The Acid-Labile Subunit of Human Ternary Insulin-Like Growth Factor-Binding Protein Complex in Girls with Central Precocious Puberty before and during Gonadotropin-Releasing Hormone Analog Therapy

Objective: The aim of this study is to determine the cutoff values of gonadotropin response to gonadotropin-releasing hormone analogs (GnRHas) corresponding to the activation of the hypothalamic–pituitary–gonadal axis that could differentiate central precocious puberty (CPP) from premature thelarche (PT) and using the electrochemiluminescence assay method. Methods: A total of 49 girls underwent the stimulation test with the intramuscular injection of 3.75 mg leuprolide acetate. Based on the clinical and laboratory characteristics, they were divided into two groups: CPP (n = 22) and PT (n = 27). Baseline estradiol, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) were collected before GnRHa administration, and LH and FSH at 60 and 120 min, respectively, after GnRHa administration. Results: The girls with CPP presented an increased height Z-score, advanced bone age, and higher baseline LH, FSH, estradiol, and LH/FSH ratio in relation to PT (p < 0.001). Stimulated LH differed significantly between the two groups, and the LH cutoff values were ≥4.29 IU/L (p < 0.001) and ≥3.95 IU/L at 60 and 120 min, respectively (p < 0.001). LH peak was found at 60 min after stimulation. Conclusions: The GnRHa test is effective in distinguishing CPP from PT, and a single sampling, at 60 min, with LH concentrations above 4.29 may be the parameter of choice with the advantage of greater convenience and practicality.

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Combined treatment with gonadotropin-releasing hormone analog and growth hormone in central precocious puberty

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/jc.81.3.948 ◽

1996 ◽

Vol 81 (3) ◽

pp. 948-951 ◽

Cited By ~ 11

Author(s):

A. M. Pasquino

Keyword(s):

Growth Hormone ◽

Precocious Puberty ◽

Combined Treatment ◽

Central Precocious Puberty ◽

Gonadotropin Releasing Hormone ◽

Releasing Hormone ◽

Hormone Analog

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Molecular cloning of the acid-labile subunit of the rat insulin-like growth factor binding protein complex

Biochemical and Biophysical Research Communications ◽

10.1016/0006-291x(92)92385-b ◽

1992 ◽

Vol 188 (1) ◽

pp. 304-309 ◽

Cited By ~ 14

Author(s):

Jin Dai ◽

Robert C. Baxter

Keyword(s):

Growth Factor ◽

Molecular Cloning ◽

Protein Complex ◽

Binding Protein ◽

Insulin Like Growth Factor ◽

Factor Binding ◽

Acid Labile Subunit ◽

Acid Labile

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Measurement of the acid-labile subunit of the insulin-like growth factor binding protein complex in human serum: a comparison of four immunoassays

Journal of Endocrinology ◽

10.1677/joe.0.1650271 ◽

2000 ◽

Vol 165 (2) ◽

pp. 271-279 ◽

Cited By ~ 6

Author(s):

RC Baxter ◽

M Svejkar ◽

MJ Khosravi ◽

GL Bennett ◽

KV Hardman ◽

...

Keyword(s):

Growth Hormone ◽

Growth Factor ◽

Protein Complex ◽

Binding Protein ◽

Serum Marker ◽

Healthy Children ◽

Insulin Like Growth Factor ◽

Factor Binding ◽

Acid Labile Subunit ◽

Acid Labile

The acid-labile subunit (ALS) of the high molecular weight insulin-like growth factor binding protein complex is a liver-derived glycoprotein which is regulated by growth hormone and serves as a serum marker of growth hormone action. We have compared the measurement of ALS by four immunoassay methods (two RIAs, two ELISAs) utilizing various polyclonal and monoclonal antibodies raised against natural or recombinant human ALS, or synthetic ALS peptides. Despite the variety of methodologies and reagents, results obtained by the four methods were highly correlated for 125 sera from various patient groups, and when compared for individual groups of sera from healthy children and adults, growth hormone-deficient children and adults, and subjects with acromegaly. Some weaker correlations among methods were seen when measuring ALS levels in groups of sera from pregnant subjects and subjects with chronic renal failure. An assay using antibodies raised against recombinant ALS yielded lower apparent values than the other methods in patient sera, the discrepancy probably being attributable to a difference in standardization. We conclude that a variety of assay formats and reagents can yield serum ALS values of potential clinical utility.

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