Thyroid specific T helper cell analysis by ELISPOT assay with thyrotropin receptor (TSH-R) peptides

The Mediation Role of Thyrotropin Receptor Antibody in the Relationship Between Age and Severity of Hyperthyroidism in Graves' Disease

Background: The severity of hyperthyroidism in Graves' disease (GD) has been reported to be worse in younger patients and to gradually improve with advancing age, accompanied by declining thyrotropin (TSH) receptor antibody (TRAb) values. This study was conducted to explore the extent to which the declining TRAb production may contribute to a decrease in severe hyperthyroidism with advancing age in patients with GD. Methods: This study was a cross-sectional analysis of retrospectively reviewed data. The medical records of patients newly diagnosed with GD at Ito Hospital, between January 2005 and June 2019, were examined. Patients were divided into age-stratified groups for evaluation. Multivariable logistic regression was performed to estimate the odds ratio (OR) of severe hyperthyroidism by increasing age. Mediation analyses were also conducted to quantify the association between age and declining severity of hyperthyroidism mediated through decreased TRAb productivity. Results: A total of 21,018 patients with newly diagnosed GD (3848 male and 17,170 female) were included. A correlation was observed between TRAb value and thyroid hormone values in each age-stratified group, which became weaker with an increase in age. Patients aged <40 years had a higher risk of severe hyperthyroidism (free thyroxine [fT4] level >7.0 ng/dL [n = 5616], OR [confidence interval, CI] = 1.80 [1.68-1.92]; free triiodothyronine [fT3] level >25 pg/mL [n = 4501], OR [CI] = 2.06 [1.92-2.23]) than those aged ≧40 years. In examining the relationship between age and severe hyperthyroidism, the proportion mediated through TRAb productivity was 8.5% and 8.4% using fT4 and fT3 as an outcome index, respectively. Conclusions: Declining TRAb value mediated only 8.5% of the negative association between age and severity of hyperthyroidism. The presence of other underlying mechanisms, such as the decline in the reactivity of thyrocytes to TSH stimulation, requires further investigation.

Interferon-gamma ELISPOT detecting reactivity of T cells to TSH receptor peptides in Graves' disease

OBJECTIVE

While thyrotrophin receptor (TSHR) is recognized as the main autoantigen in Graves' disease (GD), the actual antigen specificity of T cells that infiltrate the thyroid and the orbit is unknown. Identifying T cell responses to TSHR peptides has been difficult in the past due to the low frequency of autoreactive T cells and to the diversity of the putative epitopes identified by proliferation assays.

METHODS

We used the interferon-gamma ELISPOT assay to identify T cell reactivity to TSHR peptides in patients with GD. Peripheral blood T cells were exposed in vitro to four pools of 10 overlapping TSHR peptides.

RESULTS

T cells from 11 of 31 (35%) patients with GD and 1 of 22 (4%) healthy controls reacted to at least one peptide pool (P = 0·009). Mean time since diagnosis was 3·2 years in responder patients and 5·6 years in nonresponders (P = 0·07). In two patients, T cell reactivity was observed shortly after radioiodine treatment and not thereafter.

CONCLUSIONS

Our findings demonstrate that the ELISPOT assay is effective to test T cell reactivity in patients with GD and that patients with GD have significantly more interferon-gamma responses towards TSHR peptides than controls. The data suggest that screening for T cell responses in patients with GD might be more efficient in recent-onset disease or after radioiodine treatment.

Prognostic value of thyrotropin receptor antibodies (TRAb) in Graves' disease: a 120 months prospective study

In most trials, at least 30-60% of patients with Graves' disease treated with antithyroid drugs relapse within 2 years after therapy withdrawal. At present, there are no prognostic parameters available early in treatment to indicate patients likely to achieve long-term remission. Because thyrotropin receptor autoantibodies (TRAb) are specific for Graves' disease, we evaluated the ability of their levels and of their rate of change to predict long-term prognosis. In our study 216 consecutive patients with newly diagnosed Graves' disease started a therapy with methimazole. Patients were treated until they achieved euthyroidism and TRAb were measured at 6-month intervals throughout a follow up of 120 months. Our study demonstrated that at the onset of hyperthyroidism patients' age, sex, fT4 levels and goiter size had no prognostic value in predicting long-term prognosis (respectively p = 0.79; p = 0.98; p = 0.83; p = 0.89). On the contrary, at the time of diagnosis TRAb titer was a good predictor of the final outcome (p<0.001); a titer equal to (or) more than 46.5 UI/L could identify patients who had never achieved long-term remission with a sensitivity of 52% and a specificity of 78%. Also fall rate of TRAb at 6 months of follow up and after therapy withdrawal were useful to predict the final outcome (p<0.001). At 6 months of follow up the time of therapy withdrawal, a decrease of TRAb lower than 52.3% or even its increase could identify patients who had never achieved permanent remission with a sensitivity of 55% and a specificity of 79.1%. No single parameter among TRAb, satisfactory identified a sub-set of patients who achieved long remission. Accordingly to our data, the best result in predicting long term remission is probably given by the presence of at least one of the two features evaluated at 6 months (TRAb titer and/or percentage of TRAb fall rate), with a sensitivity of 63% and specificity of 88%. TRAb titers evaluated both at the onset of hyperthyroidism that at 6 months of therapy or their rate of fall at 6 months and at ATD withdrawal are predictors of outcome. However, the presence of at least one, between titers of TRAb or their rate of fall at six months, resulted to be the best predictor of remission with the higher sensitivity and specificity.

Effects of peptides, with emphasis on feeding, pain, and behavior A 5-year (1999-2003) review of publications in Peptides

Novel effects of naturally occurring peptides are continuing to be discovered, and their mechanisms of actions as well as interactions with other substances, organs, and systems have been elucidated. Synthetic analogs may have actions similar or antagonistic to the endogenous peptides, and both the native peptides and analogs have potential as drugs or drug targets. The journal Peptides publishes many leading articles on the structure-activity relationship of peptides as well as outstanding reviews on some families of peptides. Complementary to the reviews, here we extract information from the original papers published during the past five years in Peptides (1999-2003) to summarize the effects of different classes of peptides, their modulation by other chemicals and various pathophysiological states, and the mechanisms by which the effects are exerted. Special attention is given to peptides related to feeding, pain, and other behaviors. By presenting in condensed form the effects of peptides which are essential for systems biology, we hope that this summary of existing knowledge will encourage additional novel research to be presented in Peptides.

Relation of CD30 molecules on T-cell subsets to the severity of autoimmune thyroid disease

The prognosis of patients with autoimmune thyroid disease (AITD) varies. To clarify the immunologic differences among patients with various severities of AITD, we examined two types of molecules on peripheral T lymphocytes: CD195 (CCR5), which express dominantly on CD4(+) type 1 helper T (T(H)1) cells, and CD30, which is known as a marker of CD4(+) type 2 helper T (T(H)2) cells and a regulatory molecule of CD8(+) autoreactive cytotoxic T cells. We found presence of patients with high proportion (> 9%) of CD30 expression in CD4(+) cells in a group of patients with Graves' disease (GD) in remission compared to the patients with intractable GD and a decrease in the intensity of CD30 expression on CD8(+) cells from patients with severe Hashimoto's disease (HD) treated for hypothyroidism compared to patients with untreated and euthyroid HD. There was no difference in CD195 expression between these patients with GD or HD with different severities, but there was a decreased intensity of CD195(+) cells in thyrotoxic patients with GD. These results indicate that CD30 molecules on CD4(+) and CD8(+) cells may be related to the severities of GD and HD, respectively.