Klaus Mohnike

Serum levels of insulin-like growth factor-I,-II and insulin-like growth factor binding proteins-2 and-3 in children with acute lymphoblastic leukaemia

AbstractThe insulin-like growth factor (IGF) signaling pathway may be of importance for the proliferation of different tumours (e.g. breast cancer and Wilms tumour). The bioavailability of both IGF-I and IGF-II is regulated by specific IGF-binding proteins (IGFBPs). IGFBP-2 is the predominant binding protein during fetal life, where it is expressed in most tissues. In contrast, postnatally it is mainly released by specific cell types (hepatocytes, astroglia, kidney cells, prostate cells) and a range of tumour cell lines. Furthermore, phytohaemagglutinin stimulated normal lymphoblasts and malignant lymphoblasts express IGFBP-2. In order to investigate the IGF regulatory pathway in leukaemia serum levels of IGF-I, IGF-II, IGFBP-2 and IGFBP-3 were determined in 28 leukaemic children. Whereas serum levels of IGF-I (mean/range: −2.7/−0.1 to −6.7 SDS), IGF-II (−3.6 SDS/−1.3 to −8.7) and IGFBP-3 (−2.0/+2.2 to −7.1 SDS) were significantly decreased comparable to levels in growth hormone deficiency, IGFBP-2 levels (+4.0/−0.45 to +7.4 SDS) were found to be markedly elevated and inversely correlated to IGF-I (r=−0.51,P=0.013). After haematological remission upon chemotherapy all four parameters had normalized in the 16 re-investigated children. Similar findings have been observed in one boy with a relapse including CNS leukaemia.ConclusionThis study demonstrates that the proliferation of malignant lymphoblasts (at diagnosis vs treatment) occurs in the presence of decreased serum levels of IGF-I, IGF-II and IGFBP-3 and that diminished production of these peptides may contribute to impaired growth. It further indicates that serum levels of IGFBP-2 may be directly related to the proliferation of lymphoblasts.

Proposal for a standardized protocol for 18F-DOPA-PET (PET/CT) in congenital hyperinsulinism

a Department of Pediatrics and Neonatology, Otto von Guericke University Magdeburg, Magdeburg , and b Department of Pediatric Endocrinology, Charité University of Medicine Berlin, Berlin , Germany; c Department of Pediatrics, Odense University Hospital, Odense , Denmark; d Department of Pediatrics, Hôpital Necker Enfants Malades, Paris , France; e London Centre for Paediatric Endocrinology and Metabolism, Great Ormond Street Hospital for Children, London , UK; f Department of Nuclear Medicine/PET Centre, University Medical Centre Groningen, Groningen , The Netherlands; g Department of Oncology and Radiotherapy, Turku University Central Hospital, Turku , Finland; h PET Centre Berlin, Berlin , Germany; i Department of Pediatrics, King Abdilaziz Medical City, Riyadh , Saudi Arabia; j University Children’s Hospital for Pediatric Endocrinology and Diabetology, Helsinki , Finland; k Department of Pathology, Cliniques Universitaires St Luc, UCL, Brussels , Belgium; l CEA Service Hospitalier Frédéric Joliot, Orsay , France; m Department of Pediatrics, University of Zurich, Zurich , Switzerland, and n Department of Pediatric Surgery, Hôpital Necker Enfants Malades, Paris , France

Expression of components of the IGF signalling system in childhood acute lymphoblastic leukaemia.

Background: Alterations in the insulin-like growth factor (IGF) system have been reported for different tumours. They are of particular interest in the search for new prognostic and therapeutic approaches in cancer. In childhood acute lymphoblastic leukaemia (ALL) the amount of “tumour mass” at diagnosis can exceed 1 kg. To understand the endocrine, paracrine, and autocrine potential of the malignant transformed progenitor cells, the ability of these cells to express components of the IGF system needs to be investigated. Aim: To characterise the expression pattern of genes of the IGF system in malignant lymphoblasts of children suffering from ALL. Methods: Reverse transcription polymerase chain reaction of Ficoll separated mononuclear cells from 142 children with ALL, 127 cord blood samples, and 55 blood samples of age matched controls were studied. Results: The expression of IGF-I, IGF-II, IGF binding protein 5 (IGFBP-5), and CTGF (IGFBP-rP2) was seen in a higher proportion of mononuclear cells of patients with ALL than in controls. Patients with ALL who were in continuous remission had a lower percentage of IGFBP-2 and IGFBP-3 expressing mononuclear cells at diagnosis than did those who developed a relapse. Only malignant lymphoblasts of B cell origin showed expression of CTGF (IGFBP-rP2). Malignant lymphoblasts of T cell origin more often expressed IGFBP-2 and IGFBP-5, whereas IGF-II and IGFBP-3 expression was seen more often in lymphoblasts of B cell origin. Conclusions: Malignant lymphoblasts of patients with ALL express components of the IGF system and therefore promote their own growth in an autocrine, paracrine, or endocrine manner. Whether these components will be useful as prognostic factors in the stratification of ALL treatment in children needs to be evaluated.

[18F]-DOPA Positron Emission Tomography for Preoperative Localization in Congenital Hyperinsulinism

In recent years, considerable progress has been made in the biochemical, morphological and molecular genetic differentiation of congenital hyperinsulinism (CHI). Fluorine-18 L-3,4-dihydroxyphenylalanine positron emission tomography (18F-DOPA-PET) has been introduced for differentiation between focal and diffuse CHI. The ability to take up L-DOPA and convert it into dopamine is correlated with the activity of the aromatic amino acid decarboxylase and increased in the hyperfunctional affected pancreatic area in comparison to normally functioning pancreas. The high sensitivity of this method allows the surgeon to perform a curative limited resection of a focus without the risk of long-term diabetes. The exact preoperative planning by 18F-DOPA-PET/CT computer tomography allows laparoscopic operation in selected cases with the focus in the tail and limits necessity to open the pancreatic duct in cases with focus in the head. Patients with persistent CHI should be managed within a strong network of diagnostic, treatment, and research institutions.

Growth hormone treatment in 35 prepubertal children with achondroplasia: a five-year dose-response trial

Background: Achondroplasia is a skeletal dysplasia with extreme, disproportionate, short stature. Aim: In a 5‐y growth hormone (GH) treatment study including 1 y without treatment, we investigated growth and body proportion response in 35 children with achondroplasia. Methods: Patients were randomized to either 0.1 IU/kg (n=18) or 0.2 IU/kg (n=17) per day. GH treatment was interrupted for 12 mo after 2 y of treatment in prepubertal patients to study catch‐down growth. Mean height SDS (HSDS) at start was −5.6 and −5.2 for the low‐ and high‐dose groups, respectively, and mean age 7.3 and 6.6 y. Results: Mean growth velocity (baseline 4.5/4.6 cm/y for the groups) increased significantly by 1.9/3.6 cm/y during the first year and by 0.5/1.5 cm/y during the second year. During the third year, a decrease of growth velocity was observed at 1.9/1.3 cm/y below baseline values. HSDS increased significantly by 0.6/0.8 during the first year of treatment and in total by 1.3/1.6 during the 5 y of study. Sitting height SDS improved significantly from −2.1/−1.7 to −0.8/0.2 during the study. Body proportion (sitting height/total height) or arm span did not show any significant change.

Long-Term Non-Surgical Therapy of Severe Persistent Congenital Hyperinsulinism with Glucagon

Background: Congenital hyperinsulinism (CHI) is characterized by severe hypoglycemia caused by dysregulated insulin secretion. The long-term outcome is dependent on prevention of hypoglycemic episodes to avoid the high risk of permanent brain damage. Severe cases are usually resistant to diazoxide or nifedipine. In addition, somatostatin analogues are ineffective in a subgroup of patients to achieve stable euglycemia. In these infants the only remaining long-term option has been subtotal pancreatectomy with high risk of diabetes mellitus. Intravenous infusions of glucagon are used as immediate treatment to stabilize euglycemia in affected newborns. The rationale of this treatment comes from the observation of an increased glycogen content of the liver when glycogenolysis is inhibited by insulin. Objective: To review the efficacy and safety of long-term subcutaneous glucagon infusion as a potential therapeutic option for blood glucose stabilization in infants with severe CHI without the need of additional intravenous glucose or immediate surgical intervention. Method: Retrospective review of 9 children with CHI who received continuous subcutaneous infusion of glucagon for weeks or months. Glucagon was added to octreotide to replace octreotide-induced suppression of endogenous glucagon secretion, thereby liberating glucose by stimulation of hepatic glycogenolysis. In 3 cases, a stabilized formulation of glucagon was used to prevent glucagon crystallization that frequently occurs in smaller volumes. Results: Introduction of glucagon allowed the reduction or discontinuation of central glucose infusion in all children studied. In 2 patients, glucagon was introduced due to recurrent hypoglycemia despite subtotal pancreatectomy. Six out of 9 children were discharged home on this treatment, which their parents were able to continue without further symptomatic hypoglycemia, convulsions or unconsciousness. In 3 children, subcutaneous glucagon was continuously administered for 1–4 years leading to stable euglycemia. However, 2 children with diffuse type still required subtotal pancreatectomy. As a possible side effect, 2 children developed erythema necrolyticum, which resolved after discontinuation of the glucagon infusion. This has been described before in glucagonoma. Conclusion: In this retrospective series, combination therapy of low-dose octreotide and subcutaneous glucagon infusion has been effective in preventing hypoglycemic episodes in severe CHI. We propose this may serve as a therapeutic option in place of high rates of glucose infusion through a central venous catheter and as an alternative to subtotal pancreatectomy in diffuse type of CHI.

Novel and Recurrent Mutations in Patients with Androgen Insensitivity Syndromes

Background/Aims: Androgen insensitivity syndrome (AIS) caused by mutations within the androgen receptor gene represents a variety of phenotypes from females with 46,XY karyotype over individuals with ambiguous genitalia to infertile males. Methods: We studied 24 patients with AIS by sequencing androgen receptor gene. 19 of the investigated patients were affected by complete androgen insensitivity syndrome (CAIS) and 5 suffered from partial androgen insensitivity syndrome (PAIS). Results: So far we have detected 12 unreported mutations as well as 9 recurrent mutations (3 recurrent mutations were detected twice) in exons 2–8 of the androgen receptor gene. Three of the novel mutations cause a frameshift with subsequent premature termination and were found in patients with CAIS. These frameshifts were induced by single nucleotide deletion or insertion, or in one case by a 13-bp deletion, respectively. Another premature stop codon found in a CAIS patient results from an already reported nucleotide substitution in exon 5. Furthermore, in a CAIS patient we found a novel duplication of codon 788. All other mutations caused single base substitutions spread through exons 2–8 and were associated with CAIS or PAIS. Conclusions: We report a broad spectrum of different mutations within the AR gene leading to various manifestations of AIS. Apart from truncating mutations, a reliable genotype/phenotype correlation cannot be established. Therefore, modifying factors must be effective.

Short stature homeobox-containing gene deletion screening by fluorescence in situ hybridisation in patients with short stature

Abstract. The short stature homeobox-containing gene (SHOX) on the short arm of the X and Y chromosomes is an important determining factor of stature phenotype. Absence of the SHOX gene is a main cause for short stature in patients with Turner syndrome. Mutations of the SHOX gene can also be responsible for Léri-Weill syndrome (dyschondrosteosis). The aim of this study was to determine the frequency of SHOX deletions in short stature children and to delineate indications for SHOX deletion screening. Out of 50 probands, 35 had idiopathic short stature, 12 cases showed additional anomalies of the forearms (in particular Madelung deformity) and three patients were affected by a congenital heart defect. Chromosomal investigations with fluoresence in situ hybridisation did not reveal a SHOX deletion in any patient with idiopathic short stature. In five of the 12 patients (41.7%) with anomalies of the forearms, a SHOX deletion on one sex chromosome could be detected. No deletion was observed in the three cases with additional heart defects. Conclusion. The frequency of short stature homeobox-containing gene deletions in patients with idiopathic short stature appears to be very low and does not require a fluorescence in situ hybridisation analysis. Short stature in association with anomalies of the forearms such as Madelung deformity makes a deletion more probable and therefore screening for such deletions is recommended in these cases.

Final height and puberty in 40 patients after antileukaemic treatment during childhood

AbstractEndocrine dysfunction and damage of the epiphysial growth plates have been reported as late effects of antileukaemic treatment during childhood. It is a common opinion that cranial irradiation (CI) is the most important factor for blunted growth. Accordingly, recent therapeutic strategies in acute lymphoblastic leukaemia (ALL) avoid cranial irradiation. Here we analysed longitudinal data on growth and puberty of 54 children in first complete remission, who were treated with 18 Gy CI or not submitted to radiotherapy. Two chemotherapeutic protocols were compared which were similar during the induction period but differed in the intensity of maintenance therapy. In cranial irradiated patients both in males and females the pubertal growth spurt started at a mean age of 1.2 years (SD: 0.93 years) earlier than controls. Age at diagnosis and age at pubertal growth spurt were significantly correlated (r = 0.35, P = 0.017). Similarly, menarche occurred at a mean age (n = 22) of 12.1 years and was correlated with the age at start of therapy in girls who were treated with 18 Gy CI (r = 0.61, P = 0.01). Adult height was reached spontaneously in 30 patients treated during prepubertal age and in 10 treated shortly before or during puberty. In all prepubertal patients treated for 2–3 years with intensive maintenance therapy blunted growth resulted in a significant loss of −1.85 H-SDS (median, P = 0.0051) compared to height at diagnosis. However, if continuation treatment used only methotrexate and 6-mercaptopurine (i.e. BFM protocol) final height equalled projected adult height, despite 18 Gy CI. Conclusions (1) multiagent chemotherapy is of major impact for growth and puberty; (2) 18 Gy cranial irradiation is below the critical dosage responsible for blunted growth; (3) loss in potential growth might be prevented by current CT strategies; (4) onset of puberty depends on age when antileukaemic therapy is applied.

Glucose metabolism and neurological outcome in congenital hyperinsulinism

Advances in imaging and surgical techniques allow a complete cure for children with focal-type congenital hyperinsulinism (CHI). In contrast, management of diffuse-type CHI remains a matter of controversy. To prevent hypoglycemic brain damage, extensive surgery has been recommended in the past, resulting in diabetes. On the basis of 2 data sets of patients with congenital hyperinsulinism, the German registry for CHI with 235 patients (ages 1 day to 19 years) and the diabetes treatment register (Diabetes Patienten-Verlaufsdokumentationssystem initiative), a follow-up study was initiated for diabetes mellitus and the intellectual and physical development as well as motor function. In our ongoing study, we investigated 20 patients with CHI (12 male, mean ages 9.9 years). Six of 20 patients had undergone subtotal pancreatectomy. In early infantile development (0-3 years) we observed a trend to motor and speech delay. In early childhood (2.5-7 years) there appeared a trend to an advantage of results of nonverbal tasks compared with verbal tasks. Before 1990 most patients (∼75%) were treated by subtotal pancreatectomy; since 2000, a more conservative approach is obvious (4/68). All patients with diabetes (n = 25) developed the condition after undergoing subtotal pancreatectomy. No spontaneous manifestation of diabetes was noted before adulthood. There was a wide range of age (0-17.7 years) at manifestation indicating a long period during which glucose tolerance is compensated. Compared with >40.000 children with type 1 diabetes mellitus from the Diabetes Patienten-Verlaufsdokumentationssystem registry, we found significant differences with a tendency for being overweight as well as small stature. Mean daily insulin dose and HbA1c was comparable in both groups.