Abstract
Plasma fibrinogen concentration is routinely measured by the automated thrombin time method, i.e., the fibrinogen functional procedure. However, the measurement of fibrinogen protein or antigenic concentration is necessary for the diagnosis of inherited fibrinogen disorders. These disorders can be divided into four types: afibrinogenemia, in which both fibrinogen functional and antigen levels are below the levels of assay sensitivity, hypofibrinogenemia, in which both fibrinogen functional and antigen levels are reduced, dysfibrinogenemia, in which the antigen level is normal but the functional level is reduced, and hypodysfibrinogenemia, in which both fibrinogen functional and antigen levels are reduced (the functional level is less than the antigen level). It is important to classify these inherited fibrinogen disorders according to the ratio of functional fibrinogen level to antigen level. In this study, we evaluated the basic performance of the Factor Auto Fibrinogen kit (antigenic fibrinogen measurement) manufactured by Q-may Laboratory Corporation (Q-method), which showed good reproducibility, linearity, and detection sensitivity. The coefficient of correlation between the Q-method and the functional method for 50 plasma samples collected from individuals without inherited fibrinogen disorders was 0.974, and the regression equation was y = 0.926x + 35.1. In addition, the coefficient of correlation between the Q-method and conventional antigen method for 19 plasma samples collected from patients with inherited fibrinogen disorders was 0.972, and the regression equation was y = 0.968x + 34.5. In conclusion, the Q-method is useful for measuring plasma fibrinogen antigen level in patients with inherited fibrinogen disorders to classify the type of disorder. It also provides useful information regarding the cause of decreased functional fibrinogen level.
