title: Development of an ICP-MS immunoassay for the detection of anti-erythropoietin antibodies.
abstract: A sandwich-type immunoassay linked with inductively coupled plasma mass spectrometry (ICP-MS) has been developed for the detection of anti-erythropoietin antibodies (anti-EPO Abs). Recombinant human erythropoietin (rhEPO) was immobilized on the solid phase to capture anti-rhEPO Abs specifically. After the immunoreactions with Au-labeled goat-anti-rabbit IgG, a diluted HNO(3) (2%) was used to dissociate Au nanoparticles which was then introduced to the ICP-MS for measurements. Under the optimized conditions, the calibration graph for anti-EPO Abs was linear in the range of 35.6-500 ng mL(-1) with a detection limit of 10.7 ng mL(-1) (3sigma, n=9). The relative standard deviation (R.S.D.) for three replicate measurements of 30.9 ng mL(-1) of anti-EPO Abs was 8.43%. The recoveries of anti-EPO Abs in sera at the spiking level of 50, 100, 150, 200 and 400 ng mL(-1) were 99.2%, 101.5%, 95.0%, 94.0% and 102.9%, respectively. For the real sample analysis, 26 samples from healthy people and 53 samples from patients with rhEPO treatments were studied. One sample from patients showed significantly higher anti-EPO Abs from other samples, indicating a possibility of immune response of this patient.
authors.affiliation: Department of Chemistry, Key Laboratory for Atomic and Molecular Nanosciences of the Education Ministry, Tsinghua University, Beijing 100084, PR China.
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Lu
authors.forename: Wenjun
authors.initials: W
authors.lastname: Wang
authors.forename: Zhi
authors.initials: Z
authors.lastname: Xing
authors.forename: Shidong
authors.initials: S
authors.lastname: Wang
authors.forename: Po
authors.initials: P
authors.lastname: Cao
authors.forename: Sichun
authors.initials: S
authors.lastname: Zhang
authors.forename: Xinrong
authors.initials: X
authors.lastname: Zhang
mesh_terms: D000818:Animals; D000906:Antibodies / Q000097:blood*; D000888:Antibodies, Anti-Idiotypic; D000917:Antibody Formation; D002138:Calibration; D016022:Case-Control Studies; D004921:Erythropoietin / Q000276:immunology*; D006041:Goats; D006046:Gold; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D013058:Mass Spectrometry / Q000379:methods*; D053768:Metal Nanoparticles; D011817:Rabbits; D011994:Recombinant Proteins
chemical_list: D000906:Antibodies; D000888:Antibodies, Anti-Idiotypic; D011994:Recombinant Proteins; C048844:anti-IgG; D004921:Erythropoietin; D006046:Gold