United States

Background: Perfluorooctanoic acid (PFOA), is a persistent fluorinated compound with oil and water repelling properties found in cookware, food packaging and municipal water systems. Adult animals exposed to PFOA develop hepatomegaly, fatty liver, peroxisome proliferation, and immunotoxicity. Rodents exposed to PFOA in utero have altered hepatic lipid metabolism, increased hepatic de novo lipogenesis and susceptibility to non-alcoholic fatty liver disease (NAFLD), but underlying molecular mechanisms remain unknown. With increasing rates of obesity, diabetes, and NAFLD it is critical to examine the mechanisms by which in utero exposure to PFOA contributes to the development of metabolic syndrome in offspring.
Objectives: To characterize how PFOA exposure during hepatocyte differentiation leads to the development of NAFLD through alterations in DNA methylation profiles and changes in the availability of transcription factor binding sites.
Methods: HepaRG cells (human-derived hepatocyte progenitor cells) were treated with 0.5uM PFOA or vehicle for 48 hours followed by differentiation. Undifferentiated and differentiated hepatocytes exposed to PFOA were assessed relative to controls (n=4). RNASeq was completed; DESeq2 identified differentially expressed genes via false discovery rate (FDR) of &lt;0.05 after Bonferroni correction. Genome-wide DNA methylation analysis via MethylSeq was completed to identify differentially methylated regions (DMRs) defined as minimum number of CpN =5, absolute change in percent methylation &gt;10%, and FDR of &lt;0.05. Enrichment analysis of transcription factor binding motifs within DMRs and single CpG sites (± 200 bp) was performed using HOMER.
Results: PFOA treatment resulted in decreased expression of the transcription factors early growth response protein 1 (EGR1), nuclear receptor Nur77 (NR4A1) , early growth response protein 2 (EGR2), krueppel-like factor 10 (KLF10) and fos-related antigen 1 (FOSL1), which are key genes linked to impaired hepatic insulin signaling, lipid metabolism, steatosis and fibrosis (q&lt;0.05) in undifferentiated hepatocytes. Differentiated hepatocytes showed decreased expression of peroxisome proliferator-activated receptor γ coactivator 1-α (PGC1α), peroxisome proliferator-activated receptor γ (PPARγ), forkhead box protein O1 (FOXO1) and increased expression of pyruvate dehydrogenase kinase isozyme 4 (PDK4), genes linked to regulation of lipid metabolism and insulin signaling (q &lt;0.05). MethylSeq analysis identified changes in DMRs located in exons, introns, and intergenic regions, with 57 DMRs in undifferentiated hepatocytes (46 with gains; 11 with losses; q &lt;0.05) and 75 DMRs in differentiated hepatocytes (32 with gains; 41 with losses; q&lt;0.05). HOMER identified 29 known transcription factor binding motifs with changes in methylation in undifferentiated hepatocytes (p&lt;0.05) and 19 in differentiated hepatocytes after PFOA treatment (p&lt;0.05), with significant changes in the EGR1 consensus sequence identified in both comparisons.
Conclusions: We conclude hepatocyte progenitor cells exposed to low dose PFOA results in changes in DNA methylation and expression of key metabolic genes linked to NAFLD, notably EGR1, a gene previously linked to NAFLD, suggesting PFOA exposure in utero has lasting effects.

ENDO 2022

Hepatocytes Exposed to PFOA Prior to Differentiation Leads to Epigenetic Changes in Genes Linked With NAFLD

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over 20 Meet the Professor sessions presented both in-person and live-streamed virtually and another 20+ presented live in Atlanta;
four Basic Science Pathways, including Diabetes and Metabolism; Neuroendocrinology; Nuclear Receptors and Signaling; and Reproductive Endocrinology; and
more than 30 oral sessions and a robust virtual poster hall for accepted scientific abstracts.

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**Basic Science Pathways**

These special “meeting-within-a-meeting” tracks integrate focused discussions, poster sessions, and networking opportunities to provide you with the latest research in:
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Discover insights from experts on treating a variety of endocrine conditions and emerging science in the field of endocrinology, and learn the latest in patient care and scientific research.

ENDO’s comprehensive program provides attendees the opportunity to learn about the latest developments in hormone science and medicine from renowned investigators, expert clinicians, and educators from all over the world. 

Background: Perfluorooctanoic acid (PFOA), is a persistent fluorinated compound with oil and water repelling properties found in cookware, food packaging and municipal water systems. Adult animals exposed to PFOA develop hepatomegaly, fatty liver, peroxisome proliferation, and immunotoxicity. Rodents exposed to PFOA in utero have altered hepatic lipid metabolism, increased hepatic de novo lipogenesis and susceptibility to non-alcoholic fatty liver disease (NAFLD), but underlying molecular mechanisms remain unknown. With increasing rates of obesity, diabetes, and NAFLD it is critical to examine the mechanisms by which in utero exposure to PFOA contributes to the development of metabolic syndrome in offspring.
Objectives: To characterize how PFOA exposure during hepatocyte differentiation leads to the development of NAFLD through alterations in DNA methylation profiles and changes in the availability of transcription factor binding sites.
Methods: HepaRG cells (human-derived hepatocyte progenitor cells) were treated with 0.5uM PFOA or vehicle for 48 hours followed by differentiation. Undifferentiated and differentiated hepatocytes exposed to PFOA were assessed relative to controls (n=4). RNASeq was completed; DESeq2 identified differentially expressed genes via false discovery rate (FDR) of <0.05 after Bonferroni correction. Genome-wide DNA methylation analysis via MethylSeq was completed to identify differentially methylated regions (DMRs) defined as minimum number of CpN =5, absolute change in percent methylation >10%, and FDR of <0.05. Enrichment analysis of transcription factor binding motifs within DMRs and single CpG sites (± 200 bp) was performed using HOMER.
Results: PFOA treatment resulted in decreased expression of the transcription factors early growth response protein 1 (EGR1), nuclear receptor Nur77 (NR4A1) , early growth response protein 2 (EGR2), krueppel-like factor 10 (KLF10) and fos-related antigen 1 (FOSL1), which are key genes linked to impaired hepatic insulin signaling, lipid metabolism, steatosis and fibrosis (q<0.05) in undifferentiated hepatocytes. Differentiated hepatocytes showed decreased expression of peroxisome proliferator-activated receptor γ coactivator 1-α (PGC1α), peroxisome proliferator-activated receptor γ (PPARγ), forkhead box protein O1 (FOXO1) and increased expression of pyruvate dehydrogenase kinase isozyme 4 (PDK4), genes linked to regulation of lipid metabolism and insulin signaling (q <0.05). MethylSeq analysis identified changes in DMRs located in exons, introns, and intergenic regions, with 57 DMRs in undifferentiated hepatocytes (46 with gains; 11 with losses; q <0.05) and 75 DMRs in differentiated hepatocytes (32 with gains; 41 with losses; q<0.05). HOMER identified 29 known transcription factor binding motifs with changes in methylation in undifferentiated hepatocytes (p<0.05) and 19 in differentiated hepatocytes after PFOA treatment (p<0.05), with significant changes in the EGR1 consensus sequence identified in both comparisons.
Conclusions: We conclude hepatocyte progenitor cells exposed to low dose PFOA results in changes in DNA methylation and expression of key metabolic genes linked to NAFLD, notably EGR1, a gene previously linked to NAFLD, suggesting PFOA exposure in utero has lasting effects.

technical paper

BPA, a widespread endocrine-disrupting compound (EDC), plays a significant role in the decline of female fertility. Granulosa cells are susceptible to EDCs and are important for oocyte competency. This research focuses on epigenetic mechanisms in granulosa cells that are disrupted by BPA, with a specific focus on microRNA-21(miR-21), which is crucial for oocyte maturation and primarily recognized as an antiapoptotic regulator. miR-21 targets the apoptotic genes PDCD4 and PTEN and limits their expression, resulting in an antiapoptotic effect. Previous studies in our laboratory demonstrate that BPA induces apoptosis and simultaneously increases miR-21 expression, leading to our hypothesis that BPA induces apoptosis in a miR-21 independent manner in bovine granulosa cells.To test this hypothesis, in vitro cultured granulosa cells were transfected with miR-21 inhibitor or scramble with or without BPA, followed by knockdown validation and apoptotic measurements. Using flow cytometry, transfection efficiencies were measured in time- and dose-dependent experiments, showing optimal knock-down greater than 95% at 0.5µM for 12 hrs. miR-21 expression measured by qPCR showed a significant decrease within inhibited groups (p=0.0008, n=3). Although PDCD4 and PTEN mRNA expression remained unaffected, PDCD4 protein expression is inhibited cells was significantly increased (p=0.0233, n=4), suggesting a miR-21 role in PDCD4 translation. PTEN protein was unaffected by miR-21 inhibition.In further experiments, transfected cells were exposed to BPA, and apoptosis was examined. Using Annexin V/PI staining, a significant decrease in healthy cells and an increase in early apoptotic cells within inhibited untreated groups was shown (p=0.0395 and 0.0193, n=3). This finding is likely due to antiapoptotic gene inhibition. BPA exposure resulted in significantly decreased healthy cells, increased late apoptotic cells (p=0.0047 and 0.0145, n=3), with no changes in necrotic cells. Furthermore, no differences were found between inhibited and non-inhibited groups, suggesting that BPA-induced apoptosis is miR-21 independent.Additionally, three proapoptotic (BAX, BAD, Casp-9) and two antiapoptotic (Bcl-2 and HSP70) genes were quantified by qPCR. Unexpectedly, BPA increased the expression of all genes at the mRNA level (p= 0.0021, 0.0283, 0.0143, 0.025, 0.0145, n=4). Quantification of protein levels will reveal whether this change is functional. Moreover, no differences were found between inhibited and non-inhibited groups, suggesting these changes are likely miR-21 independent. Lastly, initiator caspase 9 activity was measured after 6, 12, 24, 48, 72 hrs of BPA exposure, as caspases are primary effectors of apoptosis. 6 and 12hrs timepoints showed no changes; however, at 24 and 48 hrs significantly increased caspase activity was detected (p=0.0087 and 0.0014, n=4). At 72hrs, BPA exposure was lethal, resulting in insufficient cell numbers for measurements.Overall, this research focuses on effects of EDCs on apoptotic regulation within granulosa cells and aims to uncover epigenetic consequences of BPA's mechanism of action, ultimately affecting oocyte competency and fertility.

The effects of Bisphenol A on miR-21 expression and miR-21 mediated apoptosis in bovine granulosa cells.

Endocrine-disrupting compounds (EDCs) elicit adverse responses in the body, including the disruption of female reproductive functions. A common EDC is Bisphenol A (BPA), which is a frequently used plasticizer. Due to the negative effects of BPA on human health, production of BPA-free products using analogs, such as BPS and BPF, has increased; yet their effects are still largely unknown. Adequate oocyte maturation requires proper functioning of the surrounding environment, consisting of granulosa cells that impact oocyte competency. Granulosa cells are also susceptible to BPA disruption, affecting oocyte maturation and, ultimately, fertility.
In our lab, we showed that BPA and BPS significantly increased apoptosis in bovine embryos through increased DNA fragmentation (Saleh et al., 2021). However, the apoptotic pathway used is not fully characterized. Thus, the aim of this study is to investigate how bisphenols affect granulosa cell viability and through which apoptotic pathway. In vitro cultured granulosa cells were exposed for 12 or 48 hrs to six treatment groups: control, vehicle, estradiol, BPA, BPS and BPF at a low dose (0.005 mg/mL) and at the BPA Lowest Observed Adverse Effect Level (LOAEL-0.05 mg/mL). Live cells were counted using trypan exclusion. A significant decrease in the number of live cells after BPA treatment at the LOAEL dose for 12 hrs was observed (P=0.02, n=9).
 mRNA expression of three proapoptotic (BAX, BAD, Casp9) and two antiapoptotic (HSP70 and BCl-2) genes was quantified by qPCR. A significant increase in BAX transcript levels after 12 hrs of exposure to BPA and BPF at the LOAEL dose (P=0.046, P= 0.033, n=6) as well as in BAD (P= 0.049, n=3) and Casp9 (P=0.049, n=4) levels after BPA exposure at the LOAEL dose was detected. Interestingly, at the 48 hr timepoint, a significant increase in BAD (P= 0.018, n= 9), BAX (P=0.002, n=10), and Casp9 (P=0.015, n=5) transcript levels was observed only following BPF treatment at the LOAEL dose. Despite expecting a decrease, both anti-apoptotic transcripts, at 12 and 48 hrs, showed increased levels following exposure to BPA and/or BPF at the LOAEL dose. This suggests an early first line of defense or shock response. Future protein analysis will help in further understanding these unexpected findings.
To quantify apoptosis levels, flow cytometry together with Annexin V/PI staining was used. Results indicate that after 48 hrs of treatment, BPA at the LOAEL dose significantly increases late apoptosis (P=0.004, n=5) and necrosis (P=0.0014, n=5), while showing a significant decrease in the number of healthy cells (P=0.0007, n=5). Preliminary data also show a similar pattern after BPA treatment for 12 hrs. This research aims to further our knowledge of the mechanisms by which bisphenols affect oocyte competency and suggests that BPF might have equivalent potency and effects to BPA.

BPA and BPF, but not BPS, alter pro- and anti-apoptotic transcript levels in granulosa cells, affecting cell viability.

Humans are exposed to a mixture of endocrine disrupting chemicals (EDCs) in everyday life, believed to contribute to a range of non-communicable diseases. While the adverse health impacts of exposure to individual EDCs have been extensively investigated, studies on effects of real-world exposures characterized by chronic low doses of a mixture of chemicals, are only recently emerging. Biosolids derived from human wastes, exemplify both the array and dosage of chemicals humans are exposed to in real life and represents a novel model to investigate the risk posed by the EDCs. Previous studies in sheep have demonstrated aberrant reproductive and metabolic phenotypic effects in offsprings, as a result of maternal biosolid exposure. We hypothesize that EDC-mediated disruption in the maternal metabolic milieu is a potential mediator of the aberrant phenotypic outcomes in offsprings in the biosolid-exposure model. Recent untargeted metabolomic studies provide evidence of the technique's ability to unravel biomarkers of both exposure and effect by identifying the disrupted endogenous metabolite profile and xenobiotic mixture, respectively. In this study, we sought to identify biosolid exposure-induced maternal metabolic fingerprints that could influence fetal programming.
Ewes were grazed on either organic fertilizer or biosolid-treated pastures from 1 month before mating until close to parturition. Plasma from blood samples collected on day 90 of the 147-day gestation period, from ewes carrying singleton pregnancies (Control n=15, Treatment n=15) were subjected to untargeted metabolomics using liquid chromatography-quadrupole time-of-flight mass spectrometry. Metabolites were identified by matching the retention time, mass and isotope profile to authentic standards or metabolome databases using Agilent's MassHunter Find by Molecular Feature workflow (v7.0).
Untargeted metabolomics identified 1006 and 1295 annotated features from the negative and positive mode respectively. Principal component analysis and orthogonal signal correction partial least-squares discriminant analysis discriminated the metabolomes of control sheep and sheep grazed in biosolid-treated pasture. The key differential metabolites identified by variable importance in projection score primarily belonged to the super-class organic acids, fatty acids, benzenoids, glycerophospholipids and organoheterocyclic compounds. These differentially expressed metabolites are implicated in metabolic pathways including carnitine synthesis, alanine metabolism, glucose alanine cycle, phosphatidyl choline biosynthesis and glutathione metabolism. Some of the top differential metabolites- oleamide, pyroglutamic acid and 15-HETrE have been implicated in fetal development. Oleamide, an endocannabinoid, has growth inhibitory properties. 15-HETrE modulates arachidonic acid metabolism and upregulate PPARγ expression, which plays a pivotal role in fetal development and metabolic outcomes.
These findings indicate that biosolids exposure results in alterations in the maternal metabolome which likely contributes to the aberrant phenotypic outcomes reported in offspring of biosolid-exposed mothers. This is the first study to apply metabolomics to validate the effect of real-life EDC exposure in sheep, a translationally relevant precocial model with a developmental trajectory similar to humans.

Exposure to a Real Life Environmental Chemical Mixture Alters the Metabolite Profile in the Plasma of Sheep: An Untargeted Metabolomics Study.

Prenatal exposure to bisphenol-A (BPA), an ubiquitously present endocrine-disrupting chemicals, induces peripheral insulin resistance as well as lipotoxicity and oxidative stress in the liver and muscle along with tissue-specific transcriptional changes in female sheep. To gain a mechanistic understanding of contributors to these liver and muscle-specific transcriptional changes, we hypothesized that prenatal BPA exposure impacts non-coding RNA (ncRNA), regulators of transcriptional and post-transcriptional control of coding RNAs. We sequenced ncRNA (including lncRNA, microRNA, snoRNA, and snRNA) in the liver and muscle obtained during the late follicular phase from 21-month-old control and prenatal BPA-treated (0.5mg/kg/day from days 30 to 90 of gestation; Term: 147days) female sheep (n=4 control and 4 prenatal BPA treated). The sequence data were subjected to differential expression analysis and multivariate modeling to identify specific ncRNA signatures. In the liver, 77 lncRNA (49 down, 28 up), 14 microRNAs (6 down, 8 up), 127 snoRNAs (63 down, 64 up) and 55 snRNAs (15 down, 40 up) were dysregulated (FDR<0.1, absolute log2FC>0.5) with BPA exposure. In the muscle 6 lncRNA were upregulated and 65 snoRNAs (47 down, 18 up) were dysregulated (FDR<0.1, absolute log2FC>0.5). Orthogonal Projections to Latent Structures Discriminant Analysis (OPLS-DA) plots identified microRNAs MIR200B, MIR409, MIR30B, and MIR154A in the liver and miRNAs MIR26B, MIR29A, MIR125B, and MIR127 in muscle and several uncharacterized ncRNAs as signatures of prenatal BPA exposure. Multiple ncRNA signatures correlated with coding genes including LCORL, MED17, and ZNF41 in the liver, but none were correlated in the muscle. Among the coding genes which correlated with ncRNA, LCORL is reported to be related to steatosis of the liver in geese, a feature also observed in livers from prenatal BPA-treated female sheep. Since lipid accumulation in the liver may result from increased fatty acid biosynthesis, MED17 which is involved in transcriptional activation of lipogenic genes that correlated with multiple ncRNA in the liver may be a contributor to the steatosis observed in this model. In addition, MIR200B and MIR30B in the liver and MIR26B and MIR29A in the muscle are linked to lipid dysfunction, endoplasmic reticulum stress, and fibrosis. These findings provide mechanistic clues into the role of ncRNA in the prenatal BPA-induced lipid accumulation and oxidative stress in the liver and muscle, contributors to metabolic dysfunction observed in this female sheep model of gestational BPA exposure. In addition, findings from this precocial model of human translational relevance is a step towards gaining mechanistic insights in the programming of metabolic dysfunctions from environmental exposure to BPA, an endocrine disruptor of public health relevance.

Non-coding RNA Signatures of Prenatal BPA Exposure in Liver and Muscle of Female Sheep

Introduction: Many patients in the US with hypothyroidism receive suboptimal treatment with thyroid hormone. Sustained off-target TSH levels have been shown to cause serious harm to patients, including increased risk of cardiovascular disease and excess mortality over time. Suboptimal treatment may also impact hospital outcomes. The primary objective of the study was to identify differences in hospital outcomes between patients with and without hypothyroidism.Methods: This is a retrospective cohort study that utilized the propensity score-based fine stratification method to balance covariates. Patient data was extracted from a large, US-based, IBM MarketScan® Commercial Claims and Encounters Database from January 1, 2008 to December 31, 2015. Participants included patients 64 years and younger who had commercial insurance and a thyrotropin (TSH) level collected prior to a medical or surgical hospital admission. Covariates included age, sex, US region, type of admission (medical vs surgical), year of admission, and co-morbidities. The primary exposure was defined as clinical hypothyroidism, which was divided into 4 subgroups based on pre-hospitalization TSH level: low (TSH <0.40 mIU/L), normal (TSH 0.40 – 4.50 mIU/L), intermediate (TSH 4.51 – 10.00 mIU/L), and high (TSH >10.00 mIU/L). Non-hypothyroidism was the non-exposure (control). The primary outcomes were length of stay (LOS), in-hospital mortality, and readmission outcomes following medical and surgical admission.Results: A total of 46,235 patients were included in the final study population, of whom 9,394 had a diagnosis of hypothyroidism. Those with a high pre-hospitalization TSH level had a LOS that was 1.2 days longer (95% CI [1.1 – 1.3]; p = 0.001), a 41% higher risk of 30-day readmission (RR 1.41, 95% CI [1.13 – 1.75]; p = 0.002), and 33% higher rate of 90-day readmission (RR 1.33, 95% CI [1.13 – 1.56]; p <0.001) compared to balanced controls. Patients with intermediate TSH levels exhibited increased likelihood of 30-day readmission (RR 1.20, 95% CI [1.01 – 1.43]; p = 0.04). Conversely, those with a normal pre-hospitalization TSH level had a decreased risk of in-hospital mortality (RR 0.55, 95% CI [0.34 – 0.89]; p = 0.02) and 90-day readmission (RR 0.91, 95% CI [0.85 – 0.99]; p = 0.02).Conclusions: Suboptimal treatment of hypothyroidism appears to be associated with worse hospital outcomes, including longer LOS and higher rate of readmission. Public health strategies designed to deliver appropriate, consistent outpatient treatment of hypothyroidism are needed to improve hospital outcomes in those patients with off-target TSH levels.

Suboptimal Thyroid Hormone Replacement is Associated with Worse Hospital Outcomes

Levothyroxine (LT4) is the recommended treatment for hypothyroidism and the second most prescribed medication in the US. Several formulations are available, however most patients take LT4 tablets. Evidence suggests that absorption of levothyroxine tablets is decreased when taken with food, especially those rich in soy, iodine, and fiber. In order to avoid erratic absorption of LT4, it is recommended that oral formulations are taken on an empty stomach, 30-60 minutes before breakfast. However, compliance with this recommendation is often difficult for patients with busy schedules or on multiple medications, yet important in patients with conditions that are sensitive to changes in TSH levels such as pregnancy and thyroid cancer.There is evidence that oral liquid LT4 formulations that bypass the gastric dissolution phase of absorption may mitigate this food effect. ThyquidityTM (levothyroxine sodium) oral solution has demonstrated bioequivalence to Synthroid® under fasting conditions and allows individualized dosing flexibility. A bioavailability study was conducted to assess the rate and extent of absorption of the oral LT4 solution (100 mcg /5 mL) administered either 10 or 30 minutes before a standardized high-calorie, high-fat breakfast in an open-label, randomized, single-dose, 2-period, 2-sequence, crossover study. A single 600 μg oral dose of LT4 solution (ThyquidityTM, 30 mL) was administered to healthy adults either 10 or 30 minutes before consuming a 950 kcal, high fat (56%) breakfast in each study period and blood was collected for total (bound and free) T4 for 48 hours after drug administration. Treatment periods were separated by a 40-day wash-out period.The ratios of geometric LS means with corresponding 90% confidence intervals were calculated from the exponential of the difference between the LT4 solution administration 10 and 30 minutes prior to the meal for AUC0-48 and Cmax. An absence of food effect (bioequivalence) would be concluded if the baseline corrected 90% confidence intervals of this ratio fell within 80.00% to 125.00% for Ln-transformed AUC0-48 and Cmax.Forty healthy volunteers participated in the trial, 38 were included in the data analysis. There were no serious adverse events or discontinuations due to AEs. The geometric LS mean ratios of AUC0-48 and Cmax for baseline-adjusted LT4 were 88.74% (84.71-92.95%) and 85.07% (81.1-89.33%) respectively. The corresponding 90% CIs were included within the acceptable range for bioequivalence, indicating the absence of a meaningful difference in LT4 absorption when administering at 10 or 30 minutes before a meal.Based on these results, it may be possible to decrease the interval between the administration of Thyquidity (levothyroxine sodium) oral solution to 10 minutes before breakfast, thus offering patients further dosing flexibility.

Comparable Bioavailability of a Novel Levothyroxine Solution taken 10 or 30 minutes prior to a High-Fat, High-Calorie Breakfast

Introduction:Thyroid storm is a life-threatening condition with a high morbidity and mortality rate. It can lead to severe end organ damage including liver injury, which can preclude the use of thionamides. Therapeutic plasma exchange can be a lifesaving option for treatment of thyroid storm in such cases. Multiorgan failure can also necessitate the use of extracorporeal membrane oxygenation (ECMO) and continuous renal replacement therapy (CRRT).Case Presentation:A 34-year-old woman with a history of Graves' disease, untreated for several years, presented to the emergency department with fatigue, palpitations, dyspnea, and edema which developed over 1 month. Labs showed suppressed thyroid stimulating hormone (TSH) with significantly elevated free T4 of 10.8 ng/dL (normal 0.89-1.76 ng/dL). She had evidence of atrial fibrillation and heart failure. She was started on treatment with propylthiouracil, propranolol, and hydrocortisone and then Lugol's iodine was added. However, she quickly deteriorated with worsening mentation, dyspnea, and hypotension. She progressed to multiorgan failure including significant liver injury likely due to ischemic hepatitis. Thus, thianomides could not be used any further. She was started on cholestyramine; hydrocortisone and Lugol's iodine were continued.An echocardiogram revealed global hypokinesis with a left ventricular ejection fraction of 20%. Beta blockers were discontinued due to hypotension. The cardiogenic shock worsened despite aggressive medical therapy requiring initiation of veno-arterial (V-A) ECMO. She also required CRRT due to renal failure.Plasmapheresis was initiated for treatment of thyroid storm and she received 4 treatments with normalization of free T4: 1.48 ng/dL and T3 levels: 3.4 ng/dL (normal 2.3-4.2 ng/dL). Her condition subsequently improved and she was decannulated from the ECMO device after 5 days. She was then able to receive definitive treatment with thyroidectomy 11 days following admission. The patient was discharged in improved condition after a 10-week hospital course.Discussion:Thyroid storm is a rare complication of thyrotoxicosis with a mortality rate of 10-30%. Treatment classically involves inhibiting the synthesis, release, and peripheral conversion of thyroid hormone as well as supportive management. Major causes of mortality in thyroid storm, present in our patient, include cardiogenic shock, arrhythmia, and multiorgan failure. Cardiac and hepatic failure can preclude the use of beta blockers and thionamides, which may necessitate the use of extracorporeal treatments, such as plasmapheresis for clearance of high burden of circulating thyroid hormone; V-A ECMO and CRRT for end organ damage. These therapeutic measures were used in our patient and led to a favorable outcome. This case highlights the successful use of these extracorporeal treatments as a bridge to thyroidectomy when standard medical treatment is contraindicated or unsuccessful.

Plasmapheresis and Extracorporeal Membrane Oxygenation (ECMO) for Treatment of Thyroid Storm with Multiorgan Failure

The relationship between obesity and thyroid function tests (TFT) has been studied in the past decades with increasing interest, however, studies have been inconsistent . The objectives of this study were to examine the effect of weight loss induced by laparoscopic sleeve gastrectomy(LSG) on TFT in obese euthyroid subjects and to correlate that with the changes in serum leptin, adiponectin, and insulin resistance.55 euthyroid obese subjects(BMI > 30) and 52 non-obese (BMI < 30), age-matched controls were recruited at baseline. We measured body weight, BMI, body composition, thyroid-stimulating hormone (TSH), Free T4 (FT4), Free T3(FT3), fasting leptin, adiponectin. Insulin resistance was quantified by HOMA-IR. Data are presented as mean ± SEM. The same parameters were repeated at 3- and 6-months in the obese group. Obese subjects had significantly higher TSH compared to non-obese subjects, 2.7 ±0.18 V.s 1.7±0.13 ( normal range 0.27-4.2 mIU/L . Mean FT3 was 3.9± 0.1pmol/L ( normal 3.1-6.8) in obese subjects compared to 5.0 ± 0.1 pmol/L in the non-obese controls, respectively, P value 0.001, however, FT4 (Normal 12-22 pmol/L) was similar in the two groups.Repeated measures ANOVA showed significant reduction in body weight from 140±26.5 kg at baseline to 115.8 ± 22.3 kg at 3 months, P < 001, and 104.2 ± 21.1 kg at 6 months, P<0.001, respectively. Serum TSH (N=48) reduced from 2.6 ±0.86 at baseline, to 2.0 ± 0.85 at 3 months, P = 0.06, and was 2.2± 0.78, at 6 months , P=0.23, in comparison with baseline, N=47). Free T3 reduced from 3.7.0 ± 0.41 pmol/L at baseline to 3.2 ±0.4 at 3 months (P < 0.9) and increased to 3.9± 0.53 at 6 months, P < 0.33. Changes in FT4 were not significant at 3 and 6 months, respectively. HOMA-IR reduced within 6 months and correlated with baseline FT3 .Serum leptin (N=38) significantly reduced from 25.9 ng/ml at baseline to 17.5 ng/ml at 3 months( p=0.037) to 15.2 ng/ml at 6 months, respectively, P < 0.011 compared to baseline. On the other hand , serum adiponectin (N=22) significantly increased from the baseline value of 9.2 ng/ml to 12.4 ng/ml at 3 months (p=0.001) and 16.6 ng/ml at 6 months( p<0.001 from baseline). TSH and Free T3 tend to decrease within 6 months following weight loss with LSG in obese subjects . Serum leptin significantly decreased and serum adiponectin significantly increased following LSG, however, there were no correlations between the changes in these adipose tissue markers and TFTs . We speculate that the changes in TSH and FT3 in obese euthyroid subjects may be due to the influence of the obesity and are unlikely to be causative, since they tend to reverse after weight loss, however, further studies on larger numbers of patients are needed to further explore the relationship between obesity and TFTs.

The Relationship Between Thyroid Function and Body Mass Index, Leptin, Adiponectin, and Insulin Resistance in Euthyroid Subjects Before and After Laproscopic Sleeve Gastrectomy

Interpretation of abnormal thyroid function tests (TFTs) is routine in endocrine practice. However, when there is a discrepancy between biochemical parameters and the clinical picture, sleuthing is necessary to provide appropriate care.A 34-year-old woman was evaluated by an outside endocrine clinic for abnormal TFTs in the setting of worsening anxiety, night sweats, and menstrual irregularities. These showed elevated free thyroxine (FT4) levels (7.3; ref: 0.9-1.7 ng/dL), free triiodothyronine (FT3) levels (13.9; ref: 2.3-4.1 pg/mL) and total triiodothyronine (T3) (186; ref: 94-170 ng/dL) with normal TSH (0.65; ref: 0.27-4.20 mIU/L), negative microsomal and thyroid receptor antibodies. She denied use of contraceptives, biotin, lithium, glucocorticoids, prior radiation, or recent intravenous contrast. Mother and maternal aunt had unspecified thyroid disease. No physical signs of overt hyperthyroidism/hypothyroidism were noted. Our workup also showed elevated FT4 (1.8 ng/dL), FT3 (13.3 pg/mL), total thyroxine (T4) (24.8; ref: 5.5-10.2 µg/dL), T3 (>651; ref: 79-165 ng/dL), normal TSH (0.71; ref: 0.4-5.5 mIU/L), and normal gonadotropin alpha subunit; ultrasound showed no nodules nor evidence of thyroiditis. FT4 by equilibrium dialysis and liquid chromatography-mass spectrometry was normal (1.3; ref: 0.8-2.0 ng/dL). Human anti-mouse antibodies (HAMA) treated TSH was within normal limits (1.4; ref: 0.4-4.5 mIU/L; Siemens). Leading differential diagnosis was initially thyroid hormone resistance; however subsequent labs, done by PCP for non-specific symptoms, revealed a suppressed parathyroid hormone (PTH) (<6; ref 15-65 pg/mL) with normal serum calcium levels. Given no clinical correlate, lab interference was considered. All the testing, with the exception of the FT4 by mass spectrometry and HAMA TSH, were analyzed utilizing Roche Diagnostics (electrochemiluminescent immunoassays). To evaluate vendor-specific interferences, labs were analyzed utilizing Siemens (chemiluminescent immunoassay) which showed normal T4, T3, FT3, and PTH levels. Unlike the Siemens assays, Roche depends on the formation of a biotin-streptavidin complex during measurement and a ruthenium complex to produce a signal. HAMA and polyethylene glycol treatment also returned differing results from untreated samples possibly indicating the interference was a heterophilic antibody to an unknown target. An investigation by Roche Diagnostics showed evidence of streptavidin antibodies. Streptavidin is a common reagent in endocrine assays. The endogenous streptavidin antibody produces an unintended competition between streptavidin-biotin and streptavidin-antibody in the assay; resulting in falsely-low results for sandwich assays (e.g. PTH) and falsely-high results for competitive assays (e.g. FT3 and T4). The impact to the individual analyte is variable due to assay formulation (e.g. TSH).Interference from anti-streptavidin antibodies is a rare phenomenon and may cause unnecessary diagnostics or treatment. Analytical interference should be considered when clinically suspicious of results, and lab consultation is recommended. The patient was advised to obtain a Medic-Alert bracelet. She was also provided a letter detailing the findings so that providers may consult the laboratory prior to testing.

The Curious Case of Abnormal Thyroid Function Tests: Think Streptavidin Interference

Levothyroxine (LT4) is the treatment of choice for hypothyroidism and the second most prescribed medication in the United States. Despite its established efficacy and widespread availability, approximately 40% of patients treated with LT4 fail to achieve thyroid stimulating hormone (TSH) levels within the normal range. Current LT4 product guidelines recommend administration in the fasting state 30-60 minutes before breakfast to avoid a food interaction leading to reduced intestinal absorption of LT4. This recommendation may impact compliance, as over 50% of adult Americans drink coffee every day, 65% of which is consumed during breakfast.While the majority of patients receive LT4 tablets, there is evidence that liquid formulations that bypass the gastric dissolution phase may mitigate the interference with coffee. ThyquidityTM (levothyroxine sodium) oral solution has demonstrated bioequivalence to Synthroid® under fasting conditions and allows individualized dosing flexibility in a variety of clinical scenarios. A bioavailability study was conducted to assess the rate and extent of absorption of the oral LT4 solution (100 mcg /5 mL) administered with coffee compared to administration under fasting conditions in an open label, randomized, two-period, two-treatment, two-sequence, crossover, single dose bioavailability study in 40 healthy adults. A single 600 μg oral dose of LT4 solution (ThyquidityTM, 30 mL) was administered 5 minutes before drinking 8 ounces of American coffee (without milk or sweeteners) or under fasting conditions in each study period. Blood samples were collected for total (bound and free) T4 for 48 hours after drug administration. Treatment periods were separated by a 40-day wash-out period.The ratios of geometric LS means with corresponding 90% confidence intervals (CI) were calculated from the exponential of the difference between the LT4 solution administration 5 minutes prior to coffee and administration under fasting condition for AUC0-48 and Cmax. An absence of a food effect would be concluded if the baseline corrected 90% CIs of this ratio fell within 80.00% to 125.00% for Ln-transformed AUC0-48 and Cmax.Forty healthy adults participated in the trial. There were no serious adverse events (AE) or discontinuations due to AEs. The geometric LS mean ratio of AUC0-48 and Cmax for baseline-adjusted LT4 were 93.98% (90.06-98.07%) and 95.99% (92.64- 99.45%) respectively. The corresponding 90% CIs were included within the acceptance range for bioequivalence.This study demonstrated comparable bioavailability of a single oral 600 μg dose of Thyquidity oral solution administered, 5 minutes prior to coffee or under fasting conditions. These results are consistent with earlier evidence that liquid LT4 overcomes the interference from coffee seen with LT4 tablets and may offer additional flexibility for patients.

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