Automation of a Factor XIII Activity Assay Utilizing a Plasma Blank Measurement

Factor XIII (FXIII) is an essential coagulation factor that stabilizes fibrin clots and allows the clot to resist fibrinolysis. Inherited or acquired FXIII deficiency is a severe bleeding disorder with manifestations that can include fatal intracranial hemorrhage. Accurate FXIII laboratory testing is necessary for diagnosis, subtyping, and treatment monitoring. The recommended first-line test is FXIII activity, most commonly performed by commercial ammonia release assays. In these assays, it is important to perform a plasma blank measurement to correct for FXIII-independent ammonia production, which can lead to clinically significant overestimation of FXIII activity. Automated performance of a commercial FXIII activity assay (Technoclone, Vienna, Austria), including blank correction, on the BCS XP instrument is described.