PB0563 - Evaluation of the rapid and easy-to-use point-of-care qLabs FIB® system to quantify functional fibrinogen levels in patients undergoing plasma exchange therapy

Background: Plasma exchange therapy (PET) with albumin replacement results in coagulation factors depletion. Repetitive PET may lower plasma fibrinogen level by 60-80%. A close and timely monitoring of fibrinogen is therefore warranted before repetitive PET, particularly in patients at risk of bleeding or those planned to receive large volume exchanges. Nevertheless, standard laboratory coagulation tests often have long turnaround times, thereby delaying the identification and correction of hypofibrinogenemia. The qLabs FIB® system (Stago BioCare, Asnières, France) is a new point-of-care (POC) device which allows functional fibrinogen levels measurement within 5-10 minutes using a single drop of citrated whole blood. It is insensitive to platelet count (until 700 000/µL) and heparin therapy (until 2 UI/mL).

Aims: To compare the qLabs FIB® system for near-POC monitoring of coagulation to the fibrinogen von Clauss assay in patients undergoing repetitive PET.

Methods: This prospective, single-center, observational study was conducted in the apheresis unit of a tertiary care center hospital in November 2022. Blood sampling was performed just before PET. Fibrinogen level was immediately determined using a qLabs FIB® system. For each sample, fibrinogen level was also assessed at the core laboratory using the STA®-Liquid Fib reagent on a STA-R Max analyzer (both from Stago, Asnières, France).

Results: 20 patients were prospectively enrolled in the study. Passing Bablok regression analysis demonstrated an excellent correlation between the qLabs FIB® system and the predicate assay (r=0.76, p=0.0001). Bland-Altman analysis revealed a high agreement between the qLabs FIB® system and the predicate assay (Figure 1). Result delivery was much faster with the qLabs FIB®system compared to the predicate assay (mean time 5 versus 78 minutes, p< 0.0001).

Conclusion(s): The qLabs FIB® system enables a rapid and reliable measurement of fibrinogen levels from a single drop of citrated whole blood, providing prompt information to manage hemostasis in patients undergoing repetitive PET.