OBJECTIVE: To determine the benefit of periodical clinical screening of carriers of a mutation in the multiple endocrine neoplasia type 1 (MEN-1) gene, because any useful discussion requires more concrete data. DESIGN AND METHODS: Our study population consisted of all the patients with MEN-1 (n=58) who were treated at the University Medical Centre Utrecht, The Netherlands, during the period 1975-2003, and their affected relatives (n=29). Records of affected individuals who died were analysed for morbidity, cause of death and age at death. We discuss our results in the light of the literature on MEN-1 regarding the benefit of screening. RESULTS: Over a period of 28 Years, we identified 87 individuals affected with MEN-1, from 16 families. A mutation in the MEN-1 gene was detected in 57%, 18% were obligate carriers, and in 24% the diagnosis was only clinically confirmed. Thirty individuals died, 17 from MEN-1-related causes, including malignancies (n=12: pancreatic islet cell tumours n=6 and carcinoid tumours n=6), the Zollinger-Ellison syndrome (n=4) and Cushing's disease (n=1). The remaining patients died of causes probably related to MEN-1 (n=3), unrelated to MEN-1 (n=7) or of unknown causes. Mean ages at death from MEN-1 were 55.4 Years for men and 46.8 Years for women, in both cases significantly lower than the mean age at death in the average Dutch population (P<0.05). CONCLUSIONS: We feel that the significantly increased risk of premature death found in patients with MEN-1 justifies the periodical clinical screening of carriers of the MEN-1 gene mutation. Early detection and treatment of abnormalities will probably reduce this risk.
EA Geerdink, RB Van der Luijt and CJ Lips
KL van Hulst, C Oosterwijk, W Born, TM Vroom, MG Nieuwenhuis, MA Blankenstein, CJ Lips, JA Fischer and JW Hoppener
OBJECTIVE: Islet amyloid polypeptide (IAPP), also named amylin, is the predominant protein component of amyloid deposits in human islet beta cell tumours of the pancreas (insulinomas). IAPP is co-produced with insulin by islet beta cells. We investigated IAPP expression in relation to insulin expression and to amyloid formation in eleven insulinomas. DESIGN AND METHODS: RNA and protein extracts were prepared from the same pieces of tumour tissue, and from specimens of two normal human pancreata. IAPP and insulin mRNA and peptide content were quantified using Northern blot analysis and radioimmunoassay (RIA) respectively. Molecular forms of IAPP immunoreactivity were analysed by reversed-phase high-performance liquid chromatography (HPLC). The presence of islet hormones and of amyloid was assessed by (immuno)histochemical staining of paraffin sections. Plasma levels of IAPP and insulin prior to tumour resection were determined by RIA. RESULTS: IAPP and insulin mRNA and peptide content varied widely between the tumour specimens, and there was considerable intratumour heterogeneity of peptide content. HPLC analysis indicated correct proteolytic processing of the IAPP precursor protein. Amyloid deposits were detected only in the three tumours with the highest IAPP content. In contrast to insulin, plasma levels of IAPP were not elevated in the insulinoma patients. CONCLUSIONS: The spectrum of hormone production by insulinomas cannot be inferred from only a few tissue sections due to intratumour heterogeneity. Expression of the IAPP and insulin genes is not coupled in insulinomas, which produce properly processed mature IAPP. In addition to IAPP overproduction, additional factors such as intracellular accumulation of IAPP are involved in amyloidogenesis in insulinomas.
AP van Beek, ER de Haas, WA van Vloten, CJ Lips, JF Roijers and MR Canninga-van Dijk
The glucagonoma syndrome is a rare disease in which a typical skin disorder, necrolytic migratory erythema, is often one of the first presenting symptoms. Weight loss and diabetes mellitus are two other prevalent characteristics of this syndrome. Necrolytic migratory erythema belongs to the recently recognized family of deficiency dermatoses of which zinc deficiency, necrolytic acral erythema and pellagra are also members. It is typically characterized on skin biopsies by necrolysis of the upper epidermis with vacuolated keratinocytes. In persistent hyperglucagonemia, excessive stimulation of basic metabolic pathways results in diabetes mellitus at the expense of tissue glycogen stores, and muscle and fat mass. Multiple (essential) nutrient and vitamin B deficiencies develop, which contribute to the dermatosis. In addition, glucagonomas may produce various other products, like pancreatic polypeptide, that add to the catabolic effects of glucagon.