Measurement of insulin-like growth factor I (IGF-I) in normal adults, patients with liver cirrhosis and acromegaly: experience with a new competitive enzyme immunoassay

• Published in: Experimental and clinical endocrinology Vol. 101; no. 3; p. 144
• Main Authors: Kratzsch, J, Blum, W F, Schenker, E, Keller, E, Jahreis, G, Haustein, B, Ventz, M, Rotzsch, W
• Format: Journal Article
• Language: English
• Published: Germany 1993
• Subjects: Acromegaly - blood; Adolescent; Adult; Aged; Aged, 80 and over; Female; Growth Hormone - blood; Humans; Immunoenzyme Techniques; Insulin-Like Growth Factor I - immunology; Insulin-Like Growth Factor I - metabolism; Liver Cirrhosis - blood; Male; Middle Aged; Radioimmunoassay; Reference Values
• ISSN: 0232-7384
• DOI: 10.1055/s-0029-1211221

A competitive enzyme immunoassay for the determination of human insulin-like growth factor I in microtiter plates was established. Using a polyclonal antiserum raised in rabbits against hIGF-I ovalbumin conjugate the assay system was able to detect IGF-I at a range of 12-800 pg/well with a sensitivity of 10 pg/well. It showed a low (< 0.5%) cross reactivity with hIGF-II. The serum concentrations of IGF-I found by EIA agreed well with those found in a conventional RIA (r = 0.965, p < 0.001). Effects of age and sex on IGF-I levels were studied in 260 normal adults. There was no evidence for sex differences but a steep decline of values from the third to the fourth and from the eight to the ninth decade, respectively. To asses the diagnostic capability of the IGF-I determination in liver cirrhosis, 71 sera of patients classified according to Child classes (A-C) were measured. Although significantly diminished concentrations were found in class B vs A and in class C vs B, the diagnostic sensitivity in cross-sectional examinations proved to be low (class A: 0.33, class B: 0.67). Only in the case of extensively destroyed liver parenchyma (Child C: 0.94) IGF-I was a good indicator of impaired hepatocellular capacity. In 29 patients with acromegaly serum IGF-I levels were investigated. All patients with active acromegaly showed increased IGF-I levels. In contrast, in inactive or weakly active acromegaly values were considerably lower.