Comparison of pathophysiology in subclinical hyperthyroidism with different etiologies.

Subclinical hyperthyroidism (SHyper) is defined as normal levels of free thyroxine (fT4) and free triiodothyronine (fT3) with suppressed levels of TSH. Previous studies have reported the individual pathophysiology of endogenous SHyper patients and athyreotic patients receiving TSH suppression therapy with levothyroxine; however, apparently no studies have compared the two conditions. Five-hundred-forty untreated endogenous SHyper patients and 1,024 patients receiving TSH suppression therapy who underwent total thyroidectomy for papillary thyroid carcinoma were sampled. Thyroid hormone profiles and peripheral indices related to thyrotoxicosis were investigated in endogenous SHyper patients, athyreotic patients receiving TSH suppression therapy, and healthy participants. Endogenous SHyper patients showed significantly higher thyroid hormone levels (fT4 [p < 0.001] and fT3 [p < 0.001]), and peripheral indices showed a significant tendency towards thyrotoxicosis (strong TSH suppression: alkaline phosphatase [ALP, p < 0.001], creatinine [Cre, p < 0.001], pulse rate [p < 0.05]; and mild TSH suppression: Cre [p < 0.05]) than healthy participants. In contrast, athyreotic patients receiving TSH suppression therapy showed a significant tendency towards thyrotoxicosis than healthy participants only when TSH was strongly suppressed (fT3 [p < 0.001] and Cre [p < 0.001]). Endogenous SHyper patients showed significantly higher fT3 levels (p < 0.001) than athyreotic patients receiving TSH suppression therapy; however, there was a significant tendency towards thyrotoxicosis only when TSH was strongly suppressed (ALP [p < 0.05] and pulse rate [p < 0.05]). The effects of endogenous SHyper and TSH suppression therapy on target organ function are different. Although the serum thyroid hormone profile is similar to that of the thyrotoxic state, athyreotic patients receiving TSH suppression therapy with mildly suppressed serum TSH levels are not thyrotoxic.

Thyrotropin receptor antagonists and inverse agonists, and their potential application to thyroid diseases.

The thyrotropin receptor (TSHR) plays critical roles in thyroid growth and function and in the pathogenesis of several thyroid diseases including Graves' hyperthyroidism and ophthalmopathy, non-autoimmune hyperthyroidism and thyroid cancer. Several low-molecular weight compounds (LMWCs) and anti-TSHR monoclonal antibodies (mAbs) with receptor antagonistic and inverse agonistic activities have been reported. The former binds to the pocket formed by the receptor transmembrane bundle, and the latter to the extracellular TSH binding site. Both are effective inhibitors of TSH/thyroid stimulating antibody-stimulated cAMP and/or hyaluronic acid production in TSHR-expressing cells. Anti-insulin-like growth factor 1 inhibitors are also found to inhibit TSHR signaling. Each agent has advantages and disadvantages; for example, mAbs have a higher affinity and longer half-life but are more costly than LMWCs. At present, mAbs appear most promising, yet the development of more efficacious LMWCs is desirable. These agents are anticipated to be efficacious not only for the above-mentioned diseases but also for resistance to thyroid hormone and have utility for thyroid cancer radionuclide scintigraphy/therapy as a new theranostic.

Hypothyroidism due to nephrotic syndrome: a notable clinical entity.

Nephrotic syndrome (NS) is characterized by massive urinary protein leakage and associated hypoproteinemia due to increased protein permeability caused by impaired renal glomerular connections. Although there have been several sporadic reports regarding the relationship between NS and thyroid dysfunction, a consensus has yet to be reached. The mechanism of hypothyroidism in NS is attributed to the loss of protein-bound thyroid hormones, such as thyroxine-binding globulin, transthyretin, and albumin, into the urine. Herein, we report four adults with hypothyroidism that developed or worsened due to the onset of NS. The patients' underlying thyroid status was post-total thyroidectomy with supplemental levothyroxine (L-T4) in two patients, hypothyroidism with supplemental L-T4 due to Hashimoto's disease in one patient, and Hashimoto's disease with normal thyroid function in one patient. Our results suggest that the presence of a reduced thyroid reserve may predispose patients to hypothyroidism in NS. We conclude that NS may cause or exacerbate hypothyroidism. In such cases, an NS assessment, including a urine test, is required.

The magnitude of increased Levothyroxine dose during pregnancy in patients on thyroid-stimulating hormone (TSH) suppression treatment after total thyroidectomy for papillary carcinoma.

The dose of L-T4 replacement for hypothyroidism often needs to be increased after pregnancy. In our institution, patients are instructed to double the dose 2 days a week after pregnancy. However, there is scarce evidence supporting the need for a dose increase after pregnancy in patients with preconception thyroid-stimulating hormone (TSH) suppression (TSH <0.3 µIU/mL). This study aimed to determine the need for a dose increase in L-T4 among women with a TSH-suppressive dose of L-T4 before pregnancy. In this retrospective observational study, between January 2008 and December 2018, we analyzed 166 pregnancies in 134 patients on TSH suppression treatment after total thyroidectomy for papillary carcinoma. Thyroid function tests were performed before and in the first trimester of pregnancy. The dose was adjusted and maintained during the first trimester of pregnancy in 76 pregnancies (group A) and 90 pregnancies (group B), respectively. The median serum TSH level was significantly lower in group A than that in group B (0.014 µIU/mL (IQR, 0.005-0.071) vs. 0.155 µIU/mL (IQR, 0.021-0.657), p < 0.001). TSH suppression could not be maintained after pregnancy in 15.8% and 38.9% of the pregnancies in groups A and B, respectively. Increasing the post-pregnancy dose by an average of 27.4% resulted in maintenance of TSH suppression after pregnancy in 84.2% of pregnancies. In conclusion, this study suggests that increasing the L-T4 dose after pregnancy may be appropriate in postoperative thyroid cancer patients whose serum TSH levels should be suppressed.

Favorable outcomes of papillary thyroid microcarcinoma concurrent with Graves' disease after radioactive iodine therapy.

Graves' disease (GD) may coexist with papillary thyroid microcarcinoma (PTMC). The main purpose of this study was to evaluate whether treatment with radioactive iodine (RAI) may cause acute exacerbation of PTMC concurrent with GD or not. From the medical records of 10,257 GD patients who underwent RAI therapy between 2000-2017, 12 subjects with concurrent PTMC were retrieved. Further, 49 patients with concurrent GD and PTMC who underwent no RAI administration throughout their clinical course were enrolled as controls. Size of the PTMC nodules was evaluated based on maximal diameter and tumor volume-doubling rate (TV-DR). Among the 12 subjects who underwent RAI therapy (median dose, 13 mCi), 2 showed tumors >10 mm in maximal diameter with slow growth for more than 10 years, while the other 10 showed tumors with maximal diameter ≤10 mm. No subject showed any clinical findings of nodal or distant metastasis during the follow-up periods (0.4-11.5 years) before surgery or during active surveillance. No significant differences were observed in the TV-DR values (median, 0.044/year; range, -0.81-1.40) between the study subjects and controls (median, 0.025/year; range, -0.70-1.29; p = 0.69). When comparing the TV-DR before and after RAI administration in 3 individuals in particular, in whom PTMC were cytologically confirmed before RAI administration and whose prospective follow-up data were available, tumor progression was observed to be stable or decreased after RAI administration. There were no acute exacerbations or unfavorable outcomes of concurrent PTMC and GD after low-dose RAI administration.

Proposal of diagnostic criteria for IgG4-related thyroid disease.

Patients with IgG4-related disease (IgG4-RD) are diagnosed in Japan by comprehensive or organ-specific diagnostic criteria. To date, organ-specific criteria have been established for several organs, but not for the thyroid. We attempted to establish diagnostic criteria for IgG4-related thyroid disease (IgG4-RTD) based on IgG4-RD research by The Research Program on Intractable Diseases from the Ministry of Health, Labour and Welfare of Japan. These criteria have been publicly reported to members of both the Japan Endocrine Society and the Japan Thyroid Association. Thyroid diseases associated with IgG4 include Hashimoto's thyroiditis, Graves' disease and Riedel's thyroiditis. As a comprehensive definition that includes both systematic and organ-specific forms, we use the broad term 'IgG4-related thyroid disease'. Diagnostic criteria for IgG4-RTD comprise the following five items: I) enlargement of the thyroid, II) hypoechoic lesions in the thyroid by ultrasonography, III) elevated serum IgG4 levels, IV) histopathological findings in the thyroid lesion (IgG4+ plasma cells >20/HPF and IgG4+/IgG+ plasma cell ratio >30%) and V) involvement of other organs. "Definitive" diagnosis of IgG4-RTD is made when I, II, III and IV are all fulfilled, while "probable" diagnosis of IgG4-RTD is when I, II, and IV or V are fulfilled. Patients who fulfill I, II and III criteria are considered as "possible" IgG4-RTD. We believe that the proposed diagnostic criteria contribute to more accurate diagnosis of IgG4-RTD as well as exclusion of mimicry. Furthermore, they may lead to better understanding of the clinical implications and underlying pathogenesis of IgG4-RTD.

Association between serum thyroid hormone balance and thyroid volume in patients treated with levothyroxine monotherapy for hypothyroidism.

Many previous studies including ours have reported that athyreotic patients on levothyroxine (LT4) have relatively low serum free triiodothyronine (FT3) levels, whereas patients with large goitrous diseases often have high serum FT3 levels. Here we investigated Hashimoto thyroiditis (HT) patients on LT4 to study the relationship between thyroid volume (TV) and thyroid hormone status in hypothyroid patients on LT4. We retrospectively studied 408 euthyroid HT patients treated with LT4 for hypothyroidism; divided them as per TV and compared serum levels of free thyroxine (FT4) and FT3 and the FT3/FT4 ratio in each patient group with those in euthyroid matched control group. We also evaluated the association between serum FT3 level and FT3/FT4 ratio and TV among HT patients on LT4. In patients with TV <15 mL, serum FT3 levels were significantly lower than those in controls. In patients with TV 15-80 mL, serum FT3 levels were equivalent to those in controls. In patients with TV ≥80 mL, the serum FT3 levels were significantly higher than those in controls. The serum FT3 level (r = 0.35, p < 0.01) and FT3/FT4 ratio (r = 0.42, p < 0.01) showed a positive correlation with TV. TVs in HT patients on LT4 caused differences in serum thyroid hormone balance, as increasing volume increases the serum FT3 level and FT3/FT4 ratio. Serum thyroid hormone balance in HT patients with smaller thyroids was similar to that in athyreotic patients. Mild thyrotropin suppression with LT4 is needed to achieve normal FT3 levels in such patients.

Quality of Life in Patients with Low-Risk Papillary Thyroid Microcarcinoma: Active Surveillance Versus Immediate Surgery.

OBJECTIVE: This study aimed to compare the quality of life (QoL) and psychological issues of patients with papillary thyroid microcarcinoma (PMC) who were under active surveillance (AS) and those who underwent immediate surgery (OP). METHODS: This was a cross-sectional study conducted on 347 patients with low-risk PMC who were under AS (n = 298) or who underwent OP (n = 49). They were asked to complete two questionnaires (thyroid cancer-specific health-related QoL [THYCA-QoL] and the Hospital Anxiety and Depression Scale [HADS]). The results between the AS and OP groups were compared. RESULTS: The mean ages of patients in the AS and OP groups were 58.6±12.5 and 58.4±13.1 years (P =.94), respectively, and the male ratios were 34/298 (11%) and 2/49 (4.1%) (P =.14), respectively. The median follow-up periods from diagnosis in the AS and OP groups were 56.5 months (interquartile range [IQR], 32 to 88 months) and 84 months (IQR, 64 to 130 months) (P<.001), respectively. In the THYCA-QoL questionnaire, the OP group had more complaints about "voice" (P<.001), "psychological" (P =.025), "problems with scar" (P<.001), and "gained weight" (P =.047) than the AS group. Other scales of the THYCA-QoL were comparable in the two groups. In the HADS questionnaire, the AS group had significantly better anxiety (P =.020), depression (P =.027), and total scores (P =.014) than the OP group. CONCLUSION: PMC patients in the OP group had more complaints and were more anxious and depressed than the AS group. These findings suggest that AS is a reasonable alternative to surgery for patients with low-risk PMC from the point of view of QoL and psychology. ABBREVIATIONS: AS = active surveillance; CI = confidence interval; HADS = Hospital Anxiety and Depression Scale; LT4 = levothyroxine; OP = immediate surgery; PMC = papillary microcarcinoma; PTC = papillary thyroid carcinoma; QoL = quality of life; STAI = State-Trait Anxiety Inventory; THYCA-QoL = thyroid cancer-specific health-related quality of life; TSH = thyrotropin.

Papillary thyroid carcinomas are highly obscured by inflammatory hypoechoic regions caused by subacute thyroiditis: a longitudinal evaluation of 710 patients using ultrasonography.

Subacute thyroiditis is a self-limited inflammatory disease and very few patients undergo ultrasonographic re-examination if no nodules are found at the initial examination. The objective of the study was to assess the diagnostic accuracy of ultrasonography in detecting nodular lesions in patients with subacute thyroiditis. We conducted a longitudinal study involving 710 patients with subacute thyroiditis who underwent ultrasonographic examinations in a single center between 2008 and 2018. These examinations were performed at initial diagnosis and during follow-up, with subsequent evaluation of nodules using fine needle aspiration cytology. Ultrasonographic examination used for the initial screening of thyroid nodules in patients with subacute thyroiditis showed a sensitivity of 72.4%, specificity of 89.0%, positive predictive value of 80.4%, and negative predictive value of 83.8%. Twenty-two patients (3.1%) had concomitant papillary thyroid carcinoma, 10 of whom underwent thyroidectomy while the remaining 12 opted for active surveillance owing to having low-risk microcarcinomas. Approximately 30% of papillary carcinomas (7/22) were identified during follow-up ultrasonography, but not during the initial scan. All tumors in this false-negative group were latently localized in the bilateral hypoechoic regions of the thyroid and showed no calcified components. Of the 15 tumors that were detected during both initial and follow-up examinations, 7 exhibited calcified components and 5 were located in unaffected areas apart from the inflammatory hypoechoic region. Subacute thyroiditis highly obscures any coexisting papillary carcinoma when inflammatory hypoechoic regions are present. Ultrasonographic re-examination after a sufficient interval is indispensable for patients with subacute thyroiditis.

Thyroid function related symptoms during levothyroxine monotherapy in athyreotic patients.

Previous reports by us and other investigators showed that among athyreotic patients on levothyroxine (LT4) following total thyroidectomy patients with normal serum thyroid-stimulating hormone (TSH) levels had mildly low serum free triiodothyronine (FT3) levels, whereas patients with mildly suppressed serum TSH levels had normal serum FT3 levels and patients with strongly suppressed serum TSH had elevated serum FT3 levels. The objective of this study was to clarify which of these three patient groups are closer to their preoperative euthyroid condition based on reported subjective symptoms. We prospectively studied 148 consecutive euthyroid patients with papillary thyroid carcinoma who underwent a total thyroidectomy. Symptoms reflecting thyroid function documented preoperatively and following 12 months of LT4 after thyroidectomy were compared. In 65 patients with strongly suppressed TSH levels significant changes in symptoms with tendencies towards thyrotoxicosis were seen with regards to heat and cold tolerance (p < 0.01), bowel movements (p < 0.05), and hand tremors (p < 0.05). In 33 patients with normal TSH levels, significant changes in symptoms with tendencies towards hypothyroidism were seen with regards to heat and cold tolerance (p < 0.05) and activity (p < 0.05). Lastly, in 50 patients with mildly suppressed TSH levels and FT3 levels equivalent to preoperative levels, all symptom items remained equivalent to their preoperative levels. Symptoms reflecting thyroid function in patients on LT4 following total thyroidectomy suggested that patients with mildly suppressed TSH levels were closest to a euthyroid status. These data provide useful findings regarding the management of patients following total thyroidectomy.

The association between thyroid hormone balance and thyroid volume in patients with Hashimoto thyroiditis.

While patients with large goitrous thyroid diseases often have a relatively high serum free triiodothyronine (FT3)/free thyroxine (FT4) ratio, athyreotic patients have a relatively low FT3/FT4 ratio. Here we investigated the relationship between thyroid hormone status and thyroid volume (TV) among a large number of euthyroid Hashimoto thyroiditis (HT) patients. We retrospectively enrolled 2,603 untreated HT patients who visited the Kuma hospital from 2012 to 2016, and divided them into four groups as per the TV: normal TV (<20 mL), slight goiter (20 ≤ TV < 50 mL), moderate goiter (50 ≤ TV < 80 mL), and the large goiter group (≥80 mL). Baseline characteristics and laboratory data of each group were compared to those of 1,554 control subjects. The association between FT3/FT4 ratio and TV among HT patients was then analyzed. We observed a change in laboratory parameters among 13 patients in the large goiter group who were prescribed levothyroxine (LT4) for reducing TV. Compared to normal subjects, the moderate and large goiter groups exhibited significantly higher serum FT3 levels, while all HT groups exhibited lower serum FT4 levels. Serum FT3/FT4 ratios showed a positive correlation with TV (r = 0.35, p < 0.01), which was independent of age, sex, body mass index, and TgAb and TSH levels. LT4 treatment lowered serum FT3 levels and FT3/FT4 ratios significantly. Our results indicated that HT patients with increased TV tended to present with high serum FT3, low FT4, and high FT3/FT4 ratios. The elevation of deiodinase activity may be an important factor affecting thyroid hormonal balance in such patients.

Warthin-like papillary thyroid carcinoma with immunoglobulin G4-positive plasma cells possibly related to Hashimoto's thyroiditis.

Hashimoto's thyroiditis with heavy lymphoplasmacytic infiltration is a common comorbidity of immunoglobulin G4 (IgG4)-related thyroiditis and Warthin-like papillary thyroid carcinoma (WL-PTC). We hypothesized that WL-PTC may have a strong association with IgG4-related thyroiditis. To validate this hypothesis, we clinically and immunohistochemically studied 17 WL-PTC cases. Fourteen patients (82.4%) had anti-thyroglobulin antibody and were confirmed to have Hashimoto's thyroiditis through microscopic analysis. Among them, five (29.4%) had disease consistent with IgG4-related thyroiditis but did not exhibit a "storiform" pattern or obliterative phlebitis. IgG4-related diseases were not found in other organs. No cases with serum IgG4 level of >135 mg/dL were noted. A total of 94.1% of WL-PTC cases had IgG4-positive plasma cells (+PCs) in the stroma, and cases with rich IgG4+PCs were more frequently associated with Hashimoto's thyroiditis than those with poor IgG4+PCs. In this study, all three cases without Hashimoto's thyroiditis had poor IgG4+PCs, and one of them did not exhibit IgG4+PCs in the stroma of WL-PTC and Hashimoto's thyroiditis. Nodal metastatic lesions were seen in eight cases, all of which were not WL-PTC. As such, we should consider that the Hashimoto's disease with rich IgG4+PCs seen in our cases is representative of non-IgG4-related disease and not IgG4-related disease involving multiple organs. This study is the first to demonstrate the presence of IgG4+PCs in the stroma of WL-PTC. We concluded that the appearance of IgG4+PCs in the stroma of WL-PTC may be related to Hashimoto's thyroiditis with rich IgG4+PC.

Comparison of thyroglobulin and thyroid peroxidase antibodies measured by five different kits in autoimmune thyroid diseases.

It is generally believed that the detection of thyroid peroxidase antibodies (TPOAb) is superior to that of thyroglobulin antibodies (TgAb) for the diagnosis of Hashimoto's thyroiditis. However, limited data are available on the comparison of TgAb and TPOAb prevalence as a diagnostic measurement for Hashimoto's thyroiditis using sensitive immunoassays. We herein used five different current immunoassay kits (A-E) to compare the prevalence of TgAb and TPOAb in Hashimoto's thyroiditis (n = 70), Graves' disease (n = 70), painless thyroiditis (n = 50), and healthy control subjects (n = 100). In patients with Hashimoto's thyroiditis, positive TgAb was significantly more frequent than positive TPOAb in kits A-D (mean ± SD of the four kits: 98.6 ± 1.7 vs 81.4 ± 2.0%). In patients with Graves' disease, TgAb prevalence was almost equivalent to that of TPOAb in five kits. Patients with painless thyroiditis exhibited positive TgAb significantly more frequently than positive TPOAb in kits A-D (73.5 ± 4.1 vs 33.0 ± 3.4%). The prevalence of TgAb alone was significantly higher than that of TPOAb alone in both Hashimoto's thyroiditis and painless thyroiditis in kits A-D. In kit E, TgAb and TPOAb prevalence did not differ significantly for any disease, and TgAb distribution was different from other kits. In conclusion, the prevalence of TgAb was higher than that of TPOAb in patients with Hashimoto's thyroiditis and painless thyroiditis using commercially available kits. We suggest that TgAb immunoassay is the first choice of screening test for thyroid autoimmune abnormalities in Japan.

Kinetic analyses of changes in serum TSH receptor antibody values after total thyroidectomy in patients with Graves' disease.

We often recommend total thyroidectomy for patients with Graves' disease who wish to have a child in the near future in order to prevent fetal or neonatal hyperthyroidism, especially if the patients' serum thyrotropin receptor antibody (TRAb) values are high. The aim of this study was to analyze changes in serum TRAb values using a quantitative third-generation assay after total thyroidectomy and the half-lives of serum TRAb values to estimate the postoperative time needed to achieve the safe TRAb value for mothers. We retrospectively examined the records of 45 Graves' disease patients who underwent a total thyroidectomy and had high serum TRAb values. We also evaluated factors that prolonged the postoperative reduction of serum TRAb values. The serum TRAb values decreased rapidly in most of the patients, especially within the early postoperative (3-month) period. The presence of Graves' ophthalmopathy (GO) (p=0.001), smoking (p=0.004), and serum thyroglobulin values > 0.5 ng/mL at postoperative 12 months (p=0.039) were significantly associated with prolonged half-lives of the serum TRAb values. The median TRAb value half-life was 93.5 days in the patients without GO or smoking, 162.5 days in the patients with GO or smoking, and 357.4 days in the patients with both GO and smoking. Our findings indicate that using the half-life of patients' serum TRAb values determined by this third-generation assay would be effective to evaluate the reduction of serum TRAb values after total thyroidectomy and to estimate the postoperative time needed to achieve the maternal safe value.

Partial prediction of postpartum Graves' thyrotoxicosis by sensitive bioassay for thyroid-stimulating antibody measured in early pregnancy.

Graves' disease often occurs after delivery. However, it has been difficult to predict who will develop Graves' hyperthyroidism. We attempted to predict postpartum onset of Graves' disease by measuring anti-TSH receptor antibodies (TRAb) and thyroid-stimulating antibodies (TSAb) in early pregnancy. TRAb was measured by a third generation assay and TSAb was measured by a newly developed sensitive bioassay. In 690 early pregnant women, 2 showed borderline TRAb positive reactions. However, none of them developed Graves' disease after delivery. Thirty-eight of 690 pregnant women were positive for anti-thyroid peroxidase antibodies (TPOAb) and 4 were positive for TSAb. Two of these 4 women developed postpartum Graves' hyperthyroidism. These findings indicate that the third generation TRAb assay was not useful, but that the sensitive TSAb bioassay was moderately useful for predicting the postpartum onset of Graves' hyperthyroidism.

Occurrence of thyroxine tablet (Thyradin S(®)) - induced liver dysfunction in a patient with subclinical hypothyroidism.

A 54-year-old woman with subclinical hypothyroidism developed liver dysfunction after increasing dose of levothyroxine (L-T4) in tablet form (Thyradin S(®)) from 25µg to 50µg. Viral hepatitis, autoimmune hepatitis and NASH were ruled out with examinations. After cessation of levothyroxine in 50µg tablet form, liver enzymes gradually returned to normal. She was diagnosed levothyroxine-induced liver injury, based on criteria proposed in DDW-J 2004 workshop. Thyradin S(®) powder 0.01% (here in after referred to as L-T4 in powder form) was tried as an alternative, and liver enzymes have remained within normal range. As for Thyradin S(®) tablet, additives are different for each type of levothyroxine sodium content. The difference of additive is whether Fe2O3 is contained or not: it is not included in Thyradin S(®) 50µg tablet and powder form. Although there are two case reports in the Japanese literature and three case reports in the English literature of liver dysfunction suspected due to L-T4, we cannot find past reports about cases of drug induced liver dysfunction due to Fe2O3 free levothyroxine tablet form. This is a rare case report of drug induced liver injury due to Fe2O3 free levothyroxine tablet form, and administration of L-T4 in powder form may be useful for treatment of cases similar to this one.

Thyroxine treatment may be useful for subclinical hypothyroidism in patients with female infertility.

Infertile women sometimes associated with subclinical hypothyroidism (SCH). The guidelines of the American Endocrine Society, and American Association of Clinical Endocrinologists and American Thyroid Association recommend treatment with thyroxine (T4) for patients with SCH who want to have children. We examined 69 female infertile patients with SCH and the effects of levothyroxine (l-T4) therapy on pregnancy rates and pregnancy outcomes were observed. Fifty-eight (84.1%) patients successfully conceived during the T4 treatment period (Group A), although 17 patients (29.3%) had miscarriage afterward. The remaining 11 patients continued to be infertile (Group B). The median TSH value in Group A before the T4 treatment was 5.46 µIU/mL (range 3.1-13.3) and this significantly decreased to 1.25 µIU/mL (range 0.02-3.75) during the treatment (p<0.001). The estimated duration of infertility before the T4 treatment was 2.8±1.7 years and the duration until pregnancy after the treatment was significantly shorter at 0.9±0.9 years (p<0.001). Shortening of the infertile period after the T4 therapy was observed not only in patients who were treated with assisted reproductive technology (ART) but also in patients who conceived spontaneously in Group A. Administered T4 dose was 54.3±14.2 µg before pregnancy and 68.5±22.8 µg during pregnancy (p<0.001). Anti-thyroid autoantibodies were identified in 42.0% of all patients and no significant difference was observed in positivity between Group A and Group B. High successful pregnancy rate and shorter duration of infertility until pregnancy after T4 treatment strongly suggest that T4 enhanced fertility in infertile patients with SCH.

TERT promoter mutations increase tumor aggressiveness by altering TERT mRNA splicing in papillary thyroid carcinoma.

CONTEXT: Telomerase reverse transcriptase promoter (TERT-p) mutations, which upregulate TERT expression, are strongly associated with tumor aggressiveness and worse prognosis in papillary thyroid carcinomas (PTCs). TERT expression is also observed in a proportion of PTCs without TERT-p mutations, but such tumors show less aggressiveness and better prognosis compared with TERT-p mutation-positive tumors. OBJECTIVE: TERT has multiple splicing variants whose relationships with the TERT-p status and clinicopathological characteristics remain poorly understood. We examined the relationship between the TERT-p mutational status, the TERT splicing pattern, and clinicopathological features. METHODS: We investigated the expression of two major variants, α deletion (dA) and ß deletion (dB), in a series of 207 PTCs operated between November 2001 and March 2020 in Nagasaki University Hospital and Kuma Hospital. RESULTS: The TERT-p mutations were found in 33 cases, and among 174 mutation-negative cases, 24 showed TERT expression. All cases were classified into three groups: the TERT-p mutation-negative/expression-negative group (mut-/exp-), the TERT-p mutation-negative/expression-positive group (mut-/exp+), and the TERT-p mutation-positive group (mut+/exp+). The +A + B/dB ratio in mut+/exp + was significantly higher than that in mut-/exp + PTCs. Analysis with clinicopathological data revealed that +A + B expression was associated with higher PTC aggressiveness, whereas dB expression counteracted this effect. Functional in vitro study demonstrated that dB strongly inhibited cell growth, migration, and clonogenicity, suggesting its tumor suppressive role. CONCLUSION: These results provide evidence that the TERT-p mutations alter the expression of different TERT splice variants, which, in turn, associates with different tumor aggressiveness.

Interference against a newly labeled substance with ruthenium sulfonate complexes showing discrepant thyroid function test results.

We report here two patients exhibiting a combination of falsely elevated serum levels of free thyroxine (FT4), free triiodothyronine (FT3), and thyrotropin receptor antibodies (TRAb), measured using Elecsys assay kits (Roche Diagnostics GmbH). The first patient was a 74-year-old man misdiagnosed with Graves' disease and treated with methimazole. The second patient was a 48-year-old woman whose serum FT4 and FT3 concentrations were found to be high during a blood test. These patients denied taking biotin or any other supplements. Further detailed examination, including a heterophilic blocking tube test, revealed the presence of serum antibodies. The abnormal reactions were observed only using the improved assay kits using ruthenium (Ru) sulfonate instead of Ru as a chemiluminescent agent. Therefore, serum antibodies to the Ru sulfonate complex caused the pseudo-high levels of FT4, FT3, and TRAb. To our knowledge, this is the first report showing that antibodies to the Ru sulfonate complex in the electrochemiluminescence immunoassay can cause falsely elevated levels of the combination, leading to discrepant thyroid function test results. We emphasize that in cases of abnormal test results, alternative assay methods should be considered for further examination; unusual test results should not be impulsively interpreted, even when using revised assay kits.

Functional variants in a TTTG microsatellite on 15q26.1 cause familial nonautoimmune thyroid abnormalities.

Insufficient thyroid hormone production in newborns is referred to as congenital hypothyroidism. Multinodular goiter (MNG), characterized by an enlarged thyroid gland with multiple nodules, is usually seen in adults and is recognized as a separate disorder from congenital hypothyroidism. Here we performed a linkage analysis of a family with both nongoitrous congenital hypothyroidism and MNG and identified a signal at 15q26.1. Follow-up analyses with whole-genome sequencing and genetic screening in congenital hypothyroidism and MNG cohorts showed that changes in a noncoding TTTG microsatellite on 15q26.1 were frequently observed in congenital hypothyroidism (137 in 989) and MNG (3 in 33) compared with controls (3 in 38,722). Characterization of the noncoding variants with epigenomic data and in vitro experiments suggested that the microsatellite is located in a thyroid-specific transcriptional repressor, and its activity is disrupted by the variants. Collectively, we presented genetic evidence linking nongoitrous congenital hypothyroidism and MNG, providing unique insights into thyroid abnormalities.