title: Absolute quantification of monoclonal antibodies in biofluids by liquid chromatography-tandem mass spectrometry.
abstract: The development of a quantification method for monoclonal antibodies in serum has been accomplished by high-performance liquid chromatography multiple reactions monitoring mass spectrometry. A human monoclonal antibody (HmAb) was used as the model protein for method development and validation. A peptide from the CDR3-region of its heavy chain was selected and used for quantifying the entire mAb. This signature peptide served as a template for the internal standard. Prior to mass spectrometric analysis approximately 50% of the total serum protein content was removed by albumin depletion. The accuracy of the method ranged between 99 and 112% in cynomolgus monkey serum. The intra-assay coefficient of variation (CV) was lower than 4% at 4 microg/mL and 200 microg/mL HmAb (n = 3). The CV at 400 microg/mL corresponded to 9% (n = 3). In addition, the interassay variation was investigated in a male cynomolgus serum pool and in a female cynomolgus serum pool. The CV for the male cynomolgus pool at 4 microg/mL HmAb was 7% (n = 3). The CV obtained from the female pool was 8% (n = 3), at 4 microg/mL. The dynamic range of the method was 3 orders of magnitude. After albumin depletion of 25 microL of serum, a lowest limit of quantification of 2 microg/mL HmAb was reached in both human and cynomolgus monkey samples.
authors.affiliation: BioAnalytical Sciences, Discovery Technologies, Novartis Institutes for BioMedical Research, Novartis, Basel, Switzerland.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Hagman
authors.forename: Darrell
authors.initials: D
authors.lastname: Ricke
authors.forename: Stefan
authors.initials: S
authors.lastname: Ewert
authors.forename: Stephan
authors.initials: S
authors.lastname: Bek
authors.forename: Rocco
authors.initials: R
authors.lastname: Falchetto
authors.forename: Francis
authors.initials: F
authors.lastname: Bitsch
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D001774:Blood Chemical Analysis / Q000379:methods*; D002853:Chromatography, Liquid / Q000379:methods; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D005260:Female; D006801:Humans; D007143:Immunoglobulin Heavy Chains / Q000097:blood* / Q000276:immunology*; D008252:Macaca fascicularis; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D053719:Tandem Mass Spectrometry / Q000379:methods
chemical_list: D000911:Antibodies, Monoclonal; D007143:Immunoglobulin Heavy Chains