Coagulation factor XIII activation peptide and subunit levels in patients with acute ischaemic stroke: a pilot study

We have recently shown that FXIII activation peptide (AP-FXIII) can be measured in plasma. The objective of this pilot study was to investigate for the first time if AP-FXIII can be detected in plasma from patients with acute ischaemic stroke.

We included 66 patients with acute ischaemic stroke admitted between 1 and 7 hours after the onset of clinical symptoms. We collected plasma samples upon admission and on the two following days and measured AP-FXIII and subunit levels by ELISA. Clinical stroke severity was assessed by NIHSS stroke score.

AP-FXIII could be detected in 34 patients upon admission (range 0.2-26.3 ng/ml), on day 1 in 15 patients (0.2-10.4 ng/ml), and on day 2 in 11 patients (0.1-15.1 ng/ml. AP-FXIII was higher in patients with severe stroke. Lower AP-FXIII levels upon admission were associated with clinical improvement. FXIII-A and FXIII-B subunit levels decreased significantly from day 0 to day 1.

For the first time, we detected AP-FXIII in patients upon an acute thrombotic event. The decrease in FXIII subunit levels during acute ischaemic stroke is evidence for ongoing coagulation activity and FXIII consumption. Our results suggest that FXIII activation and concomitant AP-FXIII release might be associated with an unfavourable short-term clinical outcome. Larger studies are needed to further investigate whether AP-FXIII might serve as a diagnostic and/or prognostic marker for acute thrombotic diseases.