Application of a bridging ELISA for detection of anti-erythropoietin binding antibodies and a cell-based bioassay for neutralizing antibodies in human sera.
Although erythropoietin (EPO)-related pure red-cell aplasia (PRCA) is a rare disorder, attention still needs to be paid because underline mechanism of EPO immunogenicity is various and controversial. Among several assay systems for screening of anti-EPO binding antibodies (Abs), we adopted and setup the bridging ELISA using streptavidin-coated plate. To test their neutralizing activities, cell-based neutralizing (NT) bioassay was setup. When we analyzed serum samples by using these two assays, we found two positive results in the two samples. In the sample 1, 411.9 ng/ml of anti-EPO Abs were found and neutralizing activity of 36.2% at 1:5 serum dilution was detected. In the sample 2, 40.5 ng/ml of anti-EPO Abs were found and neutralizing activity of 96.7% was detected. Our results indicate that the higher anti-EPO antibody (Ab) level in a serum does not always lead to the stronger neutralizing activity. This report gives crucial consideration to the needs of establishing clear criteria to link various assay parameters with the onset of PRCA and its progression.
Department of Internal Medicine, Ilsan Hospital, National Health Insurance Cooperation, Goyang-shi, Republic of Korea.
Sug Kyun
SK
Shin
Sung Kyu
SK
Ha
Kang Wook
KW
Lee
Tae-Hyun
TH
Yoo
Sung-Ro
SR
Yun
Se-Hee
SH
Yoon
Sung-Jo
SJ
Kim
Soo-Kyeong
SK
Lee
Tae-Hwe
TH
Heo
D000888:Antibodies, Anti-Idiotypic / Q000276:immunology*; D057134:Antibodies, Neutralizing / Q000276:immunology*; D001681:Biological Assay / Q000379:methods; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D004921:Erythropoietin / Q000276:immunology*; D006801:Humans; D011994:Recombinant Proteins; D044967:Serum / Q000276:immunology*
D000888:Antibodies, Anti-Idiotypic; D057134:Antibodies, Neutralizing; D011994:Recombinant Proteins; D004921:Erythropoietin