scholarly journals Case report: clues to the diagnosis of an unsuspected massive levothyroxine overdose

CJEM ◽  
2015 ◽  
Vol 17 (6) ◽  
pp. 692-698 ◽  
Author(s):  
Kirstie M. Allen ◽  
Veronica B. Crawford ◽  
John V. Conaglen ◽  
Marianne S. Elston
Keyword(s):  
Thyroid Hormone ◽  
Pediatric Population ◽  
Thyroid Stimulating Hormone ◽  
Sex Hormone Binding Globulin ◽  
Hormone Binding ◽  
Free Triiodothyronine ◽  
History Of ◽  
Symptoms And Signs ◽  
Free Thyroxine Level ◽  
Biochemical Features

AbstractThere is currently little literature pertaining to levothyroxine overdose apart from minor or accidental overdoses in the pediatric population. In particular, there is little information available on how to confidently differentiate levothyroxine overdose from endogenous causes of thyrotoxicosis when there is no history available at the time of assessment.We report a levothyroxine (15,800 mcg) and citalopram (2,460 mg) overdose in a 55-year-old woman presenting with seizure and tachycardia in which the diagnosis was not initially suspected. Clinical data, including a long history of treated hypothyroidism and lack of a goiter; and biochemical findings, such as an incompletely suppressed thyroid-stimulating hormone (TSH) level, despite a markedly elevated free thyroxine level (FT4), a normal sex hormone-binding globulin level at baseline, and an undetectable thyroglobulin, supported the diagnosis of thyrotoxicosis due to a massive exogenous thyroid hormone overdose. Treatment was given to decrease free triiodothyronine (FT3) conversion and increase thyroid hormone clearance with dexamethasone and cholestyramine. The patient made a full recovery.Levothyroxine overdose can result in subtle symptoms and signs clinically, even when in massive quantities. This can make diagnosis challenging. Biochemical features, such as the pattern of thyroid hormone elevation and thyroglobulin levels, help differentiate exogenous thyroid hormone overdose from endogenous causes of thyrotoxicosis.

scholarly journals Misleading results from immunoassays of serum free thyroxine in the presence of rheumatoid factor

1997 ◽  
Vol 43 (6) ◽  
pp. 957-962 ◽  
Author(s):  
Anthony G W Norden ◽  
Rodwin A Jackson ◽  
Lorraine E Norden ◽  
A Jane Griffin ◽  
Margaret A Barnes ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Rheumatoid Factor ◽  
Equilibrium Dialysis ◽  
Thyroid Stimulating Hormone ◽  
Normal Serum ◽  
Free Thyroxine ◽  
Free Triiodothyronine ◽  
Serum Free ◽  
Serum Free Thyroxine ◽  
Stimulating Hormone

Abstract A novel interference with measurements of serum free thyroxine (FT4) caused by rheumatoid factor (RhF) is described. We found misleading, sometimes gross, increases of FT4 results in 5 clinically euthyroid elderly female patients with high RhF concentrations. All 5 patients had high FT4 on Abbott AxSYM® or IMx® analyzers. “NETRIA” immunoassays gave misleading results in 4 of the 5 patients; Amerlex-MAB® in 2 of 4 patients; AutoDELFIA®in 2 of the 5; and Corning ACS-180® and Bayer Diagnostics Immuno 1® in 1 of the 5. BM-ES700® system results for FT4 in these women remained within the reference range. Results for serum T4, thyroid-stimulating hormone, free triiodothyronine, thyroid-hormone-binding globulin, and FT4 measured by equilibrium dialysis were normal in all 5 patients. Drugs, albumin-binding variants, and anti-thyroid-hormone antibodies were excluded as interferences. Addition to normal serum of the RhF isolated from each of the 5 patients increased the apparent FT4 (Abbott AxSYM). Screening of 83 unselected patients demonstrated a highly significant positive correlation between FT4 (Abbott AxSYM) and RhF concentrations. Discrepant, apparently increased FT4 with a normal result for thyroid-stimulating hormone should lead to measurement of the patient’s RhF concentration.

Evaluation of long-term follow-up and methimazole therapy outcomes of pediatric Graves’ disease: a single-center experience

2019 ◽  
Vol 32 (4) ◽  
pp. 341-346 ◽  
Author(s):  
Elvan Bayramoğlu ◽  
Selin Elmaogulları ◽  
Elif Sagsak ◽  
Zehra Aycan
Keyword(s):  
Remission Rate ◽  
Pediatric Population ◽  
Clinical Signs ◽  
Thyroid Stimulating Hormone ◽  
Graves Disease ◽  
Free Triiodothyronine ◽  
Management Options ◽  
Single Center Experience ◽  
Male Sex

Abstract Background The management options for Graves’ disease in children are limited and there is controversy regarding optimal treatment. Remission rate with anti-thyroid drug (ATD) treatment in children is said to be lower than in adults. Definitive treatments are effective, but they often result in permanent hypothyroidism. The objective of this study was to investigate the outcome of methimazole treatment, identify significant predictors of a remission and evaluate the adverse effects of methimazole in a pediatric population of GD patients. Methods Medical records of the patients who had been diagnosed with Graves’ disease were screened retrospectively. Diagnostic criteria included elevated free thyroxine (fT4) and total triiodothyronine (T3), suppressed thyroid-stimulating hormone (TSH) and either positive thyroid-stimulating immunoglobulin (TSI) or thyroid receptor antibodies (TRABs) or clinical signs suggestive of Graves’ disease, for example, exophthalmos. Remission was defined as maintenance of euthyroidism for more than 12 months after discontinuing methimazole treatment. Results Of the 48 patients, provisional remission was achieved in 21 patients. Of the 21 patients, 14 experienced a relapse (66.6%). Remission was achieved in seven (24.1%) of 29 patients who received methimazole treatment for more than 2 years. In patients who achieved long-term remission, the male sex ratio and fT4 levels at diagnosis were significantly lower than the relapsed and non-remission groups, whereas the free triiodothyronine (fT3)/fT4 ratio and duration of methimazole treatment were significantly higher than the relapse group. Conclusions Long-term methimazole treatment in pediatric Graves’ disease would be appropriate. High fT4 levels at the time of diagnosis and male sex were associated with a risk of relapse.

scholarly journals Correlations of Free Thyroid Hormones Measured by Tandem Mass Spectrometry and Immunoassay with Thyroid-Stimulating Hormone across 4 Patient Populations

2009 ◽  
Vol 55 (7) ◽  
pp. 1380-1388 ◽  
Author(s):  
Jacqueline Jonklaas ◽  
Natasa Kahric-Janicic ◽  
Offie P Soldin ◽  
Steven J Soldin
Keyword(s):  
Mass Spectrometry ◽  
Thyroid Hormone ◽  
Tandem Mass Spectrometry ◽  
Thyroid Hormones ◽  
Thyroid Stimulating Hormone ◽  
Free Thyroxine ◽  
Tandem Mass ◽  
Free Triiodothyronine ◽  
Free Thyroid Hormones ◽  
Free Thyroid Hormone

Abstract Background: Accurate measurement of free thyroid hormones is important for managing thyroid disorders. Ultrafiltration liquid chromatography tandem mass spectrometry (LC-MS/MS) can reliably measure the concentrations of small molecules, including thyroid hormones. Our study was designed to compare free thyroid hormone measurements performed with immunoassay and LC-MS/MS. Methods: We studied the performance of LC-MS/MS in 4 different populations comprising pediatric patients, euthyroid adults, and healthy nonpregnant and pregnant women. The samples obtained from each population numbered 38, 200, 28, and 128, respectively. Free thyroxine, free triiodothyronine, and thyroid-stimulating hormone (TSH) concentrations were documented. Results: LC-MS/MS measurement of free thyroid hormones provided better correlation with log-transformed serum TSH in each population and also the populations combined. The correlations between free thyroxine measured by LC-MS/MS and log TSH in the pediatric outpatients and healthy adults were −0.90 and −0.77, respectively. The correlations for immunoassay were −0.82 and −0.48. The correlations between free triiodothyronine measured by LC-MS/MS and TSH for both pediatric and healthy adult populations were −0.72 and −0.68, respectively. Conclusions: Free thyroid hormone concentrations measured by LC-MS/MS correlate to a greater degree with log TSH values compared to concentrations measured by immunoassay. This correlation was maintained across the patient populations we studied and may reflect the accuracy and specificity of LC-MS/MS. The superior ability of LC-MS/MS to enable documentation of the well-known thyroid hormone–TSH relationship supports the use of this measurement technique in a variety of clinical situations.

THYROID PROFILE IN CHILDREN WITH NEPHROTIC SYNDROME

2021 ◽  
pp. 75-77
Author(s):  
Meiyappan Kavitha ◽  
Mallaiyan Manonmani
Keyword(s):  
Nephrotic Syndrome ◽  
Thyroid Hormone ◽  
Thyroid Hormones ◽  
Thyroid Stimulating Hormone ◽  
The Body ◽  
Urinary Protein ◽  
Creatinine Ratio ◽  
Free Triiodothyronine ◽  
Free T4 ◽  
Renal Disorder

Objectives: Nephrotic syndrome is a common renal disorder seen in children, with proteinuria as the hallmark. Growth retardation is a known feature of nephrotic syndrome, either due to the disease or treatment with steroids. Thyroid hormone strongly inuences growth of the body. So, the present study was undertaken with the objective to assess the thyroid prole in children with nephrotic syndrome Methods: The study involved 41 cases of nephrotic syndrome and 41 age and sex matched controls. Serum total triiodothyronine (T3), total thyroxine (T4), free triiodothyronine (T3), free thyroxine (T4) and thyroid stimulating hormone (TSH) were assessed in these subjects. The thyroid hormones were correlated with urinary protein creatinine ratio. The cases were followed up after one month and the levels of thyroid hormones were reassessed. Results: Total T3, total T4, free T3 and free T4 are signicantly decreased and TSH signicantly increased among cases when compared to controls. TSH is positively correlating with urinary protein creatinine ratio in cases. After one month of treatment, total T3 and total T4 are signicantly increased in cases. Conclusions: The thyroid hormone levels are altered in children with nephrotic syndrome during the episode. A state of subclinical hypothyroidism exists during the nephrotic stage. The alteration is normalized with remission and does not require treatment.

scholarly journals Molecular dynamics approach to the I431V mutational impact on thyroid hormone receptor-beta

BIBECHANA ◽  
2018 ◽  
Vol 16 ◽  
pp. 79-91
Author(s):  
Tika Ram Lamichhane ◽  
Sharma Paudel ◽  
Binod Kumar Yadav ◽  
Hari Prasad Lamichhane
Keyword(s):  
Thyroid Hormone ◽  
Hormone Receptor ◽  
Thyroid Hormone Receptor ◽  
Point Mutations ◽  
Binding Pocket ◽  
Accessible Surface Area ◽  
Thyroid Stimulating Hormone ◽  
Solvent Accessible Surface Area ◽  
Free Triiodothyronine ◽  
Receptor Beta

The point mutations like I431V on thyroid hormone receptor-beta (THR-β) gene cause resistance to thyroid hormones (RTH) with the clinical diagnosis of elevated free triiodothyronine (T3) and free thyroxin (T4) but not suppressed thyroid stimulating hormone (TSH) on the blood serum. Some ultrasonographic (USG) reports of the patients with RTH show thyroid gland disorder with goiter or nodule(s) or cyst(s) and some USG reports even with RTH are normal. I431V-mutant causes more steric hindrance while binding T3 into THR-β than the native wild type THRT3. The residue on the 431-codon is dynamic in nature showing its flexibility over the course of entry and release of T3-hormone into/from the ligand binding pocket. The more increased solvent accessible surface area of I431V-mutant than that of native I431-residue makes the partial unfolding of the globular THR-β protein. The smaller height of radial distribution function between I431-mutant and T3 shows the decrease in probability of finding the atomic particles nearby T3-hormone in THRT3-MT than in THRT3-WT. The electrostatic interaction energy between native I431 and T3 is negative, but it is positive between I431V and T3. Moreover, the internal energy of I431V-mutant has been found smaller than that of native I431-residue in THRT3 systems.BIBECHANA 16 (2019) 79-91

PITUITARY-THYROID RESPONSES TO SURGICAL STRESS

1978 ◽  
Vol 88 (3) ◽  
pp. 490-498 ◽  
Author(s):  
Vivian Chan ◽  
Christina Wang ◽  
Rose T. T. Yeung
Keyword(s):  
Thyroid Hormone ◽  
Thyroid Function ◽  
Surgical Stress ◽  
Hormone Binding ◽  
Free Triiodothyronine ◽  
Operative Complication ◽  
Reverse Triiodothyronine ◽  
Early Increase ◽  
Total Thyroxine ◽  
Triiodothyronine Concentration

ABSTRACT The effect of surgery on pituitary-thyroid function was studied in 12 euthyroid patients. There was a sharp early increase in total thyroxine level, causing displacement of triiodothyronine from thyroid hormone binding proteins resulting in the elevation of the biologically more potent free triiodothyronine fraction. The serum triiodothyronine concentration fell rapidly during and after the operation, with a concomitant rise in reverse triiodothyronine level. Increased prolactin levels were found during and after surgery. With no post-operative complication, recovery of normal pituitary-thyroid function occurred after 4 to 7 days of convalescence.

Hyperthyroidism in an infant of a mother with autoimmune hypothyroidism with positive TSH receptor antibodies

2018 ◽  
Vol 31 (5) ◽  
pp. 577-580 ◽  
Author(s):  
Kriti Joshi ◽  
Margaret Zacharin
Keyword(s):  
Thyroid Function ◽  
Thyroid Stimulating Hormone ◽  
Thyroid Disorder ◽  
Free Triiodothyronine ◽  
Autoimmune Hypothyroidism ◽  
Normal Thyroid Function ◽  
Neonatal Hyperthyroidism ◽  
History Of ◽  
Blocking Antibodies ◽  
Receptor Antibodies

Abstract Background: Neonatal hyperthyroidism is rare, seen in infants of mothers with Graves’ disease (GD), with transplacental transfer of thyroid-stimulating hormone receptor (TSHR) antibodies (TRAbs). We describe a neonate with severe hyperthyroidism due to TRAbs, born to a mother with autoimmune hypothyroidism. Case presentation: A baby boy born preterm at 35 weeks had irritability, tachycardia and proptosis after birth. The mother had autoimmune hypothyroidism, from age 10, with thyroxine replacement and normal thyroid function throughout her pregnancy. She had never been thyrotoxic. There was a family history of Hashimoto’s thyroiditis (HT) and GD. The baby’s thyroid function on day 3 demonstrated gross thyrotoxicosis, TSH<0.01 mIU/L (normal range [NR]<10 mIU/L), free thyroxine (FT4)>77 pmol/L (20–35), free triiodothyronine (FT3) 15.4 pmol/L (4.2–8.3) and TRAb 18.4 IU/L (<1.8). The mother’s TRAb was 24.7 IU/L. Thyrotoxicosis required propranolol and carbimazole (CBZ). Thyroid function normalized within 10 days. The baby was weaned off medication by 7 weeks. He remains euthyroid. Conclusions: We postulate that this mother had co-existing destructive thyroiditis and thyroid-stimulating antibodies (TSAbs) and TSHR blocking antibodies (TBAb), rendering her unable to raise a thyrotoxic response to the TSAbs but with predominant TSAb transmission to her infant. Maternal history of any thyroid disorder may increase the risk of transmission to an infant, requiring a careful clinical assessment of the neonate, with important implications for future pregnancies.

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