A75 COMPARISON OF TWO DIFFERENT ASSESSMENT TECHNIQUES FOR MEASUREMENT OF VEDOLIZUMAB TROUGH LEVELS IN ADULT PATIENTS WITH IBD
Bibliographic record
Abstract
Vedolizumab (VLZ), an α4β7 integrin antagonist, is a therapeutic monoclonal antibody approved by Health Canada in 2017 for use in moderate to severe Crohn’s disease (CD) and ulcerative colitis (UC). Since loss of response to VLZ in patients with inflammatory bowel disease is likely due to low drug serum levels, modifying dosage on the basis of VLZ drug concentrations may improve patient outcomes. However, there are limited data on the diagnostic accuracy and utility of currently available assays for measuring VLZ levels. In this study, our aim was to compare serum VLZ concentrations as determined using two different techniques. Up to Nov. 2017, we assessed serum VLZ concentrations in 63 IBD patients (30 CD/33 UC). Serum VLZ trough levels were assessed using a sandwich principle-based enzyme-linked immunosorbent assay (ELISA; Berger et al. JCC 2017;11:S320) and an ultra performance liquid chromatography (UPLC)-MS/MS system (Thermo Scientific, Waltham, MA, USA) with an H-ESI II ionization source. Tryptic peptides for quantification were identified for VLZ using a selective reaction monitoring (SRM) mass spectrometry method. VLZ trough levels were significantly lower in patients who experienced relapse compared to patients in remission, using both ELISA: 19.7 mcg/mL vs. 33.9 mcg/mL in CD (p=0.002) and 15.6 mcg/mL vs. 34.2 mcg/mL in UC (p=0.005) and LC-MS/MS: 12.3 mcg/mL vs. 35.1 mcg/mL in CD (p=0.003) and 16.9 mcg/mL vs. 36.2 mcg/mL in UC (p=0.004). There was a significant correlation between ELISA and LC-MS/MS VLZ trough levels at both week 48 (r = 0.691, P=0.0003) and week 96 (r = 0.822, P=0.0001). ELISA and LC-MS/MS are accurate methods to assess VLZ trough levels in both CD and UC patients and those who experience loss of response, offering effective and reliable tools for the monitoring and modification of individual treatment schedules. The preferential use of one of the two techniques should be based on local availability and the physician’s experience. Immundiagnostik AG, Bensheim, Germany.
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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 | 0.002 | 0.005 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
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".