Alpha-fodrin as a putative autoantigen in Graves' ophthalmopathy

A systematic review of multimodal clinical biomarkers in the management of thyroid eye disease

Thyroid Eye Disease (TED) is an autoimmune disease that affects the extraocular muscles and periorbital fat. It most commonly occurs with Graves' Disease (GD) as an extrathyroidal manifestation, hence, it is also sometimes used interchangeably with Graves' Ophthalmopathy (GO). Well-known autoimmune markers for GD include thyroid stimulating hormone (TSH) receptor antibodies (TSH-R-Ab) which contribute to hyperthyroidism and ocular signs. Currently, apart from radiological investigations, detection of TED is based on clinical signs and symptoms which is largely subjective, with no established biomarkers which could differentiate TED from merely GD. We evaluated a total of 28 studies on potential biomarkers for diagnosis of TED. Articles included were published in English, which investigated clinical markers in tear fluid, orbital adipose-connective tissues, orbital fibroblasts and extraocular muscles, serum, thyroid tissue, as well as imaging biomarkers. Results demonstrated that biomarkers with reported diagnostic power have high sensitivity and specificity for TED, including those using a combination of biomarkers to differentiate between TED and GD, as well as the use of magnetic resonance imaging (MRI). Other biomarkers which were upregulated include cytokines, proinflammatory markers, and acute phase reactants in subjects with TED, which are however, deemed less specific to TED. Further clinical investigations for these biomarkers, scrutinising their specificity and sensitivity on a larger sample of patients, may point towards selection of suitable biomarkers for aiding detection and prognosis of TED in the future.

Effects of glucocorticoid pulse therapy on thyroid function and thyroid antibodies in children with graves' disease

Background

Glucocorticoid treatment is used in children with Graves’ disease (GD) only in cases of exophthalmos. The purpose of this study was to observe the effects of glucocorticoid pulse therapy on thyroid function and thyroid antibodies in children with GD.

Methods

Twenty children who were treated by intravenous methylprednisolone pulse therapy (MPT) followed by oral prednisolone administration and antithyroid drugs were included in the pulse group. Twenty children who were treated with antithyroid drugs alone were included in the control group. Serum concentrations of free triiodothyronine (FT3), free thyroxine (FT4), thyrotropin (TSH), thyroid peroxidase antibodies (TPOAb), thyroglobulin antibodies (TGAb), and thyrotropin receptor antibodies (TRAb) were recorded at baseline and 10 days, 30 days, and 60 days after treatment.

Results

Significant differences in FT3, FT4, TSH, TPOAb, TGAb, and TRAb levels were found in the pulse group and the control group from baseline to follow-up time points (all p < 0.05). On the 30th day, the TRAb level in the pulse group was significantly lower than that in the control group (p = 0.023). However, the level of TRAb rose on the 60th day. For values of TRAb at baseline, 10 days, and 60 days after treatment, there were no significant differences respectively between the pulse group and the control group (all p > 0.05). No significant differences were observed in FT3, FT4, TSH, TPOAb, and TGAb levels between the pulse group and the control group (all p > 0.05).

Conclusions

The results suggested that the effect of intravenous MPT followed by oral prednisolone on TRAb level was temporary in children with GD. Glucocorticoid pulse therapy was not beneficial for the sustained recovery of thyroid function.

Autoantibody against aldehyde dehydrogenase 2 could be a biomarker to monitor progression of Graves' orbitopathy

PURPOSE

This study surveyed the novel autoantigens expressed in the orbital fat tissue of patients with Graves' orbitopathy (GO) and explored the possibility of the autoantibodies against novel autoantigens as biomarkers for GO.

METHODS

We used immuno-proteomic methods to survey novel autoantigens expressed in the orbit fat tissue of GO patients and confirmed by enzyme-linked immunosorbent assay (ELISA).

RESULTS

One protein spot (aldehyde dehydrogenase 2 (ALDH2)) revealed high reactivity with the GO serum than did the healthy control serum and was further verified by ELISA. We found that the plasma anti-ALDH2 antibody level was increased in GO patients compared to healthy control donors. In addition, anti-ALDH2 antibody level was correlated with GO activity classified by clinical activity score(r = 0.588, p < 0.001, using Pearson's correlation).

CONCLUSIONS

These increased levels of anti-ALDH2 antibody in GO serum suggested that ALDH2 could attribute target autoantigen in GO, and anti-ALDH2 autoantibody might serve as a biomarker for GO and help to predict disease activity.

Chemosensitivity of U251 Cells to the Co-treatment of D-Penicillamine and Copper: Possible Implications on Wilson Disease Patients

D-Penicillamine (PA), a copper chelator, and one of the recommended drugs for treatment of Wilson disease (WD) has been reported to worsen the symptoms of patients with neurologic presentations. However, the cause of this paradoxical response has not been fully elucidated and requires further investigations. Accordingly, we have studied the in vitro effect of Copper (Cu) and/or PA treatment on human glioblastoma U251 cells as an in vitro model of Cu cytotoxicity. Treatment of U251 cells with either Cu or PA exerted no significant effect on their morphology, viability or ROS level. In contrast, co-treatment with Cu-PA caused a decrease in viability, altered glutathione and ceruloplasmin expression coupled with marked increase in ROS; depolarization of mitochondrial membrane potential; and an increase in Sub G0 phase; along with alpha-Fodrin proteolysis. These findings along with the absence of LDH release in these assays, suggest that combined Cu-PA exposure induced apoptosis in U251 cells. In addition, pre-/or co-treatment with antioxidants showed a protective effect, with catalase being more effective than N-acetyl cysteine or trolox in restoring viability and reducing generated ROS levels. By comparison, a similar analysis using other cell lines showed that rat PC12 cells were resistant to Cu and/or PA treatment, while the neuroblastoma cell line SH-SY5Y was sensitive to either compound alone, resulting in decreased viability and increased ROS level. Taken together, this study shows that glioblastoma U251 cells provide a model for Cu-PA cytotoxicity mediated by H₂O₂. We postulate that PA oxidation in presence of Cu yields H₂O₂ which in turn permeates the plasma membrane and induced apoptosis. However, other cell lines exhibited different responses to these treatments, potentially providing a model for cell type- specific cytotoxic responses in the nervous system. The sensitivity of different neural and glial cell types to Cu-PA treatment may therefore underlie the neurologic worsening occurring in some PA-treated WD patients. Our results also raise the possibility that the side effects of PA treatment might be reduced or prevented by administering antioxidants.

Update on thyroid-associated Ophthalmopathy with a special emphasis on the ocular surface

Thyroid-associated ophthalmopathy (TAO) is a condition associated with a wide spectrum of ocular changes, usually in the context of the autoimmune syndrome, Graves’ disease. In this topical review, we attempted to provide a roadmap of the recent advances in current understanding the pathogenesis of TAO, important aspects of its clinical presentation, its impact on the ocular surface, describe the tissue abnormalities frequently encountered, and describe how TAO is managed today. We also briefly review how increased understanding of the disease should culminate in improved therapies for patients with this vexing condition.

IgG4-related ocular adnexal disease mimicking thyroid-associated orbitopathy

A 72-year-old man presented with bilateral eyelid swelling and redness. An orbital CT scan showed bilateral proptosis, extraocular muscle enlargement and swollen lacrimal glands, mimicking thyroid-associated orbitopathy (TAO) with Hashimoto's thyroiditis (HT). During the patient's clinical course, spontaneous remission of lung consolidation (35 × 26 mm) was seen. A diagnosis of IgG4-related disease (IgG4-RD) was made based on an elevated serum IgG4 level (1,020 mg/dL; normal, 4-108), predominance of IgG4-positive plasma cells (IgG4/IgG: 35/70 in HPF) in the lacrimal glands and typical features of Mikulicz's disease. This report provides a novel description of this unusual disease entity among HT, TAO and IgG4-RD.

Graves'-like orbitopathy in a patient with chronic autoimmune pancreatitis

BACKGROUND

Graves' orbitopathy is an inflammatory orbital disease that represents the commonest extrathyroidal manifestation of Graves' disease. Autoimmune pancreatitis (AIP) is a rare inflammatory disease characterized by prominent lymphocytic infiltration and fibrosis of the pancreas causing organ dysfunction.

SUMMARY

This report provides the first clinical description of severe Graves'-like orbitopathy occurring in association with AIP. Although there was no clear evidence of autoimmune thyroid disease or dysfunction in our patient, the clinical course of his orbitopathy was related to that of AIP, the relapses of orbital inflammation being temporally coincident.

CONCLUSIONS

Our data suggest that shared autoantigens between the pancreas and the orbit might be responsible for the unusual disorder observed in our patient.

Role of purinergic receptor in alpha fodrin degradation in Par C5 cells

Autoantibodies specific for alpha-fodrin fragments are found in the tissues of persons afflicted with Sjögren's syndrome (SS). However, the mechanism for alpha-fodrin degradation remains elusive. The following experiments utilized Par C5 cells to examine the role of P2X7 receptor (P2X7R) in apoptosis, particularly in the cleavage and release of alpha-fodrin, an apparent SS autoantigen. Five mM ATP stimulation induced apoptotic cell death with a sustained Ca2+ influx, which was mimicked in HEK cells transfected with P2X7R. ATP also induced cleavage of alpha-fodrin mediated by caspase-3 and calpain, releasing alpha-fodrin fragments through membrane blebs. However, both apoptotic cell death and alpha-fodrin cleavage were inhibited in the presence of 300 microM oxidized-ATP (ox-ATP), an irreversible blocker of P2X7R, or in Ca(2+)-free solution. We concluded that P2X7R plays an important role in apoptosis and alpha-fodrin degradation in salivary epithelial cells, providing an important clue elucidating the presence of alpha-fodrin fragments in SS tissues.

Discrimination between Sjögren's and non-Sjögren's sicca syndrome by sialoscintigraphy and antibodies against alpha-fodrin and Ro/La autoantigens

Both Sjögren's syndrome (SS) and non-Sjögren's syndrome (NSS) can present with the sicca symptoms of dry eyes and a dry mouth but they are distinct pathological entities that require diagnostic discrimination. This study included 82 sicca syndrome patients and examined the ability of sialoscintigraphy and antibodies against the autoantigens alpha-fodrin, Ro and La to discriminate between SS and NSS. A total of 30.8% of SS patients compared with 58.8% of NSS patients were alpha-fodrin positive. The prevalence of Ro positivity was 69.4% for SS patients compared with 0% for NSS patients. The prevalence of La positivity was 52.4% for SS compared with 0% for NSS patients. Sialoscintigraphy showed that more NSS patients had grade III salivary gland impairment compared with SS patients (64.7% versus 19.4%). These data suggest that using sialoscintigraphy in combination with measuring the levels of serum alpha-fodrin, Ro and La might be useful for SS and NSS discrimination.

Mutation and citrullination modifies vimentin to a novel autoantigen for rheumatoid arthritis

OBJECTIVE

Modification of antigens represents a trigger for the generation of autoantibodies. In the pathogenesis of rheumatoid arthritis (RA), citrullination of proteins has been shown to be a critical process, and the determination of antibodies against citrullinated antigens has been a diagnostic milestone. We undertook this study to determine whether antibodies to mutated and citrullinated vimentin (MCV) could serve as a diagnostic and prognostic marker for RA.

METHODS

We identified novel isoforms of human MCV in the synovial fluid of RA patients. The significance of these disease-related modifications was investigated by the analysis of autoantibody reactivities. In a group of 1,151 RA patients, the diagnostic significance and the prognostic value of an anti-MCV enzyme-linked immunosorbent assay (ELISA) were compared with that of an anti-cyclic citrullinated peptide (anti-CCP) ELISA.

RESULTS

In RA, sensitivities of 82% and 72% were calculated for the anti-MCV and anti-CCP assays, respectively. The specificity of both assays was comparable (98% and 96%, respectively). In followup analyses of 16 RA patients with moderate disease activity (mean Disease Activity Score in 28 joints [DAS28] of 2.72) and 26 RA patients with active disease (mean DAS28 of 5.07), disease stratification of RA was possible using the anti-MCV assay (P = 0.0084). A significant correlation of anti-MCV antibodies with the DAS28 was documented (r = 0.5334, P = 0.0003), in 42 RA patients (n = 427 antibody determinations at different time points).

CONCLUSION

Antigenic properties of vimentin were determined by mutation and citrullination. Anti-MCV antibodies are a novel diagnostic marker for RA. Furthermore, they may allow monitoring and-if confirmed in even larger series of patients-stratification of disease.

Thyroid disease in Sjögren's syndrome

From 1960 to 2007, an important number of patients with primary Sjögren's syndrome (pSS) along with thyroid disease diagnosed by laboratory data and clinical presentation were reported. The most common thyroid disorder found was autoimmune thyroiditis and the most common hormonal pattern was subclinical hypothyroidism. The coexistence of SS and thyroiditis is frequent and suggests a common genetic or environmental factor predisposition with similar pathogenic mechanisms. pSS was ten times more frequent in patients with autoimmune thyroid disease and autoimmune thyroiditis was nine times more frequent in pSS. Therefore, SS should be studied in patients with thyroid disease and vice versa. Antigens are shared by both thyroid and salivary glands, which could be responsible for the association between both diseases. Immunogenetic studies had suggested that both diseases have a common genetic predisposition. pSS and thyroid disease patients were mostly women with positive antithyroglobulin, antiparietal cell and antithyroid peroxidase antibodies. Thyroid dysfunction is frequent in pSS patients and those prone to develop thyroid disorders are identified by thyroid-related autoantibodies or by rheumatoid factor and anti-Ro/SSA activity. Patients with pSS have an increased tendency to develop other autoimmune diseases. Hypothyroidism was the most common autoimmune disease developed in pSS patients during follow-up of 10.5 years. Lymphomas are also associated with SS and thyroiditis and a 67-fold increased risk for thyroid mucosa-associated lymphoid tissue (MALT) lymphoma and a 44-fold increased risk for parotid lymphoma is being attributed to autoimmune thyroiditis and pSS. It is suggested that immune mechanism deficiency is a causal factor for B cell lymphoma in pSS and autoimmune thyroid disease. Other studies are necessary to clarify the shared pathogenesis mechanism in SS and autoimmune thyroid disease and to understand this fascinating autoimmune association.

Psychosocial morbidity of Graves' orbitopathy

OBJECTIVE

Ocular diseases markedly impair daily function. In Graves' orbitopathy (GO), an associated psychosocial burden is present due to disfiguring proptosis and/or diplopia, signs with significant impact on functional status and well-being. We have therefore surveyed and assessed the psychosocial morbidity of GO.

DESIGN

A prospective controlled study on subjects with GO using internationally validated, self-reporting questionnaires.

PATIENTS

One hundred and two consecutive patients with varying degrees of severity and activity of GO. Measurements Emotional distress, coping styles and quality of life (QoL) were assessed by the Hospital Anxiety and Depression Scale, by a German adaptation of the Ways-of-Coping Checklist, and with the 36-item Short Form, respectively. Stressful events in the 6 months preceding diagnosis were registered with the Life Experience Survey. QoL findings were compared to German reference values, as well as to 102 age- and gender-matched patients, each with type 1 diabetes (insulin-dependent diabetes mellitus, IDDM) and inflammatory bowel disease (IBD), respectively.

RESULTS

Compared to the German reference population, all QoL scales were at a lower rate and were especially decreased in subjects with active and/or severe GO, orbital pain, diplopia and stressful life events. Compared to diabetics, psychosocial scales were considerably reduced in GO (z = -1 vs. 0.1, P < 0.001) and higher scores for depressive coping (2.32 vs. 1.71, P < 0.001) and trivializing (2.37 vs. 1.97, P < 0.006) were noted. In GO, depressive coping and trivializing were negatively correlated with the mental (r = -0.603 and r =-0.411, both P < 0.001) and physical (r = -0.487 and r = -0.354, both P < 0.001) components of QoL. Depressive coping also positively correlated with anxiety (r = 0.636) and depression (r = 0.590), respectively, both P < 0.001. Emotional distress noted in 46 subjects, mostly with active and severe GO, was associated with poor QoL. Anxiety and depression were present in 41 and 24 GO patients, respectively. The number of stressful events positively correlated with the scores of anxiety (r = 0.3335) and depression (r = 0.3178), both P = 0.001. Foremost emotional distress, but also diplopia, stressful events and depressive coping had a major impact on QoL (proportion of variance explained = 13.1%, P < 0.001, multiple regression analysis). More than 75% of the psychosocial impairment in GO (R2= 0.76, P < 0.001) was associated with seven variables only (e.g. depression and anxiety). Six months prior to GO onset, 74 patients experienced a mean of 4 (range 0-13) stressful life events. Subjects with optic neuropathy had more stressful events than those without nerve involvement (5.1 vs. 2.7, P = 0.0425).

CONCLUSIONS

Psychosocial morbidity is present in severe and/or active GO, which negatively affects QoL. The patients are not only physically ill, they also exhibit emotional distress. Accompanying psychosomatic treatment is indicated among about half of all GO patients.