Abstract Number: PB0371
Meeting: ISTH 2021 Congress
Background: Lupus anticoagulants (LA) diagnosis consists in a complex multistep procedure difficult to standardize in laboratories.
Aims: To automate, standardize and find the most cost-effective solution to provide the best diagnosis for LA through a non-interventional observational study.
Methods: Forty samples with LA request were analyzed through three different protocols with Diagnostic Stago reagents and analyzer. Protocol (P) no algorithm (P0): phase 1 every day (DRVVscreen/confirm + APTTscreen then freezing positive samples for APTTscreen) and phase 2 one day/week (APTTconfirm). P1 Stago´s automated algorithm1 in two days: phase 1 every day (DRVV Screen-mix-confirm + APTT screen-mix/freezing samples found positive mixing) and phase 2 one day/week (APTTconfirm). P2 algorithm by batch: complete algorithm one day/week freezing samples each day.
Accuracy in diagnosis along with, quantification of the number of steps, manual actions and processing time were collected for each step on every protocol. Reagent usage was also registered.
1: Florin L., et al. Int J Lab Hematol. 2019;1–6.
Results: 37 samples were found with the same diagnosis. Three samples were found positive for DRVV pathway only in P0 but negative for P1/P2 (to be confirmed 12 weeks apart as per diagnostic guidelines). The percentage of human time saving per week vs P0 was 1,2% for P1 and 47,9% for P2. The percentage of total processing time saved for the diagnosis of LA per week vs P0 was 2,5% for P1 and 33,4% for P2 (Table 1). The percentage of reagents vials saved with P2 compared to P0/P1 was 62,07% (Table 2). Only P2 guaranteed double centrifugation of the samples. The algorithm ensured diagnostic standardization due to automatic test addition with associated comments.
| Table 1 | Nº Steps | Total number of manual actions | Total sum of the average sample processing time for each step (min) | Total sum of the average human processing time for each step (min) | Total processing time per week (min) | Total human processing time per week (min) | |
| P0 | Phase 1 | 5 | 7 | 72 | 3 | 1027,0 | 42 |
| Phase 1 + Phase 2 | 12 | 21 | 199 | 7,3 | |||
| P1 | Phase 1 | 5 | 5 | 70 | 3 | 1001,5 | 41,5 |
| Phase 1 + Phase 2 | 12 | 18 | 196,5 | 7 | |||
| P2 | Complete Algorithm | 9 | 13 | 114 | 3,5 | 684 | 21,9 |
Workflow analysis for three different protocols (P0, P1 and P2). P0 No algorithm: Phase 1 every day (DRVV screen and confirm + APTT screen) and Phase 2 one day/week (APTT confirm). P1 Algorithm: Phase 1 every day (DRVV Screen-mix-confirm + APTT screen-mix) and Phase 2 one day/week (APTT confirm). P2 complete algorithm: one day a week freezing samples each day.
| Reagents | Vials for P0 and P1/ week | Vials for P2/week |
| STA DRVV Screen 5 mL/vial | 2 | 1 |
| STA DRVV Confirm 2 mL/vial | 2 | 1 |
| PTT-LA 2 mL/vial | 5 | 1 |
| Staclot-LA (5 reagents) | 5 | 5 |
| STA Control LA 1 mL/vial | 5 | 1 |
| STA Control LA 2 mL/vial | 5 | 1 |
| Pool Norm 1 mL/vial | 5 | 1 |
| Total | 29 | 11 |
Number of reagent vials used for each protocol
Conclusions: Working on batches of frozen samples with the Stago’s automated algorithm demonstrated the most accurate, cost-efficient and standardized way of working for the diagnosis of LA.
To cite this abstract in AMA style:
Sáez de Cámara Álvarez A, Chang Azancot MA, Ponga Palacio C, Mugertza Berastegi G, Canibe Galindez U, Ajuria Morentin I. Standardization and Automation of Lupus Anticoagulant Diagnosis Using a Complex Automated Algorithm [abstract]. Res Pract Thromb Haemost. 2021; 5 (Suppl 2). https://abstracts.isth.org/abstract/standardization-and-automation-of-lupus-anticoagulant-diagnosis-using-a-complex-automated-algorithm/. Accessed December 11, 2023.« Back to ISTH 2021 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/standardization-and-automation-of-lupus-anticoagulant-diagnosis-using-a-complex-automated-algorithm/