Fibrinogen estimation in patients with liver disease

Abstract

Fibrinogen is a haemostatic protein which causes blood to clot. It is mainly produced in the liver thus liver diseases such as cirrhosis may affect the levels of fibrinogen leading to bleeding diatheses. There are both quantitative and qualitative tests that can be used to measure the level of fibrinogen. However, there is no agreement yet on which test is preferred for estimating fibrinogen levels in liver disease. This project aims at comparing four different methodologies (Clauss Fibrinogen, PT-derived Fibrinogen (PT-Fg), Fibrinogen Antigen and Functional Fibrinogen Thromboelastography (FF-TEG)) for estimating fibrinogen levels in patients with liver disease, to determine differences in fibrinogen levels between the assays and severity of liver disease. This project tries to determine which assay might give the best reflection of fibrinogen levels in this cohort of patients. A total of 55 liver cirrhotic patients (26 Child-Pugh A, 14 Child-Pugh B and 15 Child-Pugh C) and 20 healthy control individuals were recruited. All 4 assays correlate strongly with each other but give significantly different mean fibrinogen levels, in both patients and healthy controls. PT-Fg gave the highest mean fibrinogen levels as opposed to the Clauss, which gave the lowest. A non-significant trend was observed in all assays showing higher levels in Child-Pugh A, normal in Child-Pugh B and decreased in Child- Pugh C when compared to normal. A significant difference was only observed between Child-Pugh A and Child-Pugh C in the Clauss, PT-Fg and Fibrinogen Antigen but not Functional Fibrinogen Level (FLEV). There were no apparent differences according to Child-Pugh and healthy controls in FLEV, pointing to a normal fibrin clot strength in liver cirrhosis. Since neither of the assays could differentiate between a healthy control and any cirrhotic, this signifies that plasma fibrinogen levels alone, cannot be used to indicate the severity of the liver cirrhosis. Through linear regression models, the fitted Clauss Fibrinogen levels were established from the cheaper PT-Fg assay.