Haemostasis is a very complex process, but unlike many other processes in the human body, all of us have observed it.
Haemostasis is divided into a primary and secondary phase. Primary haemostasis includes vasoconstriction, platelet adhesion, platelet activation and platelet aggregation. These processes take place in the first 1-3 minutes. The so-called white thrombus is formed, which quickly closes the wound.
Secondary haemostasis occurs at the same time, but takes about 6-10 minutes to take effect. The secondary phase includes the intrinsic and extrinsic coagulation cascade. But I won't go into detail here, otherwise you'll probably lose interest in reading more.
To understand what the Thrombomate XRA does, we fortunately only need to focus on primary haemostasis.
As already mentioned, in this phase a vessel occlusion is formed from platelet aggregates. If the number of platelets is reduced or their function is impaired, this takes place delayed, insufficiently or not at all, resulting in a prolonged bleeding time. The aggregation test can therefore be used to detect congenital and acquired platelet dysfunction and to monitor therapies.
Light transmission aggregometry (LTA) according to Born, which is used in the Thrombomate, is still considered the gold standard today.
The method was developed as early as 1963, so what makes the Thrombomate so special?
There are several systems on the market that perform an aggregation test using LTA or other measurement methods, but these are almost exclusively semi-automatic systems that require a lot of time and experience to perform.
The Thrombomate XRA is a fully automated walk-away system that can perform 25 tests within one hour. The hands-on time is reduced immensely compared to semi-automated systems and even non-specialist staff can operate the Thrombomate. This enables 24/7 availability, where previously testing could only be offered during routine laboratory hours.
Although light transmission aggregometry (LTA) is still considered the gold standard, it has been difficult to standardise. This is changing with the Thrombomate XRA.
This is how the fully automatic device works:
The device is loaded with the consumables (cuvettes and spheres), the desired LTA kits and patient samples. One platelet-rich plasma (PRP) and one platelet-poor plasma (PPP) are currently required per patient. After starting the measurement, all procedures and pipetting steps run fully automatically.
Platelet-rich plasma (PRP) is stirred in a cuvette under defined conditions, in the case of the Thrombomate XRA by a ball moving back and forth at a defined speed. Light is sent through the cuvette and the change in light intensity is measured when platelets aggregate after the addition of reagents.
The onset of aggregation leads to the clearing of the PRP and thus to a higher light transmission (increasing transmittance).
The increase in transmission is related directly to the platelet aggregation with the respective reagent. Depending on the type of reagent, the turbidity curve and quantities determined from it allow conclusions to be drawn about the function of the platelets.
In addition to the increase in transmission, the time until the onset of the reaction, the speed and the course of the curve are also important for the diagnosis of platelet function. For some curves, the course can also be multi-phase.
Experts from the International Society for Hemostasis and Thrombosis (ISTH) have published recommendations that deal with methodological aspects, especially the concentrations of the reagents used.
These were followed in the development of the Thrombomate XRA as well as in the composition of the reagents and standardised by automating all critical steps.
Reagent combinations are available for screening (e.g. LTA 1 and LTA 3) with concentrations according to ISTH recommendations and test panels for special applications. The test kits contain all consumables for the assigned number of screenings.
Further reagent combinations and test panels are planned or in preparation.
The Thrombomate XRA is thus the only fully automated system of its kind and offers significant added value for the customer.