Elevated Preoperative TPO Ab Titers Decrease Risk for DTC in a Linear Fashion: A Retrospective Analysis of 1635 Cases.

CONTEXT: For some, chronic lymphocytic thyroiditis (Hashimoto thyroiditis) is an important risk factor for differentiated thyroid cancer (DTC). Surgical cohort studies even suggested a potential role for thyroid peroxidase antibodies (TPO-Abs) on that risk. OBJECTIVE: Our clinical observations argued against that possibility. We designed the present study to evaluate the relationship of TPO-Abs and DTC in a large patient population. METHODS: We recruited individuals who underwent thyroidectomies at 4 different clinical sites (USA: 1 clinic, 2000-2013, and Greece: 3 clinics, 2007-2021). We gathered data on TPO-Abs titers measured with commercially available chemiluminescence immunoassays, and reviewed patients' data including surgical pathology. TPO-Abs of 34 IU/mL or greater was deemed positive (TPO+) and TPO-Abs less than 34 IU/mL was deemed negative (TPO-). Odds ratios (OR) for DTC were calculated with the Fisher exact test and P less than .05 was deemed significant. RESULTS: We reviewed data from 8461 consecutive thyroid surgery cases. TPO-Abs titers were available for 1635 individuals: DTC n = 716 (43.8%), benign pathology n = 919 (56.2%), TPO+ n = 540 (33.0%), and TPO- n = 1095 (67.0%). DTC was found at a lower frequency in TPO+ (198/540, 36.7%) compared to TPO- (518/1095, 47.3%) patients, OR 0.64 (0.52-0.80; P < .0001). Rising TPO-Abs titers conferred protection against DTC in a linear fashion: TPO-Abs less than 10 IU/mL: 59.3%, TPO-Abs less than 34 IU/mL: 47.4%, TPO-Abs 34 to 100 IU/mL: 42.6%, TPO-Abs 100 to 500 IU/mL: 32.0%, TPO-Abs greater than 1000 IU/mL: 19.4%; P less than .0001. CONCLUSION: Higher TPO-Ab titers appear protective against DTC in our large multicenter cohort of patients who underwent thyroidectomies. Rising preoperative TPO-Abs titers conferred linearly increasing protection against DTC.

Large, Slowly Growing, Benign Thyroid Nodules Frequently Coexist With Synchronous Thyroid Cancers.

CONTEXT: Thyroid nodules' size should not be the sole criterion for thyroidectomy; however, many patients undergo surgery for large or slowly growing nodules. OBJECTIVE: We evaluated risk for clinically significant thyroid cancer in patients with large or slowly growing nodules. METHODS: We reviewed data from 2 prospectively collected databases of patients undergoing thyroidectomies in tertiary referral centers in the USA and Greece over 14 consecutive years. We collected data on the preoperative surgical indication, FNA cytology, and surgical pathology. We included subjects operated solely for large or growing thyroid nodules, without any known or presumed thyroid cancer or high risk for malignancy, family history of thyroid cancer, or prior radiation exposure. RESULTS: We reviewed 5523 consecutive cases (USA: 2711; Greece: 2812). After excluding 3059 subjects, we included 2464 subjects in the present analysis. Overall, 533 thyroid cancers were identified (21.3%): 372 (69.8%) microcarcinomas (<1 cm) and 161 (30.2%) macrocarcinomas (≥1 cm). The histology was consistent with papillary cancer (n = 503), follicular cancer (n = 12), Hürthle cell cancer (n = 9), medullary cancer (n = 5), and mixed histology cancers n = 4. Only 47 (1.9%) of our subjects had any form of thyroid cancer in the nodule that originally led to surgery. The cancers were multifocal in 165 subjects; had extrathyroidal extension in 61, capsular invasion in 80, lymph node involvement in 35, and bone metastasis in 2 subjects. CONCLUSION: The risk of synchronous, clinically important thyroid cancers is small, but not null in patients with large or slow growing thyroid nodules. Therefore, more precise preoperative evaluation is needed to separate the patients who would clearly benefit from thyroid surgery from the vast majority of those who do not need to be operated.

Intractable Seizures and Limbic Encephalitis, Unaccounted Complications of Type 1 Diabetes Autoimmunity.

Glutamic acid decarboxylase 65kD autoantibody (GAD65Ab) is frequently detected in patients with refractory epilepsy and stiff person syndrome. In contrast to T1D, the pathological role of GAD65Ab in neurological disorders is still debatable. As a result, the implementation of possible immunotherapy is usually delayed. This report presents 2 cases of GAD65Ab-associated brain autoimmunity and their different management. We present clinical data and discuss management based on available evidence in the reviewed literature. Both cases presented with acute on chronic neurological symptoms and were GAD65Ab positive. Case 1, a 30-year-old man with a history of early-onset type 1 diabetes mellitus at 14 months, followed by cryptogenic temporal epilepsy at 11 years of age, presented with intractable seizures. Case 2, a 48-year-old woman, presented with a history of recurrent severe headaches, cognitive impairment, decreased memory, and behavioral symptoms. GAD65Ab was detected in both patients' sera. Cerebrospinal fluid GAD65Ab was only checked and positive in case 1. Case 2 was diagnosed with limbic encephalitis, treated with immunotherapy, and showed a remarkable clinical improvement. Case 1 with refractory epilepsy failed multiple antiepileptic drugs and responsive-stimulator system treatments. He was finally diagnosed with autoimmune epilepsy. The delay in diagnosis resulted in a lost opportunity for early immunotherapy. In conclusion, autoantibody screening and early initiation of immunotherapy should be considered to manage GAD65Ab-associated neurological disorders.

Higher TSH Is Not Associated With Thyroid Cancer Risk in the Presence of Thyroid Autoimmunity.

BACKGROUND: Higher-but-within-normal thyrotropin (thyroid-stimulating hormone, TSH) is associated with higher risk for differentiated thyroid cancer (DTC) in surgical series. Our recent clinical observations suggest that this is not the case in the presence of autoimmune thyroid disease (AITD). We designed the present study to clarify this controversy. METHODS: We analyzed our prospectively collected database of patients referred for thyroid surgery at 2 tertiary care referral centers in Greece and the United States. We collected data for preoperative TSH, postoperative pathology, and thyroid peroxidase (TPO) antibodies titers. Subjects were subdivided into 2 groups, those with AITD (i.e., lymphocytic thyroiditis) and non-AITD. We excluded subjects with Graves disease, abnormal TSH (< 0.40 or > 4.50 mIU/mL), or recent use of levothyroxine. We compared the serum TSH among different groups using the Mann-Whitney test. RESULTS: A total of 3973 subjects were screened; 1357 met exclusion criteria. After all exclusions, data from 1731 non-AITD subjects and 329 AITD subjects were included in the analysis. AITD subjects had higher TSH than non-AITD subjects (2.09 vs 1.48; P < 0.0001). TSH values were higher in DTC compared with benign histology only in non-AITD subjects (1.65 vs 1.40; P < 0.0001). Progressively higher TSH was associated with higher incidence of DTC only in non-AITD subjects (P < 0.0001). In AITD subjects, TSH was similar between groups with or without DTC (2.02 vs 2.14; P = 0.21). CONCLUSIONS: TSH concentrations are not associated with the risk of developing DTC in the presence of thyroid autoimmunity, even though this seems to be the case for all other patients.

Incidentally Discovered Papillary Thyroid Microcarcinomas Are More Frequently Found in Patients with Chronic Lymphocytic Thyroiditis Than with Multinodular Goiter or Graves' Disease.

Background: Incidental finding of differentiated thyroid microcarcinomas (DTMc) in patients undergoing thyroid surgery for benign indications has become increasingly common. Even though carcinogenesis might relate to the background disease of the gland, the incidence of DTMc in the setting of various thyroid disorders remains unclear. We designed the present study to address this question. Materials and Methods: We reviewed data from two prospectively collected databases of consecutive patients undergoing thyroid surgery in two high-volume tertiary care referral centers, one in the United States (A) and the other one in Greece (B) over 18 years. We collected data on the preoperative surgical indication, fine-needle aspiration (FNA) cytology, and surgical pathology. We excluded subjects operated for thyroid cancer or with high risk for malignancy (FNA suspicious for thyroid cancer, follicular neoplasm, suspicious for follicular neoplasm, follicular lesion of undetermined significance/atypia of undetermined significance, or preoperative features of malignancy) and those with postsurgical pathology consistent with papillary thyroid cancer (PTC) ≥1 cm in largest diameter. We divided our subjects based on pathology data into those with chronic lymphocytic thyroiditis (CLT), Graves' disease (GD), or multinodular goiter (MNG). Results: We reviewed 6096 cases of thyroid surgery (A: 2711, B: 3385). We included 3909 subjects in the analysis. Overall, 569 (14.6%) PTC subjects were identified (A: 221/2003 [11%], B: 348/1906 [18.3%], odds ratios [OR] = 0.56, p < 0.0001). CLT was present in 617 subjects; PTC sonographic was present in 143 subjects (23.2%) (A: 79/404 [19.6%], B: 64/213 [30%], OR = 0.56, p = 0.003). GD was present in 359 subjects; PTC was present in 37 subjects (10.3%) (A: 12/197 [6.1%], B: 25/162 [15.4%], OR = 0.36, p = 0.004). MNG was present in 2933 subjects; PTC was present in 389 subjects (13.3%) (A: 130/1402 [9.3%], B: 259/1531 [16.9%], OR = 0.50, p < 0.0001). The incidence of PTC was significantly higher in CLT compared with MNG (OR = 1.75, p < 0.0001) or GD (OR = 2.25, p < 0.0001) but not in MNG compared with GD (OR = 1.29, p > 0.05). Conclusions: Incidentally discovered PTC are more commonly identified in surgical specimens from subjects with CLT compared with patients with MNG, while patients with GD present with a lower incidence compared with both groups. These data support previously published findings that euthyroid Hashimoto thyroiditis favors carcinogenesis, while GD may have a protective role.

The non-interventional approach to papillary thyroid microcarcinomas. An "active surveillance" dilemma.

BACKGROUND: Recent studies suggest that papillary-thyroid-microcarcinomas (PTMi) and follicular-variant-papillary-thyroid-cancers (FVPTC) are less aggressive overall. Our observations argue against. OBJECTIVES: To assess whether PTMi and FVPTC are indeed low-risk and could be safely followed without intervention. METHODS: We prospectively collected data of subjects with PTC on pathology post-thyroidectomy. Odds ratios (OR) were calculated with Fisher's exact test and differences between means were calculated using Mann Whitney's test. RESULTS: 696 met inclusion-criteria; 436 had macrocarcinomas (PTMa) and 260 had PTMi. PTMa were statistically significantly more likely to present multifocal [44.0% vs.28.1%], with extrathyroidal extension [22.1% vs.3.4%], lymph nodes involvement [25.5% vs.8.8%] and local invasion [3.1% vs.0.4%] (p < 0.05 for all), but not with distant metastasis [3.4% vs.1.3%, p > 0.05]. Therefore, PTMi measuring down to 0.01 cm, harbored aggressive features. We also identified 174 cases with FVPTC and 522 subjects with non-FVPTC. FVPTC had lower incidence of multifocality [40.1%, vs.60.9%], extrathyroidal extension [8.6% vs.17.4%] and lymphatic involvement [5.2% vs.24.0%], but not distant metastasis or local invasion [p > 0.05 for all]. Therefore, FVPTC measuring down to 0.5 cm, also harbored aggressive features. CONCLUSIONS: PTMi and FVPTC aggressive features are substantial enough to require careful evaluation, independent of their original tumor size before defaulting to just "active surveillance."

eIF5A inhibition influences T cell dynamics in the pancreatic microenvironment of the humanized mouse model of Type 1 Diabetes.

We have developed a transgenic mouse model of Type 1 Diabetes (T1D) in which human GAD65 is expressed in pancreatic ß-cells, and human MHC-II is expressed on antigen presenting cells. Induced GAD65 antigen presentation activates T-cells, which initiates the downstream events leading to diabetes. In our humanized mice, we have shown downregulation of eukaryotic translation initiation factor 5 A (elF5A), expressed only in actively dividing mammalian cells. In-vivo inhibition of elF5A hypusination by deoxyhypusine synthase (DHS) inhibitor "GC7" was studied; DHS inhibitor alters the pathophysiology in our mouse model by catalyzing the crucial hypusination and the rate-limiting step of elF5A activation. In our mouse model, we have shown that inhibition of eIF5A resets the pro-inflammatory bias in the pancreatic microenvironment. There was: (a) reduction of Th1/Th17 response, (b) an increase in Treg numbers, (c) debase in IL17 and IL21 cytokines levels in serum, (d) lowering of anti-GAD65 antibodies, and (e) ablation of the ER stress that improved functionality of the ß-cells, but minimal effect on the cytotoxic CD8 T-cell (CTL) mediated response. Conclusively, immune modulation, in the case of T1D, may help to manipulate inflammatory responses, decreasing disease severity, and may help manage T1D in early stages of disease. Our study also demonstrates that without manipulating the CTLs mediated response extensively, it is difficult to treat T1D.

Nature of coexisting thyroid autoimmune disease determines success or failure of tumor immunity in thyroid cancer.

BACKGROUND: Thyroid cancer and thyroid autoimmunity are considered opposite extremes of immune-responses. However, several studies have suggested that thyroid cancer coexists with autoimmune thyroid diseases like Hashimoto Thyroiditis (HT) and Graves disease (GD). We have shown that the risk of developing thyroid cancer is higher in patients with a silent form of autoimmune thyroid disease -Euthyroid Hashimoto Thyroiditis-(EHT). METHODS: We analyzed data from 2633 consecutive patients with GD, HT, EHT and non-Autoimmune Thyroid Disease (Non-AITD) for the presence of Differentiated Thyroid Cancer (DTC). We further investigated the microenvironment, and cellular mechanism of protection from DTC in GD/EHT by ex-vivo aspirating infiltrates from thyroid samples. We also re-constituted in vitro the in-vivo microenvironment to mimic an in-vivo context. We isolated NK cells and differentiated macrophages into M1 and M2 phenotype from healthy human peripheral blood monocytes. RESULTS: DTC was less frequent/aggressive in GD as compared to EHT or Non-AITD. Intra-thyroidal immune-cell profiling revealed differential Natural Killer (NK) cell activity and macrophage polarization in the settings of GD versus EHT. In GD, NK-cells were activated, and macrophages showed M1-like phenotype whereas, in EHT, NK-cells were less active and macrophages displayed M2-like phenotype. Furthermore, in vitro co-cultures of NK-cells with differentiated macrophage subsets revealed that the presence of activated NK (NA) cells favors M1 macrophages, boosts macrophage action and amplifies the innate defense mechanisms. Moreover, co-culture of M2 macrophages with NA, increases the cytotoxicity of NK-cells and favors a pro-inflammatory microenvironment that reverts the anti-inflammatory M2 towards pro-inflammatory M1. CONCLUSION: Surveillance innate immune-cells like Natural Killer (NK) cells and macrophages are complementary to each other in their actions. We discovered here that activated NK-cells in the background of the thyroid autoimmune disease, GD, drive macrophage differentiation to the M1/killer phenotype which in turn is cytotoxic to cancer cells and down regulates the M2/repair phenotype. Understanding the molecular basis of macrophage-NK cell interface in Thyroid Cancer, ETH and GD will open new vistas for immunopathology and therapeutic intervention. Macrophages/innate immunity can be modulated from M2 to M1 phenotype to help treat thyroid cancer as naturally done by GD.

Bacterial flagellin-a potent immunomodulatory agent.

Flagellin is a subunit protein of the flagellum, a whip-like appendage that enables bacterial motility. Traditionally, flagellin was viewed as a virulence factor that contributes to the adhesion and invasion of host cells, but now it has emerged as a potent immune activator, shaping both the innate and adaptive arms of immunity during microbial infections. In this review, we summarize our understanding of bacterial flagellin and host immune system interactions and the role flagellin as an adjuvant, anti-tumor and radioprotective agent, and we address important areas of future research interests.

Hashimoto's thyroiditis pathology and risk for thyroid cancer.

BACKGROUND: Hashimoto's thyroiditis (HT) has been found to coexist with differentiated thyroid cancer (DTC) in surgical specimens, but an association between the two conditions has been discounted by the medical literature. Therefore, we performed this study to determine any potential relationship between HT and the risk of developing DTC. METHODS: We collected data for thyrotropin (TSH), thyroxine (T4), thyroid peroxidase antibody (TPO-Ab) titers, surgical pathology, and weight-based levothyroxine (LT4) replacement dose for patients who were referred for thyroid surgery. Patients with HT at final pathology were studied further. To estimate thyroid function, patients with preoperative hypothyroid HT (Hypo-HT) were divided into three equal groups based on their LT4 replacement: LT4-Low (<0.90 µg/kg), LT4-Mid (0.90-1.43 µg/kg), and LT4-High (>1.43 µg/kg). A group of preoperatively euthyroid (Euth-HT) patients but with HT by pathology was also studied. All subjects were also grouped based on their TPO-Ab titer in TPO-high (titer >1:1000) or TPO-low/negative (titer <1:1000 or undetectable) groups. The relationship of HT and DTC was studied extensively. RESULTS: Of 2811 subjects, 582 had HT on surgical pathology, 365 of whom were Euth-HT preoperatively. DTC was present in 47.9% of the Euth-HT, in 59.7% of LT4-Low, 29.8% of LT4-Mid, and 27.9% of LT4-High groups. The relative risk (RR) for DTC was significantly elevated for the Euth-HT and LT4-Low groups (p<0.001), but not for the LT4-Mid or LT4-High replacement dose groups. TPO-low/negative status conferred an increased RR in the Euth-HT and LT4-Low replacement dose groups (p<0.001 both), while TPO-high status decreased it in Euth-HT group (p<0.05) and made it nonsignificant in the LT4-Low group. CONCLUSIONS: HT pathology increases the risk for DTC only in euthyroid subjects and those with partially functional thyroid glands (LT4-Low) but not in fully hypothyroid HT (LT4-Mid and LT4-High). High TPO-Ab titers appear to protect against DTC in patients with HT.

Lymphocytic profiling in thyroid cancer provides clues for failure of tumor immunity.

Thyroid cancers are usually surrounded by a significant number of immune-reactive cells. Tumor-associated lymphocytes as well as background lymphocytic thyroiditis are frequently mentioned in pathology reports of patients who have undergone surgery for thyroid cancer. The nature of this lymphocytic reaction is not well understood. The fact that cancer can survive in this adverse microenvironment is indicative of immune regulation. We characterized the lymphocytic infiltration that accompanies thyroid cancer and compared it with that present in thyroid autoimmunity. We found that double-negative (DN) T cells were significantly more abundant in thyroid cancer than in thyroid autoimmunity. Although FOXP3(+) regulatory T cells were also present, DN T cells were the dominant cell type, associated with thyroid cancer. Furthermore, upon stimulation, the DN T cells associated with cancer remained unchanged, while the few (<5%) DN T cells associated with thyroid autoimmunity increased in numbers (>20%). CD25 expression on DN T cells remained unchanged after stimulation, which indicates that the increase in the absolute number of DN T cells in thyroid autoimmunity was at the expense of inactivation of single-positive T cells. We concluded that in the setting of thyroid cancer, DN T cells appear to suppress tumor immunity. In contrast, in thyroid autoimmunity, DN T cells were barely present and only increased at the expense of inactivated, single-positive T cells upon induction. Together, these findings indicate that thyroid cancer-associated DN T cells might regulate proliferation and effector function of T cells and thereby contribute to tumor tolerance and active avoidance of tumor immunity.

Diabetes-associated dry eye syndrome in a new humanized transgenic model of type 1 diabetes.

PURPOSE: Patients with Type 1 Diabetes (T1D) are at high risk of developing lacrimal gland dysfunction. We have developed a new model of human T1D using double-transgenic mice carrying HLA-DQ8 diabetes-susceptibility haplotype instead of mouse MHC-class II and expressing the human beta cell autoantigen Glutamic Acid Decarboxylase in pancreatic beta cells. We report here the development of dry eye syndrome (DES) after diabetes induction in our humanized transgenic model. METHODS: Double-transgenic mice were immunized with DNA encoding human GAD65, either naked or in adenoviral vectors, to induce T1D. Mice monitored for development of diabetes developed lacrimal gland dysfunction. RESULTS: Animals developed lacrimal gland disease (classically associated with diabetes in Non Obese Diabetic [NOD] mice and with T1D in humans) as they developed glucose intolerance and diabetes. Animals manifested obvious clinical signs of dry eye syndrome (DES), from corneal erosions to severe keratitis. Histological studies of peri-bulbar areas revealed lymphocytic infiltration of glandular structures. Indeed, infiltrative lesions were observed in lacrimal/Harderian glands within weeks following development of glucose intolerance. Lesions ranged from focal lymphocytic infiltration to complete acinar destruction. We observed a correlation between the severity of the pancreatic infiltration and the severity of the ocular disease. CONCLUSIONS: Our results demonstrate development of DES in association with antigen-specific insulitis and diabetes following immunization with clinically relevant human autoantigen concomitantly expressed in pancreatic beta cells of diabetes-susceptible mice. As in the NOD mouse model and as in human T1D, our animals developed diabetes-associated DES. This specific finding stresses the relevance of our model for studying these human diseases. We believe our model will facilitate studies to prevent/treat diabetes-associated DES as well as human diabetes.

Nondiagnostic fine-needle aspirations of the thyroid: is the risk of malignancy higher?

BACKGROUND: Nondiagnostic fine-needle aspirations (FNAs) pose a dilemma in the management of patients with thyroid nodules. In most cases, these patients undergo either repeat FNA or surgical resection. However, a significant number of patients will only be observed, assuming that the risk of malignancy is low. Therefore, the purpose of this study was to determine whether the risk of malignancy is higher in patients with thyroid nodules and nondiagnostic FNAs. METHODS: We reviewed reports from 4286 consecutive FNA biopsies performed on patients with thyroid nodules at our institution between 2002 and 2010. We divided FNAs into two categories: diagnostic and nondiagnostic. We collected demographic, follow-up, and pathology data from both groups and then analyzed them with analysis of variance and chi-square tests. RESULTS: Of the 4286 FNAs, 259 were classified as nondiagnostic (6%). We saw no significant differences in age or gender between patients with diagnostic versus nondiagnostic FNAs. Of the patients with nondiagnostic FNAs, 62 underwent diagnostic thyroidectomy (24%), 74 had a repeat FNA (29%), and 123 had observation only (47%); thus, 136 patients had a cytologic or pathologic diagnosis. Patients with nondiagnostic FNAs had a significantly higher rate of all types of thyroid cancer, compared with those with diagnostic FNAs (12% versus 5%, respectively; P < 0.001). Impressively, the chance of papillary thyroid cancer was twofold higher in patients with nondiagnostic FNAs. CONCLUSIONS: The percentage of nondiagnostic FNA at our institution during this period (6%) was relatively low. However, the incidence of malignancy in these patients was significantly higher. Therefore, we recommend that patients with thyroid nodules and nondiagnostic FNAs undergo either repeat biopsy or diagnostic thyroidectomy.

Screening for parathyroid hormone resistance in patients with nonphenotypically evident pseudohypoparathyroidism.

OBJECTIVE: Hypocalcemia and hyperphosphatemia in the setting of elevated parathyroid hormone (PTH) and normal vitamin D metabolites, raises the possibility of PTH resistance. The idiopathic and inherited forms of PTH resistance are referred to as pseudohypoparathyroidism. Nonphenotypically evident pseudohypoparathyroidism can go undiagnosed for decades. We have designed a new test to diagnose PTH resistance and confirmed its clinical utility in the diagnosis of pseudohypoparathyroidism. METHODS: Our test consists of a subcutaneous injection of commercially available recombinant PTH and concomitant measurement of cyclic adenosine monophosphate in urine. We implemented the test in 2 patients with recalcitrant hypocalcemia and a healthy control subject. RESULTS: Our test unequivocally demonstrated PTH resistance in both patients. One of the patients had phenotypically evident pseudohypoparathyroidism type-1a hence, PTH resistance was suspected. The other patient with nonphenotypically evident disease, also showed PTH resistance and was later demonstrated to have pseudohypoparathyroidism type-1b at the genomic level and confirmed to be of familial type. CONCLUSION: Our results show for the first time the implementation of a simple new diagnostic tool designed to check for PTH resistance. This new test has already proven to be useful in few occasions at our institution. Larger populations, however, should be tested before implementation of such a test is considered a standard of care.

Higher serum thyroid stimulating hormone level in thyroid nodule patients is associated with greater risks of differentiated thyroid cancer and advanced tumor stage.

CONTEXT: TSH is a known thyroid growth factor, but the pathogenic role of TSH in thyroid oncogenesis is unclear. OBJECTIVE: The aim was to examine the relationship between preoperative TSH and differentiated thyroid cancer (DTC). DESIGN: The design was a retrospective cohort. SETTING, PARTICIPANTS: Between May 1994 and January 2007, 1198 patients underwent thyroid surgery at a single hospital. Data from the 843 patients with preoperative serum TSH concentration were recorded. MAIN OUTCOME MEASURES: Serum TSH concentration was measured with a sensitive assay. Diagnoses of DTC vs. benign thyroid disease were based on surgical pathology reports. RESULTS: Twenty-nine percent of patients (241 of 843) had DTC on final pathology. On both univariate and multivariable analyses, risk of malignancy correlated with higher TSH level (P=0.007). The likelihood of malignancy was 16% (nine of 55) when TSH was less than 0.06 mIU/liter vs. 52% (15 of 29) when 5.00 mIU/liter or greater (P=0.001). When TSH was between 0.40 and 1.39 mIU/liter, the likelihood of malignancy was 25% (85 of 347) vs. 35% (109 of 308) when TSH was between 1.40 and 4.99 mIU/liter (P=0.002). The mean TSH was 4.9+/-1.5 mIU/liter in patients with stage III/IV disease vs. 2.1+/-0.2 mIU/liter in patients with stage I/II disease (P=0.002). CONCLUSIONS: The likelihood of thyroid cancer increases with higher serum TSH concentration. Even within normal TSH ranges, a TSH level above the population mean is associated with significantly greater likelihood of thyroid cancer than a TSH below the mean. Shown for the first time, higher TSH level is associated with advanced stage DTC.

Suppressive effect of glutamic acid decarboxylase 65-specific autoimmune B lymphocytes on processing of T cell determinants located within the antibody epitope.

Type 1 diabetes is a T cell-mediated disease in which B cells serve critical Ag-presenting functions. In >95% of type 1 diabetic patients the B cell response to the glutamic acid decarboxylase 65 (GAD65) autoantigen is exclusively directed at conformational epitopes residing on the surface of the native molecule. We have examined how the epitope specificity of Ag-presenting autoimmune B cell lines, derived from a type 1 diabetic patient, affects the repertoire of peptides presented to DRB1*0401-restricted T cell hybridomas. The general effect of GAD65-specific B cells was to enhance Ag capture and therefore Ag presentation. The enhancing effect was, however, restricted to T cell determinants located outside the B cell epitope region, because processing/presentation of T cell epitopes located within the autoimmune B cell epitope were suppressed in a dominant fashion. A similar effect was observed when soluble Abs formed immune complexes with GAD65 before uptake and processing by splenocytes. Thus, GAD65-specific B cells and the Abs they secrete appear to modulate the autoimmune T cell repertoire by down-regulating T cell epitopes in an immunodominant area while boosting epitopes in distant or cryptic regions.