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K P Liesenkötter

Publications and source records attributed to K P Liesenkötter.

7 recordsLinked to original sources

The prevalence of anti-thyroid peroxidase antibodies and autoimmune thyroiditis in children and adolescents in an iodine replete area.

BACKGROUND: The iodine supply of the population in Berlin has normalized during the last 5 Years. Therefore autoimmune thyroiditis has become the most important differential diagnosis in children and adolescents with goiter. OBJECTIVE: The aim of the present study was to define the prevalence of anti-thyroid peroxidase (TPO) antibodies and autoimmune thyroiditis in children and adolescents with a normalized iodine intake. DESIGN: To enable the measurement of antibodies to thyroid peroxidase (anti-TPO-Ab) in a large cohort, a method to determine anti-TPO-Ab in dried filter paper blood spots was established. In co-operation with pediatricians the antibody prevalence was assessed and data regarding thyroid size, echostructure and the medical history concerning iodine intake and familial thyroid diseases were collected. METHODS: 660 children and adolescents participated in the study; urinary iodine, TSH and TPO-Ab were measured and an ultrasound of the thyroid gland was performed. RESULTS: The sensitivity of the newly established filter paper assay was 91.8% and specificity was 100%. The results confirmed the improved iodine supply, with a median urinary iodine concentration of 139 microg iodine/g creatinine. The prevalence of anti-TPO-Ab was 3.4% with a female to male ratio of 2.7:1. CONCLUSION: The prevalence of anti-TPO-Ab is lower or equal to data reported from other iodine sufficient areas. Data from a moderate iodine deficiency in schoolchildren range from 0.0 to 7.3%. Using the new filter paper method field studies can be implemented to monitor the effect of changes in iodine nutrition on thyroid autoimmunity. Furthermore, this study on the prevalence of anti-TPO-Ab in a cohort of healthy children and adolescents in an iodine replete area can serve as reference data for future investigations and for the comparison with other groups of patients with increased risks for thyroid autoimmunity.

Adolescent↗

Alterations of neonatal thyroid function.

Recent progress has been made in understanding the pathogenesis of neonatal thyroid disorders. Autosomal recessive inheritance of mutations of the thyroid peroxidase and thyroglobulin genes has been described in some patients with congenital hypothyroidism (CH) and a family history of CH. Autosomal recessive inheritance of mutations of the thyrotrophin (TSH) receptor gene has also been reported in patients with CH and thyroid hypoplasia, and autosomal dominant mutations of the PAX8 gene have been described in patients with different forms of thyroid dysgenesis. These discoveries are important for patients with CH diagnosed by neonatal screening, as these patients will have normal fertility. The molecular genetic analysis of mutations of the TSH gene in patients with familial and sporadic cases of isolated central CH, who are missed by TSH screening programmes, now enables rapid diagnosis and appropriate therapy in the neonate. In newborn infants with severe non-autoimmune hyperthyroidism, autosomal dominant gain-of-function mutations in the TSH receptor gene have been demonstrated. In these patients, molecular genetic studies are extremely helpful in therapeutic decision making, as early thyroid ablation is the only effective treatment that avoids the sequelae of long-term hyperthyroidism. Molecular genetic studies are therefore useful in the diagnostic work-up of neonatal thyroid alterations.

Congenital Hypothyroidism↗

Severe congenital hypothyroidism due to a homozygous mutation of the betaTSH gene.

Isolated TSH deficiency leading to hypothyroidism seems to be a rare condition, escaping the diagnosis by neonatal screening programs, which are based on the primary determination of TSH. This is the first report of a case with an autosomal recessive TSH defect caused by a homozygous mutation of the betaTSH gene that was diagnosed in the early neonatal period. Hypothyroidism in the first child of apparently unrelated parents was suspected because of the classical symptoms of congenital hypothyroidism, which were fully expressed already on the 11th day of life. Routine neonatal TSH-screening on the 4th day of life had been normal, but subsequent determination of serum thyroid hormone levels revealed almost undetectable levels and thyroid hormone substitution was immediately started. Because there was no indication for other pituitary hormone deficiencies, sequence analysis of the betaTSH gene was initiated. A homozygous T deletion in codon 105 was found resulting in a change of a highly conserved cysteine to valine followed by eight altered amino acids and a premature stop codon due to the frame-shift. This altered betaTSH is a biologically inactive peptide. Because of the early development of severe symptoms, it is possible that this altered TSH suppresses the physiologic constitutive activity of the unliganded TSH receptor. Rapid molecular diagnosis in this patient clarified the diagnosis without additional endocrine and imaging studies and it is concluded, that symptoms of hypothyroidism in the neonatal period should result always in an immediate comprehensive work-up of thyroid function including molecular genetic studies irrespective of the screening result.

Congenital Hypothyroidism↗

Results of the screening program for congenital hypothyroidism in Berlin (1978-1995).

Screening for congenital hypothyroidism for all newborns of the former western parts of the city of Berlin was instituted in 1978 by determination of the TSH levels in dried filter paper blood spots of the 3rd to 5th day of life. Since 1991 the newborns of the former eastern parts have been also included in the same screening program. From 1978 to 1995 a total number of 104 newborns with permanent congenital hypothyroidism have been detected resulting in a prevalence of congenital hypothyroidism of 1:3800. The etiological diagnosis of hypothyroidism was made by imaging studies (ultrasonography or 99mTc scintigraphy) and assessment of serum thyroglobulin and thyroid hormone levels. Using this approach in 37 children (30 female, 7 male) the diagnosis of athyrosis, in 20 children (15 female, 5 male) the diagnosis of ectopy and in 21 children (18 female, 3 male) the diagnosis of thyroid hypoplasia was made, 16 children (8 female, 8 male) had a normally sized gland and 4 (1 female, 3 male) had congenital goiter. In 86% of all patients the age at onset of thyroxine (L-T4) replacement therapy was 8 or 9 days of life (3-42 days) and the median initial L-T4 dose was 14 micrograms/kg/day (10-16 micrograms/kg/day). The intellectual outcome of 77 children (2-16 years) was studied and normal scores for the intelligence (IQ) and developmental (DQ) quotients were found in 71 (92%). Outcome was not correlated to the age at onset of treatment, the initial dose and the severity of hypothyroidism, but there was a positive correlation of the socioeconomic status of the family and the IQ of the patients. The results of the screening program in Berlin document that an early and efficient thyroxine replacement can normalize the intellectual outcome of patients with congenital hypothyroidism independent of the severity of the disease as assessed by the residual thyroid function detectable at diagnosis.

Berlin↗

Small thyroid volumes and normal iodine excretion in Berlin schoolchildren indicate full normalization of iodine supply.

Iodine deficiency is the major cause of an increase in thyroid gland volume in infants and children. In this field study we monitored the iodine supply and its effect on the thyroid gland volume in prepubertal and pubertal children in the eastern and western parts of the city of Berlin, so far considered as an area with borderline iodine deficiency. The thyroid gland volume was determined by ultrasound in 1080 (f = 552, m = 528) children aged 3-15 years, and was correlated to age, body-surface area and iodine excretion, which was measured in a first-morning spot urine. The mean iodine concentration was 115.8 micrograms iodine/g creatinine (12.2 micrograms iodine/dl urine), with no significant differences between eastern parts with 114.5 micrograms iodine/g creatinine (12.3 micrograms iodine/dl urine) vs 116.7 micrograms iodine/g creatinine (12.0 micrograms iodine/dl urine) in the western parts of the city. This good iodine supply of the children was surprising compared to former studies in children and adults. Moreover this normalization of the iodine excretion was reflected by smaller thyroid gland volumes in the children. The volume was found to increase with age and was 2.4 +/- 1.1 ml in prepubertal (Prader and Largo: f < or = 10.9 ys, m < or = 11.5 ys) children, compared to 4.3 +/- 1.7 ml in pubertal children. The goiter prevalence, calculated on this data was below 5%. Among all children there were only 11 (aged 8-13 ys) with abnormal findings of the thyroid gland on ultrasound: 6 with small nodules, 1 girl with a thyroid-cyst, 2 girls had an inhomogenous echo structure and 2 girls presented with a hemithyroidea. This study shows that the iodine supply of the children in Berlin has improved, resulting in smaller sized thyroid glands, compared to those which have been previously published for Germany (Müller-Leisse 1988; Klingmüller, 1991; Menken, 1992), but they correspond well to volumes described in countries with sufficient iodine supply.

Adolescent↗

Earliest prevention of endemic goiter by iodine supplementation during pregnancy.

During pregnancy complex changes of maternal thyroid function occur and they are influenced by the maternal iodine supply. It has been demonstrated that with decreasing iodine supply maternal goiter and hypothyroxinemia as well as fetal and neonatal hypothyroidism become more prevalent. Therefore iodine supplementation during pregnancy is now strongly recommended also in areas of moderate iodine deficiency. To monitor the success of iodine supplementation and its theoretical risk of increasing the frequency of thyroid autoantibodies, we have investigated the thyroid volume, thyroid function, urinary iodine excretion and antibodies to thyroid peroxidase at 10-12 weeks of gestation and postpartum in 38 mothers receiving 300 micrograms potassium iodide/day and in 70 mothers without iodine supplementation. In all of their newborns thyroid volume was determined by ultrasound. The thyrotropin (TSH) levels and antibodies to thyroid peroxidase (TPO-ab) in the neonates were measured in dried blood spots on filter paper from their newborn screening. Urinary iodine excretion was increased significantly after iodine supplementation in mothers (p < 0.001) and their newborns (< 0.05). No hypo- or hyperthyroidism was observed in the mothers or newborns. Interestingly, no difference of maternal thyroid volumes was observed between the two groups after pregnancy, but the volumes of the thyroid glands in newborns of mothers who received iodine were significantly (p < 0.004) lower (0.7 +/- 0.4 ml) than in the control group (1.5 +/- 1.1 ml). There was no change in the frequency of TPO-ab in either group after pregnancy. In four mothers transplacental passage of these antibodies was documented by positive measurement in the blood sample of the newborn. This study documents that iodine supplementation during pregnancy in an area of moderate iodine deficiency results in a lower size of neonatal thyroid volume and that this supplementation was not accompanied by an increase in the frequency of TPO-ab.

Autoantibodies↗