False positive lupus anticoagulant tests in patients with high C‐reactive protein: A comparison of two hexagonal phase reagents
Bibliographic record
Abstract
False positive lupus anticoagulant tests in patients with high C-reactive protein: A comparison of two hexagonal phase reagents Dear Editors, Lupus anticoagulants (LA) are a heterogeneous group of autoantibodies that bind to negatively charged phospholipids or protein/phospholipid complexes.The design of a laboratory testing algorithm is complicated by the biological heterogeneity of LA and by the variable sensitivity, specificity, and patterns of interference for different reagents.Three expert groups have published recommendations on LA testing: the International Society on Thrombosis and Haemostasis (ISTH), 1 the Clinical Laboratory Standards Institute (CLSI), 2 and the British Committee for Standards in Haematology (BCSH).3,4 The laboratory criteria for the diagnosis of antiphospholipid antibody syndrome (APLAS) are the presence of one or more of the following: LA, anticardiolipin antibody (ACL) (IgG/IgM), or anti-ß2 glycoprotein I antibody (anti-ß2GPI) (IgG/IgM) in two specimens collected more than 12 weeks apart.5,6 The acute phase reactant C-reactive protein (CRP) is known to bind negatively charged phospholipids, causing false positive results in the PTT-LA screen (PTT-LA, Diagnostica Stago, Inc.) and hexagonal phase (HexP) confirmatory assays.[6][7][8][9][10] The ISTH recommends that LA screening not be performed during the acute phase. 1 We compared susceptibility to CRP interference in two hexagonal (HexP) reagents: CRYOcheck HexLA (Precision BioLogic, Inc., Dartmouth, Canada) (hereafter, PB) and Staclot LA 20 (Diagnostica Stago S.A.S, Asnières-sur-Seine, France) (hereafter, STAclot).We tested 30 STAclot pos-
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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 | 0.006 | 0.026 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.002 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 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".