Hepatocellular fibrinogen storage in familial hypofibrinogenemia

In the cytoplasm of hepatocytes of liver biopsy from a 30 year old man, there were proteinaceous inclusions which by use of the peroxidase-antiperoxidase method reacted strongly with antihuman-fibrinogen IgG, but gave a negative reaction with antihuman-alpha-1-antitrypsin IgG and with antihuman-albumin IgG. As shown in the electron microscope, these protein inclusions were composed of densely packed, irregularly arranged tubules of 40 nm diameter. Clinically, the patient and members of his family showed primary hypofibrinogenemia which on the basis of the morphological findings has to be interpreted as the consequence of a disturbance in the secretion of fibrinogen. Besides the well known alpha-1-antitrypsin deficiency, familial hypofibrinogenemia with hepatocellular fibrinogen storage appears to represent another example of a plasma deficiency due to failure of hepatic secretion.