bluuebunny/crossref_metadata_2025_split huggingface dataset:
THU681 Change In The Clinicopathological Characteristics And Outcomes Of Pediatric Thyroid Carcinoma In Korea: Focusing On Data From A Tertiary Hospital In Korea
Authors: Hyun Yoo Ji , Eun Leem Da , Jin Ryu Hyun , Park Hyunju , Han Kim Jung , Lyun Oh Young , Hyuk Kim Tae , Wook Kim Sun , Hoon Chung Jae 
Published: October 2023

Abstract
Disclosure: J. Yoo: None. D. Leem: None. H. Ryu: None. H. Park: None. J. Kim: None. Y. Oh: None. T. Kim: None. S. Kim: None. J.H. Chung: None.
Introduction: The incidence of thyroid carcinoma in adults in Korea increased until 2012, but has declined rapidly since then. However, the incidence of pediatric thyroid carcinoma increased until 2013, decreased slightly, and then increased again. Changes in the clinicopathological characteristics of pediatric thyroid carcinoma over time have not yet been elucidated. In this study, we aimed to evaluate the changes in the clinicopathological characteristics and outcomes of pediatric thyroid carcinoma from 1995 to 2022. Subjects and Methods: A total of 170 patients under the age of 19 years who were diagnosed with differentiated thyroid carcinoma at tertiary hospital in Seoul, Korea were enrolled. The patients were divided into four groups based on the year of initial surgery: 1995 – 2005 (n = 33), 2006 – 2010 (n = 46), 2011 – 2015 (n = 57), and 2016 – 2022 (n = 34). Results: The age at diagnosis, gender, primary tumor size, T stage, N stage, and M stage did not significantly differ among the four groups. Also, there was no significant difference over time in the route of detection (symptomatic vs. asymptomatic; P for trend = 0.519). The incidence of diffuse sclerosing variant of papillary thyroid carcinoma tended to increase over time (P=0.06). Surgical extent (P for trend = 0.001) and cumulative radioactive iodine (RAI) dose (P for trend &lt; 0.001) significantly decreased over time. Nevertheless, the disease-free survival among the four groups did not change during the median follow-up 115.5 (62.3 – 155.3) months (log-rank P = 0.451). Conclusions: Although the overall incidence of pediatric thyroid carcinoma is gradually increasing in Korea, surgical extent and cumulative RAI dose significantly decreased and the clinicopathological characteristics and the disease-free survival did not change over time.
Presentation: Thursday, June 15, 2023
OR03-06 Transmembrane Water Channels Within The Tsh Receptor
Authors: Latif Rauf , Davies Terry F , Mezei Mihaly 
Published: October 2023

Abstract
Disclosure: R. Latif: None. T.F. Davies: Advisory Board Member; Self; Board of Kronus Inc (Starr, ID, USA);. M. Mezei: None.
Using our recently reported hydrated model of the TSH receptor transmembrane (TM) region (Endocrinology 2021,162:7;1-12), we have now identified a network of putative TM water channels within this structure. By analyzing the molecular simulation trajectory for water molecules crossing the plasma membrane embedded TSHR we found evidence of putative water channels suggestive of active transport. To ascertain the biological activity of such TSHR channels we examined the movement of water down osmotic gradients using calcein aceto-oxymethyl ester (Calcein-AM) fluorescence in rat thyrocyte cells (FRTL5). Calcein-AM is a membrane permeant fluorescent dye that is quenched in a concentration-dependent manner and is, therefore, an effective probe of cell volume changes that would result from water movement across the cell membrane. Since thyroid cells are known to contain aquaporin (AQP) channels, principally AQP4, we first blocked these channels (using 3μM of TGN020) prior to examining the effects of TSHR activation using TSH (10-103 µU/ml), stimulating TSHR monoclonal antibodies (mAbs MS1 and M22 at 10μg/ml and 1μg/ml respectively) and TSHR-specific small molecule allosteric agonists (MS437 and MS438 at 10µM) and measured the changes in fluorescence quenching. D-Mannitol at 400mM was used as the hypertonic medium to induce cell shrinkage measured by continuous fluorescence measurements with read intervals of 50msec. Analyzing the normalized fluorescence of cells treated with TSH in a dose-dependent manner we observed ∼25% quenching with 103 µU/ml of TSH. On blocking the binding of TSH using a TSHR blocking mAb K1-70 (1μg/ml), we found marked de-quenching. Furthermore, using equimolar concentrations of stimulating TSHR antibodies the quenching was even more significantly enhanced to 54-60%. These data suggested that ligands that activate the TSHR by binding to the TSHR ectodomain could influence the TM water transport. However, using the allosteric activators, which act at the TM, we also showed similar changes indicating this was not ectodomain dependent. These data confirm the presence of the modeled putative TSHR water channels indicating that TSH and TSHR autoantibodies have an important role in regulating TM water passage.
Presentation: Thursday, June 15, 2023
FRI483 Changes In Thyroid Function Test With Tirzepatide Use In Patients With Hypothyroidism
Authors: Kaylee Yu Gayoung , Nakhle Samer , John Vernetti Nicholas , Chao Alex 
Published: October 2023

Abstract
Disclosure: G.K. Yu: None. S. Nakhle, M.D.: None. N.J. Vernetti: None. A. Chao, DO: None.
Background: Incretin hormone Glucacon-like peptide-1 receptor agonist (GLP-1RA) has been established to treat type 2 diabetes or obesity. A novel dual-receptor agonist to GIPR/GLP-1R, tirzepatide has been approved for type 2 diabetes mellitus treatment and has shown greater weight loss compared to GLP1-RA. Also, since GLP-1 and GIP have effects on multiple organs/tissue including the gut, tirzepatide may have additional effects on levothyroxine absorption. Method: We retrospectively reviewed the charts of patients with hypothyroidism and newly given prescriptions of tirzepatide (Mounjaro) at our outpatient clinic from July 1, 2022, to Nov 30, 2022. Baseline thyroid function test results and follow-up test results were reviewed. Result: A total of seventy patients’ data were identified and reviewed. Patients with insufficient data, early termination of the therapy, and patients whose levothyroxine doses were adjusted at the same time of tirzepatide initiation were excluded. A total of 17 patients on stable dose of levothyroxine replacement who had lab prior to starting tirzepetide and repeated lab within 4 to 8 weeks after that were found and included in the study. TSH of 5/17 patients (29%) was suppressed below the normal range at 6 weeks. TSH of 11/17 patients (65%) decreased compared to baseline. The mean baseline TSH was 2.288. Repeat test was done in 4-8 weeks, (mean 53.28 days, median 47 days), and mean TSH was 1.569. Conclusion: We were able to review only seventeen patients’ thyroid function tests, but there was TSH reduction in 65 % of patients, and 5(29%) out of 17 patients had suppressed TSH in 6-8 weeks (mean 53.28 days, median 47 days). Our results suggest monitoring TSH early after starting tirzepatide might be necessary to avoid iatrogenic hyperthyroidism. We suspect factors other than weight loss play a role in the thyroid hormone level because of early changes in TSH prior to achieving significant weight loss.
Presentation: Friday, June 16, 2023
FRI485 High Interlaboratory Variability In Free Thyroxine Measurement Indicates Need For Method Standardization
Authors: Ribera Ashley , Danilenko Uliana , Sugahara Otoe , Collins Lynn , Buchannan Tatiana , Vazquez Norma , Pokuah Fidelia , Wirtz Douglas , Zhang Li , Lyle Alicia N , Vesper Hubert W 
Published: October 2023

Abstract
Disclosure: A. Ribera: None. U. Danilenko: None. O. Sugahara: None. L. Collins: None. T. Buchannan: None. N. Vazquez: None. F. Pokuah: None. D. Wirtz: None. L. Zhang: None. A.N. Lyle: None. H.W. Vesper: None.
Thyroid function tests are critical to diagnose diseases of the thyroid. Concerns about the accuracy and reliability of thyroid function tests, especially free thyroxine (FT4), have been stated by the clinical laboratory community for many years. In response to these concerns, the CDC Clinical Standardization Program (CSP) has created a standardization program for FT4 based on the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) reference system and is partnering with IFCC to standardize FT4 and harmonize TSH testing globally. As part of this program, CDC developed an accurate and sensitive reference measurement procedure (RMP) to assign reference values to individual donor sera. Assay manufacturers and research and clinical laboratories can use these sera to assess the analytical performance of their measurements, and monitor analytical performance over time. To obtain initial information about the analytical performance of FT4 and TSH measurements, an interlaboratory study among commercial assays and laboratory developed test was conducted. A panel of 40 blinded, fresh-frozen single donor patient serum samples with FT4 concentration ranging between 11-32 pmol/L concentrations was measured by participants and compared to the results obtained by CDC RMP for FT4. In addition, commercial assay manufacturers were asked to measure thyroid-stimulating hormone (TSH). Results from sixteen commercial assays and four laboratory developed test (LDT) participated. Preliminary results indicate a negative mean bias for all commercial FT4 assays ranging from -34.46% to -5.08%. Some of the assays agreed more closely to the RMP than others (four assays had mean bias over -25%). An equilibrium dialysis mass spectrometry-based assays had mean biases ranging from -8.86% to - 1.72% agreeing well with RMP. The data suggest that the observed bias can be effectively minimized through recalibration to the RMPs operated by the CDC CSP and the IFCC reference laboratory network. The mean TSH concentrations ranged from 0.34 to 21.56 uIU/mL with mean %CV of 11.42% (95%CI 8.07%-14.76%) suggesting good agreement between various platforms. Findings from this study will be used to customize CDC’s protocols and procedures for standardizing FT4 measurements.
Presentation: Friday, June 16, 2023
FRI519 Misleading Free T4 Due To Assay Interference
Authors: Man Pradhan Rubin , Kaur Rai Harpreet , Rai Barsa , Batra Manav 
Published: October 2023

Abstract
Disclosure: R.M. Pradhan: None. H.K. Rai: None. B. Rai: None. M. Batra: None.
Background: Despite Equilibrium Dialysis being the gold standard for measurement of Free t4 (FT4), competitive Immunoassays are the go-to test for clinicians due to its cost and fast turnover. Measuring FT4 which accounts for 0.02% of total T4 is a challenge, but several factors interfering with the assay, sometimes makes it even more difficult. Case Report: 55 years old Male with PMH of CKD III, HTN, HLD, RCC s/p left partial nephrectomy in 2015, and IgG kappa monoclonal gammopathy following with endocrinology for hypothyroidism secondary to Hashimoto’s disease. Patient was doing well on Levothyroxine 125 mcg po daily. He denied any hypothyroidism/ hyperthyroidism symptoms. Patient was not on any heparin and amiodarone. TFT was done for routine follow up. Initial TFT was done via one step automated immunoassay on the Siemens Centaur platform (Center 1): TSH was 1.34 mlU/L (N 0.4-4.5 mlU/L) and Free T4 was 4.9 ng/dL (N 0.8-1.8 ng/dL). As the free T4 was inconsistent to the clinical picture and both the TSH and free T4 were incongruent to each other, it was difficult to interpret. After discussing with the patient, the labs were repeated with total T3 and total T4 as well. Repeat labs in 10 days with same assay (Center 1) showed TSH: 2.34 mlU/L, Free T4: 5.3 ng/dL (elevated), Total T4: 6.3 mcg/ dl (N 4.9-10.5 mcg/ dL) and Total T3: 124 ng/dL (N 76-181 ng/dL). On chart review, patient had similar finding about 2 years ago when the test was done at Center 1 which showed raised free T4 with normal TSH and repeat labs in a different center (Center 2) were normal. Given the h/o monoclonal gammopathy and varied test results in different center, TFTs were repeated in a second diagnostic center. Center 2 used an Abbott’s two chemiluminescent immunoassay (CLIA) which showed that the free T4: 1.01ng/dL (N 0.8-1.8 ng/dL), TSH: 1.39 mcUnit/mL (N 0.4-5 mcUnit/mL), Total T4: 7mcg/dL (N 4.9-11.7 mcg/dL) and Total T3: 85 ng/dL (N 75-165 ng/dL). Patient was recommended to continue with the same dose of levothyroxine and follow up routinely. HAMA and other thyroid autoantibodies were not measured. Conclusion: Various medications and medical conditions that interfere with the binding proteins are sometimes easy to discern by history, but the difference is assays need clinical suspicion from the physicians to avoid further unnecessary labs and radiological investigations. Thyroid hormone autoantibodies/other interfering molecules are likely culprit for our patient’s abnormally high free T4 in the one-step automated immunoassay as the wash out in the two-step CLIA likely resulted in normal values on a clinically euthyroid patient.
Presentation: Friday, June 16, 2023
FRI522 Impact Of TIRADS Score On Thyroid Nodule Biopsy
Authors: Blessing Adeniran Uchechi , Olabumuyi Adeniyi , Adeniran Omolara , Bahtiyar Gul , Rodriguez Giovanna 
Published: October 2023

Abstract
Disclosure: U.B. Adeniran: None. A. Olabumuyi: None. O. Adeniran: None. G. Bahtiyar: None. G. Rodriguez: None.
Introduction: Thyroid nodules are prevalent, however many thyroid nodules biopsied are benign. In 2017, the Thyroid Imaging Reporting and Data systems Committee of the American college of Radiology (TI-RADS) presented the use of TI-RADS score to risk stratify nodules to TR1 to TR5 with recommendations on biopsy vs follow up. The aim of our study was to ascertain any changes in thyroid biopsy rate before and after the use of ACR TI-RADS in thyroid ultrasound scans in a community hospital in Brooklyn, NY. Methods: We conducted a retrospective single center observational cohort study on patients referred for thyroid nodule assessment between March 2019 - March 2020 & March 2021 - March 2022. Inclusion criteria- all patients with thyroid ultrasound scans without TI-RADS scoring from March 2019- March 2020, all patients with TI-RADS scoring from March 2021-March 2022. Duplicate referrals, patients lost to follow up, incomplete records were excluded. Primary endpoint was to ascertain any differences in thyroid biopsy recommendation rate before and after the use of TI-RADS score in ultrasounds. Chi square test was used to determine the association between TI-RADS use in ultrasound scans and thyroid biopsy recommendation rate. Thyroid nodules were categorized based on the Bethesda System for Reporting Thyroid Cytopathology (BSRTC). Results: A total of 91 patients met the inclusion/exclusion criteria, 13 men and 78 women (M:F- 1:6). Thyroid nodules of 53 patients on ultrasound were reported using TI-RADS score and 38 patients without using the TI-RADS score. TI-RADS group and non TI-RADS group were similar in age, gender, race, and ethnicity. The use of the TI-RADS reporting system was associated with a statistically significant reduction in recommendation for biopsy. Only 26.4% of the patients who had TI-RADS were recommended for biopsy compared to 47.4% of the patients who did not have TI-RADS (P-Value 0.039).A total of 32 patients were recommended for biopsy, however biopsy was done in 26 patients. Majority of the nodules biopsied were benign (BSRTC II), 10 of 14 patients (71.5%) were benign (BSRTC II) in Non TI-RADS group, and 8 of 12 (66.7%) were benign (BSRTC II) in TI-RADS group. Conclusion: TI-RADS score significantly reduced the biopsy recommendations. Its implementation thus results in saving the Healthcare commission a significant cost of unnecessary biopsy in the region of $1,999 per biopsy. With the implementation of TIRADS, the proportion of malignant biopsies was expected to rise. However, there was no significant difference in this group. This may be because the total number of biopsies analyzed was small. It could also be that some of the nodules the TIRADS score did not recommend for biopsy may have been malignant. Further studying of a larger cohort is thus warranted.
Presentation: Friday, June 16, 2023
FRI526 Geographic Trends In Thyroid Hormone Prescribing In The US: 2010 - 2020
Authors: Ettleson Matthew D , Laiteerapong Neda , Wan Wen , Bianco Antonio C 
Published: October 2023

Abstract
Disclosure: M.D. Ettleson: None. N. Laiteerapong: None. W. Wan: None. A.C. Bianco: Consulting Fee; Self; Abbvie, Acella, Synthonics, Thyron, Madrigal.
Introduction: Levothyroxine (LT4) is the first line treatment of hypothyroidism. However, some clinical guidelines suggest a trial of adding triiodothyronine (T3) therapy if LT4 monotherapy does not adequately resolve symptoms despite a normal thyrotropin (TSH) level. It is unknown how patterns of thyroid hormone (TH) prescribing (LT4 vs T3-containing therapy) differ across the US. Methods: We conducted a cross-sectional study of TH prescription data from a large, US-based claims database from January 1, 2010 to December 31, 2020. TH type (LT4, liothyronine [LT3], or desiccated thyroid extract [DTE]), geographic, and clinical data were collected. Only patients with a new TH prescription and a diagnosis of hypothyroidism were included. The study population was subdivided into 4 TH treatment classes: 1) LT4 monotherapy, 2) LT3 therapy with or without LT4, 3) DTE therapy with or without LT4, and 4) other. Statewide physician density and urban-rural classification were the primary geographic covariates analyzed. Other covariates included in the analytical models were age, sex, comorbidities, and co-prescribed medications. Results: A total of 524,818 adult patients accounted for 537,594 new TH prescriptions over the 11 year study period. Of the total population, 89.0% received LT4 monotherapy, 8.8% received DTE therapy, and 2.0% received LT3 therapy. The proportion of patients receiving DTE increased from 5.4% to 10.2% during the study period. DTE and LT3 prescriptions were not uniformly distributed throughout the US, with higher rates in the West and South regions. Residence in a state with higher endocrinologist density (3.0/100k population) was associated with a decreased likelihood of receiving LT3 or DTE therapy (adjusted OR 0.33, 95% CI [0.20 – 0.55], p &lt;0.001; adjusted OR 0.18, 95% CI [0.08 – 0.41], p &lt;0.001, respectively). Residence in large central metro zones was associated with an increased likelihood of receiving LT3 or DTE therapy (adjusted OR 1.32, 95% CI [1.22 – 1.42]; p &lt;0.001; adjusted OR 1.05, 95% CI [1.01 – 1.10], p = 0.008, respectively). Conclusions: There do appear to be geographic disparities in the patterns of TH prescribing in the US. Differences in access to endocrine care may contribute to these disparities. Also, patients in more urban zones were more likely to receive LT3 or DTE therapies. Further investigation is necessary to understand the patient and physician-level factors underlying the geographic disparities identified.
Presentation: Friday, June 16, 2023
FRI527 Timing Of Thyroxine Dose During Ramadan: A Randomized Controlled Trial
Authors: Mohammad Alamoudi Reem , Majed Nawar Samah , Saleh Alharbi Hibah , Al Qarni Ali Ahmed , Alzahrani Abdullah , Khaled Almulla Abdulrhman , Tawfeeq Busaad Walaa , Alahmari Nasser F , Daghash Alshamrani Nouf , Alkhalifa Lujain , Mohd Saleh Yousef , Ramadan Majed , Borai Anwar 
Published: October 2023

Abstract
Disclosure: R.M. Alamoudi: None. S.M. Nawar: None. H.S. Alharbi: None. A.A. Al Qarni: None. A. Alzahrani: None. A.K. Almulla: None. W.T. Busaad: None. N.F. Alahmari: None. N.D. Alshamrani: None. L. Alkhalifa: None. Y.M. Saleh: None. M. Ramadan: None. A. Borai: None.
Background: The effect of Ramadan fasting on the thyroid profile, and the best time for L-thyroxine (LT4) intake in relation to fasting during Ramadan remains undetermined. Objectives: To compare two different time points of taking LT4 therapy during fasting the month of Ramadan in regards to thyroid profile and patient satisfaction. Methods: A multicenter open-label randomized controlled trial. Patients with primary hypothyroidism were recruited from three centers in three cities in Saudi Arabia (Jeddah, Riyadh, and Alhasa). Patients with thyroid cancer were excluded. TSH and FreeT4 (FT4) were measured two weeks before Ramadan, and four to six weeks after Ramadan. Results: 303 patients with primary hypothyroidism were randomized; 156 to take the LT4 dose at sunset with sips of water at the time of breaking fast and wait 30-60 minutes to eat the main Iftar meal (pre-Iftar), and 147 to take the LT4 dose just before the start of fasting (pre-dawn) regardless of their last meal intake. There were no significant differences between the two groups in demographics or comorbidities. The mean age was 49 ±12 years, 87% were female, and the average duration of hypothyroidism was 9.7 ±8.25 years. The mean weekly LT4 dose in the pre-Iftar vs. pre-dawn group was 753.3 ±349.4 vs. 733.2 ±265.6 mcg, p=0.001, and the Pre-Ramadan thyroid profile was: TSH 2.56 ±2.16 vs. 2.46 ±1.72 mIU/L, p=0.3, FT4 13.45 ±2.1 vs 13.08 ±2.4 pmol/L, p=0.16. Post-Ramadan thyroid profile values were: TSH 3.64 ± 4.1 vs. 4.07 ±4.17 mIU/L, p=0.78, FT4 12.96 ±0.1 vs. 12.64 ±0.22 pmol/L, p=0.003. The estimated difference within the group means post-Ramadan was - 0.41 ±0.51 mIU/L, p=0.43 for TSH, and 0.32 ±0.28 pmol/L, p=0.24 for FT4. Generalized linear model repeated measures analysis of variance showed no significant difference over time in TSH or FT4 within or between groups (p = 0.47 vs. 0.81). Patient compliance and satisfaction with the regimens were similar between groups. Conclusion: There is no significant change nor difference in thyroid profile between the two regimens related to the change in LT4 intake during the fasting months of Ramadan. Both regimens can be utilized depending on patient preferences. ClinicalTrials.gov: NCT05421468. Saudi FDA: SCTR # 22041002
Presentation: Friday, June 16, 2023