A radioimmunoassay for pancreatic elastase 1: use of alpha 1-antitrypsin-elastase 1 conjugate as both standard and tracer to eliminate the influence of anti-elastase 1 autoantibodies.
We have recently reported the occurrence of anti-elastase 1 autoantibodies in human sera (Asada et al., Biochim Biophys Acta, 1991;1080:34-39). The usual radioimmunoassay of elastase 1 in autoantibody-positive sera gave abnormally high levels of elastase 1 and low recoveries of elastase 1 added to the sera. Now we have established a new radioimmunoassay system for determining pancreatic elastase 1 in serum, in which alpha 1-antitrypsin elastase 1 conjugate, the major conjugation form of elastase 1 in serum, is used as standard and alpha 1-antitrypsin-[125I]elastase 1 as tracer, because we found that the conjugate could bind to the elastase 1 specific antiserum but not to the autoantibodies. Thus the new assay system completely eliminate the unfavorable effects of the autoantibodies. The elastase 1 levels determined by the new assay method exhibited a good correlation with those obtained by a commercial assay kit in the autoantibody-negative sera, while no correlation was observed in the autoantibody-positive sera.
Asada
H
H
Shionogi Diagnostics Research Laboratories, Shionogi & Co. Ltd., Osaka, Japan.
Shibata
K
K
Uchida
K
K
Takeyama
Y
Y
Saitoh
Y
Y
Ohyanagi
H
H
D000208:Acute Disease; D001323:Autoantibodies / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D005069:Evaluation Studies as Topic; D006801:Humans; D019272:Leukocyte Elastase; D010182:Pancreatic Diseases / Q000175:diagnosis / Q000201:enzymology; D010196:Pancreatic Elastase / Q000037:antagonists & inhibitors / Q000097:blood* / Q000276:immunology / Q000592:standards; D010195:Pancreatitis / Q000175:diagnosis / Q000201:enzymology; D011863:Radioimmunoassay / Q000379:methods* / Q000592:standards / Q000706:statistics & numerical data; D012015:Reference Standards; D015203:Reproducibility of Results; D000515:alpha 1-Antitrypsin / Q000592:standards
D001323:Autoantibodies; D015415:Biomarkers; D000515:alpha 1-Antitrypsin; C037741:alpha 1-antitrypsin-leukocyte elastase complex; D010196:Pancreatic Elastase; D019272:Leukocyte Elastase