Misleading FT4 and FT3 Due to Immunoassay Interference From Autoantibodies.

BACKGROUND: Immunoassays used to measure total and free thyroxine (T4 and FT4) and total and free triiodothyronine (T3 and FT3) can provide inaccurate results due to interference from endogenous autoantibodies. CASE REPORT: A 74-year-old female treated for hypothyroidism with levothyroxine replacement had elevated thyroid stimulating hormone (TSH), FT4, and FT3. Due to concern for hyperthyroidism, levothyroxine was discontinued and further workup was initiated. A pituitary MRI revealed a microadenoma but the alpha-subunit was normal. She was given octreotide for suspected TSH secreting pituitary adenoma without improvement in her TSH, FT4, or FT3 levels. She was referred to our clinic, where inaccurate lab values for FT4 and FT3 were suspected. RESULTS: Testing via equilibrium dialysis liquid chromatography tandem mass spectrometry (LC-MS/MS) method revealed lower levels of FT4 and FT3. Subsequent testing included heterophile blocking tube treatment, polyethylene glycol (PEG) precipitation, and anti-T3/T4 autoantibody levels. The tests revealed thyroid hormone autoantibodies (THAAs) as the cause of immunoassay interference. CONCLUSIONS: When thyroid hormones are elevated and TSH is not suppressed, confirmatory testing with another method such as equilibrium dialysis LC-MS/MS, which is not susceptible to interference from autoantibodies, should be considered.

Experimental study on abnormal thyroid function in patients with Hashimoto's thyroiditis caused by interference of thyroid hormone autoantibodies.

INTRODUCTION: Thyroid hormone autoantibody (THAAb) is one of the important factors affecting thyroid function measurement. By analyzing the examination of a patient suffered with Hashimoto's thyroiditis, we sought to find a correct assessment method. MATERIAL AND METHODS: Radioimmunoassay, chemiluminescence immunoassay on an ADVIA Centaur XP system and Architect i2000sr platform, and electrochemiluminescence immunoassay on a Roche Cobas 601 system were used for detecting thyroid function. Polyethylene glycol (PEG) precipitation were performed to eliminate the influence of THAAbs. RESULTS: The results showed that the patient's thyroid function was consistent with the clinical manifestations and conformed to the law of the hypothalamic-pituitary-thyroid axis at Architect-i2000sr platform and Roche-Cobas-601 system. The content of FT4 was significantly reduced and lower than the normal reference range, after the patients' serum was treated with PEG, which was in line with the clinical practice. The serum THAAb titer of the patients was nearly 100 times higher than that of the control group. CONCLUSIONS: Considering an abnormal thyroid function examination, it is necessary for laboratory staff to retest samples on different platforms. It is of great significance to provide a true and accurate result to clinicians and patients.

Association of IL6 gene methylation in peripheral blood cells with the development and prognosis of autoimmune thyroid diseases.

Autoimmune thyroid diseases (AITDs), including Hashimoto's disease (HD) and Graves' disease (GD), are archetypes of organ-specific autoimmune diseases, but the prognosis of patients with AITD varies. Autoimmune diseases, including AITDs, are believed to develop in response to both genetic and environmental factors. Interleukin (IL)-6 plays a major role in B cell differentiation and T cell proliferation, and methylation of the IL6 gene is associated with IL-6 production. To clarify the role of IL6 gene methylation in the pathogenesis and prognosis of AITDs, we measured the methylation levels of -666, -664, -610, -491 and -426 CpG sites in the IL6 gene. We measured the methylation levels of 5 CpG sites in 29 patients with HD, 31 patients with GD and 16 healthy volunteers using pyrosequencing. The methylation level at each of the -664, -491 and -426 CpG sites was negatively correlated with the age at the time of sampling. Multiple regression analysis indicated that patients with HD, including severe or mild HD, showed higher methylation levels at the -426 CpG site than control subjects. Patients with intractable GD showed lower methylation levels at the -664 and -666 CpG sites than patients with GD in remission. In conclusion, IL6 gene methylation levels were related to the susceptibility to HD and the intractability of GD.

[Successful oral desensitization to levothyroxine. Report of one case]. / Desensibilización a levotiroxina. Caso clínico.

We report a 39-year-old female who underwent a total thyroidectomy as treatment for a thyroid papillary cancer. She suffered several episodes of mild angioedema in lips and tongue, after using different commercial Levothyroxine formulations, with and without excipients. Given the need to use this drug, the patient was admitted in our hospital and we proceeded to desensitize her with oral Levothyroxine. The patient fasted throughout the whole procedure, was properly monitored and had an adequate peripheral venous access. On the first day of the procedure, a 15-step protocol was performed, first administering placebo and then, compounded formulations of Levothyroxine starting from 0.01 ug, followed by doubling doses every 15 minutes until the cumulative dose of 111.95 ug was completed, corresponding to the daily dose of Levothyroxine her endocrinologist prescribed (112 ug). The patient was monitored at baseline, between each dose and up to 3 hours after the procedure was completed. There were no incidents such as urticaria, angioedema, or others. On the second day, the patient received a single-full dose of 112 ug on an empty stomach. The medication was successfully tolerated and she was discharged. Thereafter, she tolerates daily Levothyroxine.

Preconception management of thyroid dysfunction.

Uncorrected thyroid dysfunction in pregnancy has well-recognized deleterious effects on foetal and maternal health. The early gestation period is one of the critical foetal vulnerability during which maternal thyroid dysfunction may have lasting repercussions. Accordingly, a pragmatic preconception strategy is key for ensuring optimal thyroid disease outcomes in pregnancy. Preconception planning in women with hypothyroidism should pre-empt and mirror the adaptive changes in the thyroid gland by careful levothyroxine dose adjustments to ensure adequate foetal thyroid hormone delivery in pregnancy. In hyperthyroidism, the goal of preconception therapy is to control hyperthyroidism while curtailing the unwanted side effects of foetal and maternal exposure to antithyroid drugs. Thus, pregnancy should be deferred until a stable euthyroid state is achieved, and definitive therapy with radioiodine or surgery should be considered in women with Graves' disease planning future pregnancy. Women with active disease who are imminently trying to conceive should be switched to propylthiouracil either preconception or at conception in order to minimize the risk of birth defects from carbimazole or methimazole exposure. Optimal strategies for women with borderline states of thyroid dysfunction namely subclinical hypothyroidism, isolated hypothyroxinaemia and thyroid autoimmunity remain uncertain due to the dearth of controlled interventional trials. Future trial designs should aspire to recruit and initiate therapy before conception or as early as possible in pregnancy.

Desensibilización a levotiroxina: caso clínico / Successful oral desensitization to levothyroxine: report of one case

We report a 39-year-old female who underwent a total thyroidectomy as treatment for a thyroid papillary cancer. She suffered several episodes of mild angioedema in lips and tongue, after using different commercial Levothyroxine formulations, with and without excipients. Given the need to use this drug, the patient was admitted in our hospital and we proceeded to desensitize her with oral Levothyroxine. The patient fasted throughout the whole procedure, was properly monitored and had an adequate peripheral venous access. On the first day of the procedure, a 15-step protocol was performed, first administering placebo and then, compounded formulations of Levothyroxine starting from 0.01 ug, followed by doubling doses every 15 minutes until the cumulative dose of 111.95 ug was completed, corresponding to the daily dose of Levothyroxine her endocrinologist prescribed (112 ug). The patient was monitored at baseline, between each dose and up to 3 hours after the procedure was completed. There were no incidents such as urticaria, angioedema, or others. On the second day, the patient received a single-full dose of 112 ug on an empty stomach. The medication was successfully tolerated and she was discharged. Thereafter, she tolerates daily Levothyroxine.

Occupational pesticide exposure and subclinical hypothyroidism among male pesticide applicators.

OBJECTIVES: Animal studies suggest that exposure to pesticides may alter thyroid function; however, few epidemiologic studies have examined this association. We evaluated the relationship between individual pesticides and thyroid function in 679 men enrolled in a substudy of the Agricultural Health Study, a cohort of licensed pesticide applicators. METHODS: Self-reported lifetime pesticide use was obtained at cohort enrolment (1993-1997). Intensity-weighted lifetime days were computed for 33 pesticides, which adjusts cumulative days of pesticide use for factors that modify exposure (eg, use of personal protective equipment). Thyroid-stimulating hormone (TSH), thyroxine (T4), triiodothyronine (T3) and antithyroid peroxidase (anti-TPO) autoantibodies were measured in serum collected in 2010-2013. We used multivariate logistic regression to estimate ORs and 95% CIs for subclinical hypothyroidism (TSH >4.5 mIU/L) compared with normal TSH (0.4-<4.5 mIU/L) and for anti-TPO positivity. We also examined pesticide associations with TSH, T4 and T3 in multivariate linear regression models. RESULTS: Higher exposure to the insecticide aldrin (third and fourth quartiles of intensity-weighted days vs no exposure) was positively associated with subclinical hypothyroidism (ORQ3=4.15, 95% CI 1.56 to 11.01, ORQ4=4.76, 95% CI 1.53 to 14.82, ptrend <0.01), higher TSH (ptrend=0.01) and lower T4 (ptrend=0.04). Higher exposure to the herbicide pendimethalin was associated with subclinical hypothyroidism (fourth quartile vs no exposure: ORQ4=2.78, 95% CI 1.30 to 5.95, ptrend=0.02), higher TSH (ptrend=0.04) and anti-TPO positivity (ptrend=0.01). The fumigant methyl bromide was inversely associated with TSH (ptrend=0.02) and positively associated with T4 (ptrend=0.01). CONCLUSIONS: Our results suggest that long-term exposure to aldrin, pendimethalin and methyl bromide may alter thyroid function among male pesticide applicators.

Thyroid Autoimmunity and Reproductive Function.

Thyroid hormones are important for normal reproductive function, and maternal thyroid dysfunction has been associated with infertility, miscarriage, preterm birth, and poor neurodevelopment in the offspring. Thyroid autoimmunity is the leading cause of thyroid dysfunction in women of reproductive age. Women with thyroid autoimmunity, even with normal thyroid function, appear to be at a higher risk for poor reproductive outcomes, including miscarriage and preterm birth. Thyroxine replacement in women with thyroid autoimmunity with or without appreciable thyroid dysfunction may improve pregnancy outcomes. Thus, identification and treatment of women with thyroid autoimmunity may optimize reproductive success.

Thyroid autoimmunity and function among Ugandan children and adolescents with type-1 diabetes mellitus.

INTRODUCTION: Up to 30% of type-1 diabetes mellitus (T1DM) patients have co-existent thyroid autoimmunity with up to 50% of them having associated thyroid dysfunction. Routine screening for thyroid autoimmunity and dysfunction is recommended in all T1DM patients. However, this was not currently practiced in Ugandan paediatric diabetes clinics. There was also paucity of data regarding thyroid autoimmunity and dysfunction in African children and adolescents with diabetes mellitus. The objective of this study was to quantify the magnitude of thyroid autoimmunity and dysfunction in Ugandan children with TIDM. METHODS: This was a cross sectional descriptive study to determine the prevalence of thyroid autoantibodies and describe thyroid function among children and adolescents aged 1-19 years with diabetes mellitus attending the paediatric diabetes clinic at Mulago National Referral Hospital, Kampala, Uganda. Following enrollment, we obtained details of clinical history and performed physical examination. Blood (plasma) was assayed to determine levels of antibodies to thyroid peroxidase (antiTPO), free thyroxine (FT4) and thyrotropin (TSH). RESULTS: The prevalence of thyroid autoimmunity was 7.3% (5/69). All antiTPO positive subjects were post pubertal, aged between 13-17 years with females comprising 3/5 of the antiTPO positive subjects. All study subjects were clinically euthyroid; however, 7.3% (5/69) of the study subjects had subclinical hypothyroidism. CONCLUSION: These data strengthen the argument for routine screening of all diabetic children and adolescents for thyroid autoimmunity (particularly anti-TPO) as recommended by international guidelines. We also recommend evaluation of thyroid function in diabetic children and adolescents to minimize the risk of undiagnosed thyroid dysfunction.

Hypothyroxinemia and TPO-antibody positivity are risk factors for premature delivery: the generation R study.

CONTEXT: Premature delivery is an important risk factor for child mortality and psychiatric, metabolic, and cardiovascular disease later in life. In the majority of cases, the cause of prematurity cannot be identified. Currently, it remains controversial whether abnormal maternal thyroid function during pregnancy increases the risk of premature delivery. Therefore, we investigated the relation between maternal serum thyroid parameters and the risk of premature delivery in a large prospective population-based study. DESIGN: Serum TSH, free T4 (FT4), T4, and TPO antibodies (TPOAbs) were determined during early pregnancy in 5971 pregnant women from the Generation R study. Data were available on maternal age, parity, smoking, socioeconomic status, ethnicity, maternal anthropometrics, and urinary iodine levels. RESULTS: Of all women, 5.0% had a premature delivery (<37 weeks), 4.4% had a spontaneous premature delivery, and 1.4% had a very premature delivery (<34 weeks). High TSH levels and subclinical hypothyroidism were associated with premature delivery but not with spontaneous premature delivery. Maternal hypothyroxinemia was associated with a 2.5-fold increased risk of premature delivery, a 3.4-fold increased risk of spontaneous premature delivery, and a 3.6-fold increased risk of very premature delivery (all P < .01). TPOAb positivity was associated with a 1.7-fold increased risk of premature delivery (P = .01), a 2.1-fold increased risk of spontaneous premature delivery (P = .02), and a 2.5-fold increased risk of very premature delivery (P = .04). These effects remained similar after correction for TSH and FT4 levels. CONCLUSIONS: Hypothyroxinemia and TPOAb positivity are associated with an increased risk of premature delivery. The increased risk in TPOAb-positive women seems to be independent of thyroid function.

[Is polycystic ovary syndrome associated with autoimmune thyroiditis?]. / Je syndróm polycystických ovárií asociovaný s autoimunitnou tyreoiditídou?

INTRODUCTION: Polycystic ovary syndrome (PCOS) is one of the most common endocrinopathies in women of fertile age and lately there is a discussion about its possible association with autoimmune diseases. The aim of the study was to examine incidence of autoimmune thyreoiditis (AIT) in PCOS women. PATIENTS AND METHODS: 64 PCOS patients were enrolled and 68 healthy menstruating women served as controls. All subjects were examined for thyrotropin (TSH), free thyroxin (fT4) and the presence as well as titers of antithyroid antibodies aTG (anti-thyreoglobulin) and aTPO (anti-thyreoperoxidase). RESULTS: There was no difference between PCOS and controls in average TSH levels (2.37 ± 1.46 mIU/l vs 2.37 ± 1.46 mIU/l) (p = 0.953), and fT4 levels (16.36 ± 5.34 pmol/l vs 16.49 ± 2.32 pmol/l) (p = 0.852). Autoantibodies titers were also non-significant aTG (53.09 ± 157.07 IU/ml vs 29.8 ± 100.77 IU/ml, p = 0.386) and aTPO (59.74 ± 149.03 IU/ml vs 45 ± 204.77 IU/ml, p = 0.805). However, PCOS women had significantly higher prevalence of aTPO (18.75 vs 7.35%, p = 0.045). On the other hand, the overall prevalence of AIT was similar in both groups. CONCLUSION: Our results show PCOS patients have slightly but significantly higher positivity of aTPO antibodies but the prevalence of AIT was insignificant.

[Determination of serum neopterin levels in patients with autoimmune thyroid diseases]. / Szérumneopterin-szintek vizsgálata autoimmun pajzsmirigybetegekben.

UNLABELLED: An elevated serum level of neopterin indicates the activation of the cellular immune system. AIM: The objective was to find a correlation in autoimmune thyroid patients between neopterin levels and the clinical stage of the disease and to examine whether neopterin can predict the relapse of the disease. METHODS: Serum neopterin, thyroid stimulating hormone, free thyroxine, free triiodothyronine, anti-thyroglobulin and anti-thyroid peroxidase antibody levels were determined in 137 patients with Graves' disease (in different stages), 25 with Hashimoto's thyroiditis and 14 with toxic adenoma. RESULTS: The neopterin levels were significantly higher in patients with Graves' disease (hyper-, eu-, hypothyroidism and relapsed hyperthyroidism) and Hashimoto's thyroiditis. Positive correlation was found between neopterin and anti-thyroglobulin and anti-thyroid peroxidase antibody levels, but no correlation was detected between neopterin levels and thyroid hormones, thyroid stimulating hormone values and antibodies against thyroid stimulating hormone receptors. CONCLUSIONS: Higher level of serum neopterin reflects an underlying autoimmune process, and does not correlate with changes in thyroid hormone levels. Determination of neopterin level can be an important indicator in the exacerbation of autoimmune processes.

Value of repeat stimulated thyroglobulin testing in patients with differentiated thyroid carcinoma considered to be free of disease in the first year after ablation.

BACKGROUND: In patients with differentiated thyroid carcinoma considered to be free of the disease after initial therapy, the appropriate timing or necessity of subsequent stimulated thyroglobulin (Tg) testing is uncertain. The objective of this study was to determine the value of a repeat stimulated Tg in patients considered to be free of disease 6-12 months after thyroid ablation, and also who continued to have serum Tg <1 ng/mL while on thyrotropin suppressive doses of thyroxine (T4) (Tg/T4), negative anti-Tg antibodies (TgAb), and a normal clinical examination 5 years after their initial therapy. METHODS: The study participants were 203 patients who had total thyroidectomy followed by ablation with (131)I, who were considered to be free of disease 6-12 months after ablation (stimulated Tg <2 ng/mL in the absence of TgAb and negative diagnostic whole-body scanning), who had no recurrence, and who continued to have serum Tg/T4 of <1 ng/mL, negative TgAb and a normal clinical examination 5 years after initial therapy. These patients were evaluated with repeat stimulated Tg testing after 4 weeks of T4 withdrawal. RESULTS: Repeat stimulated Tg values after 5 years were <2 ng/mL in 192 (94.6%) patients of whom 188 were <1 ng/mL. Subsequent follow-up after a mean of 102 months did not detect new cases of tumor recurrence in this subgroup. Eleven patients (5.4%) had stimulated Tg levels of >2 ng/mL. Neck ultrasonography (US) revealed metastases in three and other imaging methods detected metastases in five patients with negative US. In the other three patients, no metastases were detected initially or during follow-up. Gender, age, and tumor stage were not predictors of recurrence or elevated Tg upon repeat testing after 5 years. CONCLUSIONS: The present results favor repeating stimulated Tg 5 years after ablation in patients who were initially considered to be free of disease and who continued to have Tg/T4 values of <1 ng/mL and negative TgAb tests. A negative predictive value of 100% was obtained for patients who continued to have low stimulated Tg values.

Experience with lentivirus-mediated CD40 gene silencing in a mouse model of Graves' disease.

CD40 plays an important role in the pathogenesis of Graves' disease (GD). Inhibition of CD40 expression may be a promising treatment for GD. In this study, we used an animal model to investigate whether lentivirus expressing siRNA for CD40 (LV-CD40-siRNA) could be useful for the therapy of GD. BALB/c mice were injected with PBS alone (PBS group), negative lentivirus (control siRNA group), or LV-CD40-siRNA (CD40 siRNA group), 3 days before being treated with adenovirus expressing human TSHR A subunit (Ad-TSHR289) three times at 3-week intervals to induce GD model. Sera thyroxine (T(4)) levels were assayed by RIA. The expression of CD40 was detected at the mRNA level by real-time PCR and protein level by flow cytometry. The expression of CD40, CD80, and CD86 was significantly decreased in the CD40 siRNA group (P<0.05), while FOXP3 expression was increased compared to the control siRNA group (P=0.05). Mean T(4) levels were decreased 14% in the CD40 siRNA group compared to the control siRNA group. The rate of disease induction was similar among the three groups injected with Ad-TSHR289. LV-CD40-siRNA is a useful tool to inhibit the expression of CD40 in vivo, but it cannot decrease the incidence of hyperthyroidism in a limited period of time.

Low-level laser therapy in chronic autoimmune thyroiditis: a pilot study.

BACKGROUND AND OBJECTIVES: Chronic autoimmune thyroiditis (CAT) remains the most common cause of acquired hypothyroidism. There is currently no therapy that is capable of regenerating CAT-damaged thyroid tissue. The objective of this study was to gauge the value of applying low-level laser therapy (LLLT) in CAT patients based on both ultrasound studies (USs) and evaluations of thyroid function and thyroid autoantibodies. STUDY DESIGN/MATERIALS AND METHODS: Fifteen patients who had hypothyroidism caused by CAT and were undergoing levothyroxine (LT4) treatment were selected to participate in the study. Patients received 10 applications of LLLT (830 nm, output power 50 mW) in continuous mode, twice a week, using either the punctual technique (8 patients) or the sweep technique (7 patients), with fluence in the range of 38-108 J/cm(2). USs were performed prior to and 30 days after LLLT. USs included a quantitative analysis of echogenicity through a gray-scale computerized histogram index (EI). Following the second ultrasound (30 days after LLLT), LT4 was discontinued in all patients and, if required, reintroduced. Triiodothyronine, thyroxine (T4), free T4, thyrotropin, thyroid peroxidase (TPOAb) and thyroglobulin (TgAb) antibodies levels were assessed before LLLT and then 1, 2, 3, 6, and 9 months after LT4 withdrawal. RESULTS: We noted all patients' reduced LT4 dosage needs, including 7 (47%) who did not require any LT4 through the 9-month follow-up. The LT4 dosage used pre-LLLT (96 +/- 22 microg/day) decreased in the 9th month of follow-up (38 +/- 23 microg/day; P < 0.0001). TPOAb levels also decreased (pre-LLLT = 982 +/- 530 U/ml, post-LLLT = 579 +/- 454 U/ml; P = 0.016). TgAb levels were not reduced, though we did observe a post-LLLT increase in the EI (pre-LLLT = 0.99 +/- 0.09, post-LLLT = 1.21 +/- 0.19; P = 0.001). CONCLUSION: The preliminary results indicate that LLLT promotes the improvement of thyroid function, as patients experienced a decreased need for LT4, a reduction in TPOAb levels, and an increase in parenchymal echogenicity.

Perchlorate and thiocyanate exposure and thyroid function in first-trimester pregnant women.

CONTEXT: Thyroid hormone, requiring adequate maternal iodine intake, is critical for fetal neurodevelopment. Perchlorate decreases thyroidal iodine uptake by competitively inhibiting the sodium/iodide symporter. It is unclear whether environmental perchlorate exposure adversely affects thyroid function in pregnant women. Thiocyanate, derived from foods and cigarette smoke, is a less potent competitive sodium/iodide symporter inhibitor than perchlorate. OBJECTIVE: Our objective was to determine whether environmental perchlorate and/or thiocyanate exposure is associated with alterations in thyroid function in pregnancy. DESIGN AND SETTING: We conducted a cross-sectional study at health centers in Cardiff, Wales, and Turin, Italy. PATIENTS: During 2002-2006, 22,000 women at less than 16 wk gestation were enrolled in the Controlled Antenatal Thyroid Screening Study. Subsets of 261 hypothyroid/hypothyroxinemic and 526 euthyroid women from Turin and 374 hypothyroid/hypothyroxinemic and 480 euthyroid women from Cardiff were selected based on availability of stored urine samples and thyroid function data. MAIN OUTCOME MEASURES: Urinary iodine, thiocyanate, and perchlorate and serum TSH, free T(4) (FT(4)), and thyroperoxidase antibody were measured. RESULTS: Urinary iodine was low: median 98 microg/liter in Cardiff and 52 microg/liter in Turin. Urine perchlorate was detectable in all women. The median (range) urinary perchlorate concentration was 5 microg/liter (0.04-168 microg/liter) in Turin and 2 microg/liter (0.02-368 microg/liter) in Cardiff. There were no associations between urine perchlorate concentrations and serum TSH or FT(4) in the individual euthyroid or hypothyroid/hypothyroxinemic cohorts. In multivariable linear analyses, log perchlorate was not a predictor of serum FT(4) or TSH. CONCLUSIONS: Low-level perchlorate exposure is ubiquitous but did not affect thyroid function in this cohort of iodine-deficient pregnant women.

Effect of levothyroxine treatment on clinical symptoms and serum cytokine levels in euthyroid patients with chronic idiopathic urticaria and thyroid autoimmunity.

BACKGROUND: Screening for thyroid autoimmunity in patients with chronic idiopathic urticaria (CIU) is generally recommended. However, there are not yet sufficient data as to whether levothyroxine treatment is beneficial for the clinical symptoms of CIU in patients with thyroid autoimmunity. AIM: We investigated the effect of levothyroxine treatment on clinical symptoms and serum tumour necrosis factor (TNF)-alpha, interleukin (IL)-10 and interferon (IFN)-gamma levels in euthyroid patients with CIU and thyroid autoimmunity. METHODS: In total, 15 patients with CIU and positive thyroid autoantibodies were randomized to receive either levothyroxine plus 5 mg/day desloratadine (suppression group, n = 8) or 5 mg/day desloratadine alone (control group, n = 7) for 12 weeks. Clinical symptoms of CIU, thyroid hormone levels, thyroid antibodies and serum cytokine levels were assessed at baseline and after the treatment. RESULTS: There were significant improvements in pruritus score and severity of weals in both groups compared with baseline values, but when the two groups were compared, there was no significant difference in the patients' clinical symptoms. Thyroid antibody titres were not different according to intragroup and intergroup analysis. In the suppression group, serum IFN-gamma and TNF-alpha levels were increased after treatment with levothyroxine compared with baseline values and there was a borderline statistical significance (P = 0.05 for both). CONCLUSIONS: These results suggest that levothyroxine treatment is not a reasonable option in euthyroid patients with CIU and thyroid autoimmunity. Augmentation of cytokine production after levothyroxine treatment seems to be related to the immunomodulatory effects of TSH-suppressive treatment.

Thyroxine autoantibody interference is an uncommon cause of inappropriate TSH secretion using the Immulite 2000 assay.

BACKGROUND: Inappropriate TSH secretion, as defined by an elevated free thyroxine (fT4) and non-suppressed thyrotropin (TSH) result, can be caused by acute illness, medications, TSH secreting tumours, thyroid hormone resistance or immunoassay interference including thyroid hormone autoantibody interference. T4 autoantibody (T4AAb) prevalence has not been determined. We determined the prevalence of inappropriate TSH secretion using the Immulite 2000 assay and the prevalence of T4AAb within this subgroup. METHODS: Samples were stored over 13 months and thawed once for batch analysis. T4AAb was detected using radioimmunoprecipitation with >5% of the radiolabel within the immunoprecipitate indicating true positivity. All case notes and medication charts were reviewed. RESULTS: Of 13,286 thyroid profiles reviewed, 85 (0.64%) samples demonstrated inappropriate TSH secretion. One of these 85 samples (1.2%) was positive for T4AAb with a radioimmunoprecipitate of 21%. 46/85 (54%) samples were collected on hospitalised patients, 7 patients were prescribed amiodarone, 12 patients were taking beta blockers, 30 patients were on thyroxine replacement and 7/85 (8%) were collected on outpatients not taking medication known to affect thyroid function. CONCLUSION: T4AAb interference is an extremely rare explanation for inappropriate TSH secretion with the Immulite 2000 assay but should be excluded before investigating for rarer causes of this biochemical picture.

[The effect of selenium therapy on autoimmune thyroiditis]. / A szelénkezelés hatása az autoimmun thyreoiditisre.

UNLABELLED: Selenium as an essential trace element is capable of exerting complex effects on the endocrine and immune system by its antioxidant capacity. The role of selenium is important because the level of free oxygen radicals is elevated in the physiological thyroid hormone synthesis. THE AIM OF STUDY: was to determine whether selenium therapy can influence the level of antithyroid peroxidase and antithyroglobulin antibodies or whether there is a correlation between antioxidant capacity and the titer of autoantibodies. METHOD: 132 patient with autoimmune thyroiditis were investigated in a prospective, blind and placebo-controlled study. L-thyroxine substitution therapy was made in both groups and the level of TSH remained in the normal range. The selenium-treated group (n = 70 patients, 68 female, mean age 41,4 +/- 9,5 year) was compared with the placebo-treated group (n = 62 patients, 61 female, mean age 42,7 +/- 8,3 year). Selenium therapy was continued by L-seleno-methionine (per os 2 x 100 microg/day) for one year. Determination of TSH, fT4, fT3 and autoantibodies was carried out by chemiluminescence method. Total antioxidant capacity was determined by Randox kit, the level of selenium in the sera by atomic absorption technique was measured. In the follow-up study, patients were controlled every third month and at the end of a one-year observation period. RESULTS: The level of selenium in the untreated patients was significantly lower than in treated patients and controls. The fT3/fT4 ration proved to be higher in patients after selenium therapy. The titer of antithyroid antibodies (mostly the antithyroid peroxidase) significantly decreased at the end of the study. An inverse correlation was found between antioxidant capacity and the level of antithyroid peroxidase antibodies. The volume of thyroid gland slightly diminished in treated patients. Side effects were not observed. CONCLUSIONS: Selenium completed with L-thyroxine is a suitable therapy for patients with autoimmune thyroiditis.