Abstract Number: PB0620
Meeting: ISTH 2020 Congress
Background: The Q family of analysers (Grifols) are fully automated, random access, cap piercing analysers using clotting, chromogenic and immunoturbidometric endpoints. The QSmart, QNext and QXpert are suitable for low, medium and high throughput laboratories. Liquid PT/INR (recombinant human tissue factor), and APTT (ellagic acid/synthetic phospholipids) reagents are available for ease of use.
Aims: Compare INRs and APTTs determined using the Q family to ACL TOP.
Methods: We compared QNext, QSmart and ACL TOP in study 1, and then compared QXpert and QNext in study 2 using the following: PT/INR; liquid human recombinant thromboplastin (DG-PT RecombiLIQ)/Q series compared to Recombiplastin 2G/ACL TOP): APTT; liquid ellagic acid APTT (DG-APTT Synth)/Q series vs Synthasil/ACL TOP. The patient groups and numbers are shown in tables.
Results: INR Study 1 – Results with DG-PT RecombiLIQ were significantly lower than those with Recombiplastin 2G/ACL TOP (ANOVA p< 0.05) by on average < 5% for INRs < 4.0. There was excellent agreement between QNext and QSmart results. INR Study 2 - There was excellent agreement between QXpert and QNext INR results. The biggest difference was an average of < 3% for INRs >4.0.
| Study 1 n= | QSmart RLIQ | QNext RLIQ | IL TOP Rec 2G | Study 2 n = | QNext RLIQ | QXpert RLIQ | ||
| All | 61 | 2.98 | 2.92 | 3.12 | 89 | 2.75 | 2.76 | |
| <4.0 | 49 | 2.51 | 2.47 | 2.57 | 77 | 2.42 | 2.45 | |
| >4.0 | 12 | 4.86 | 4.77 | 5.39 | 12 | 4.88 | 4.78 |
[INR]
APTT Study 1- APTT ratios with DG-APTT Synth were significantly higher than those with Synthasil/ACL TOP in subjects with isolated clotting factor deficiency, on critical care or during unfractionated heparin therapy. There were no significant differences between QNext and QSmart results in any group. APTT Study 2 – there was excellent agreement between QXpert and QNext with < 3% difference in all groups.
| Study 1 n= | QSmart APTT ratio | QNext APTT ratio | IL TOP APTT ratio | Study 2 n= | QNext APTT ratio | QXpert APTT ratio | ||
| All | 139 | 1.48 | 1.44 | 1.35 | 134 | 1.62 | 1.63 | |
| Single factor deficiency | 16 | 1.58 | 1.54 | 1.46 | 26 | 1.87 | 1.85 | |
| UFH | 15 | 3.90 | 3.69 | 2.79 | 16 | 2.73 | 2.73 | |
| Investigated for LAC | 15 | 1.15 | 1.13 | 1.23 | 10 | 1.18 | 1.19 | |
| Liver disease | 15 | 1.25 | 1.24 | 1.23 | 15 | 1.45 | 1.48 | |
| Critical care/DIC | 14 | 1.25 | 1.21 | 1.13 | 9 | 1.33 | 1.36 | |
| others | 64 | 1.06 | 1.06 | 1.08 | 58 | 1.36 | 1.39 |
[APTT Ratio]
Conclusions: There was excellent agreement between results obtained on the 3 members of the Q family of analysers across a wide range of INRs and APTTs in all patient groups. DG-PT RecombiLIQ and Recombiplastin 2G INRs below 4.0 were < 5% different. DG-APTT Synth was more sensitive than SynthaSIL to some causes of prolonged APTT.
To cite this abstract in AMA style:
Woolley A, Hickey K, Bryant M, Marley L, Kitchen S. Evaluation of INR and APTTs Using the Q Family of Analysers in Comparison to ACL TOP [abstract]. Res Pract Thromb Haemost. 2020; 4 (Suppl 1). https://abstracts.isth.org/abstract/evaluation-of-inr-and-aptts-using-the-q-family-of-analysers-in-comparison-to-acl-top/. Accessed October 1, 2023.« Back to ISTH 2020 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/evaluation-of-inr-and-aptts-using-the-q-family-of-analysers-in-comparison-to-acl-top/