J Pharm Biomed Anal. 2025 Aug 14;266:117117. doi: 10.1016/j.jpba.2025.117117. Online ahead of print.
ABSTRACT
Infliximab (IFX) is the first biologic to be approved to treat inflammatory bowel disease (IBD). Serum IFX concentrations can be correlated with the clinical prognosis of IBD. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is an alternative to clinical immunoassays owing to its higher selectivity and sensitivity. An efficient antibody-free LC-MS/MS method was developed in this study to determine serum IFX levels. Methods Protein G-coated magnetic beads were used to capture IFX and the internal standard (cadonilimab [CADO]) in human serum. After enrichment, IFX and CADO were digested using trypsin, and signature peptides were selected for subsequent LC-MS/MS analysis. The results were compared with those from the corresponding immunoassay. Results The selected peptides had good specificity, and the total precision was within 10.5 %. The accuracy was between 92.8 % and 97.6 % in the linear range of 0.5-100 mg/L. The results from the sample assay were in agreement with those from the immunoassay. Conclusion Determination of IFX using LC-MS/MS is more sensitive and robust than other analytical methods. Therefore, the method reported in this study shows potential for use in therapeutical drug monitoring and developing individualized treatment modalities.
PMID:40850002 | DOI:10.1016/j.jpba.2025.117117
