20 Quantification of sBCMA in human plasma using a high-throughput mass spectrometry workflow for exploratory, CAP/CLIA or regulated studies
Bibliographic record
Abstract
Background Bioanalytically validated methods are needed for reliable measurement of B cell maturation antigen (BCMA) in clinical samples. BCMA contributes to multiple myeloma (MM) pathophysiology and is targeted by various novel immunotherapies. Soluble BCMA (sBCMA) is a promising novel biomarker for disease monitoring and prediction. To address the need for sBCMA measurement, we developed a mass spectrometry-based assays for the quantitation of total sBCMA in plasma. Methods Immunoaffinity enrichment of sBCMA from human plasma was performed on a Agilent AssayMap Bravo platform using streptavidin cartridges. Recovered sBCMA protein was digested to peptides using trypsin, spiked with a fixed level of stable isotope labeled (SIL) peptide standard, and analyzed by multiple-reaction-monitoring (MRM) mass spectrometry. The MRM assay targeted a BCMA-specific endogenous peptide used as a surrogate measure of the protein, as well as the corresponding spiked SIL peptide at known concentration. An 8-point external calibration curve was prepared by spiking varying amounts of recombinant BCMA and fixed amounts of SIL peptides in surrogate matrix. Endogenous sBCMA levels were determined by back-calculating against the curve. To assess the performance of the method, ≥ 2 precision and accuracy runs were performed. To assess the impact of ligand or drug binding on the developed assay, performance of the assay was tested using plasma spiked at a range of concentrations with rhAPRIL, rhBAFF or simulated mAb drug. Results The developed assay allowed the quantitation of sBCMA from 1 to 1000 ng/mL. The precision and accuracy at different QC levels was within 20% CV and 20% bias. The presence of binding proteins (rhAPRIL, rhBAFF, simulated mAb) did not interfere with the measurement of sBCMA indicating that the assay measures total sBCMA. Conclusions We have developed an assay for the absolute quantitation of total sBCMA in human plasma. The assay can be analytically validated and deployed for clinical studies with a ~ 3-day turnaround time.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.003 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.003 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".