Immunomodulatory therapy in recurrent acute necrotizing encephalopathy ANE1: is it useful?

Acute Necrotizing Encephalopathy (ANE) is a rare disorder characterized by fever, seizures and rapid progression to coma after the onset of a viral infection. Most cases are sporadic, however the observation of multiple cases in the same family with recurrent episodes of ANE led to the identification of a genetic form of the disorder, called ANE1, and to the discover of the causative mutation in RANBP2 gene. We report the first Italian child with ANE1 carrying the common c.1880C>T mutation in the RANBP2 gene, who presented three episodes of acute encephalopathy in the first two years of life. The child showed a less severe clinical and neuroradiological course with respect to the previously reported patients. During the acute encephalopathy episodes he was treated with steroids and immunoglobulin. A very low steroid maintenance therapy was administered after the second episode until the onset of the third. Thirty days after the last episode he started monthly intravenous immunoglobulin that might be used for prevention of viral infections. At the moment he is still continuing a low steroid maintenance therapy and monthly IVIG. We could hypothesize that the less severe clinical presentation of the third episode might be correlated to the steroid treatment or that the patient grew older. Despite there is no evidence to support that ANE1 is an immune-mediated disease, immunomodulatory therapy might be considered in the management of ANE1 cases especially in early childhood, in which a fatal course has been frequently reported. Further studies will be necessary to define the clinical, immunological and genetic aspects, as well as the outcome of immunomodulatory therapy in patients with ANE1.

The accuracy of the glucagon test compared to the insulin tolerance test in the diagnosis of adrenal insufficiency in young children with growth hormone deficiency.

CONTEXT: The accuracy of the glucagon test in the diagnosis of central adrenal insufficiency in young children has not yet been definitively established. OBJECTIVE: The aim of this study was to investigate the diagnostic accuracy of the glucagon test as an alternative to the insulin tolerance test (ITT) in children with GH deficiency under 6 yr of age. DESIGN AND SETTING: This was a prospective study conducted in two Pediatric Endocrinology Centers. PATIENTS AND METHODS: Forty-eight children (median age, 4.2 yr) with GH deficiency confirmed by a peak GH to ITT and arginine less than 10 microg/liter were enrolled: 24 with normal hypothalamic-pituitary anatomy, seven with isolated anterior pituitary hypoplasia, and 17 with structural hypothalamic-pituitary abnormalities at magnetic resonance imaging. Twelve subjects had central adrenal insufficiency defined by a peak cortisol response of less than 20 microg/dl to ITT. All children underwent a glucagon stimulation test with blood sampling for cortisol and glucose (time 0 to 180 min) after the im administration of 30 microg/kg of glucagon. RESULTS: The mean peak cortisol after glucagon was not significantly different from that obtained after ITT in the whole cohort (25.9 vs. 26.0 microg/dl; P = 0.908), and it was significantly reduced in patients with structural hypothalamic-pituitary abnormalities (P < 0.001). Receiver operating characteristic curve analysis showed that the best diagnostic accuracy was obtained with a peak cortisol cutoff to glucagon of 14.6 microg/dl (sensitivity, 66.67%; specificity, 100%; area under the curve = 0.91; 95% confidence interval, 0.82-0.99). Using this cutoff, 91.67% of the patients were correctly classified. CONCLUSIONS: This study shows that glucagon is an accurate and safe diagnostic test for adrenal function in young children who are at risk for adrenal insufficiency.

Deterioration of growth hormone (GH) response and anterior pituitary function in young adults with childhood-onset GH deficiency and ectopic posterior pituitary: a two-year prospective follow-up study.

CONTEXT: The current criteria for definition of partial GHD in young adults are still a subject of debate. OBJECTIVES: The objective of the study was to reinvestigate anterior pituitary function in young adults with congenital childhood-onset GHD associated with structural hypothalamic-pituitary abnormalities and normal GH response at the time of first reassessment of GH secretion. DESIGN AND SETTING: This was a prospective explorative study conducted in a university research hospital. PATIENTS AND METHODS: Thirteen subjects with a mean age of 17.2 +/- 0.7 yr and a peak GH after insulin tolerance test (ITT) higher than 5 microg/liter were recruited from a cohort of 42 patients with childhood-onset GHD and ectopic posterior pituitary at magnetic resonance imaging. GH secretion after ITT and GHRH plus arginine, IGF-I concentration, and body mass index, waist circumference, blood pressure, total cholesterol, and fibrinogen were evaluated at baseline and at 2-yr follow-up. RESULTS: At mean age of 19.2 +/- 0.7 yr, the mean peak GH response decreased significantly after ITT (P = 0.00001) and GHRH plus arginine (P = 0.0001). GH peak values after ITT and GHRH plus arginine were less than 5 and 9 microg/liter in 10 and eight patients, respectively. Additional pituitary defects were documented in eight patients. Significant changes were found in the values of IGF-I sd score (P = 0.0026), waist circumference (P = 0.00001), serum total cholesterol (P = 0.00001), and serum fibrinogen (P = 0.0004). CONCLUSIONS: The results of this study underline the importance of further reassessment of pituitary function in young adults with GHD of childhood-onset and poststimulation GH responses suggestive of partial GHD.

Idiopathic central diabetes insipidus in children and young adults is commonly associated with vasopressin-cell antibodies and markers of autoimmunity.

OBJECTIVES: Autoimmune targeting of hypothalamic-neurohypophyseal structures in children and young adults with posterior pituitary and anterior pituitary dysfunction, as well as pituitary stalk involvement, are not yet completely understood. DESIGN: We aimed to (1) evaluate the presence of circulating vasopressin-cell autoantibodies (AVPc-Abs) in young patients with central diabetes insipidus (CDI), (2) detect organ-specific autoantibodies as markers of autoimmunity, and (3) define the relationship between immune markers and neuroimaging findings. PATIENTS: Twenty patients were evaluated at a median age of 16.3 years. Twelve patients had idiopathic CDI, six had Langerhans cell histiocytosis (LCH) and two had germinoma. AVPc-Abs were evaluated in 40 healthy children. Magnetic resonance imaging (MRI) of the hypothalamic-pituitary region was performed longitudinally in all subjects. MEASUREMENTS: Circulating arginine vasopressin (AVP), protein tyrosine phosphatase (IA2), glutamic acid decarboxylase (GAD), 21-hydroxylase (21-OH), endomysium antibodies (EMA), parietal cell (PCA), thyroid peroxidase (TPO), thyroglobulin (TG) and TSH-receptor (TSHr) autoantibodies were evaluated. RESULTS: Circulating AVPc-Abs were found in 15 patients (75%), nine with idiopathic CDI, four with LCH and two with germinoma; the pituitary stalk was involved in most of them. Five patients with idiopathic CDI showed a persistence of AVPc-Abs during follow-up and one became positive subsequently. Serum IA2 autoantibodies were demonstrated in 14 patients (70%) and 21-OH autoantibodies in three of them. CONCLUSION: In idiopathic CDI, circulating AVPc-Abs suggest an autoimmune involvement of the neurohypophyseal system. The identification of AVPc-Abs in subjects who could have either idiopathic CDI or LCH or germinoma, however, indicates that AVPc-Abs cannot be considered a completely reliable marker of autoimmune CDI. Thus, close clinical and MRI follow-up are needed because AVPc-Abs may mask germinoma or LCH.

Adult height in patients with permanent growth hormone deficiency with and without multiple pituitary hormone deficiencies.

CONTEXT: It has been reported that patients with multiple pituitary hormone deficiencies (MPHDs) achieve a greater final height, compared with patients with isolated GH deficiency (IGHD). However, the outcome of patients with permanent GH deficiency (GHD) has not yet been reported. OBJECTIVES: The objectives of the study were to evaluate and compare adult height data and the effect of spontaneous or induced puberty after long-term treatment with GH in young adults with either permanent IGHD or MPHD. DESIGN AND SETTING: This was a retrospective multicenter study conducted in university research hospitals and a tertiary referral endocrine unit. PATIENTS AND METHODS: Thirty-nine patients with IGHD (26 males, 13 females) and 49 with MPHD (31 males, 18 females), diagnosed at a median age of 7.7 and 6.9 yr, respectively, were reevaluated for GH secretion after adult height achievement (median age 17.6 and 19.8 yr). The diagnosis of permanent GHD was based on peak GH levels less than 3 microg/liter after an insulin tolerance test or peak GH levels less than 5 microg/liter after two different tests. Fifteen subjects had idiopathic GHD and seventy-three had magnetic resonance imaging evidence of congenital hypothalamic-pituitary abnormalities. Height sd score (SDS) was analyzed at diagnosis, the onset of puberty (either spontaneous or induced), and the time of GH withdrawal. RESULTS: The subjects with IGHD entered puberty at a median age of 12.6 yr (females) and 13.4 yr (males). Puberty was induced at a median age of 13.5 and 14.0 yr, respectively, in males and females with MPHD. Median height SDS at the beginning of puberty was similar in the IGHD and MPHD subjects. Total pubertal height gain was similar between patients with IGHD or MPHD. Median adult height was also not significantly different between IGHD and MPHD patients (males, 168.5 vs. 170.3 cm; females, 160.0 vs. 157.3 cm). The adult height SDS of the IGHD subjects was positively correlated with height at the time of diagnosis and with total pubertal height gain. Conversely, the adult height SDS of the MPHD subjects was positively correlated with both the duration of GH treatment and height SDS at the time of GHD diagnosis. CONCLUSIONS: Adult height in patients with permanent IGHD and spontaneous puberty is similar to adult height in patients with MPHD and induced puberty.