Cases Of Transient Hypothyroidism Research Articles

Clinical characteristics of children and adolescents with thyroid disorders seen at the University of Port Harcourt Teaching Hospital: A five year review

Background: Thyroid disorders constitute a large proportion of endocrine diseases in children and adolescents. Diseases of the thyroid have profound effect on metabolism, cognition, growth and development in children. The pattern of thyroid disorders in children in our region is still under reported.Objectives: To describe the clinical characteristics of children and adolescents with thyroid diseases seen over a 5 year period in a tertiarycentre in Port HarcourtMethods: A retrospective review of all cases of thyroid disorders seen in the Paediatric endocrinology clinic of the University of Port Harcourt Teaching Hospital from January 2009 to December 2013.The information obtainedfrom endocrine registers and case files were patients’ biodata, clinical features, diagnosis, management, challenges and outcome. Diagnosisof each disorder was based on clinical features, relevant laboratoryinvestigations and imaging studies.Result: Eighteen (29.3%) out of 62 children with various endocrine disorders had thyroid diseases, accounting for 0.1% of all childrenseen in the specialist outpatient clinics. Age range at presentationof children reported was 5days to 13 years with male to female ratio1.7:1. Of the 18 children, 5(27.8%) had hyperthyroidism with a case of neonatal thyrotoxicosis, 10(55.6%) hypothyroidism and 3(16.7%) euthyroidism. eight (44.4%) had goiter. Nine (90.0%) of the children with hypothyroidism had congenital hypothyroidism with two cases of transienthypothyroidism. Mean age at diagnosis of children with congenital hypothyroidism was 9.81months. Only 2(22.2%) with congenital hypothyroidism presented before the age of 3weeks, the mean durationof neck swelling before presentation of children with goitre was 19.6months. One (5.6%) child had thyroid cancer. Initial wrong referrals and lost to follow up in 22.2% of cases each were common challenges encountered in management.Conclusion: Congenital hypothyroidism was the commonest thyroid disorder in this report, delayed diagnosis and its consequences were noted, emphasizing the need for routine new-born screening in Nigeria.Keywords: Thyroid disorders, children, endocrine diseases, antithyroid treatment

Transient Hypothyroidism in Premature Infants After Short-term Topical Iodine Exposure: An Avoidable Risk?

Studies in preterm infants have shown that prolonged treatment with topical iodine (multiple doses, often over multiple days) can transiently suppress thyroid function. However, it is uncertain if topical iodine exposure for very short periods of time can cause significant changes in thyroid function. We report two cases of transient hypothyroidism in preterm infants after short-term exposure to topical iodine during surgical preparation, and review their clinical and laboratory findings before and after iodine exposure. We conclude that premature infants are at risk of developing transient hypothyroidism in response to a single, short-term exposure to topical iodine, even in iodine-sufficient geographical areas. We advise monitoring of thyroid function in these infants after iodine exposure, as treatment with levothyroxine may be needed for a limited duration to prevent the sequelae of untreated hypothyroidism. Consideration of using alternative cleansing agents is also advised.

Incidence of congenital hypothyroidism in the city of Uberaba/Minas Gerais and etiological evaluation of the affected subjects

The objective of this study was to determine the incidence and etiology of congenital hypothyroidism (CH) in Uberaba, MG. From 2001 to 2010, by reviewing patient files from a public reference outpatient unit. The screening program covered 88% of live-born children. CH was diagnosed in 16 children, representing an incidence of 1:2,017 live-born children screened. The etiological evaluation was done in 15 children and revealed seven cases of thyroid dysgenesis, seven of dyshormonogenesis, and one case of transient hypothyroidism. One child moved away from the state before etiological investigation was carried out. We concluded that both the incidence of CH and of dyshormonogenesis as the main causes of CH were increased in the investigated region, but molecular studies are necessary for a better definition of etiology.

Trends in Incidence Rates of Congenital Hypothyroidism Related to Select Demographic Factors: Data From the United States, California, Massachusetts, New York, and Texas

Primary congenital hypothyroidism (CH) is a common and preventable cause of intellectual disability. The incidence rate of CH has been reported to be increasing in the United States, but the factors behind the observed rate increase are not known. We summarize here the data presented at a workshop on CH, at which factors potentially related to the CH-incidence-rate increase (namely, race, ethnicity, sex, and birth outcomes) were evaluated. Data sources for the analyses included a national data set of newborn-screening results and state-specific data from newborn-screening programs in California, Massachusetts, New York, and Texas. The incidence rate of CH increased in the United States by 3% per year; however, an increase did not occur in all states, at a constant rate, or even at the same rate. Analysis of US data (1991-2000) showed a CH-incidence-rate increase only among white newborns. More recently, in California (2000-2007), the rate was constant in non-Hispanic newborns, but it increased among Hispanic newborns. In the national data, the CH-incidence rate increased similarly among boys and girls, whereas in Texas (1992-2006), the rate among boys increased significantly more than among girls and varied according to race and ethnicity. In Massachusetts (1995-2007), low birth weight newborns or newborns who had a delayed rise in thyrotropin concentration accounted for the majority of the recent rate increase. Race, ethnicity, sex, and pregnancy outcomes have affected the observed increasing incidence rate of CH, although there have been some inconsistencies and regional differences. The association with preterm birth or low birth weight could reflect the misclassification of some cases of transient hypothyroxinemia as true CH. Future studies of risk factors should focus on correct initial identification and reporting of demographic characteristics and pregnancy outcomes for cases of CH. In addition, long-term follow-up data of presumed cases of CH should be ascertained to differentiate true cases of CH from cases of transient hypothyroidism.

Is Umbilical Cord Blood Total Thyroxin Measurement Effective in Newborn Screening for Hypothyroidism?

To assess the performance of the use of umbilical cord blood for screening of primary congenital hypothyroidism in the Saudi Aramco Medical Services Organization newborn thyroid screening programme. Umbilical cord blood total thyroxin (CB-TT4) was measured. In samples with low T4 concentrations, an additional measurement of cord blood thyroid-stimulating hormone was made. A total of 96,015 newborn infants were screened in the period January 1990-December 2007. Twenty-six cases of primary congenital hypothyroidism, six cases of transient hypothyroidism and 13 cases of central hypothyroidism were detected. This method of screening resulted in 100% sensitivity and 98% specificity (95% CI 84-100, and 95% CI 98-98.2, respectively). However, there was a high mean recall rate of 1.9%. The use of CB-TT4 is a valid screening strategy for primary congenital hypothyroidism. It meets the metabolic screening demands of early discharge policy and guarantees screening all newborns delivered in the hospital.

Neonatal screening for congenital hypothyroidism in West Black Sea area, Turkey

The aim of this study was to investigate the incidence of congenital hypothyroidism (CH) in the West Black Sea Area, a mild-to-moderate iodine deficient area in Turkey. Neonatal screening for CH was performed using blood specimens collected onto filter paper. Thyrotropin [thyroid-stimulating hormone (TSH)] was measured by radioimmunoassay, and a value >20 microU/ml was considered as cut-off point for re-examining. Venous serum was obtained to measure TSH, thyroxin (T4), free T4 (FT4) and thyroglobulin (TG). To determine the iodine status of the study area, median urinary iodine was measured in 212 randomly selected neonates and their mothers. A total of 18606 neonates were screened from three cities (Bolu, Düzce, and Zonguldak) between 2000 and 2002. With a cut-off point of TSH value >20 microU/ml, the recall rate was found 1.6%. Eight cases of CH were diagnosed (incidence 1/2326). There were three cases of transient hypothyroidism, with an incidence of 1/6202. Twenty-six percent of the TSH values was greater than 5 microU/ml. Median urinary iodine concentrations in neonates and their mothers were 85 microg/l and 40 microg/l, respectively. The incidences of CH, transient hypothyroidism and the recall rate were higher in our study area than many countries in Europe. The study area has been affected by mild-to-moderate iodine deficiency. Neonatal screening for CH should be introduced in Turkey without delay. A national comprehensive infantile hypothyroidism and iodine prophylaxis policies should be developed.

Recurrent Hyperthyroidism After Radioiodine-Induced Hypothyroidism: Report of Two Cases and Literature Review

The practice at the Mayo Clinic in treating Graves' disease with radioiodine (131 I) is to achieve a hypothyroid state. Less than 10% of the patients need more than one dose. Although cases of transient hypothyroidism have been reported after treatment with 131 I, the recurrence of hyperthyroidism is unusual after hypothyroidism has been induced with 131 I. We studied two cases seen at our institution in the past year in which the circumstances behind the recurrence have never been reported previously. The first case illustrates a recurrence of hyperthyroidism after the patient had received 38.5 mCi of 131 I. The second patient had recurrence of hyperthyroidism after 22 years of replacement therapy with levothyroxine. Both patients had increased levels of thyroid-stimulating immunoglobulin. We believe that the recurrence of the hyperthyroid state in these two patients was due to incomplete ablation of the thyroid. Apparently 131 I caused hypothyroidism, but residual cells remained viable and under continuous stimulation of thyroid-stimulating immunoglobulin produced recurrent thyrotoxicosis.

A case of transient hypothyroidism: Sequential serum measurements of autoantibodies inhibiting thyrotropin-stimulated thyroid cAMP production in a neonate

Transient neonatal hypothyroidism has been observed in three successive offspring of a mother with autoimmune thyroiditis. Thyroxine replacement therapy was initiated in a 23-year-old woman with overt clinical and laboratory findings of non-goitrous primary hypothyroidism. While on such treatment, she gave birth to three infants manifesting hypothyroidism immediately after birth. The neonates were treated with thyroxine replacement therapy which was discontinued in the three siblings at ages 2 1/2 years, 3 1/2 years, and 13 months. Continuous observation following cessation of therapy revealed clinical and biochemical euthyroidism in the children. Thyroid scanning during the neonatal period in the first child failed to identify functional thyroid tissue, suggesting thyroid agenesis, whereas thyroid scan performed on subsequent follow-up revealed a normal gland. Sequential serum measurements of autoantibodies directed towards the thyrotropin receptor were made in the mother and third child by a cAMP bioassay. High titres (five-six fold above normal) of blocking antibodies (tested by measuring the inhibition of TSH-stimulated cAMP production of cultured human thyroid cells by serum immunoglobulin preparations) were present in the mother and newborn 10 days after birth. The levels remained persistently high in the mother, whereas they declined and were undetectable in the child at four months. Thyroid-stimulating immunoglobulin was absent in both mother and child. The data are compatible with transient neonatal hypothyroidism caused by transplacental transfer of antibodies which block thyroid response to TSH. The half-life of the maternally-derived blocking antibody in the infant was estimated as 1-2 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Screening for congenital hypothyroidism in Hong Kong.

A pilot cord blood TSH screening program for congenital hypothyroidism was commenced in Hong Kong in April 1982. By April 1984, 14 411 neonates born in two hospitals were screened for this disorder. Five cases of primary hypothyroidism and two cases of transient hypothyroidism were detected. The detection of cases of congenital hypothyroidism with only moderately elevated cord blood TSH values means that the recall rate will remain high.

Pilot study for congenital hypothyroidism, preliminary report.

Preliminary results of a pilot study on congenital hypothyroidism performed on 8,025 newborns in Italy over a 10-month period are reported. The determination of both T4 and TSH on dried blood, spotted on filter paper, as screening procedure at day 3-5 of life revealed three cases of primary hypothyroidism and one case of hypo-thyroxin-binding-globulinemia (hypo-TBG-emia). The diagnosis of primary hypothyroidism was established on the basis of low T4 and high TSH levels in two of the three cases; in the third, with elevated TSH and normal T4 levels at screening, thyroid scintiscan showed an ectopic gland located at the base of the tongue. In the case of hypo-TBG-emia, low T4 and TBG levels were associated with normal TSH values. Some cases of transient hypothyroidism were observed in premature infants.

The method of T4 radioimmunoassay using filter paper blood samples and its application for the early detection of neonatal hypothyroidism (author's transl)

We examined the method of radioimmunoassay of the Disc T4 (dried blood spot T4) for the purpose of mass screening of neonatal hypothyroidism and tried the parallel assay of T4 and TSH in dried blood spotted on filter paper at the fifth day of life, and we compared the results. By changing the volumes of T4 antibody and T4 antigen solutions, it is possible to measure thyroxine using two discs 3mm in diameter. Disc T4 values obtained in 45 unknown samples by this method were in good correlation with serum T4 values of the same subjects (Y = 0.97X + 0.06). The coefficients of variation were 5.6 to 18.9% in the range of 5.3 to 10.7 micrograms/100ml of Disc T4 (within assay), and 7.9 to 20.8% in the range of 2.4 to 10.3 micrograms/100ml of Disc T4 (between assay). We measured both Disc T4 and Disc TSH of 26,067 newborn infants born between June 1978 and May 1979. Out of 26,067 measurements, four cases of primary hypothyroidism, fourteen cases of TBG deficiency and two cases of transient hypothyroidism were discovered. Out of the four cases of primary hypothyroidism, three showed low Disc T4 (1.3 to 4.0 micrograms/100ml) and high Disc TSH (200 to 240 micromicrons/ml), one showed normal Disc T4 (7.1 micrograms/100ml) and high Disc TSH (30 micromicrons/ml). It was thought the last case might be mild hypothyroidism. In 14 cases of TBG deficiency, Disc T4 was not detectable to 3.4 micrograms/100ml while Disc TSH was within the normal range. In two cases of transient hypothyroidism, Disc T4 measurements showed normal range (6.5, 10.6 micrograms/100ml), and Disc TSH showed high values (41, 120 micromicrons/ml). Therefore, Disc TSH was more sensitive and showed less false positive cases than did Disc T4 for screening hypothyroidism. Although no secondary hypothyroidism existed in the 26,067 measurements, it continues to be important to measure Disc T4 for the discovery of secondary or tertiary hypothyroidism.