Hyperinsulinism in infancy and childhood

Generation and characterization of human insulin-releasing cell lines

Background

The in vitro culture of insulinomas provides an attractive tool to study cell proliferation and insulin synthesis and secretion. However, only a few human beta cell lines have been described, with long-term passage resulting in loss of insulin secretion. Therefore, we set out to establish and characterize human insulin-releasing cell lines.

Results

We generated ex-vivo primary cultures from two independent human insulinomas and from a human nesidioblastosis, all of which were cultured up to passage number 20. All cell lines secreted human insulin and C-peptide. These cell lines expressed neuroendocrine and islets markers, confirming the expression profile found in the biopsies. Although all beta cell lineages survived an anchorage independent culture, none of them were able to invade an extracellular matrix substrate.

Conclusion

We have established three human insulin-releasing cell lines which maintain antigenic characteristics and insulin secretion profiles of the original tumors. These cell lines represent valuable tools for the study of molecular events underlying beta cell function and dysfunction.

Hyperinsulinaemic hypoglycaemia in preterm neonates

Hyperinsulinism in infancy (HI) is an important cause of severe and recurrent hypoglycaemia in newborn infants. It usually appears in infants born at term, and only one case of its occurrence in a prematurely born infant has been reported as an incidental finding. This is a report of seven infants born at 31-36 weeks gestation who experienced severe persistent hyperinsulinism. Two infants were large for dates. All infants were difficult to manage, suggesting that the occurrence of HI with prematurity may be associated with a particularly aggressive illness. HI should be considered in the differential diagnosis of severe hypoglycaemia in preterm infants.

Practical management of hyperinsulinism in infancy

Hyperinsulinism in infancy is one of the most difficult problems to manage in contemporary paediatric endocrinology. Although the diagnosis can usually be achieved without difficulty, it presents the paediatrician with formidable day to day management problems. Despite recent advances in understanding the pathophysiology of hyperinsulinism, the neurological outcome remains poor, and there is often a choice of unsatisfactory treatments, with life long sequelae for the child and his or her family. This paper presents a state of the art overview on management derived from a consensus workshop held by the European network for research into hyperinsulinism (ENRHI). The consensus is presented as an educational aid for paediatricians and children's nurses. It offers a practical guide to management based on the most up to date knowledge. It presents a proposed management cascade and focuses on the clinical recognition of the disease, the immediate steps that should be taken to stabilise the infant during diagnostic investigations, and the principles of definitive treatment.

Hyperinsulinism in asphyxiated and small-for-dates infants with hypoglycaemia

Hypoglycaemia in birth-asphyxiated and small-for-dates infants is commonly attributed to glycogen depletion. However, 3 infants with asphyxia at birth and 3 small-for-dates infants had unequivocal hyperinsulinism. This suggests that hyperinsulinism may contribute to hypoglycaemia in small-for-dates and asphyxiated neonates.

Transient lactic acidosis and hyperalaninaemia associated with neonatal hyperinsulinaemic hypoglycaemia: the effects of dichloroacetate (DCA)

Soon after birth a 36-week-gestational age, appropriate for dates, newborn infant developed hyperinsulinaemic hypoglycaemia which responded to diazoxide and glucose infusion. While normoglycaemic, he became increasingly ill with high lactate, pyruvate, and alanine levels. Provocation tests suggested a defect in lactate handling. Dichloroacetate (DCA) was given and resulted in the prompt normalisation of his metabolic profile with no recurrence after discontinuation of the drug. A second episode of hyperinsulinaemic hypoglycaemia followed and this was controlled satisfactorily by short term diazoxide treatment. Diazoxide treatment could be stopped at the age of 1 month. Although at the age of 1.5 years the infant is retarded developmentally, there has been no recurrence of lactic acidosis nor hyperinsulinaemic hypoglycaemia. The association of lactic acidosis and hyperinsulinism, and the use of DCA in this circumstance have not been reported previously.