Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019621 (Langerhans cell histiocytosis)
 3,250 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Pituitary dwarfism is a genetically heterogeneous group of disorders associated with a variety of pathogenetic mechanisms which may involve any level of the hypothalamic-pituitary-somatomedin-peripheral tissue axis. Developmental defects of the pituitary, such as congenital absence of the pituitary, and developmental defects of the hypothalamus, such as anencephaly and holoprosencephaly, have been described. Degeneration of the hypothalamus and pituitary, as in histiocytosis X, may also result in pituitary dwarfism. In "idiopathic" forms of pituitary dwarfism, defects limited to either the hypothalamus or pituitary have been suggested by releasing hormone stimulation studies and it is quite likely that specific defects of the hypothalamus, and pituitary, as well as defects in releasing hormonal synthesis and secretion and growth hormone synthesis and secretion all exist. In Laron dwarfism the basic defect appears to lie in the ability to generate somatomedin, in the Pygmy the defect appears to involve peripheral unresponsiveness to somatomedin. Further pathologic studies of the hypothalamus and pituitary in pituitary dwarfism; analysis of growth hormone and somatomedin cellular receptors; and elucidation of the structure of growth hormone releasing factor and techniques for its synthesis and assay should allow for the delineation of the specific pathogenetic mechanism in each of these syndromes.
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PMID:Hereditary forms of growth hormone deficiency and resistance. 82 85

Children treated for Langerhans cell histiocytosis (LCH) are at risk for short and long term endocrine sequelae, but biological predictors of specific deficits are not well defined. We evaluated the frequency and progression of LCH-related endocrine deficits during long term follow-up and assessed the ability of dynamic endocrine testing to identify patients at risk for late anterior or posterior pituitary hormone dysfunction. The 17 patients (5 males and 12 females) were followed a median of 10 yr after diagnosis of single system (n = 6) or multisystem (n = 11) disease. Study evaluations, performed a median of 4.1 yr after the diagnosis, comprised pituitary hormone responses to the appropriate challenge, 7-h water deprivation test, 3% hypertonic saline infusion, and magnetic resonance imaging (MRI). The six patients with GH deficiency at the time of evaluation had a significantly lower GH response to GHRH than the other patients [median peak, 7.3 vs. 21.5 micrograms/L (P = 0.03); median area under the curve, 4.7 vs. 13.5 micrograms/L (P = 0.03)]; levels in the latter group did not differ significantly from those in 20 age- and sex-matched controls with constitutional or familial short stature. Two patients who had GH responses to GHRH of 20.6 and 23 ng/mL at 2.8 and 9.5 yr of age developed GH deficiency at 6.5 and 11.2 yr of age, respectively. The TSH response to TRH was less than 10 mU/L in three patients, two of whom later developed central hypothyroidism. ACTH and cortisol responses to CRF, and PRL responses to TRH were normal in all cases, and LH and FSH responses to GnRH were compatible with pubertal stage. Abnormalities in arginine vasopressin responses to water deprivation or hypertonic saline infusion were seen only in four patients who had preexisting diabetes insipidus (DI); one patient who later developed DI had normal findings. On standard MRI, posterior pituitary hyperintensity was absent only in the patients with DI. Pituitary stalk thickening was seen in seven patients, including three who did not have DI and had normal arginine vasopressin responses. Delayed posterior and anterior enhancement on dynamic MRI was present in two patients, both of whom later developed central hypothyroidism. Patients with single system disease had a lower 5-yr probability of LCH reactivation (41% vs. 83% for those with multisystem disease; P = 0.21) and a significantly lower risk of endocrine dysfunction (P = 0.007). In this series, dynamic evaluation of pituitary function was not a useful predictor of late endocrine sequelae, with the possible exception of the progressively decreasing TSH response to TRH. Similarly, a standard MRI was not predictive, although dynamic imaging may be informative regarding evolving pituitary hormone deficiency.
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PMID:Dynamic endocrine testing and magnetic resonance imaging in the long-term follow-up of childhood langerhans cell histiocytosis. 974 8

We evaluated the GH-releasing effect of GHRH plus arginine (ARG) in 36 patients (22 males and 14 females) with acquired GH deficiency including idiopathic inflammatory pituitary stalk thickness (n = 15), Langerhans cell histiocytosis (LCH) affecting the hypothalamic-pituitary area (n = 11), and craniopharyngioma (n = 10). All of the patients (mean age, 9.6 +/- 3.1 yr; range, 5.6-20.8) showed GH response less than 10 microg/liter after 2 pharmacological stimuli and were tested with GHRH plus ARG at a mean age of 11.2 +/- 4.1 yr. Twenty-nine patients had vasopressin deficiency, 10 had TSH deficiency, 8 had gonadotropin deficiency, and 4 had ACTH deficiency. The median peak GH response to insulin test was 2.1 microg/liter (range, 1.1-2.9), whereas it was 1.5 microg/liter (range, 1.3-2.4) after ARG. The median peak GH response to insulin was significantly lower in the patients with craniopharyngioma (1.4 microg/liter; range, 0.8-1.7) than in the patients with idiopathic pituitary stalk thickness (2.2 microg/liter; range, 1.0-2.4) or with LCH (2.6 microg/liter; range 2.0-4.3, P = 0.02). The median peak GH response to ARG was significantly lower in the patients with idiopathic inflammatory pituitary stalk thickness (1.3 microg/liter; range, 0.8-1.8) than in those with craniopharyngioma (1.5 microg/liter; range, 1.1-1.6) or with LCH (2.8 microg/liter; range, 1.9-3.2, P = 0.00007). The median peak GH response after GHRH plus ARG was significantly lower in the overall patient population (8.3 microg/liter; range, 4.4-28.4) than in the age-matched controls (49.8 microg/liter; range, 39.9-81.6, P < 0.00001). The median peak GH response was significantly lower in the patients with craniopharyngioma (4.6 microg/liter; range, 3.6-6.3) than in those with LCH (8.9 microg/liter; range, 4.4-28.4) or with idiopathic pituitary stalk thickness (12.6 microg/liter, range, 6.4-24, P = 0.07). Ten patients had a GH response of more than 20 microg/liter after GHRH plus ARG. There was a trend toward a decrease in peak GH response to GHRH plus ARG (r = -0.57, P = 0.06) as patient age increased. For cut-off values of 20 microg/liter, the sensitivity of GHRH plus ARG was 75% (95% CI, 57.8-87.9%) and the specificity was 96.4% (95% CI, 89.9-99.2%); whereas, for cut-off values of 24.2 microg/liter, sensitivity was 86.1% (95% CI, 70.5-95.3%), and specificity was 95.2% (95% CI, 88.2-98.7%). The median IGF-I level did not differ between the children with idiopathic pituitary stalk thickness (57 microg/liter; range, 46-68), those with LCH (55 microg/liter; range, 34-63), and those with craniopharyngioma (41 microg/liter; range, 39-49). The present study confirmed the diagnostic potential of the GHRH-plus-ARG test in children with acquired GH deficiency caused by hypothalamic-pituitary lesion. It stimulates GH secretion to a greater extent in those patients with GH deficiency with primary involvement of the hypothalamic area, e.g. patients with idiopathic pituitary stalk thickness or LCH, than in those with both hypothalamic and pituitary lesion, as in craniopharyngioma. In some patients, the GHRH-plus-ARG test stimulates GH response to a so-called: normal value, suggesting that pituitary responsiveness to GHRH plus ARG may fail to recognize acquired GHD. Finally, the number of pituitary hormone deficits and the patient's age affect the GH response to GHRH plus ARG.
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PMID:GHRH plus arginine in the diagnosis of acquired GH deficiency of childhood-onset. 1205 Feb 43