硒对桥本甲状腺炎患者TPOAb及TGAb水平的影响

目的：观察硒对桥本甲状腺炎（HT）患者甲状腺过氧化物酶抗体（TPOAb）、甲状腺球蛋白抗体（TGAb）的影响。方法：选取TPOAb在100～600IU／ml之间,TGAb在200IU／ml到2000IU／ml之间的HT患者66例,随机分为硒治疗组与对照组,硒治疗组（n=46）服硒酵母片（100I．Lg,2次,d）和左甲状腺素钠片（维持TSH至O．27～4．2μIU／m1）治疗;对照组（n=20）服左甲状腺素钠片（维持TSH至0．27—4．2μIU／m1）治疗,比较两组治疗3个月后TPOAb及TGAb水平的变化。结果：治疗3个月后两组TGAb水平与治疗前相比,差异无统计学意义（P〉0．05）。治疗3个月后,两组TPOAb水平明显降低,但降低值差异无统计学意义（P〈0．05）。结论：硒对桥本甲状腺炎患者轻度增高的TPOAb及TGAb水平无明显影响。     

Selenium Supplementation in Pregnant Women with Autoimmune Thyroiditis: A Practical Approach

Selenium (Se) is an essential trace element with antioxidant and anti-inflammatory properties and a pivotal role in thyroid metabolism. Ensuring a sufficient Se supply is possible via a balanced, wholesome diet; however, Se content in foods may be different throughout geographical areas. Se supplementation is expected to improve inflammatory status in patients with autoimmune thyroiditis, especially in those with high activity, and has been demonstrated as effective in reducing the thyroid peroxidase antibodies titer. Se status seems to affect thyroid function in pregnancy, which prompts the potential role of Se supplementation in such patients. Few clinical trials have investigated the effectiveness of Se supplementation in pregnant women with thyroiditis, and their results suggest the safety and effectiveness of this element in reducing autoantibody levels and preventing postpartum thyroiditis development, although limited. Hence, more robust evidence is needed to confirm these data. The current study aims to summarize published data on the relationship between Se and thyroid status in pregnant women with thyroiditis and the potential use of Se. Moreover, an algorithm for Se supplementation is proposed for pregnant women with thyroiditis to help endocrinologists in daily clinical practice to consider Se status.     

Antioxidant and thyroid hormone status in selenium-deficient phenylketonuric and hyperphenylalaninemic patients

BACKGROUND: Subjects consuming protein-restricted diets, such as patients with phenylketonuria (PKU) or milder hyperphenylalaninemias (HPAs) are at risk of selenium deficiency. Selenium is a cofactor of the antioxidant enzyme glutathione peroxidase and of the thyroid hormone converting enzyme thyroxine deiodinase. OBJECTIVE: Our goal was to investigate the effects of low plasma selenium on antioxidant and thyroid hormone status. DESIGN: We assessed plasma selenium, plasma total antioxidant status and the individual components thereof, erythrocyte antioxidant status, and plasma thyroid hormones in 24 PKU and 10 HPA patients and in 42 age-matched control subjects. RESULTS: Selenium was significantly lower in both PKU and HPA patients than in control subjects and the PKU patients had lower values than did the HPA patients. Total antioxidant status was lower in both patient groups than in the control group, whereas alpha-tocopherol, albumin, and uric acid were not significantly different among groups. Plasma selenium correlated well (r = 0.76) with erythrocyte glutathione peroxidase. PKU patients had lower glutathione peroxidase activity than did HPA patients and control subjects and lower glutathione concentrations than did control subjects. Both patient groups had lower superoxide dismutase activity than did control subjects. Free triiodothyronine was higher in both patient groups than in control subjects, whereas free thyroxine was higher in the PKU patients only. Free thyroxine and reverse triiodothyronine were inversely correlated with selenium. CONCLUSION: Supplementation with selenium seems to be advisable for patients consuming diets low in natural protein.     

Chronic autoimmune thyroid disease in children and adolescents in the years 1999-2004 in Lower Silesia, Poland

The aim of the study was to analyze data related to chronic autoimmune thyroid disease at diagnosis and at follow-up of children and adolescents in Lower Silesia in the years 1999-2004. Age, gender, incidence of thyroid disease in the family, clinical presentation, hormonal findings, levels of thyroid antibodies, results of ultrasonography, and fine needle aspiration biopsy (FNAB) were recorded. 100 children, 10 boys and 90 girls, were included in the analysis. The mean age at diagnosis was 12.3+/-2.3 years and at last examination 14.9+/-1.9 years. At diagnosis, increased levels of TSH without overt hypothyroidism was observed in 26 children. In 11 children hyperthyroidism was detected whereas 63 children were euthyroid. An increased level of thyroid peroxidase antibodies was observed in 65% of the children. Ultrasonography was characteristic for Hashimoto's thyroiditis in all patients. Fine needle biopsy was performed when there were diagnostic difficulties (35% children). Thus, in all the children the diagnosis of Hashimoto's thyroiditis was ascertained either by high antibody titer or FNAB. Associated diseases were observed in 33% of the children. Thyroid disease in the family was present in 25% of the children. There was a gradual decline in the number of new cases presented from 1999 to 2004. The reason for this decline remains speculative.     

The role of hereditary and environmental factors in autoimmune thyroid diseases

Autoimmune thyroid diseases are the most common organ-specific autoimmune disorders affecting 5% to 10% of the population in Western countries. The clinical presentation varies from hyperthyroidism in Graves' disease to hypothyroidism in Hashimoto's thyroiditis. While the exact etiology of thyroid autoimmunity is not known, the interaction between genetic susceptibility and environmental factors appears to be of fundamental importance to initiate the process of thyroid autoimmunity. The identified autoimmune thyroid disease susceptibility genes include immune-modulating genes, such as the major histocompatibility complex, and thyroid-specific genes, including TSH receptor, thyroglobulin and thyroid peroxidase. The majority of the anti-TSH-receptor antibodies have a stimulating capacity and are responsible for hyperthyroidism. The anti-thyroglobulin- and anti-thyroid peroxidase antibodies belonging to the catalytic type of antibodies destroy the thyrocytes resulting in hypothyroidism. The appearance of anti-thyroid peroxidase antibodies precedes the induction of thyroiditis and the manifestation of hypothyroidism. The molecular analysis of thyroglobulin gene polymorphism is important in the mechanism of autoimmune thyroiditis. The autoantigen presentation by major histocompatibility complex molecules is a key point of the autoimmune mechanism. It has been shown that a HLA-DR variant containing arginine at position 74 of the DRβ1 chain confers a strong genetic susceptibility to autoimmune thyroid diseases, Graves' disease and Hashimoto's thyroiditis, while glutamine at position DRβ1-74 is protective. Human thyroglobulin 2098 peptide represents a strong and specific DRβ1-Arg74 binder, while a non-binding control peptide, thyroglobulin 2766 fails to induce this response. Moreover, thyroglobulin 2098 stimulated T-cells from individuals who were positive for thyroglobulin antibodies, demonstrating that thyroglobulin 2098 is an immunogenic peptide capable of being presented in vivo and activating T-cells in autoimmune thyroid diseases. Taken together these findings suggest that thyroglobulin 2098, a strong and specific binder to the disease-associated HLA-DRβ1-Arg74, is a major human T-cell epitope and it participates in the pathomechanism of the autoimmune thyroid disease. The exact nature of the role of environmental factors in the autoimmune thyroid disease is still not well known, but the importance of several factors such as iodine, drugs and infections has been reported. Further knowledge of the precise mechanisms of interaction between environmental factors and genes in inducing thyroid autoimmunity could result in the development of new strategies for diagnosis, prevention and treatment. Orv. Hetil., 2012, 153, 1013-1022.     

慢性丙型肝炎患者干扰素诱发甲状腺炎的研究进展

IFN诱发的甲状腺炎(IIT)是慢性丙型肝炎(CHC)患者接受IFN治疗时最常见的内分泌疾病之一,引起了临床广泛关注.IIT的发病机制可能为IFN引起的免疫调节异常和(或)对甲状腺的直接毒性作用.IIT可分为自身免疫紊乱导致的Graves病(GD)、桥本甲状腺炎(HT)和无症状的甲状腺自身抗体阳性;对甲状腺直接毒性作用诱发的破坏性甲状腺炎和非自身免疫性甲状腺功能减退.检测基线促甲状腺激素(TSH)及甲状腺抗体水平、治疗中密切监测TSH有利于及时发现IIT并进行处理,减少其发生和发展.大多数IIT是可控的而无需停止IFN治疗;非自身免疫性甲状腺炎通常较容易恢复.     

Assessment of the Effect of Selenium Supplementation on Production of Selected Cytokines in Women with Hashimoto’s Thyroiditis

The impact of selenium on the course of Hashimoto’s thyroiditis (HT) was mainly assessed by monitoring the titer of antithyroid autoantibodies in most of the studies conducted hitherto. On the other hand, the imbalance in activity of T cells such as Th1, Th2, Th17, and Treg may be relevant in the pathogenesis of this disease. Hence, the assessment of changes in the secretion of cytokines by these cells during selenium supplementation in patients with HT seems to be an important issue and was the main goal of this study. A further aim was to search for correlations among these cytokines, as well as markers of thyroid function, selenium/iodine status in the body, and other biochemical parameters. The group of 29 women with newly diagnosed Hashimoto’s thyroiditis was supplemented with selenium in a dose of 100 µg/day for 6 months. Immunological parameters: interferon γ, tumor necrosis factor α, chemokine CXCL10, interleukin 4, interleukin 1β, interleukin 17, transforming growth factor β, and C-reactive protein, as well as selenium status parameters were determined in serum twice, i.e., before and after supplementation. Selenium supplementation was associated with a change in the production of two cytokines: interferon γ and interleukin 1β, for which a decrease and an increase in concentration were observed, respectively. The partial least squares (PLS) model revealed the presence of many relevant correlations among analyzed parameters. The stage of HT development, degree of thyroid dysfunction, and selenium supplementation of diet are interdependent factors which shape the profile of some cytokines secreted by cells participating in the autoimmunity process.     

A pregnant woman with autoimmune thyroiditis and recurrent goiter

A 27-year-old woman was first referred at the age of 14 with cosmetic complaints due to an echographically diffuse, euthyroid goitre. Tests for antibodies against thyroid peroxidase and thyroglobulin were positive. Thyroid-suppression therapy with levothyroxine resulted in regression of the goitre. At the age of 26 there was a transitory recurrence of the goitre during a pregnancy, during which time the thyroid peroxidase antibodies became strongly positive. Six months post partum the goitre recurred again, accompanied by pain in the throat and fever. The C-reactive protein level was strongly elevated. Serology established the diagnosis of viral thyroiditis due to a Coxsackie-B virus. The size of the goitre decreased after treatment with acetylsalicylic acid and prednisone. Two months later the goitre again showed further growth, now in association with cervical lymphadenopathy and an enlarged left parotid gland. Histology revealed a non-Hodgkin lymphoma of the type diffuse large B-cell (stage II), very likely a primary thyroid lymphoma. The lymphoma was refractory to cyclophosphamide-doxorubicin-vincristine-prednisolone (CHOP); this was followed by intensive chemotherapy and autologous stem-cell transplantation, resulting finally in a complete remission. The goitre disappeared and thyroid peroxidase antibodies were no longer detectable. Primary thyroid lymphoma is a rare disease, but autoimmune thyroiditis appears to be an important predisposing factor.     

The Impact of Kohlrabi Sprouts on Various Thyroid Parameters in Iodine Deficiency- and Sulfadimethoxine-Induced Hypothyroid Rats

Brassica sprouts, as the rich source of dietary glucosinolates, may have a negative effect on thyroid function. In this study, kohlrabi sprouts diet, combined with two models of rat hypothyroidism, was tested. TSH, thyroid hormones and histopathology analysis were completed with the evaluation of immunological, biochemical, haematological parameters, cytosolic glutathione peroxidase, thioredoxin reductase in the thyroid, and plasma glutathione peroxidase. A thermographic analysis was also adapted to confirm thyroid dysfunction. The levels of TSH, fT3 and fT4, antioxidant enzyme (GPX) as well as histopathology parameters remained unchanged following kohlrabi sprouts ingestion, only TR activity significantly increased in response to the sprouts. In hypothyroid animals, sprouts diet did not prevent thyroid damage. In comparison with the rats with iodine deficiency, kohlrabi sprouts diet decreased TNF-α level. Neither addition of the sprouts to the diet, nor sulfadimethoxine and iodine deficiency, caused negative changes in red blood cell parameters, glucose and uric acid concentrations, or kidney function. However, such a dietary intervention resulted in reduced WBC levels, and adversely interfered with liver function in rats, most likely due to a higher dietary intake of glucosinolates. Moreover, the possible impact of the breed of the rats on the evaluated parameters was indicated.     

Transient congenital hypothyroidism due to maternal autoimmune thyroid disease

The neonatal screening program for congenital hypothyroidism (CH) in Greece shows an overall incidence of the disease of 1:2321. The cases with permanent CH have an incidence of 1:2542, whereas the transient forms of CH account for 8.7% of all cases diagnosed as CH. Transplacental passage of maternal thyrotropin receptor-blocking antibodies is a rare cause of transient CH. In our program, a retrospective analysis of 508,358 screened newborns revealed 6 infants with transient CH caused by maternal thyroid autoimmunity, representing 2.7% of all cases of CH. All the newborns with transient CH, due to maternal autoimmune thyroid disease, had high serum TSH concentration (ranging from 98 to 689 mU/L), whereas serum thyroxine (T4) values were low normal to normal in 3 of them. Replacement therapy with L-thyroxine was initiated at a mean age of 6.5 days. The newborns with transient CH belonged to 4 families, one of which had 4 and another 2 children with the same pathology. Thyrotropin-receptor antibodies (TSH-R Abs), present at the initial examination in newborns' serum, had disappeared from the infants' circulation by the third month of life. One mother carried the Abs for at least 8 years during which period she delivered four babies. The diagnosis of transient CH should be suspected if the mother has autoimmune thyroid disease, if there are siblings with transient CH or if there is no need for an increase in L-thyroxine dose with advancing age. The diagnosis is very important for genetic counseling, early treatment initiation of subsequent offspring and adequate control of the mother's thyroid function during subsequent pregnancies so that any neurodevelopmental abnormality of the fetus could be avoided.     

硒对实验性自身免疫性甲状腺炎大鼠甲状腺功能及脱碘酶活力的影响

目的探讨不同水平硒摄入对实验性自身免疫性甲状腺炎(EAT)大鼠甲状腺功能、肝组织Ⅰ型脱碘酶(DⅠ)和脑组织Ⅱ型脱碘酶(DⅡ)活力的影响。方法将雌性清洁级Lewis大鼠随机分为4组:对照组、模型组、补硒+造模组和低硒+造模组,每组8只。适应性喂养两周后,以不同硒含量饲料干预9周,每日总硒摄入量分别为4、4、40和0.4μg,并在干预第3～8周对模型组、补硒+造模组和低硒+造模组大鼠进行免疫,以建立实验性自身免疫性甲状腺炎模型。观察大鼠甲状腺病理改变,测定全血硒含量、血清甲状腺自身抗体、甲状腺激素水平、DⅠ和DⅡ活力。结果模型组、补硒+造模组和低硒+造模组大鼠甲状腺自身抗体和甲状腺激素水平明显高于对照组(P0.05)。补硒+造模组血硒含量高于对照组和模型组,而低硒+造模组血硒含量低于对照组和模型组(P0.05)。此外,不同硒水平EAT大鼠甲状腺组织出现不同程度的病理损伤,缺硒组病变最严重,补硒组病变轻微。模型组DⅡ活力明显低于对照组(P0.05);且与模型组相比,补硒+造模组DⅠ和DⅡ活力升高(P0.05),低硒+造模组DⅠ活力降低(P0.05)。结论补硒可减轻EAT所致大鼠甲状腺组织损伤,提高DⅠ和DⅡ活力;反之缺硒可加重其损伤,降低DⅠ活力。     

碘剂对自身免疫性甲状腺病大鼠甲状腺功能影响

目的观察补充碘剂对自身免疫性甲状腺病大鼠甲状腺功能的影响。方法采用皮下注射甲状腺球蛋白诱发实验性自身免疫性甲状腺炎动物模型(EAT),通过饮水中给予碘剂观察对大鼠甲状腺重量、形态学改变、促甲状腺激素(TSH)和甲状腺激素谱以及甲状腺自身抗体滴度变化。雌性Wisrar大鼠分为A空白对照组、B抗原免疫组、C碘剂喂养组及D抗原免疫加碘剂组。免疫组大鼠给予猪甲状腺球蛋白100μg/只,与全弗氏佐剂(CFA)乳化后皮下注射,第2周后给予不完全弗氏佐剂(IFA)乳化抗原加强免疫。碘剂干预组给予0.05%碘化钠溶液喂养。分别于第0,2,4,6,8周内眦静脉采集血样。结果D组甲状腺绝对及相对重量显著高于A、B组。P<0.05,略高于C组;C组高于A、B组,但P>0.05。B组小叶间散见淋巴细胞浸润;碘剂组滤泡异质性改变,小叶间少量淋巴细胞浸润;D组甲状腺滤泡灶性萎缩、炎症细胞浸润明显,范围较广,滤泡周围可见纤维组织增生。第8周B组FT3、FT4高于A、B组;D组升高更为显著。P<0.01。B组大鼠血清TgAb、TmAb自第2周开始升高,至第4周达到最高水平,随后略有下降,但仍然显著高于对照组;C组抗体水平缓慢升高,第8周时升高达到高峰;D组抗体水平升高最快,而且维持时间更长,P<0.01。结论碘剂可以加重EAT大鼠甲状腺病理损害,升高甲状腺自身抗体滴度,     

Features of selenium metabolism in humans living under the conditions of North European Russia

Purpose

Selenium supplementation and its effects on Northerners have been little studied. The aim of our study was to assess the selenium levels of the inhabitants of North European Russia, the seasonal aspects of selenium supplementation, and the interrelationships between selenium levels and the levels of thyroid gland hormones.

Methods

To study the particular features of selenium metabolism in Northerners over the course of 1 year, 19 healthy male Caucasian volunteers (18–21 years old) were recruited for the present study. The subjects were military guards in a Northern European region of Russia (Syktyvkar, Russia, 62°N latitude) who spent 6–10-h outdoors daily. The study was conducted over a 12-month period. Selenium levels, glutathione peroxidase (GP) activity, as well as total triiodothyronine (T3), total thyroxin (T4), free thyroxin, free triiodothyronine, and thyrotropin (TSH) levels, were determined in the blood serum.

Results

The study subjects showed low levels of plasma selenium throughout the year. We observed a noticeable decrease in plasma selenium levels during the period from May to August, with the lowest levels in July. Selenium levels in the military guards correlated with the levels of selenium-dependent GP enzyme activity throughout the year. Additionally, we demonstrated a significant correlation between selenium and pituitary-thyroid axis hormones (total T3, free T4, and TSH) in periods in which plasma selenium levels were lower than the established normal ranges.

Conclusion

Over the course of 1 year, low levels of plasma selenium affect GP activity and thyroid hormone levels in humans living in North European Russia.     

慢性病毒性肝炎干扰素治疗后致甲状腺功能异常的临床特征及危险因素分析

目的 探讨慢性病毒性肝炎患者干扰素治疗后致甲状腺功能异常的临床特征及其相关危险因素.方法 回顾性分析干扰素治疗的96例慢性病毒性肝炎患者的临床资料,观察甲状腺功能的血清学指标及甲状腺自身抗体变化,治疗结束后继续随访1年,采用Logistic回归分析甲状腺功能异常发生的相关危险因素.结果 96例患者中,干扰素治疗后未发生甲状腺功能异常84例（正常组）;发生甲状腺功能异常12例（异常组）,发生率为12.5％（12/96）,依次为桥本甲状腺炎5例,Graves病和破坏性甲状腺炎各3例,非自身免疫性甲状腺功能减退1例.治疗后发生甲状腺功能异常的时间为2 ～ 7（3.8±1.9）个月,甲状腺功能异常持续时间l～ 11（4.2±0.9）个月.5例进行内分泌治疗,2例停用干扰素.治疗结束后随访1年,所有患者甲状腺功能均恢复正常.Logistic多元回归分析结果显示,女性（OR=3.767）和抗甲状腺过氧化物酶抗体（OR=1.117）是发生甲状腺功能异常的独立危险因素.结论 慢性病毒性肝炎患者干扰素治疗后致甲状腺功能异常以桥本甲状腺炎、Graves病、破坏性甲状腺炎和非自身免疫性甲状腺功能减退为主要类型.接受干扰素治疗的慢性病毒性肝炎患者在治疗过程中均应密切监测甲状腺功能及甲状腺自身抗体,尤其是女性及已有甲状腺自身抗体者.     

Thyroid autoimmunity: really an important cause of sporadic congenital hypothyroidism?

The transplacental transfer of maternal antithyroid antibodies has recently been hypothesised as an aetiological factor in CH. In order to test this hypothesis, mothers and newborns identified by neonatal screening as suffering from hypothyroidism were tested for TgAb, MAb and TSHBAb. Significant titres of MAb and TgAb antibodies were found in 5% of the newborns and their mothers. TSHBAb was found in 1 out of 18 newborns and 1 out of 14 mothers. A causal link was found between the transplacental transfer of IgG inhibiting thyroid growth and function induced by TSH from a mother with Hashimoto's thyroiditis a newborn with CH and in her CH newborn. However the present series did not reveal the high percentage of cases with CH and thyroid antibodies reported by others and particularly not among the neonates born to mothers without any kind of maternal thyroid pathology. It therefore seems that the role of autoimmunity in the pathogenesis of CH and TH is yet to be clarified.     

The role of selenium in iodine metabolism in children with goiter

Possible interactions between selenium and iodine metabolism were investigated in 7- to 16-year-old children with goiter (n = 136) living in southeastern Poland in iodine-deficient areas influenced by a sulfur industry. The Se-iodine interactions in these children were compared to the interactions in children from outside of that region (n = 38). Blood selenium (BSe) concentration and plasma glutathione peroxidase activity were much lower in the study group (64.1 +/- 15.7 microg/L; 111.0 +/- 27.6 U/L) than in the control group (85.3 +/- 19.6 microg/L; 182.4 +/- 35.6 U/L). Almost all of the data [plasma thyroid-stimulating hormone (TSH) concentration, plasma free thyroxine (fT(4)) concentration] fell within the reference limits. There was no statistically significant difference between the control and the study groups with respect to fT(4) and TSH. However, statistically significant differences of fT(4) and TSH in the study group were revealed between females belonging to the lower (n = 21; fT(4), 16.1 +/- 3.3 pmol/L; TSH, 1.83 +/- 1.05 mU/L) and upper Se quartiles (n = 24; fT(4), 14.5 +/- 2.2 pmol/L; TSH, 1. 26 +/- 0.90 mU/L), p < 0.05. Neither group differed in iodine in urine concentration, age, and body mass index. The difference in fT(4) concentrations can be attributed to an Se deficiency. The relationship exists only for females, which suggests a sex-linked hormonal response to concomitant Se and iodine deficiencies.     

Clinical inquiries: How useful are autoantibodies in diagnosing thyroid disorders?

They're useful in diagnosing Graves' disease and, to a lesser extent, autoimmune thyroid disease; they can also help predict hypothyroidism. Thyrotropin receptor antibodies (TRAb) may be mildly elevated in a variety of thyroid disorders, but a TRAb level >10 U/L increases the probability of Graves' disease by a moderate to large degree (strength of recommendation [SOR]: cross-sectional study). A positive or negative thyroid peroxidase antibody (TPOAb) test increases or decreases the probability of autoimmune thyroid disease by only a small to moderate degree (SOR: 3 cross-sectional studies). Thyroid-stimulating hormone (TSH) levels >2 mU/L, although still in the normal range, can be followed up with TPOAb testing to determine whether the patient has an increased probability of developing hypothyroidism (SOR: cohort study with a vague hypothyroidism reference standard).     

Cross-Sectional Associations of Serum Perfluoroalkyl Acids and Thyroid Hormones in U.S. Adults: Variation According to TPOAb and Iodine Status (NHANES 2007–2008)

Background:

Perfluoroalkyl acids (PFASs) are suspected thyroid toxicants, but results from epidemiological studies are inconsistent.

Objectives:

We examined associations between serum PFASs and thyroid hormones (THs) in a representative, cross-sectional sample of U.S. adults. We hypothesized that people with high thyroid peroxidase antibodies and low iodine would be more susceptible to PFAS-induced thyroid disruption.

Methods:

Our sample included 1,525 adults (≥ 18 years) from the 2007–2008 NHANES study with available serum PFASs and THs. We examined associations between four serum PFASs [perfluorohexane sulfonate (PFHxS), perfluorononanoate (PFNA), perfluorooctanoate (PFOA), and perfluorooctane sulfonate (PFOS)], and serum THs [free triiodothyronine (fT3), free thyroxine (fT4), fT3/fT4, thyroid-stimulating hormone (TSH), total T3 (TT3), and total T4 (TT4)] using multivariable linear regression. We stratified subjects into four groups by two indicators of thyroid “stress”: thyroid peroxidase antibody (TPOAb ≥ 9 IU/mL) and iodine status (< 100 μg/L urine).

Results:

Of 1,525 participants, 400 (26%) had low iodine only (T0I1), 87 (6%) had high TPOAb only (T1I0), and 26 (2%) had both high TPOAb and low iodine (T1I1). In general, associations were similar among participants in the groups with neither (T0I0) or only one thyroid stressor (T0I1 or T1I0), suggesting that PFAS–TH associations were not modified by high TPOAb or low iodine alone. However, PFHxS and PFOS were negatively associated (p < 0.05) with fT4, and all four PFASs were positively associated (p < 0.05) with fT3, fT3/fT4, TSH, and TT3 in the group with joint exposure to high TPOAb and low iodine (T1I1).

Conclusions:

We found evidence of PFAS-associated thyroid disruption in a subset of U.S. adults with high TPOAb (a marker of autoimmune hypothyroidism) and low iodine status, who may represent a vulnerable subgroup. However, the small sample size, cross-sectional design, and possibility of reverse causation are limitations of this work.

Citation:

Webster GM, Rauch SA, Ste Marie N, Mattman A, Lanphear BP, Venners SA. 2016. Cross-sectional associations of serum perfluoroalkyl acids and thyroid hormones in U.S. adults: variation according to TPOAb and iodine status (NHANES 2007–2008). Environ Health Perspect 124:935–942; http://dx.doi.org/10.1289/ehp.1409589     

Variable manifestations of Hashimoto's encephalopathy]

Two women (aged 12 and 32 years) and a man aged 40 years presented with fluctuating confusional states, depressed level of consciousness, seizures and tremor or myoclonic activity; hallucinations occurred in two of them. Laboratory examinations showed antibodies to thyroid peroxidase in serum, elevated protein levels in CSF and normal cerebral MRI. The EEG findings were indicative of diffuse encephalopathy. Hashimoto's encephalopathy was diagnosed. One patient improved dramatically on prednisone therapy, the other two patients recovered spontaneously. Hashimoto's encephalopathy is a subacute, fluctuating encephalopathy with combinations of impaired level of consciousness, involuntary movements, and epileptic or psychiatric symptoms. It occurs in patients with antithyroid antibodies. It is important to consider this diagnosis, since some patients may benefit from treatment with corticosteroids.     

The relationship between iron status and thyroid hormone concentration in iron-deficient adolescent Iranian girls

Extensive data from animal and human studies indicate that iron deficiency impairs thyroid metabolism. The aim of this study was to determine thyroid hormone status in iron-deficient adolescent girls. By stepwise random sampling from among all public high schools for girls in Lar and its vicinity in southern Iran, 103 out of 431 iron deficient subjects were selected. Urine and serum samples were collected and assayed for urinary iodine and serum ferritin, iron, total iron binding capacity (TIBC), thyroid stimulating hormone (TSH), thyroxine (T4), triiodothyronine (T3), free thyroid hormones (fT4 and fT3), triiodothyronine resin uptake (T3RU), reverse triiodothyronine (rT3), selenium and albumin concentrations. Hematological indices for iron status confirmed that all subjects were iron-deficient. There was a significant correlation between T4 and ferritin (r = 0.52, P < 0.001) and between TSH and ferritin (r = -0.3, P < 0.05). Subjects with low serum ferritin had a higher ratio of T3/T4 (r = -0.42, P < 0.01). Using stepwise regression analysis, only ferritin contributed significantly to the rT3 concentration (r = -0.35, P < 0.01). The results indicate that the degree of iron deficiency may affect thyroid hormone status in iron-deficient adolescent girls.