title: Highly specific and sensitive measurements of human and monkey interleukin 21 using sequential protein and tryptic peptide immunoaffinity LC-MS/MS.
abstract: A highly specific and sensitive immunoaffinity LC-MS/MS assay for quantification of human and cynomolgus monkey interleukin 21 (IL-21) was developed, qualified, and implemented. The workflow includes offline enrichment of IL-21 using an anti-IL-21 capture antibody, followed by isolation using magnetic beads, trypsin digestion, online enrichment of IL-21 derived tryptic peptides using antipeptide antibodies, and quantification using nanoflow LC-MS/MS. This assay was developed and qualified in human and cynomolgus monkey serum and tissues with a lower limit of quantitation of 0.78 pg/mL based on the intact cytokine. Both intra- and interbatch precision and accuracy, as well as stability and recovery, were found to be acceptable. IL-21 was not detected in serum from normal healthy volunteers or from autoimmune disease patients. However, IL-21 levels were quantified in cynomolgus monkey spleen and colon tissue and normal and inflammatory bowel disease (IBD) human colon tissue as well as hyperplasia human tonsils.
authors: Pfizer Worldwide Research & Development, Andover, MA 01810, USA. joe.palandra@pfizer.com
authors: Joe
authors: J
authors: Palandra
authors: Alyce
authors: A
authors: Finelli
authors: Ming
authors: M
authors: Zhu
authors: Jaime
authors: J
authors: Masferrer
authors: Hendrik
authors: H
authors: Neubert
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology / Q000378:metabolism; D001798:Blood Proteins / Q000032:analysis; D016022:Case-Control Studies; D002846:Chromatography, Affinity; D002853:Chromatography, Liquid / Q000379:methods*; D003106:Colon / Q000378:metabolism; D006801:Humans; D018189:Immunomagnetic Separation; D015212:Inflammatory Bowel Diseases / Q000378:metabolism; D007378:Interleukins / Q000032:analysis* / Q000276:immunology; D008252:Macaca fascicularis; D014066:Palatine Tonsil / Q000378:metabolism; D010446:Peptide Fragments / Q000032:analysis*; D011994:Recombinant Proteins / Q000378:metabolism; D012680:Sensitivity and Specificity; D013154:Spleen / Q000378:metabolism; D053719:Tandem Mass Spectrometry / Q000379:methods*; D014357:Trypsin / Q000378:metabolism; D000098546:Interleukin-21
chemical_list: D000911:Antibodies, Monoclonal; D001798:Blood Proteins; D007378:Interleukins; D010446:Peptide Fragments; D011994:Recombinant Proteins; D014357:Trypsin; D000098546:Interleukin-21