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IMMUNOLOGY OF PREGNANCY

R. G. Edwards

The presentation made by Dr. Verbickij is important in several respects. First, it is an excellent piece of work on the immunology of pregnancy. Next, it shows how a model can be established in a non-human primate to facilitate research on clinical problems.

There has been a great amount of interest in the immunology of pregnancy in recent years. The stimulus to much of the early research was the development of methods to prevent rhesus haemolytic disease in human neonates. We are all familiar with the great progress being made in these studies following the introduction of the use of anti-Rh serum (Clarke 1968). There has been a significant reduction in the incidence of afflicted children, and this progress seems bound to continue as more experience is gained on the best ways of using the antiserum.

Yet there are still many cases of sensitised mothers carrying foetuses at risk of

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Post-parathyroidectomy restoration of normal calcium homeostasis in neonatal primary hyperparathyroidism

J. L. C. Ch'ng, A. Kaiser, J. Lynn, and G. F. Joplin

Abstract. Total parathyroidectomy is required to cure neonatal primary hyperparathyroidism (NPH) as any parathyroid remnant quickly becomes hyperplastic, causing recurrent hypercalcaemia. We present a patient with NPH who had total removal of his eutopic parathyroid glands but continued to have parathyroid hormone secretion from presumed ectopic parathyroid tissue. Hypercalcaemia initially recurred but normal calcium homeostasis was established as the child grew older. We postulate that the underlying defect in NPH is decreased sensitivity to the serum ionic calcium feedback inhibition at the parathyroid receptor level and that this sensitivity can improve with age.

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Concentration of plasma thyroglobulin and urinary excretion of iodinated material in the diagnosis of thyroid disorders in congenital hypothyroidism

M. H. Gons, J. H. Kok, W. H. H. Tegelaers, and J. J. M. de Vijlder

Abstract. In this paper we describe methods for the early aetiological diagnosis of congenital hypothyroidism, using beside the classical T4, T3 and TSH plasma concentrations, four additional parameters in plasma and urine. The first one is thyroglobulin (Tg). In normal children of more than one year of age and in adults, 5–35 ng/ml plasma is found, in neonates 2–3 weeks old, this level is 10–250 ng/ml. In patients with a stimulated thyroid gland, as in primary congenital hypothyroidism, plasma Tg levels increase. High Tg values are found in iodine deficiency and in organification defects. In the absence of the thyroid gland plasma Tg is undetectable. Low to normal levels are found in cases with hypoplasia of the gland. In patients with a disturbed synthesis of Tg, resulting in Tg deficiency of the gland, plasma Tg levels vary from undetectable to normal. The PBI-T4 plasma difference, which is caused by circulating abnormal iodoproteins is the second parameter. The products of thyroidal breakdown processes of the abnormal iodoproteins are excreted in the urine and used as the third parameter. We found that the excretion of this low molecular weight iodinated material (LOMWIOM) was increased only in Tg-deficient patients.

If the neonate is found to be hypothyroid, thyroid hormone substitution must be given immediately. Blood and urine sampling can be done just before or even directly after starting the therapy. The measurements extended with the determination of the total iodine excretion (fourth parameter) can be carried out within 1 week. With these additional methods it appeared to be possible to distinguish between several types of congenital hypothyroidism in neonates found by screening.

Open access

An optimal growth pattern during pregnancy and early childhood associates with better fertility in men

Johanna Laru, Marja Ojaniemi, Stephen Franks, Marjo-Riitta Järvelin, Elisa Korhonen, Terhi T Piltonen, Sylvain Sebert, Juha S Tapanainen, and Laure Morin-Papunen

Objective

This study aimed to evaluate the association between birth weight (BW), childhood and adolescent BMI, with reproductive capacity in men.

Design

A prospective, population-based cohort study (Northern Finland birth cohort 1966).

Methods

Around 6196 men born in 1966 were followed from birth to age 50 years. Weight and height were measured repeatedly by professionals. Reproductive capacity (infertility assessment, male factor infertility and infertility treatment by age 46 years) was evaluated by questionnaires at ages 31 and 46 years. The number of children by the age of 50 years was recovered from registers. After excluding the men who reported never having attempted to have children or not answering the question at age 31 or 46 years (n = 2041), 4128 men were included in the final study population. Results were adjusted for BW, BW for gestational age (GA), mother’s smoking status, marital status, educational level and smoking status.

Results

Being small for GA (10.5% vs 8.2%, P = 0.012) or having a lower BW (3495 g vs 3548 g, P = 0.003) were associated with childlessness. The association was however no longer significant after adjusting for marital status. Being underweight in early childhood was associated with an increased risk of infertility assessment (adjusted, aOR: 2.04(1.07–3.81)) and childlessness (aOR: 1.47(1.01–2.17)) compared to the normal weight group. Conversely, overweight or obesity in early childhood was associated with a decreased risk of infertility assessment (aOR: 0.60 (0.41–0.87)), treatment (aOR: 0.42 (0.25–0.70)) and male factor infertility (aOR: 0.45 (0.21–0.97)). BMI in mid-childhood or puberty had no association with infertility or childlessness.

Conclusion

In boys, an optimal growth trajectory during pregnancy and early childhood seems to be very important for life-long fertility.

Open access

MECHANISMS IN ENDOCRINOLOGY: The pathophysiology of transient congenital hypothyroidism

Catherine Peters and Nadia Schoenmakers

Transient congenital hypothyroidism (TCH) refers to congenital hypothyroidism which spontaneously resolves in the first few months or years of life. Currently, there is a paucity of reliable markers predicting TCH at diagnosis, and the diagnosis is established following the withdrawal of levothyroxine therapy around 3 years of age. The incidence of TCH is increasing, and it is a major contributor to the overall increase in the incidence of CH in recent studies. Both genetic factors, in particular mutations affecting DUOX2 and DUOXA2, and environmental factors, for example, iodine deficiency and excess, anti- TSHR antibodies and exposure to antithyroid or iodine-rich medications, may cause TCH. Resolution of TCH in childhood may reflect both normal thyroid physiology (decreased thyroid hormone biosynthesis requirements after the neonatal period) and clearance or cessation of environmental precipitants. The relative contributions and interactions of genetic and environmental factors to TCH, and the extent to which TCH may be prevented, require evaluation in future population-based studies.

Free access

Distribution of the homeostasis model assessment of insulin resistance in Mexican children and adolescents

Celia Aradillas-García, Martha Rodríguez-Morán, María Eugenia Garay-Sevilla, Juan Manuel Malacara, Ramón Alberto Rascon-Pacheco, and Fernando Guerrero-Romero

Objective

Several cutoff points of the homeostasis model assessment of insulin resistance (HOMA-IR; varying from 2.5 to 4.0) have been suggested for diagnosing IR in youth. In this study, we determined the distribution of the HOMA-IR in Mexican children and adolescents.

Design and methods

A total of 6132 children and adolescents from San Luis Potosi, León, Queretaro, and Durango, which are cities in central and northern Mexico, were enrolled in a population-based cross-sectional study. Eligible participants were apparently healthy children and adolescents aged 6–18 years. Pregnancy and the presence of chronic illnesses were exclusion criteria.

Results

A total of 3701 (60.3%) girls and 2431 (39.7%) boys were included in this study. In the overall population, the mean body mass index, insulin levels, and fasting glucose levels were 21.8±1.3 kg/m2, 7.1±3.2 μU/ml, and 86.2±10.0 mg/dl respectively. The concentrations of insulin and fasting glucose gradually increased from 6 to 12 years of age, whereas the concentrations tended to plateau in the 13- to 18-year-old population. The absolute mean of the HOMA-IR was 2.89±0.7. The HOMA-IR gradually increased with age and reached a plateau at 13 years of age.

Conclusions

Because the insulin concentrations, glucose levels, and HOMA-IR exhibited a gradual increase with age that was not related to obesity, our results suggested that the evaluation of IR in children should be based on percentiles of the HOMA-IR rather than a dichotomous value derived from a single cutoff point.

Free access

Acylated/unacylated ghrelin ratio in cord blood: correlation with anthropometric and metabolic parameters and pediatric lifespan comparison

S Bellone, F Prodam, S Savastio, D Avanzo, A Pagani, L Trovato, G E Walker, G Genoni, and G Bona

Context

Ghrelin is a peptide with multiple functions that circulates in acylated (AG) and unacylated (UAG) forms. However, the role of ghrelin in neonates (NN) remains to be clarified.

Objective

The aim of this study was to determine ghrelin concentrations of the two forms in NN to clarify their biological roles. As such, ghrelin levels at birth were compared with those in later life.

Setting and design

Tertiary Care Center. In this cross-sectional study, we evaluated AG, UAG, AG/UAG ratio, and insulin levels in venous cord blood from NN and in fasted normal weight (NW) and obese (OB) children, both prepubertal and pubertal.

Subjects

We studied 82 NN, 82 NW, and 58 OB children.

Results

AG levels were lower in NN than in NW and OB children (P<0.0001), more specifically the prepubertal NW and OB children (P<0.0001). UAG levels were higher in NN than in NW and OB children (P<0.0001). Therefore, the AG/UAG ratio was lower in NN than in NW and OB children (P<0.0001). NN showed insulin levels similar to NW and lower than OB children (P<0.0001). At birth UAG was positively correlated with AG (Pearson: 0.425; P<0.0001) and negatively with insulin (−0.253; P<0.02). In NW and OB, UAG and AG were positively correlated to each other and negatively correlated with insulin and body mass index (−0.566; P<0.0001).

Conclusions

NN compared with children, showed higher UAG and lower AG levels. The AG/UAG ratio showed a very different profile in NN, being lower than in NW and OB children, thus suggesting a different metabolic function for the two forms in NN. Further studies are needed to clarify the exact role of the different ghrelin forms in NN.

Free access

Molecular and clinical analysis of a neonatal severe hyperparathyroidism case caused by a stop mutation in the calcium-sensing receptor extracellular domain representing in effect a human ‘knockout’

D T Ward, M Z Mughal, M Ranieri, M M Dvorak-Ewell, G Valenti, and D Riccardi

Objective

Loss-of-function calcium-sensing receptor (CAR) mutations cause elevated parathyroid hormone (PTH) secretion and hypercalcaemia. Although full Car deletion is possible in mice, most human CAR mutations result from a single amino acid substitution that maintains partial function. However, here, we report a case of neonatal severe hyperparathyroidism (NSHPT) in which the truncated CaR lacks any transmembrane domain (CaRR392X), in effect a full CAR ‘knockout’.

Case report

The infant (daughter of distant cousins) presented with hypercalcaemia (5.5–6 mmol/l corrected calcium (2.15–2.65)) and elevated PTH concentrations (650–950 pmol/l (12–81)) together with skeletal demineralisation. NSHPT was confirmed by CAR gene sequencing (homozygous c.1174C-to-T mutation) requiring total parathyroidectomy during which only two glands were located and removed, resulting in normalisation of her serum PTH/calcium levels.

Design and methods

The R392X stop codon was inserted into human CAR and the resulting mutant (CaRR392X) expressed transiently in HEK-293 cells.

Results

CaRR392X expressed as a 54 kDa dimeric glycoprotein that was undetectable in conditioned medium or in the patient's urine. The membrane localisation observed for wild-type CaR in parathyroid gland and transfected HEK-293 cells was absent from the proband's parathyroid gland and from CaRR392X-transfected cells. Expression of the mutant was localised to endoplasmic reticulum consistent with its lack of functional activity.

Conclusions

Intriguingly, the patient remained normocalcaemic throughout childhood (2.5 mM corrected calcium, 11 pg/ml PTH (10–71), age 8 years) but exhibited mild asymptomatic hypocalcaemia at age 10 years, now treated with 1-hydroxycholecalciferol and Ca2 + supplementation. Despite representing a virtual CAR knockout, the patient displays no obvious pathologies beyond her calcium homeostatic dysfunction.

Free access

Newborn TSH concentration and its association with cognitive development in healthy boys

Carmen Freire, Rosa Ramos, Esperanza Amaya, Mariana F Fernández, Piedad Santiago-Fernández, Maria-Jose Lopez-Espinosa, Juan-Pedro Arrebola, and Nicolas Olea

Objective

An association between thyroid function during pregnancy or infancy and neurodevelopment in children has been demonstrated. We aimed to investigate whether newborn TSH concentrations are related to subsequent neurocognitive development.

Design

We conducted a longitudinal study on 178 children from a general population birth cohort in Granada (Spain) born in 2000–2002.

Methods

TSH concentrations were measured in umbilical cord blood, and cognitive functions were assessed at 4 years of age using the McCarthy's scales of children's abilities (MSCA). Organochlorine (OC) compound concentrations and the combined oestrogenicity (total effective xeno-oestrogenic burden (TEXB)) were also determined in the placentae.

Results

Mean newborn TSH was 3.55 mU/l (range=0.24–17 mU/l). In multivariate regression analyses, adjusting for maternal and child characteristics, higher newborn TSH concentrations showed a decrease of 3.51 and 3.15 points on the MSCA general cognitive and executive function scores respectively and were associated with a higher risk of scoring below the 20th percentile (P20) on the quantitative score (odds ratio (OR)=2.64). Children with TSH in the upper quartile (4.19–17.0 mU/l) were at higher risk of scoring <P20 on span memory (OR=5.73), whereas children with TSH in the second quartile (2.05–2.95 mU/l) were at lower risk of scoring <P20 on the verbal scale (OR=0.24). Neonatal TSH status was also associated with general cognitive and executive function outcomes when controlling for prenatal exposure to OCs or placental TEXB.

Conclusions

Newborn thyroid hormone status expressed by TSH in cord blood may adversely affect later cognitive function. A more thorough screening for neonatal thyroid deficiency is warranted.

Free access

Novel GLIS3 mutations demonstrate an extended multisystem phenotype

P Dimitri, J T Warner, J A L Minton, A M Patch, S Ellard, A T Hattersley, S Barr, D Hawkes, J K Wales, and J W Gregory

Introduction

Mutations in the GLI-similar 3 (GLIS3) gene encoding the transcription factor GLIS3 are a rare cause of neonatal diabetes and congenital hypothyroidism with six affected cases from three families reported to date. Additional features, described previously, include congenital glaucoma, hepatic fibrosis, polycystic kidneys, developmental delay and facial dysmorphism.

Subjects

We report two new cases from unrelated families with distinct novel homozygous partial GLIS3 deletions. Both patients presented with neonatal diabetes mellitus, severe resistant hypothyroidism in the presence of elevated thyroglobulin and normal thyroid anatomy, degenerative liver disease, cystic renal dysplasia, recurrent infections and facial dysmorphism. These novel mutations have also resulted in osteopenia, bilateral sensorineural deafness and pancreatic exocrine insufficiency, features that have not previously been associated with GLIS3 mutations. Gene dosage analysis showed that the parents were carriers of a deletion encompassing exons 1–2 (case 1) or exons 1–4 (case 2) of the 11 exon gene. Genome-wide SNP analysis did not reveal a common ancestral GLIS3 haplotype in patient 2.

Conclusions

Our results confirm partial gene deletions as the most common type of GLIS3 mutations, accounting for four of five families identified to date. We propose that mutations in GLIS3 lead to a wider clinical phenotype than previously recognised. We also report the first case of a recessive GLIS3 mutation causing neonatal diabetes and congenital hypothyroidism in a child from a non-consanguineous pedigree, highlighting the importance of molecular genetic testing in any patient with this phenotype.