OBJECTIVE: To establish the cut-off values of GH measured by immunofluorometric assay, a more sensitive and specific assay, in normal prepubertal children and compare their values with those of proven GH-deficient patients. METHODS: 30 normal children (20 males) and 26 patients with known causes of GH deficiency were submitted to the clonidine test and their GH values were compared. A powdered clonidine tablet (0.1 mg/m(2)) was given orally and blood samples for GH measurements were drawn at times -30, 0, 60, 90 and 120 min. RESULTS: GH peak values presented a wide variation ranging from 1.7 to 25 micro g/l (mean +/- SD = 12.87 +/- 5.8 micro g/l) in the normal group. The cut-off values for the 5th and 10th percentiles of the distribution curve were 3.3 and 5.5 micro g/l, respectively. In the GH deficiency group, maximum GH levels after clonidine stimulation ranged from <0.1 to 2.1 micro g/l (0.56 +/- 0.58 micro g/l). CONCLUSIONS: The cut-off values obtained with the immunofluorometric method are lower than the ones obtained by radioimmunoassay. We suggest a cut-off value of 3.3 micro g/l (5th percentile) that ensures 100% of sensitivity along with 93% of specificity to exclude the diagnosis of GH deficiency when using this immunofluorometric method. Copyright 2003 S. Karger AG, Basel
OBJECTIVE: To establish the cut-off values of GH measured by immunofluorometric assay, a more sensitive and specific assay, in normal prepubertal children and compare their values with those of proven GH-deficientpatients. METHODS: 30 normal children (20 males) and 26 patients with known causes of GH deficiency were submitted to the clonidine test and their GH values were compared. A powdered clonidine tablet (0.1 mg/m(2)) was given orally and blood samples for GH measurements were drawn at times -30, 0, 60, 90 and 120 min. RESULTS: GH peak values presented a wide variation ranging from 1.7 to 25 micro g/l (mean +/- SD = 12.87 +/- 5.8 micro g/l) in the normal group. The cut-off values for the 5th and 10th percentiles of the distribution curve were 3.3 and 5.5 micro g/l, respectively. In the GH deficiency group, maximum GH levels after clonidine stimulation ranged from <0.1 to 2.1 micro g/l (0.56 +/- 0.58 micro g/l). CONCLUSIONS: The cut-off values obtained with the immunofluorometric method are lower than the ones obtained by radioimmunoassay. We suggest a cut-off value of 3.3 micro g/l (5th percentile) that ensures 100% of sensitivity along with 93% of specificity to exclude the diagnosis of GH deficiency when using this immunofluorometric method. Copyright 2003 S. Karger AG, Basel
Authors: Aline P Otto; Marcela M França; Fernanda A Correa; Everlayny F Costalonga; Claudia C Leite; Berenice B Mendonca; Ivo J P Arnhold; Luciani R S Carvalho; Alexander A L Jorge Journal: Pituitary Date: 2015-08 Impact factor: 4.107
Authors: João Soares Felício; Luísa Corrêa Janaú; Marcelle Alves Moraes; Nathalie Abdallah Zahalan; Fabrício de Souza Resende; Manuela Nascimento de Lemos; Norberto Jorge Kzan de Souza Neto; Isabela Imbelloni Farias de Franco; Loyane Tamyres Costa Leitão; Lilian de Souza d'Albuquerque Silva; Maria Clara Neres Iunes de Oliveira; Angélica Leite de Alcântara; Ana Carolina Contente Braga de Souza; Wanderson Maia da Silva; Márcia Costa Dos Santos; Natércia Neves Marques de Queiroz; Lorena Vilhena de Moraes; Antônio Bentes de Figueiredo; Ana Luiza Prieto Farinassi; Luciana Marques da Costa Farias; Danielle Dias da Silva; Karem Miléo Felício; João Felício Abrahão Neto Journal: Front Endocrinol (Lausanne) Date: 2019-09-19 Impact factor: 5.555