Prothrombin consumption as an indicator of hemorrhagic phenotype in mild platelet function disorders

Eur J Haematol. 2023 Nov;111(5):787-795. doi: 10.1111/ejh.14079. Epub 2023 Aug 8.

Abstract

Background: The bleeding risk of patients with mild platelet function disorders is difficult to assess and their phenotype remains ill-explored.

Aim: This study was designed to establish a comprehensive biological phenotype of patients with mild platelet function disorders.

Methods: Twenty patients were included with persistent abnormal light transmission aggregometry (LTA). The ISTH bleeding assessment tool (ISTH-BAT) was assessed to identify laboratory analyses associated with an abnormal hemorrhagic score.

Results: The majority of patients had defects that might affect Gαi protein signaling pathways or minor abnormalities. No LTA nor flow cytometry parameters were associated with an above-normal hemorrhagic score. However, prothrombin consumption, which corresponds to the ratio of serum residual factor II to plasma residual factor II, was significantly higher (p = .006) in the abnormal ISTH-BAT group (mean = 14%, SD = 6) compared with the normal ISTH-BAT group (mean = 8%, SD 4). Prothrombin consumption was significantly associated with ISTH-BAT score (r = .5287, IC 95% 0.0986-0.7924, p = .0165).

Conclusion: In this group of patients, there was an association between a pathological bleeding score and increased prothrombin consumption. This test could be used as an additional indicator of platelet function abnormality liable to be related to bleeding risk.

Keywords: bleeding score; blood platelet disorders; flow cytometry; light transmission aggregometry; platelet function test; prothrombin consumption.