Roberto Rocchi

Thyroglobulin Autoantibodies in Patients with Papillary Thyroid Carcinoma: Comparison of Different Assays and Evaluation of Causes of Discrepancies

CONTEXT Thyroglobulin autoantibodies (TgAb) have been proposed as a surrogate marker of thyroglobulin in the follow-up of differentiated thyroid carcinoma. Commercially available TgAb assays are often discordant. We investigated the causes of discrepancy. DESIGN TgAb were measured by three noncompetitive immunometric assays and three competitive RIA in 72 patients with papillary thyroid carcinoma and associated lymphocytic thyroiditis (PTC-T), 105 with papillary thyroid carcinoma and no lymphocytic thyroiditis (PTC), 160 with Hashimotos thyroiditis, and in 150 normal subjects. The results of the six assays were correlated. TgAb epitope pattern, evaluated by inhibition of serum TgAb binding to thyroglobulin by TgAb-Fab regions A, B, C, and D, were compared in sera which were positive in all six assays (concordant sera) and positive in only one to five assays (discordant sera) were compared. TgAb International Reference Preparation (IRP) was measured in 2007 and 2009. RESULTS The correlations of the six assays ranged from -0.01 to 0.93 and were higher in PTC-T and Hashimotos thyroiditis than in PTC and normal subjects. Two uncorrelated components, one including the three immunometric assays, the other the three RIA, explained 40 and 37% of the total variance of the results of the six assays. The levels of inhibition were higher in concordant sera than in discordant sera by TgAb-Fab region B (27.0%, 21.2-34.0 vs. 6.0%, and 2.7-12.7%) and region C (30.5%, 21.3-37.7 vs. 4.0%, and 1.0-6.5%); thus, the epitope pattern was more homogeneous in concordant sera than in discordant sera. TgAb IRP ranged from 157 to 1088 (expected 1000) IU/ml in 2009; results in 2007 were similar in all but two assays. CONCLUSIONS TgAb assays are highly discordant. Discrepancy is lower when comparing assays with similar methodology. Results of TgAb from PTC-T are more concordant than those from PTC because their epitope pattern is more restricted. The internal standardization of TgAb is generally, but not completely, satisfactory.

Novel aspects of immunosuppressive and radiotherapy management of Graves’ ophthalmopathy

Treatment of severe Graves’ ophthalmopathy (GO) is a complex therapeutic challenge and, in spite of any efforts, about one third of patients are disappointed with the outcome of treatment. Glucocorticoids (GC), orbital radiotherapy (RT), or a combination of both, are most frequently used for their immunosuppressive effects. Novel immunosuppressive treatment procedures (or novel modalities of established treatments) are reviewed in the present article. GC has recently been used by the iv route and this treatment modality has been shown to be more effective and better tolerated than the oral route. Promising preliminary results have been reported by some authors with somatostatin analogs, octreotide and lanreotide. The number of patients treated so far is limited, most of the results have been obtained in nonrandomized or uncontrolled studies, and comparison with other validated methods of treatment is also needed. Because of the pathogenic role of cytokines, cytokine antagonists, currently evaluated in other autoimmune diseases, have been tested with positive results also in a small series of GO patients. The use of antioxidants might also be envisioned in the future, since in vitro studies have shown that oxygen free radicals might be involved in GO. Based on the shared antigen(s) theory, total thyroid ablation, by removing the bulk of shared antigens(s), might be beneficial for the course of GO. New data on recently performed placebocontrolled studies on orbital radiotherapy are discussed, together with studies on long-term safety of orbital radiotherapy.

Dissecting the Genetic Susceptibility to Graves’ Disease in a Cohort of Patients of Italian Origin

Graves’ disease (GD) is an autoimmune oligogenic disorder with a strong hereditary component. Several GD susceptibility genes have been identified and confirmed during the last two decades. However, there are very few studies that evaluated susceptibility genes for GD in specific geographic subsets. Previously, we mapped a new locus on chromosome 3q that was unique to GD families of Italian origin. In the present study, we used association analysis of single-nucleotide polymorphism (SNPs) at the 3q locus in a cohort of GD patients of Italian origin in order to prioritize the best candidates among the known genes in this locus to choose the one(s) best supported by the association. DNA samples were genotyped using the Illumina GoldenGate genotyping assay analyzing 690 SNP in the linked 3q locus covering all 124 linkage disequilibrium blocks in this locus. Candidate non-HLA (human-leukocyte-antigen) genes previously reported to be associated with GD and/or other autoimmune disorders were analyzed separately. Three SNPs in the 3q locus showed a nominal association (p < 0.05): rs13097181, rs763313, and rs6792646. Albeit these could not be further validated by multiple comparison correction, we were prioritizing candidate genes at a locus already known to harbor a GD-related gene, not hypothesis testing. Moreover, we found significant associations with the thyroid-stimulating hormone receptor (TSHR) gene, the cytotoxic T-lymphocyte antigen-4 (CTLA-4) gene, and the thyroglobulin (TG) gene. In conclusion, we identified three SNPs on chromosome 3q that may map a new GD susceptibility gene in this region which is unique to the Italian population. Furthermore, we confirmed that the TSHR, the CTLA-4, and the TG genes are associated with GD in Italians. Our findings highlight the influence of ethnicity and geographic variations on the genetic susceptibility to GD.

VARIABLES AFFECTING THE LONG-TERM OUTCOME OF GRAVES ORBITOPATHY FOLLOWING HIGH-DOSE INTRAVENOUS GLUCOCORTICOID PULSE THERAPY IN PATIENTS NOT TREATED WITH ORBITAL RADIOTHERAPY.

OBJECTIVE Intravenous (iv) glucocorticoids (GC) (ivGC) are used for active Graves orbitopathy (GO), but factors affecting GO outcome are poorly understood. We performed a retrospective study to investigate the variables affecting GO after ivGC. METHODS We evaluated 83 consecutive GO patients treated with ivGC but not orbital radiotherapy (ORT) and re-examined them after a median of 47 months. The endpoints were the relationships between GO outcome or additional treatments with age, sex, smoking habits, thyroid volume, thyroid treatment, time since thyroid treatment, antithyroid-stimulating hormone receptor antibodies (TRAb), GO duration, GO features, and follow-up time. RESULTS GO features improved after treatment, resulting in moderate and marked amelioration in ~75% and ~41% of patients respectively. By multivariate analysis, a moderate GO improvement correlated with diplopia at first observation, which was more severe in responders. A marked GO improvement correlated with time between first and last observation and time after thyroid treatment, which were longer in responders. This likely reflected the combination of an early effect of GC and a late, spontaneous improvement of GO, as shown by analyses of GO outcome at various time points. Additional treatments after ivGC correlated by multivariate analysis with eyelid aperture, diplopia and NOSPECS score (NOSPECS stands for no GO signs [N], only eyelid sign [O], soft tissue involvement [S], proptosis [P], extraocular motility restriction [E], corneal involvement [C], and sight loss [S]) at first observation, which were more severe in responders. CONCLUSION Our study shows that response to ivGC increases with time, likely reflecting the known tendency of GO to improve spontaneously, and is more pronounced when GO is more severe to begin with, which is associated with more additional treatments. ABBREVIATIONS ANOVA = analysis of variance CAS = clinical activity score GC = glucocorticoids GO = Graves orbitopathy 131I = radioactive iodine iv = intravenous ivGC = high-dose intravenous glucocorticoid pulse therapy MMI = methimazole OD = orbital decompression ORT = orbital radiotherapy TRAb = antithyroid-stimulating hormone receptor antibodies.

Optic Neuropathy in 2 Thyroidectomized Patients with Moderate to Severe Graves Ophthalmopathy Following L-Thyroxine Withdrawal Prior to Radioiodine Treatment for Thyroid Carcinoma

ABSTRACT Objective: To report on 2 patients with moderate to severe Graves ophthalmopathy (GO) who developed dysthyroid optic neuropathy following levothyroxine (LT4) withdrawal in preparation for ...

Occurrence of Graves’ Orbitopathy and Graves’ Hyperthyroidism after a Trauma to the Eye

Background: Graves’ orbitopathy (GO) is believed to be the consequence of autoimmunity against antigens that are present both in the thyroid and orbital tissues. Massive release of thyroid antigens causes the appearance or deterioration of GO in patients with Graves’ hyperthyroidism (GH), as it occurs following radioiodine treatment. In theory, a similar release of autoantigens may occur at the eye level, for example due to an orbital trauma or surgical manipulation. To our knowledge, this is the first report of a case of de novo appearance of GO and then GH after an eye trauma, possibly reflecting spreading of autoantigens and activation of the immune system against shared orbital and thyroid antigens. Case Report: An otherwise healthy, 57-year-old man presented 6 months after the appearance of a monolateral right orbitopathy, which occurred 40 days after a trauma in the ipsilateral eye. His thyroid function was normal, with positive serum anti-TSH receptor autoantibodies. The thyroid was normal on ultrasound. A month later he developed hyperthyroidism and orbitopathy in the left eye. Discussion: The development of GO after an eye trauma may reflect tissue damage with release of autoantigens and consequent autoimmunity in a predisposed individual (our patient had a familial history of autoimmune thyroid disease). The subsequent development of hyperthyroidism is in keeping with the hypothesis that GH and GO are due to autoimmunity against antigens present both in the thyroid and in orbital tissues.

Does Graves’ Orbitopathy Ever Disappear Answers to an Old Question

Objectives: There is a general belief that Graves’ orbitopathy (GO) is a “chronic” disease, namely that patients’ eyes do not return to how they were before GO appeared. Here, we investigate this issue from both the patient’s and the physician’s point of view. Study Design: We studied the disappearance of GO, regardless of treatment, in all consecutive patients with a GO history of at least 10 years who came for a follow-up visit over a period of 5 years. Patients underwent an ophthalmological examination and were asked to answer a questionnaire on self-perception related to GO. Results: We studied 99 consecutive patients with a GO duration ≥10 years. Between the first and the last observation, patients received several types of treatment for their thyroid disease and/or for GO. At the end of follow-up, GO was considered disappeared based on objective criteria in 8 patients (∼8%) and based on subjective criteria in 24 patients (∼24%). When we considered both subjective and objective criteria, only 2 patients (∼2%) had all criteria fulfilled and could be considered as GO-free. Conclusions: GO is a chronic disease in the vast majority of patients. Even after a very long time since its onset, complete disappearance is rare, although a minority of patients believe they do not have GO anymore and an even lower proportion do not have relevant GO signs. Our findings have obvious implications in patient management and counseling.