Capillary Thyroid Stimulating Hormone Research Articles

Thyroid Function in Neonates with Hypoxic Ischemic Encephalopathy.

We aimed to examine heel prick (capillary) and serum thyroid function test (TFT) results in neonates with hypoxic ischemic encephalopathy (HIE) to evaluate the effect of asphyxia and therapeutic hypothermia (TH) on thyroid functions. This retrospective chart review included infants who were born after 34 weeks of gestation, were diagnosed and treated for HIE. The patients were divided into those who did and did not undergo TH and the groups were compared in terms of demographic characteristics, laboratory results, capillary thyroid-stimulating hormone (cTSH) levels, and serum thyroid-stimulating hormone (TSH) and free thyroxine (fT4) levels. A total of 111 neonates were included in the study. There was no difference between the TH group (n = 90) and the nonhypothermia group (n = 21) in terms of median gestational age (38.3 ± 2.1 weeks vs. 38.6 ± 1.8 weeks, p = 0.42) or birth weight (3182 ± 509 g vs. 3174 ± 573 g, p = 0.72). Serum TFT was performed at a median of 10 days (range, 2-43) and capillary TSH analyzed at a median of 6 days (range, 1-26). Capillary TSH at 96 hours was analyzed in 36 patients in the TH group and 19 patients in the nonhypothermia group. Serum TSH and fT4 levels were similar in both groups (p = 0.29, p = 0.1). Overall cTSH and cTSH obtained in the first 4 days were 2.2 (0.5-10) and 4.3 (0.5-94), p = 0.059; 2 (0.5-22) and 5 (0.5-94), p = 0.04, respectively, whereas cTSH obtained after day 4 was similar in both groups (p = 0.058). Abnormal serum TSH (>5.5 mU/mL) was more frequent in the hypothermia group (44.4% vs. 19%, p = 0.026). Our results suggest that TH may cause some alterations on TFTs. Therefore, it may be reasonable to repeat TSH screening after TH.

High Iodine Urinary Concentration Is Associated with High TSH Levels but Not with Nutrition Status in Schoolchildren of Northeastern Mexico

According to the Iodine Global Network, Mexico is considered a country with adequate national iodine intake (297 mg/L), but some regions have not been studied. We aimed to evaluate urinary iodine concentration (UIC) and its association with thyroid stimulating hormone (TSH) levels and the nutritional status in 307 children (aged 5 to 11 years) from three elementary schools of Monterrey, northern Mexico. UIC in spot urine samples and capillary TSH levels were measured to assess thyroid function, in addition to weight, height, body mass index (BMI), and waist circumference (WC). We found a median UIC of 442 mg/L and a significant association between UIC and TSH levels by logistic regression when data were adjusted for (1) age and sex; (2) age, sex, and WC; and (3) age, sex, and weight status. UIC values were higher in 7-year-old children compared to 11-year-old children. High prevalences of overweight/obesity (41%) and WC >90 pctl (22%) were observed. This study identified higher UIC levels in children than those previously reported in the country. The UIC showed a positive and significant correlation between TSH levels in the three models evaluated. More studies are needed to assess the causes and possible outcomes of high UIC levels.

An Optimal Capillary Screen Cut-off of Thyroid Stimulating Hormone for Diagnosing Congenital Hypothyroidism: Data from a Pilot Newborn Screening Program in Delhi

To determine an appropriate cut-off of capillary Thyroid stimulating hormone (TSH) for congenital hypothyroidism. Cross-sectional. 174,000 neonates born in different hospitals of Delhi, India, from November 2014 to October 2016. Correlation between initial and repeat capillary TSH level and subsequent venous free thyroxine (fT4) level. 102 newborns with initial/ repeat capillary TSH level of ≥20 mIU/L (n=174) were confirmed to have congenital hypothyroidism at mean (SD) age of 5 (4) days. A good correlation between capillary TSH level and confirmatory venous fT4 level and postnatal age of sampling was obtained (r -0.6, -0.4). The area under the ROC curve (AUC) was 0.81 (95%CI 0.75 to 0.88), indicating referral capillary TSH level of 20 mIU/L to be a good predictor of subsequent high venous TSH level. A cut off of ≥20 mIU/L for capillary TSH screening beyond 24 hours of life is optimal in the Indian setting for deciding further recall and workup, keeping a balance between sensitivity and recall rate.

Trends in Scottish newborn screening programme for congenital hypothyroidism 1980–2014: strategies for reducing age at notification after initial and repeat sampling

ObjectivesTo determine ages at first capillary sampling and notification and age at notification after second sampling in Scottish newborns referred with elevated thyroid-stimulating hormone (TSH).Subjects and methodsReferrals between 1980 and...

How well does the capillary thyroid-stimulating hormone test for newborn thyroid screening predict the venous free thyroxine level?

ObjectivesTo determine, in newborn infants referred with elevated capillary thyroid-stimulating hormone (TSH), a threshold below which a frankly subnormal venous free thyroxine (fT4) level of <10 pmol/L is unlikely, so...

Normative Thyroid-Stimulating Hormone Values for Healthy Nigerian Newborns

Background: Congenital hypothyroidism is a common congenital endocrine disorder prevailing all over the world. No nationwide screening exists for any sub-Saharan country. We present normative cord and capillary thyroid-stimulating hormone (TSH) values for healthy Nigerian newborns. Subjects and Methods: A cross-sectional study was carried out in 6 university hospitals in Nigeria between January 1 and December 31, 2013. Cord and heel blood placed on 4 concentric circles on a Whartman filter paper were analysed for TSH within 1 week of collection using AutoDelfia 1235 immunoassay (Perkin Elmer Wallace, Boston, Mass., USA) at Charité - Universitätsmedizin Berlin, Berlin, Germany. The mean TSH levels of the newborns were determined, considering their sex, birthweight, socioeconomic status, and birth city. The association between the mean TSH level and other parameters was determined by analysis of variance. Results: A total of 2,014 subjects were recruited during the study period. The mean TSH value for the subjects was 1.86 μIU/ml, and 98.1% of the newborns were within the 2.5th and 97.5th percentiles (range: 0.09-7.90 μIU/ml) of the TSH levels. We collected 247 cord and 1,767 heel samples, respectively, and the range was slightly higher in samples from cord blood. Conclusion: The study highlights the normal reference values for capillary/cord TSH levels in term Nigerian newborns. TSH was higher in one region, attributable to earlier sampling, but was not influenced by gender, socioeconomic status, or birthweight.

Capillary blood screening for hypothyroidism in Down syndrome?

Children and adolescents with Down syndrome carry a lifelong increased risk of acquired hypothyroidism, particularly from autoimmune disease. Their hypothyroidism can be difficult to detect clinically, as symptoms such as short stature, constipation, dry skin, and lethargy occur commonly in these children. Thus, multiple societies have endorsed various thyroid hormone screening guidelines, based upon venipuncture. Screening programs are almost always debated and need to take into account disease prevalence, test sensitivity and specificity, cost of screening, and test acceptability, among other factors. In this issue of The Journal, McGowan et al consider whether the Scottish capillary thyroid stimulating hormone (TSH) screening program might contain data to establish a threshold value below which low venous free T4 and elevated venous TSH are unlikely, so that capillary blood screening could serve as a first-stage screening for children in lieu of venipuncture. Using a limited cohort of 99 children with Down syndrome identified over 10 years by capillary TSH ≥ 4 mU/L, they determine that a cutoff TSH value of 6 mU/L was 73.5% sensitive and 80.8% specific in predicting venous TSH >10 mU/L. Correlation between capillary TSH and venous free T4 was low. The authors propose an algorithm for management based upon capillary TSH. For any child with capillary TSH > 6 mU/L, they recommend clinical assessment and immediate venipuncture. For those children <5 years of age with capillary TSH in the 4-5.9 mU/L range they also suggest immediate venipuncture. In those children aged 5 years and older with a result in the 4-5.9 mU/L range, they suggest repeat capillary screening six months later because decompensated hypothyroidism was so rare in these patients, only 1 of 38. Whether their less invasive and likely less expensive approach should be adopted more globally will require additional study. Article page 1013▶ Screening for Hypothyroidism in Down Syndrome Using the Capillary Thyroid Stimulating Hormone MethodThe Journal of PediatricsVol. 166Issue 4PreviewTo analyze data from the Scottish capillary thyroid stimulating hormone (TSH) screening program for hypothyroidism in Down syndrome to identify a threshold for capillary TSH elevation below which low venous free thyroxine (fT4) (<9 pmol/L) and/or frank venous TSH elevation (>10 mU/L) range is unlikely. Full-Text PDF

Screening for Hypothyroidism in Down Syndrome Using the Capillary Thyroid Stimulating Hormone Method

To analyze data from the Scottish capillary thyroid stimulating hormone (TSH) screening program for hypothyroidism in Down syndrome to identify a threshold for capillary TSH elevation below which low venous free thyroxine (fT4) (<9 pmol/L) and/or frank venous TSH elevation (>10 mU/L) range is unlikely. Review of proformas prospectively submitted on all children with Down syndrome referred via the screening program between 2003 and 2013. Ninety-nine patients with Down syndrome (50 females, 49 males) were identified, 76 school-age (≥ 5 years) and 23 preschool (<5 years), mean (range) age at referral 9.4 (0.9-18.1) years. Pearson correlation between capillary TSH and venous TSH was 0.814; between capillary TSH and venous fT4 -0.522 (P = .01). Receiver operator curve analysis showed that capillary TSH values of 4 and 6 mU/L were 95.9% and 73.5% sensitive, 5.8% and 80.8% specific, respectively, in predicting venous TSH >10 mU/L. Fifty-three children had capillary TSH values of 4-5.9 mU/L of whom only one, a boy of 15.8 years, had subnormal venous fT4 (<9 pmol/L), and venous TSH >10 mU/L was found in 13 (4 preschool). Venous fT4 is normal in almost all patients with Down syndrome with capillary TSH 4-6 mU/L. We propose an algorithm incorporating rescreening by finger prick after 6 months, rather than venepuncture, in school-aged children with borderline capillary TSH elevation. Further data are needed before this approach can be recommended for preschool children.

The role of scintigraphy and ultrasound in the imaging of neonatal hypothyroidism: 5‐year retrospective review of single‐centre experience

Congenital hypothyroidism (CH), as indicated by an elevation of capillary thyroid-stimulating hormone (TSH) at newborn screening, is a preventable cause of mental retardation with varying aetiology; it can be transient or permanent. Radionuclide assessment is currently the gold standard for imaging CH. This study aimed to (i) review the different scintigraphic patterns and correlate them with TSH levels/patient outcomes, (ii) assess the role of sonography in neonates with apparent agenesis as indicated by scintigraphy and (iii) develop a diagnostic investigative algorithm. The technetium thyroid scans of 83 consecutive patients (49 females, average age 32 days) with CH scanned between 2005 and 2009 were retrospectively reviewed. Two nuclear medicine physicians blinded to the clinical details interpreted the scans in consensus. Scintigram appearances were categorised into five groups. Patients scintigraphically diagnosed with thyroid agenesis were evaluated with ultrasound. TSH values and scintigraphic and sonographic findings were correlated with patients' final diagnosis. Based on scintigraphy, 14, 13 and 19 patients out of 83 were assessed as having normal thyroid sites with normal, increased and decreased uptake, respectively. Twenty-two of 83 patients had no uptake, and 15 of 83 patients had ectopic uptake. Higher median TSH levels were seen in no-uptake and ectopic uptake subgroups. Eighteen of 22 patients with no uptake were evaluated with ultrasound. Three of the 18 patients had a normal thyroid gland, and three of 18 patients had a hypoplastic thyroid. Scintigram findings in patients with congenital hypothyroidism fall into five major categories, which have therapeutic implications (lifelong thyroxine in agenesis versus trial of stopping thyroxine in other subgroups). Sonographic demonstration of thyroid tissue in patients scintigraphically diagnosed with thyroid agenesis has major management implications.

Optimising outcome in congenital hypothyroidism; current opinions on best practice in initial assessment and subsequent management

Congenital hypothyroidism (CH), usually of the primary and permanent variety, is an eminently preventable cause of growth retardation and mental handicap whose outlook has been transformed by newborn screening, usually involving the measurement of capillary thyroid stimulating hormone (TSH). Severe primary CH, due for example to athyreosis, may result in subtle cognitive, behavioural and sensori-motor deficits, but the extent to which these can be offset by optimal postnatal diagnosis and management remains uncertain. This is because the available adult follow-up data reflect the outcome of previous management in the 1970’s and 1980’s, and also because the accurate neuro-psychological assessment of children is difficult, particularly in the preschool population. There is an urgent need to develop new consensus guidelines and to ensure that the children managed according to such guidelines are systematically and prospectively assessed so that good quality outcome data become available. In this review, key recommendations in the management of CH include: screening at day 3 so that severely affected infants can begin treatment within the first 10 days of life; setting the TSH referral cut-off at 8-10 mU/L; adopting a disciplined diagnostic algorithm to evaluate referred cases, with measurement of venous free thyroxine (T4), TSH and thyroglobulin combined with dual ultrasound and radioisotope imaging; initial treatment with a T4 dose of 50 μg daily in infants weighing ≥ 2.5 kg and 15 μg/kg/day in infants weighing < 2.5 kg followed by weekly review until thyroid function is normalised; and maintenance of free T4 levels between 15-26 pmol/L and TSH between 0.5-5 mU/L thereafter to avoid both under- and overtreatment. Conflict of interest:None declared.

Capillary TSH screening programme for Down's syndrome in Scotland, 1997–2009

ObjectivesTo assess uptake of community-based capillary thyroid stimulating hormone (TSH) screening in Scotland and determine the optimal frequency of screening, the justification for preschool screening and strategies for treatment.MethodsSubjects with...

Cord Blood Thyroxine and Thyroid Stimulating Hormone Screening for Congenital Hypothyroidism: How Useful Are They?

To determine and compare the usefulness of cord blood screening for free thyroxine (FT4) and thyroid stimulating hormone (TSH). There is a vast amount of literature on capillary heel prick screening tests, but relatively little on cord blood testing particularly FT4. For a decade all infants born at Tawam Hospital had cord blood FT4 and at Oasis Hospital cord TSH measured through the hospital-based screening programme. On January 1st 1998, the national screening programme (NSP) for congenital hypothyroidism (CH) in the United Arab Emirates (UAE) started using capillary TSH measurement (Delfia method). Since then newborns in both hospitals have been screened both ways, i.e. cord blood and capillary blood screening. We reviewed retrospectively all infants born from January 1998 until the end of June 2004 with CH who had double screening: cord FT4 or TSH and 4th-5th day TSH screening. Thirteen infants (one in 1,778) had CH in Tawam Hospital. In six of these the cord blood FT4 was low (<9.1 pm/l) (0.73 ng/dl) and in seven the cord blood FT4 was normal, i.e., over half were missed. Eight infants (one in 1,198) had CH in the Oasis Hospital. Cord blood TSH was high in six of them (>13 IU/l) and two were normal. Cord FT4 detected the most severe cases, but missed most others. Cord TSH detected six out of eight cases, but there was a recall rate of one in 23. Cord FT4 identifies only infants with severe CH. Cord TSH is more sensitive than cord FT4 screening. Capillary TSH dried blood spot testing on the 3rd-5th day is the most sensitive method.

Combined ultrasound and isotope scanning is more informative in the diagnosis of congenital hypothyroidism than single scanning

Background: Thyroid imaging is helpful in confirming the diagnosis of congenital hypothyroidism and in establishing the aetiology. Although isotope scanning is the standard method of imaging, ultrasound assessment may be...

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

OBJECTIVETo 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...