School based screening for hypothyroidism in Down's syndrome by dried blood spot TSH measurement.

OBJECTIVE: To determine the feasibility of annual hypothyroid screening of children with Down's syndrome by measuring thyroid stimulating hormone (TSH) on dried blood spots at school, and to describe the outcome in positive children. DESIGN: Establishment of a register of school children with Down's syndrome, and procedures for obtaining permission from parents, annual capillary blood samples, TSH measurement, and clinical assessment of children with TSH values > 10 mU/litre. SUBJECTS: All school age children with Down's syndrome within Lanarkshire and Glasgow Health Boards during 1996-7 and 1997-8. RESULTS: 200 of 214 school children with Down's syndrome were screened. Four of the unscreened children were receiving thyroxine treatment, and only 5 remained unscreened by default. 15 of the 200 children had capillary TSH > 10 mU/litre, and all but 1 had evidence of Hashimoto's thyroiditis. Seven of the 15 children started thyroxine treatment immediately, 6 with a pronounced rise in venous TSH and subnormal free thyroxine (fT4), and one with mildly raised TSH and normal fT4 but symptoms suggesting hypothyroidism. Eight children with mildly raised venous TSH and normal fT4 were left untreated; 1 year after testing positive, fT4 remained > 9 pmol/litre in all cases, but 4 children were started on thyroxine because of a rise in TSH. TSH fell in 3 of the 4 remaining children and there was a marginal rise in 1; all remain untreated. The prevalence of thyroid disease in this population is >/= 8.9%. CONCLUSION: Dried blood spot TSH measurement is effective for detecting hypothyroidism in Down's syndrome and capillary sampling is easily performed at school. The existing programme could be extended to the whole of Scotland within a few years.     

Ectopic Thyroid: Residual Function after Withdrawal of Treatment in Infancy and Later Childhood

ABSTRACT. Plasma thyroxine (T4) and thyrotrophin (TSH) were estimated in 34 children identified by neonatal hypothyroid screening and subsequently found to have ectopic thyroid tissue on isotope scan. Before treatment plasma T4 ranged from 8–143 nmol/1 and TSH from 39–1230 mU/l. After one week off treatment during their second year, repeat T4 in 26 of these cases showed a significant correlation with the pre-treatment values ( r = 0.57). However, only 3 of the 5 children with pre-treatment T4 levels over 100 nmol/1 at diagnosis had normal T4 values when retested. Similarly, when 10 children with pre-treatment T4 values over 65 nmol/1 were retested off treatment at the ages of 5.8–8.2 years, only 4 had plasma T4 levels in the normal range. These results illustrate the wide range of thyroid function which can occur in children with ectopic thyroid tissue and indicate that some continue to have near-normal thyroid function for considerable periods. However, pre-treatment T4 results do not allow accurate identification of these latter cases.     

Ectopic thyroid: residual function after withdrawal of treatment in infancy and later childhood

Plasma thyroxine (T4) and thyrotrophin (TSH) were estimated in 34 children identified by neonatal hypothyroid screening and subsequently found to have ectopic thyroid tissue on isotope scan. Before treatment plasma T4 ranged from 8-143 nmol/l and TSH from 39-1,230 mU/l. After one week off treatment during their second year, repeat T4 in 26 of these cases showed a significant correlation with the pre-treatment values (r = 0.57). However, only 3 of the 5 children with pre-treatment T4 levels over 100 nmol/l at diagnosis had normal T4 values when retested. Similarly, when 10 children with pre-treatment T4 values over 65 nmol/l were retested off treatment at the ages of 5.8-8.2 years, only 4 had plasma T4 levels in the normal range. These results illustrate the wide range of thyroid function which can occur in children with ectopic thyroid tissue and indicate that some continue to have near-normal thyroid function for considerable periods. However, pre-treatment T4 results do not allow accurate identification of these latter cases.     

Euthyroid sick syndrome in children with Hodgkin disease

Euthyroid sick syndrome is related to profound changes in thyroid metabolism induced by nonthyroidal diseases. To determine whether children with newly diagnosed Hodgkin disease might present thyroid abnormalities and to establish their predictive value, the authors performed regular thyroid function testing. Seven children (5 M, 2 F) with a mean age of 10.4 years (range: 4.6-15 years) at diagnosis were studied for a period of 6.9 years (4.2-10.5 years). Five patients presented at diagnosis with euthyroid sick syndrome characterized by borderline low thyroxine circulating levels (T3 0.8-1.3 ng/mL, FT3 1.5-1.7 pg/mL) and mildly raised TSH (4.6-5 microU/mL). Thyroid function turned normal within 6 months of therapy. Subsequently, 3 children developed overt hypothyroidism (T4 35-40 ng/mL, FT4 2-7 pg/mL, TSH 5.5-11 microU/mL) requiring substitution therapy. Euthyroid sick syndrome was not associated with a poorer outcome in terms of survival or long-term thyroid consequences. Thyroid function testing should be performed routinely at diagnosis and thereafter in children with Hodgkin disease to detect subtle abnormalities.     

Thyroid dysfunction in antiretroviral treated children

BACKGROUND: A high rate of thyroid disorders has been described in HIV-infected adults treated with highly active antiretroviral therapy (HAART), but data on children are lacking. We aimed to assess thyroid function in pediatric patients. METHODS: Fifty-two HIV-infected children receiving HAART were assessed for signs of thyroid dysfunction and serum concentrations of thyrotropin (TSH), free thyroxin (FT4), free triiodothyronine (FT3), thyroglobulin (TG), reverse triiodothyronine (rT3), anti-TG and antimicrosomal (anti-TSM) antibodies. RESULTS: Eighteen (35%) children showed thyroid abnormalities: isolated low FT4 value in 16; subclinical hypothyroidism in 1; and symptomatic hypothyroidism in 1.Children with low FT4 values as compared with the 34 children without thyroid dysfunction were similar for stage of disease, number of patients with undetectable HIV-RNA, FT3, TSH, TG, rT3, anti-TSM and anti-TG values, whereas they had shorter duration of HAART exposure (P = 0.019) and lower CD4 cell percentage (P = 0.035). The thyrotropin-releasing hormone (TRH) test was normal in all children with low FT4 values. Among children with low FT4, FT4 concentrations correlated positively with CD4 cell percentage (P < 0.05) and duration of HAART exposure (P < 0.05).The case with subclinical hypothyroidism had high basal TSH (7.3 microunits/ml), normal TSH response to TRH test and normal FT4, FT3, TG, rT3, anti-TG and anti-TSM antibodies.The case with symptomatic hypothyroidism had low FT4 (6.6 pg/ml) and high TSH (44 microunits/ml), TG (55 ng/ml), anti-TG (666 IU/ml) and anti-TSM (123 IU/ml). CONCLUSION: Thyroid abnormalities occur frequently in HAART-treated children even in the absence of clinical symptoms. These data suggest a need of regular thyroid function monitoring.     

Thyroid function in young children with Down syndrome

A retrospective review of thyroid function tests (TFTs) was performed on 49 young children (aged 4 months to 3 years) with Down syndrome compared with age-matched controls screened for hypothyroidism because of developmental delay or failure to thrive. Three of the 49 children with Down syndrome had congenital hypothyroidism; of the three, one had Hirschsprung's disease and two had duodenal atresia. Thyroiditis was uncommon, with only two children having thyroid antibodies present: one had acquired hypothyroidism and the other acquired hyperthyroidism. Twenty-seven percent of the Down syndrome cohort had mildly increased thyrotropin (TSH) and normal thyroxine levels. When compared with children with Down syndrome who had normal TFTs, no significant differences in sex, growth rate, maternal age, associated anomalies, developmental or specific thyroid symptoms were present. Transient elevations of TSH level were common in children with Down syndrome whether or not TSH values were initially normal or elevated. Routine neonatal and sequential thyroid screening in young children with Down syndrome is warranted.     

Thyroid dysfunction in Down's syndrome and screening for hypothyroidism in children and adolescents using capillary TSH measurement

Thyroid dysfunction is more common in individuals with Down's syndrome (DS) than in the general population, whose clinical features can mask the presenting signs and symptoms of hypothyroidism. Biochemical screening is necessary; however, venepuncture may be difficult. AIMS: To assess the prevalence of thyroid dysfunction in children and adolescents with DS and the feasibility of screening for hypothyroidism using capillary dried blood spot thyroid stimulating hormone (TSH) from infancy. METHODS: 394 children (217 boys, 177 girls) were clinically assessed for thyroid dysfunction and 305 children (aged 4 months to 18.9 years) were screened for hypothyroidism by capillary whole blood TSH sample. RESULTS: Thyroid dysfunction was detected in 4.6%, with 50% unscreened since neonatal screening. Parents reported minimal distress by fingerprick screening. CONCLUSION: DS is associated with an increased prevalence of thyroid dysfunction, particularly in preschool children. Biochemical screening is essential and capillary whole blood TSH sampling for hypothyroidism is feasible, less invasive and acceptable.     

Thyroid dysfunction and high thyroid stimulating hormone levels in children with Down's syndrome

In order to delineate the spectrum of thyroid abnormalities in children with Down's syndrome (DS), first visit height data (SDS) and serum TSH, T4 and antiperoxidase antibodies concentrations were retrospectively evaluated in 137 children (71 girls) with DS (0.04-16 years). RESULTS: Congenital hypothyroidism was detected in 2.9% of patients. Thyroid disease occurred in 9%: four hyperthyroidism and eight hypothyroidism. Overt thyroid disease was always related to thyroid autoimmunity. The remaining 121 patients had normal T4 levels but increased mean TSH compared with controls (4.7 +/- 2.8 vs 2.3 +/- 1.3 mU/l). According to TSH levels, they were divided into two groups: G1 (n = 68) with normal TSH (<5 mU/l), and G2 (n = 53) with high TSH (> 5 mU/l). T4 levels were significantly lower in G2 (p < 0.01 vs G1 and controls). Height SDS was not different. CONCLUSIONS: Thyroid disorders are frequent in children with DS. Subtle thyroid abnormalities found in patients with DS with no evidence of clinical dysfunction need further investigation to demonstrate whether there is a need for therapeutic intervention.     

Thyroid dysfunction in Down syndrome

We investigated the thyroid function of 151 patients with Down syndrome. Compared with a control group of 89 siblings nearest in age to their brother or sister with Down syndrome, the mean thyroid-stimulating hormone (TSH) value was significantly higher in patients with Down syndrome than in subjects without Down syndrome. However, the mean thyroxine (T4) levels in both groups were nearly the same. In the Down syndrome group there was a trend for TSH values to increase and for T4 values to decrease with advancing age. Of the 151 patients with Down syndrome, ten had both significantly elevated TSH levels (greater than or equal to 9.5 microU/mL) and significantly decreased T4 levels (less than or equal to 5.5 micrograms/dL), 21 had only abnormally high TSH values, seven had only markedly increased T4 levels (greater than or equal to 12.0 micrograms/dL), and three had only significantly decreased T4 levels. The intellectual function of patients with both abnormal TSH and T4 levels was significantly lower (mean IQ, 41.7) than that of Down syndrome patients with only increased TSH values (mean IQ, 53.8) and that of Down syndrome patients with normal thyroid function (mean IQ, 55.3). This study provides further evidence that there is an increased prevalence of thyroid dysfunction in patients with Down syndrome.     

南京地区1998-2009年新生儿先天性甲状腺功能减低症筛查及治疗随访结果分析

目的 总结并分析1998年1月- 2009年12月南京地区新生儿先天性甲状腺功能减低症(CH)的筛查结果.方法 采集出生72 h新生儿442 454例的足跟血滴于滤纸上,采用时间分辨免疫法测定滤纸血斑促甲状腺激素(TSH),阳性者召回进一步测定静脉血TSH、三碘甲状腺原氨酸(T3)、四碘甲状腺原氨酸(T4)、游离T3(FT3)、游离T4(FT4)以明确诊断.确诊者立即开始予左旋甲状腺素片(4.3～12.0μg·kg-1·d-1)替代治疗,定期监测其甲状腺功能,测量其身高、体质量,其中68例患儿子智力测试,以评估疗效.结果 12 a共筛查442 454人,确诊CH 183例,发病率为0.41‰,对117例进行随访.初始治疗时间的中位数为18 d(7～67d),初始左旋甲状腺素的平均剂量为7.35 μg·kg-1·d-1.CH患儿的身高、体质量结果基本达到正常参照标准.盖泽尔婴幼儿发展量表(GESELL)测试结果显示1例智能发育落后,8例智能发育迟缓.T4、FT4的治疗前水平与患儿的GESELL测试总分、适应性及精细运动均呈正相关(Pa＜0.05).结论 经筛查确诊的CH患儿,应尽可能早地进行激素替代治疗,可有效改善其预后.因此新生儿筛查及随访治疗工作值得推广和完善.     

Neonatal seizures

AIMS—To define the aetiology of neonatal transient hypothyroidism (NTH) and recommend preventive measures.METHODS—Maternal and perinatal clinical data on the use of antiseptics, drugs, and contrast agents containing iodine were collected from 40 subjects. Thyroid stimulating hormone (TSH), free thyroxine (FT4), thyroxine (T4), thyroglobulin (TG), TSH receptor antibodies, thyroid peroxidase antibodies and urinary iodine were measured in random neonatal samples. In the mothers with known or suspected thyroid disorders, TSH, FT4, TSH receptor antibodies and thyroid peroxidase antibodies were also measured.RESULTS—The NTH aetiology was identified in 85% of cases. More than 50% of the babies with transient hypothyroidism had been exposed to iodine; maternal transfer of antibodies had occurred in a third of them.CONCLUSIONS—It is suggested that the practice of using iodine containing disinfectants should be withdrawn, and chlorhexidine substituted instead; that pregnant women should be advised of the adverse effects of using iodine products; and that thyroid function should be monitored whenever iodine is used.     

Elevated serum creatinine levels in infants with congenital hypothyroidism: reflection of decreased renal function?

The effects of hypothyroid status on renal function have been poorly studied in children. We assessed the renal function of hypothyroid infants detected during neonatal mass screening for congenital hypothyroidism (CH). Eighty hypothyroid infants and 20 age-matched normal infants for controls were enrolled. The 80 patients, aged 1 mo, were divided into two groups based on the initial thyroid stimulating hormone (TSH) and free thyroxine (FT4) values: a mild-moderately hypothyroid (MHT) group (n = 64, 31M and 33F) and a severely hypothyroid (SHT) group (n     

特发性肾病综合征患儿血清游离甲状腺激素检测的临床意义

探索特发性肾病综合症（ＩＮＳ）患儿血清游离甲状腺激素（ＴＨ）、甲状腺激素结合球蛋白（ＴＢＧ）的变化情况及其变化的机理和临床意义。对１６例ＩＮＳ患儿及１５例正常儿童对照,用放免法测Ｔ３、Ｔ４、ＦＴ３、ＦＴ４,化学发光酶免疫分析法测ＴＳＨ、ＴＢＧ,放射配基单点饱和饱和结合分析法测糖皮质激素受体（ＧＣＲ）。结果：①ＩＮＳ患儿Ｔ３、Ｔ４、ＦＴ３、ＦＴ４均低于对照组,ＴＳＨ升高,差异非常显著。②ＴＢＧ降低,ＴＢＧ与ＴＨ呈正相关。③ＩＮＳ患儿ＧＣＲ升高,ＴＨ与ＧＣＲ未见相关性。提示对糖皮质激素（ＧＣ）治疗敏感的ＩＮＳ患儿,虽然其ＴＨ是降低的,但其ＧＣＲ是升高的。     

Umbilical cord blood TSH levels in term neonates: a screening tool for congenital hypothyroidism

This study was conducted to find normative values for thyroid stimulating hormone (TSH) in 1200 cord blood samples of term babies whose mothers were not on any thyroid medications. TSH was estimated within 24 hrs by enzyme immunoassay. A full thyroid profile, viz, T3, T4, TSH, fT3 and fT4 was done at 7-10 days of age in all babies with cord TSH >20 mIU/L. The mean, median and standard deviation for the TSH values for the cohort were 6.13 mIU/L, 5.8 mIU/L and 4.523 respectively. 22 babies with TSH values >20 mIU/L were given repeat tests. Hypothyroidism was confirmed in two of these babies. We conclude that a cut off value of TSH >20 mIU/L is adequate for neonatal thyroid screening in Indian settings.     

Longitudinal assessment of L-T4 therapy for congenital hypothyroidism: differences between athyreosis vs ectopia and delayed vs normal bone age

To study the effects of LT4 dose on thyroid hormone serum levels, a prospective, longitudinal and comparative study was designed, including 56 term eutrophic 1-89 day-old infants with congenital hypothyroidism (CH) detected by neonatal screening. Patients were divided into four groups according to delayed or normal bone age at birth, and athyreosis or ectopic thyroid. All received an initial dose of 50 micrograms/day (12.9-13.7 micrograms/kg/day) LT4 and were followed bimonthly (first year) and quarterly (second year) with thyroid profile and bone age determinations at 6, 12 and 24 months. At diagnosis, hormone levels were higher in cases of ectopia than in athyreosis (p < 0.001), and T4 was lower in children with delayed than in normal bone age at birth (p < 0.05). During treatment, all groups were clinically euthyroid despite T4 and FT4 serum levels higher than the upper normal limit (p < 0.0.001), though T3 and FT3 were within the normal limit (p > 0.05). TSH normalized within 8 weeks. Bone age accelerated at 2 years in eight children of the bone age delayed group. No patient had craniosynostosis.     

Thyroid dysfunction in children with Down's syndrome

Thyroid function tests were carried out on 320 children with Down's syndrome aged between 5 d and 10 y. Thyroid function was normal in 230 patients (71.9%) and abnormal in 90 (28.1%). Six patients (1.8%) had primary congenital hypothyroidism, one patient had acquired hypothyroidism and two had transient hyperthyrotropinaemia of the newborn. Sixteen of the remaining 81 patients (25.3%) had compensated hypothyroidism with increased thyroid-stimulating hormone (TSH) levels (11-20 mU l -1 ). Their T 4 levels were found to be either normal or close to the lower limit of normal. These cases were started on thyroxine therapy. Sixty-five of the 81 patients had a mild compensated hypothyroidism with mild TSH elevation (6-10 mU l -1 ). None of the patients had hyperthyroidism. The antithyroid antibodies were positive in the acquired hypothyroidism case.

Conclusion: The prevalence of congenital hypothyroidism was 1.8% in children with Down's syndrome while 25.3% of them had compensated hypothyroidism. It is suggested that Down's syndrome patients with normal thyroid functions and those with compensated hypothyroidism should be followed annually and every 3 mo, respectively. Besides congenital hypothyroidism cases, those with TSH levels between 11 and 20 mU l -1 may benefit from treatment with low-dose thyroxine.     

Relationship between serum leptin and thyroid hormones in children

BACKGROUND: Because leptin decreases food intake and increases energy expenditure, the possible influence of thyroid status on the leptin system has been investigated mainly in adults and animals. However, the data available at present are very confusing. The aim of the present study was to assess the possible interaction of thyroid hormones with the leptin system. METHODS: Serum free thyroxine (FT4), a biologically active thyroid hormone, and thyroid stimulating hormone (TSH), a sensitive and reliable index of thyroid status, were examined in 51 children (19 males, 32 females) with mass screening-detected congenital hypothyroidism on continuous L-thyroxine (L-T4) substitution therapy. The subjects were divided into younger (n = 35, aged 1 month-5 years) and older (n = 16, 6 years-11 years) children groups. Serum levels of leptin and thyroid hormones were measured in the subjects. Body mass index (BMI) was estimated by the formula bodyweight (kg)/height x height (m2), which is known as the Kaup index in younger children and BMI in older children and adults. RESULTS: In the younger children group, serum leptin levels showed no correlation with serum TSH, FT4 or T4. In the older children group, serum leptin concentrations significantly correlated with T4 (r = 0.510, P < 0.05) and BMI (n = 16, r = 0.647, P < 0.01), but not with TSH or FT4. CONCLUSION: The role of thyroid hormones in modulating leptin synthesis and secretion seems to have little, if any, clinical or biological relevance.     

Comparison of mental development in individuals with mosaic and trisomy 21 Down's syndrome.

During the past 15 years about 350 children with Down's syndrome have been seen at Children's Hospital of Los Angeles for psychological evaluation along with medical visits and other laboratory tests. Among this group there were 25 mosaic Down's syndrome children identified by chromosome analyses. They were matched for sex and chronological age with 25 trisomy 21 subjects and compared on psychological tests. The mosaic group demonstrated significantly higher intellectual potential, better verbal facility, and less visual perceptual difficulties than the trisomy 21 group. Their behavioral adjustment and personality characterisitcs were similar to those observed in other types of Down's syndrome. Since present psychological assessment techniques do not permit reaching valid conclusions about the ultimate intellectual status in very young infants with Down's syndrome, physicians and other professionals need to be careful when recommending early placement outside the home based merely upon the diagnosis.     

Hypothalamo-pituitary hypothyroidism detected by neonatal screening for congenital hypothyroidism using measurement of thyroid-stimulating hormone and thyroxine

The optimal strategy in neonatal screening for congenital hypothyroidism is still a subject of controversy. In Kanagawa Prefecture in Japan, simultaneous thyroid-stimulating hormone (TSH) and T4/fT4 determination has been used, while the results of our program may provide valuable information. Cumulative findings were analysed to determine the type and frequency of thyroid disorders in infants detected by simultaneous TSH and T4/fT4 determination, and the TSH and T4/fT4 screening strategy was validated. A total of 1284130 neonates were screened between October 1979 and September 1997 and infants followed because of low T4/fT4 without elevated TSH (T4 < 51.5 nmol/L or fT4 < 9 pmol/L and TSH < 15 mU/L) were retrospectively analysed. The first survey was carried out within 6 mo of birth and the second in 1998; 258 infants were diagnosed with congenital hypothyroidism at the first medical evaluation, 15 of them with hypothalamo-pituitary hypothyroidism. However, in the second survey, only 8 children were confirmed as having hypothalamo-pituitary hypothyroidism, therefore the incidence detected by the present strategy was 1/160516. Of 8 children with hypothalamo-pituitary hypothyroidism, mental retardation was prevented in 3 owing to early treatment. CONCLUSIONS: Simultaneous measurement of TSH and T4/fT4 is a useful strategy for detecting hypothalamo-pituitary hypothyroidism, but more studies are needed to show the cost-benefits of using this strategy.