Thromboelastography-based screening and diagnosis of Factor XIII inhibitor: A case report

We discovered a young male with normal conventional coagulation test results but abnormal Thromboelastography (TEG) results, ultimately identifying acquired Factor ⅩⅢ (FⅩⅢ) deficiency. Initial whole blood TEG revealed a normal reaction time (R) (6 min), prolonged kinetic time (K) (4.9 min), and reduced maximum amplitude (MA) (36.3 mm). The antigenic pFⅩⅢ-A subunit level was 2.8 %. By mixing normal pooled plasma (NPP; fibrinogen: 4.91 g/L) and the patient's plasma (fibrinogen: 4.85 g/L) in various ratios, we observed a correlation between FⅩⅢ-A levels (ranging from 2.8 % to 89.3 %) and TEG parameters. MA and angle showed strong correlations with FⅩⅢ-A levels. To determine the presence of an FXⅢ inhibitor in the patient's serum, experimental samples were prepared by mixing plasmas from seven healthy volunteers (with varying fibrinogen levels) with the patient's serum at initial diagnosis in a 1:1 ratio, while control samples consisted of the same healthy plasmas mixed with serum from a healthy volunteer. TEG analysis of the mixtures demonstrated a significantly lower MA in the experimental group compared to the control group (p < 0.05), indicating the presence of FXIII inhibitor. Based on this case, we explored the correlation between FⅩⅢ levels and TEG parameters, and developed a TEG-based screening method for FⅩⅢ inhibitors.