Comparison of RIA kits with polyclonal antiserum and IRMA kits with monoclonal antibodies for the determination of plasma prolactin and somatotropin in patients with pituitary adenoma.
Size heterogeneity of prolactin and somatotropin has been demonstrated in human plasma. In patients with pituitary adenomas the ratio of some hormone fragments has been reported to be changed. Monoclonal antibodies that are used now in some commercial IRMA kits can theoretically differ from polyclonal antisera in the recognition of hormone variants or fragments. In this study, we found a perfect correlation between plasma levels of prolactin or somatotropin of patients with pituitary hypersecretion as measured by commercial RIA kits with polyclonal antiserum and IRMA kits with monoclonal antibodies. A negative bias of 30% for the somatotropin IRMA was found. We observed no discrepancies for plasma samples of patients with pituitary adenomas. Thus, the investigated IRMA kits with monoclonal antibodies seem to detect "tumour" prolactin and somatotropin equally as well as conventional RIA kits.
D000236:Adenoma / Q000097:blood*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal; D005260:Female; D013006:Growth Hormone / Q000097:blood*; D006801:Humans; D007106:Immune Sera; D008297:Male; D008875:Middle Aged; D010911:Pituitary Neoplasms / Q000097:blood*; D011388:Prolactin / Q000097:blood*; D011863:Radioimmunoassay; D011869:Radioligand Assay; D011933:Reagent Kits, Diagnostic
D000911:Antibodies, Monoclonal; D007106:Immune Sera; D011933:Reagent Kits, Diagnostic; D011388:Prolactin; D013006:Growth Hormone