stepwise multiple regression analysis, we confirmed the association between higher serum NAMPT/visfatin level and GD (coefficient = 1.5723; p = 0.0212), and between NAMPT leukocyte expression and GO (coefficient = 2.4619; p = 0.0001) and TRAb (coefficient = 0.08742; p = 0.006). Increased NAMPT leukocyte expression in patients with GO might suggest a presently undefined role in the pathogenesis of GO.

Histamine induces NF-κB controlled cytokine secretion by orbital fibroblasts via histamine receptor type-1

Mast cells and their products are likely to be involved in regulating orbital fibroblast activity in Graves' Ophthalmopathy (GO). Histamine is abundantly present in granules of mast cells and is released upon mast cell activation. However, the effect of histamine on orbital fibroblasts has not been examined so far. Orbital tissues from GO patients and controls were analyzed for the presence of mast cells using toluidine blue staining and immunohistochemical detection of CD117 (stem cell factor receptor). Orbital fibroblasts were cultured from GO patients and healthy controls, stimulated with histamine and cytokines (IL-6, IL-8, CCL2, CCL5, CCL7, CXCL10 and CXCL11) were measured in culture supernatants. Also hyaluronan levels were measured in culture supernatants and hyaluronan synthase (HAS) and hyaluronidase (HYAL) gene expression levels were determined. In addition, histamine receptor subtype gene expression levels were examined as well as the effect of the histamine receptor-1 (HRH1) antagonist loratadine and NF-κB inhibitor SC-514 on histamine-induced cytokine production. Mast cell numbers were increased in GO orbital tissues. Histamine stimulated the production of IL-6, IL-8 and CCL2 by orbital fibroblasts, while it had no effect on the production of CCL5, CCL7, CXCL10, CXCL11 and hyaluronan. Orbital fibroblasts expressed HRH1 and loratadine and SC-514 both blocked histamine-induced IL-6, IL-8 and CCL2 production by orbital fibroblasts. In conclusion, this study demonstrates that histamine can induce the production of NF-κB controlled-cytokines by orbital fibroblasts, which supports a role for mast cells in GO.

Orbital inflammation: Corticosteroids first

Orbital inflammation is common, and may affect all ages and both genders. By combining a thorough history and physical examination, targeted ancillary laboratory testing and imaging, a presumptive diagnosis can often be made. Nearly all orbital inflammatory pathology can be empirically treated with corticosteroids, thus obviating the need for histopathologic diagnosis prior to initiation of therapy. In addition, corticosteroids may be effective in treating concurrent systemic disease. Unless orbital inflammation responds atypically or incompletely, patients can be spared biopsy.