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.
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.(ABSTRACT TRUNCATED AT 250 WORDS)
Kratzsch
J
J
Department of Medicine, University of Leipzig, FRG.
Blum
W F
WF
Schenker
E
E
Keller
E
E
Jahreis
G
G
Haustein
B
B
Ventz
M
M
Rotzsch
W
W
D000172:Acromegaly / Q000097:blood*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D013006:Growth Hormone / Q000097:blood; D006801:Humans; D007124:Immunoenzyme Techniques; D007334:Insulin-Like Growth Factor I / Q000276:immunology / Q000378:metabolism*; D008103:Liver Cirrhosis / Q000097:blood*; D008297:Male; D008875:Middle Aged; D011863:Radioimmunoassay; D012016:Reference Values
D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone