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

J. Kratzsch; W. F. Blum; E. Schenker; E. Keller; G. Jahreis; B. Haustein; M. Ventz; W. Rotzsch

doi:10.1055/s-0029-1211221

Experimental and Clinical Endocrinology & Diabetes, Table of Contents

Exp Clin Endocrinol Diabetes 1993; 101(3): 144-149
DOI: 10.1055/s-0029-1211221

Original

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

J. Kratzsch, W. F. Blum, E. Schenker, E. Keller, G. Jahreis, B. Haustein, M. Ventz, W. Rotzsch

Institute of Clinical Chemistry and Laboratory Diagnosis, Departments of Medicine and Pediatrics, University of Leipzig; Departments of Pediatrics, Universities of Jena and Tübingen; Department of Clinical Endocrinology, Medical Faculty (Charite), Humboldt-University of Berlin/FRG

Abstract

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Summary

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 10pg/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 eigth 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 crossectional examinations proved to be low (class A: 0.33, class B: 0.67). Only in the case of extensively destroyed liver parenchym (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. The data suggest, that the EIA is a useful tool for the evaluation of the IGF-I concentrations in disturbances of the growth hormone (GH)/IGF-I axis in adults.

Key words

Insulin-like growth factor I - ElA - Age - Liver cirrhosis - Acromegaly

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