We report a woman in her 30s with dysferlinopathy whose diagnosis was masked by superimposed hypothyroidism. Laboratory studies revealed Hashimoto\'s thyroiditis and markedly raised serum creatine kinase (CK of 6255 U/L; reference range 0-170 U/L). Electromyography, nerve conduction studies and MRI of the hip and thigh were consistent with a diagnosis of hypothyroid myopathy, but thyroxine failed to resolve her clinical presentation or normalise the CK level. Immunohistochemical (IHC) staining of right vastus lateralis muscle biopsy revealed the selective absence of dysferlin leading to a diagnosis of limb-girdle muscular dystrophy type IIB. Dysferlinopathy is a challenging diagnosis due to a varied clinical picture and low incidence. Misdiagnosis is common even in uncomplicated presentations, and this case outlines the need for routine inclusion of IHC and a low threshold for genetic testing, in the workup of complex myopathy.

BACKGROUND: This study reports the first case of congenital hypothyroidism (CH) and alpha thalassemia in a child in China, with anemia and muscle damage as the main manifestations. Analyzing and studying this case is of great significance in reducing missed and misdiagnosed CH and will provide a clinical strategy for treating these patients.
METHODS: Child, female, 2 years and 7 months old, the child appeared dispirited, had poor appetite, shallow complexion, reduced activities with anemia, elevated muscle enzymes, height, and growth retardation.
METHODS: The child was diagnosed with CH with alpha thalassemia.
METHODS: The patient was treated with levothyroxine sodium and anemia correction.
RESULTS: The children\'s current spirit, appetite, red face, normal limb activity, physical development, and intelligence were significantly better than those of normal children of the same age.
CONCLUSIONS: CH with alpha thalassemia, especially anemia and muscle damage as the main manifestations, has not been reported. Administration of levothyroxine sodium is effective in correcting anemia in patients with CH and alpha thalassemia.
CONCLUSIONS: Due to CH and alpha thalassemia, there are no specific symptoms and they are prone to missed diagnosis and misdiagnosis. Therefore, patients with anemia and elevated muscle enzyme levels should be routinely tested for thyroid function to diagnose them early and provide proper treatment to avoid negative consequences.

In vitro and in silico tests were used to assess the possible genotoxicity and mutagenicity of five impurities that may be present in levothyroxine, a drug used for thyroid hormone replacement therapy. Neither ToxTree nor VEGA (Virtual Models for evaluating the properties of chemicals within a global architecture) identified cause for concern for any of the impurities. Ames test results (doses up to 1 mg per plate), with or without metabolic activation, were negative. The micronucleus test with TK6 (human lymphoblastoid) cells, at doses up to 500 µg/mL, with or without metabolic activation, also gave negative results.

BACKGROUND: Lugol solution is often administered to patients with Graves\' disease before surgery. The aim is to reduce thyroid vascularization and surgical morbidity, but its real effectiveness remains controversial. The present study was designed to evaluate the effects of preoperative Lugol solution on thyroid vascularization and surgical morbidity in patients with Graves\' disease undergoing total thyroidectomy.
METHODS: Fifty-six patients undergoing total thyroidectomy for Graves\' disease were randomly assigned to receive 7 days of Lugol treatment (Lugol+ group, 29) or no Lugol treatment (LS- group, 27) before surgery in this single-centre and single-blinded trial. Preoperative hormone and colour Doppler ultrasonographic data for assessing thyroid vascularization were collected 8 days before surgery (T0) and on the day of surgery (T1). The primary outcome was intraoperative and postoperative blood loss. Secondary outcomes included duration of surgery, thyroid function, morbidity, vascularization, and microvessel density at final pathology.
RESULTS: No differences in demographic, preoperative hormone or ultrasonographic data were found between LS+ and LS- groups at T0. At T1, free tri-iodothyronine (FT3) and free thyroxine (FT4) levels were significantly reduced compared with T0 values in the LS+ group, whereas no such variation was observed in the LS- group. No differences between T0 and T1 were found for ultrasonographic vascularization in either group, nor did the histological findings differ. There were no significant differences between the LS+ and LS- groups concerning intraoperative/postoperative blood loss (median 80.5 versus 94 ml respectively), duration of surgery (75 min in both groups) or postoperative morbidity.
CONCLUSIONS: Lugol solution significantly reduces FT3 and FT4 levels in patients undergoing surgery for Graves\' disease, but does not decrease intraoperative/postoperative blood loss, thyroid vascularization, duration of surgery or postoperative morbidity.
BACKGROUND: NCT05784792 (https://www.clinicaltrials.gov).

Thyroid dyshormonogenesis (THD) is a heterogeneous group of genetic diseases caused by the total or partial defect in the synthesis or secretion of thyroid hormones. Genetic variants in DUOX2 can cause partial to total iodination organification defects and clinical heterogeneity, from transient to permanent congenital hypothyroidism. The aim of this study was to undertake a molecular characterization and genotype-phenotype correlation in patients with THD and candidate variants in DUOX2. A total of 31 (19.38%) patients from the Catalan Neonatal Screening Program presented with variants in DUOX2 that could explain their phenotype. Fifteen (48.39%) patients were compound heterozygous, 10 (32.26%) heterozygous, and 4 (12.90%) homozygous. In addition, 8 (26.67%) of these patients presented variants in other genes. A total of 35 variants were described, 10 (28.57%) of these variants have not been previously reported in literature. The most frequent variant in our cohort was c.2895_2898del/p.(Phe966SerfsTer29), classified as pathogenic according to reported functional studies. The final diagnosis of this cohort was permanent THD in 21 patients and transient THD in 10, according to reevaluation and/or need for treatment with levothyroxine. A clear genotype-phenotype correlation could not be identified; therefore, functional studies are necessary to confirm the pathogenicity of the variants.

BACKGROUND: Hashimoto thyroiditis (HT), a common cause of hypothyroidism, has shown an increasing incidence in recent years, particularly among women. In addition to the common complications such as lipid metabolism disorders, patients with HT may also experience some serious complications, acute kidney injury and severe muscle damage for instance. This article explored the effectiveness of levothyroxine sodium tablets (L-T4) replacement therapy in severe complications of hypothyroidism, including treatment dosage, duration of complication recovery, and whether additional treatment is needed.
UNASSIGNED: We described a case of a 52-year-old woman with HT who exhibited kidney injury, muscle injury, and lipid metabolism disorders. The increased levels of serum creatinine, creatine kinase, cholesterol, triglyceride, low density lipoprotein cholesterol, high density lipoprotein cholesterol, and the decreased levels of estimated glomerular filtration rate were obviously observed. This patient was started on L-T4 (75 and 100 µg, alternate).
UNASSIGNED: Following a two-month treatment, the serum creatine kinase level decreased to within normal range. The estimated glomerular filtration rate level was restored, and the serum creatinine level was down-regulated, although slightly higher than the normal range. L-T4 partially reversed HT-induced the disorders of muscle, renal function, and lipid profile of this patient and remarkably alleviated her HT-related symptoms.

BACKGROUND: Supraphysiologic thyroxine (T4) doses are used in intermediate and high-risk patients with differentiated thyroid cancer (IR/HR-DTC) to suppress tumor progression by thyrotropin (TSH). However, preclinical data suggest that T4 can also act as a growth stimulus for cancer, but there is no clinical evidence supporting this claim.
OBJECTIVE: We analyzed the association between free T4 (FT4) and progression-free survival (PFS) in patients with IR/HR-DTC.
METHODS: This longitudinal cohort study, approved by multi-institutional review board, included patients with IR/HR-DTC treated uniformly with total thyroidectomy, radioiodine (RAI), and TSH suppression therapy, with at least three TSH and FT4 values available. Association between FT4 and PFS at landmarks 6, 12, and 18 months was assessed by Kaplan-Meier survival curves, while competing risks were assessed through Cox proportional hazards model.
RESULTS: From 739 screened patients 382 met the inclusion criteria and were characterized by a median age of 46 (34-59) years, 64.1% women, treated with a median RAI dosage of 159 (110-410) mCi. During follow up of 7.1 (3.4-12.7) years 34.6% experienced disease progression.Elevated FT4, observed in 29.3% of patients, was not associated with worse PFS (HR 0.9, CI 0.54-1.5, p=0.69), while age (HR 1.02, CI 1.004-1.04, p=0.01), tumor size (HR 1.15, CI 1.04-1.28, p=0.01), and metastases to the lateral neck lymph nodes (HR 2.9, CI 1.7-4.74, p<0.001), bones (HR 4.87, CI 1.79-13.3, p=0.002), and brain (HR 5.56, CI 2.54-12.2, p<0.001) were associated with shorter PFS.
CONCLUSIONS: Contrary to preclinical evidence, elevated FT4 levels do not affect PFS in patients with IR/HR-DTC.

Perturbation of thyroid hormone (T4) synthesis is known to cause numerous developmental, metabolic, and cognitive disorders in humans. Due to species differences in sensitivity to chemical exposures, there is a need for human-based in vitro approaches that recapitulate thyroid cellular architecture and T4 production when screening. To address these limitations, primary human thyrocytes, isolated from healthy adult donor tissues and cryopreserved at passage one (p\'1) were characterized for cellular composition, 3D follicular architecture, and thyroglobulin (TG)/T4 expression and inhibition by prototype thyroid disrupting chemicals (TDC). Flow analysis of the post-thaw cell suspension showed >80% EpCAM-positive cells with 10%-50% CD90-positive cells. When seeded onto 96-well Matrigel®-coated plates and treated with bovine thyroid stimulating hormone (TSH), thyrocytes formed 3D microtissues during the initial 4-5 days of culture. The microtissues exhibited a stable morphology and size over a 14-day culture period. TG and T4 production were highest in microtissues when the proportion of CD90-positive cells, seeding density and thyroid stimulating hormone concentrations were between 10%-30%, 6K-12K cells per well, and 0.03-1 mIU/mL, respectively. At maximal TG and T4 production levels, average microtissue diameters ranged between 50 and 200 µm. The T4 IC50 values for two prototype TPO inhibitors, 6-propyl-2-thiouracil and methimazole, were ∼0.7 µM and ∼0.5 µM, respectively, in microtissue cultures treated between days 9 and 14. Overall, p\'1 cryopreserved primary human thyrocytes in 3D microtissue culture represent a promising new model system to prioritize potential TDC acting directly on the thyroid as part of a weight-of-evidence hazard characterization.

OBJECTIVE: Adjuvant chemotherapy is often indicated in patients diagnosed with early breast cancer (EBC). Among others, weight gain is one of the observed side effects of both chemotherapy and other cancer treatments; however, the mechanism is not well-described. In this study, we aimed to assess thyroid function before and shortly after the course of chemotherapy for EBC.
METHODS: This is a prospective cohort study of women diagnosed with EBC. The main outcome was the thyroid function and body weight before and after completing chemotherapy. Secondary outcomes were the presence of thyroid autoantibodies and treatment radiation dosage. We included 72 patients treated with adjuvant chemotherapy, whereas 59 patients also received supraclavicular locoregional radiotherapy. Triple-negative breast cancer (BC) patients receiving chemoimmunotherapy were excluded.
RESULTS: After the chemotherapy, we observed an increase in thyroid-stimulating hormone (p = 0.03) and a decrease in free-thyroxine (p = 0.0006), with no significant weight change. The prevalence of autoimmune thyroiditis was low. On average 3 months post-chemo, we found no statistically significant difference in the thyroid function of women treated versus not treated with supraclavicular locoregional radiotherapy.
CONCLUSIONS: Although statistically significant changes in thyroid hormones were observed, this study suggests no obvious clinically significant changes in thyroid function in women with early BC after the course of chemotherapy. The decrease in thyroid function was not related to autoimmunity, non-thyroidal illness, radiotherapy, or high-dose corticosteroids. Further studies with a longer follow-up of thyroid function after adjuvant chemotherapy and supraclavicular locoregional radiotherapy are needed.

In recent years, there has been a significant increase in the prevalence of thyroid diseases, particularly hypothyroidism. In this study, we investigated the impact and mechanisms of Chemical permeation enhancement(CPE) on transdermal permeation of levothyroxine sodium (L-T4) patches.We found that the combination of oleic acid (OA) and Azone (NZ) yielded the best transdermal permeation effect for L-T4.Subsequently, we also investigated the relevant propermeability mechanism.The results demonstrate that the combined application of OA and NZ significantly enhances the transdermal permeation of L-T4 compared to individual applications,it is attributed to two mechanisms: firstly, OA improves drug release by increasing the flowability of the pressure-sensitive adhesive (PSA) matrix; secondly, both OA and NZ act on the stratum corneum, especially facilitating L-T4 permeation through the hair follicle pathway. No skin irritation or cytotoxicity is observed with these final patches, which exhibit a remarkable therapeutic effect on hypothyroidism. this study contributes to the development of transdermal formulations of L-T4.