Dysfibrinogenaemia associated with primary hepatoma

Tumour markers in diagnosis and management

The 20-year period since the discovery of AFP by Abelev has seen the introduction of a wide range of new tumour markers and it is now clear that PLC is biologically heterogeneous. Hepatoblastomas, fibrolamellar carcinomas, hepatocellular carcinomas and cholangiocarcinomas may secrete a variety of distinctive markers which are predominantly glycoproteins, and may resemble those found in placenta or fetal liver. Diagnostically, AFP remains the best marker for HCC, both in sensitivity and specificity; it is known to consist of isoforms. In patients with elevated serum AFP and filling defects on liver scan, Con A reactive AFP may differentiate PLC from hepatic metastases, whilst fucosylated AFP may distinguish PLC from benign disorders when AFP is non-diagnostically elevated. With this recognition of tumour heterogeneity the value of a multiple-marker approach has become apparent. The measurement of vitamin B12 binding protein and neurotensin should lead to the detection of most patients with the fibrolamellar variant of HCC and many of these should be resectable. In patients with normal serum AFP levels, HCC-associated GGTP is of major value whilst in low-incidence areas for HCC, patients should also be screened for H-ALP; using a multiple marker approach in high-risk groups, 90% of clinically diagnosed hepatocellular carcinomas are serologically positive. The Chinese and Alaskan studies, in which small, potentially resectable tumours were detected, suggest that it is now possible to achieve 5-year survival figures of up to 60% in HCC patients detected by screening. The value of such a strategy in low-incidence countries is currently under study. In patient monitoring, as in diagnosis, AFP remains the outstanding marker. In AFP-negative patients, other markers including vitamin B12-binding protein, neurotensin, HCC-specific isoenzymes, des-gamma-carboxy-prothrombin and alpha-fucosidase, are of undoubted diagnostic value, but their value as indicants of disease progression remains to be established. In monitoring the response of hepatic metastases, CEA remains the least unsatisfactory marker but should always be used in conjunction with serial ultrasound scans. Tumour markers now play an important role in the diagnosis and monitoring of PLC but a role is also emerging in tumour imaging and drug targeting. The next 20 years should see the introduction of tumour markers of high sensitivity and specificity which make a fundamental contribution not only to detection and monitoring, but also to the effective treatment of liver cancer.

Acquired dysfibrinogenaemia in liver disease

Using a new and sensitive screening method, dysfibrinogenaemia (DF) was detected in 76% of patients with cirrhosis, 78% with chronic active liver disease and 86% with acute liver failure. The incidence was much lower in obstructive jaundice (8%) and miscellaneous liver disorders (4%). It is concluded that the fibrin monomer polymerisation (FMP) ratio test is a simple and sensitive test for the detection of DF, and is useful in the differential diagnosis of hepatocellular and obstructive jaundice. Hyperfibrinogenaemia, particularly in patients with obstructive jaundice, may explain the high incidence of abnormal thrombin and Reptilase clotting times despite normal FMP ratios. Dysfibrinogenaemia dose not appear to be related to the degree of liver function impairment, but may be associated with regeneration of hepatic tissue.

Acquired dysfibrinogenemia in a hemophiliac with hepatoma: resolution of fibrinogen dysfunction following chemotherapy

A 17-year-old male with previously undiagnosed congenital Factor IX deficiency (13%) presented with gastrointestinal bleeding and a hepatic mass. Prolonged thrombin and Reptilase times, which partially corrected with CaCl2 and a discrepancy between thrombin-clottable and immunoreactive plasma fibrinogen, suggested a dysfibrinogenemia. Laparotomy disclosed metastatic hepatoma. Adequate hemostasis was obtained with clotting factor replacement, but wound healing was delayed. Patient fibrinogen purified with 2.1 M glycine migrated normally on immunoelectrophoresis and 7.5% polyacrylamide-SDS gel electrophoresis. However, fibrin monomers prepared from purified patient fibrinogen displayed impaired aggregation at high and low ionic strengths when compared with fibrin monomers from normal and control Factor IX deficient subjects. Aggregation of normal monomers was delayed when mixed 1:1 with patient monomers. Fibrinopeptide release was normal, and total sialic acid content was similar to that of normal and control fibrinogens. Chemotherapy, consisting of 5-FU given via intra-arterial hepatic infusion, was accompanied by significant transient clinical improvement which coincided with correction of thrombin clotting times and fibrin monomer aggregation. Reappearance of fibrinogen dysfunction occurred with clinical deterioration prior to death from metastatic hepatoma and sepsis. This case is the first to corroborate the postulated tumor marker role of dysfibrinogenemia in a patient with hepatoma by documenting a direct relationship with response to chemotherapy.

Abnormalities of serum cholinesterase isozyme in liver cirrhosis and hepatoma (Part II)

The pattern of serum cholinesterase (ChE) isozyme appeared to be characteristically abnormal in liver cirrhosis and hepatoma. In liver cirrhosis an abnormal fast moving peak was observed in 92.5% of fifty three patients studied. Further, diminishing activities of ChE 3 and 4, accompanied by an emergence of weak bands with unusual rates of flow, were noted in 58.5%. The latter abnormality was always associated with the former one. The pattern in hepatoma was essentially the same with liver cirrhosis, though diversity of bands was also present in some cases. It was ascertained that these abnormalities was due to sialic acid content bound to the enzyme, but was not due to production of abnormal enzyme protein moiety. It was suggested by clinical analysis that the degree of the abnormality of the isozyme may be useful for the diagnosis and prognostic evaluation of liver cirrhosis.

Dysfibrinogenemia associated with hepatoma. Increased carbohydrate content of the fibrinogen molecule

Abnormal coagulation studies indicative of a dysfibrinogen were found in the plasma of four of seven patients with malignant hepatoma. The abnormal fibrinogen was characterized by prolonged prothrombin, thrombin and reptilase times and inhibition of the coagulation of normal plasma. Purified fibrinogen revealed abnormalities similar to those in plasma. The functional defect was one of delayed polymerization of the fibrin monomer. The carbohydrate content of the abnormal fibrinogen was increased, and this change was related to the abnormal fibrinogen function. Enzymatic cleavage of sialic acid from the abnormal fibrinogen restored fibrinogen function to normal. This hepatoma-associated dysfibrinogen (acquired dysfibrinogenemia) is similar in many respects to fetal fibrinogen and may represent the presence of a fetal form of fibrinogen in hepatoma.

Abnormal sialic acid content of the dysfibrinogenemia associated with liver disease

To evaluate the possibility that the carbohydrate composition of fibrinogen may be altered in the dysfibrinogenemia associated with liver disease, we studied the sialic acid content of purified fibrinogen from 12 patients with liver disease and its relationship to the prolongation of the thrombin time. Purified fibrinogen showed that Aalpha-, Bbeta-, and gamma-chains when reduced and analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and exhibited prolongation of the thrombin time similar to that of the plasma from which it was derived. Sialic acid content of the purified fibrinogen ranged from 12.7 to 71.4% higher in patient fibrinogens when compared to normal controls. A progressive delay in thrombin time was associated with increasing sialic acid content of the patient fibrinogen. Enzymatic removal of sialic acid from four of the abnormal fibrinogens resulted in a shortening of their thrombin times to the range of the desialylated normal control. Periodic acid-Schiff reagent stained only the Bbeta- and gamma-chains of the reduced patient fibrinogens after sodium dodecyl sulfate-polyacrylamide gel electrophoresis suggesting that the excess sialic acid is located on these two chains. These studies demonstrate a biochemical alteration of the functionally abnormal fibrinogen found in some patients with liver disease, and indicate that the excess sialic acid plays an important role in the functional defect of this protein.

Dysfibrinogenaemia and liver cell growth

From the evidence presented, it is proposed that 'dysfibrinogenaemia' represents the production of normal fetal fibrinogen by rapidly proliferating liver cells in both regenerating and neoplastic tissue. Prolongation of the reptilase clotting time, which was formerly believed to reflect dysfibrinogenaemia, may be rather the result of hepatocytic death.

Hemostatic factors in primary hepatocellular cancer

Detailed coagulation studies were performed in a group of 19 patients with primary hepatocellular cancer (PHC) and the results were compared statistically with the findings in 19 control subjects. Various funcitonal and immunochemical methods were employed in determining the possible presence of functional or structural coagulant protein abnormalities. The patient group was characterized by prolonged prothrombin times, partial thromboplastin times, and Reptilase times, increased levels of fibrinogen, factor VIII, and factor VIII-related antigen, moderately devreased levels of factor V, factor IX, factor X, antithrombin III, and plasminogen, and reduced levels of factor II and factor VII. Functional, immunochemical, and biochemical analysis failed to detect the presence of acquired protein abnormalities. These findings indicate that hemostatic changes in primary hepatocellular cancer are nonspecific in character. Severe alterations in the plasma levels of one or more of these hemostatic factors may occur.

Dysfibrinogenemia associated with liver disease

To test the possibility that a functionally abnormal fibrinogen may exist in some patients with liver disease, we studied the plasma and purified fibrinogens of five patients whose plasma thrombin times were prolonged at least 40% over normal controls. In no patient was there evidence of disseminated intravascular coagulation and/or fibrinolysis. No abnormalities were detected by immunoelectrophoresis of plasmas or purified fibrinogens. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of reduced patient fibrinogens showed normal mobility and amount of Aalpha, Bbeta, and gamma chains. Alkaline polyacrylamide gel electrophoresis and gradient elution, DEAE-cellulose chromatography of admixtures of radio-iodinated patient (125)I-fibrinogen and normal (131)I-fibrinogen showed identical mobility in the gel and simultaneous elution from the column, respectively. Thrombin and Reptilase (Abbott Scientific Products Div., Abbott Laboratories, South Pasadena, Calif.) times of purified patient fibrinogens were prolonged, and calcium ions improved but did not completely correct these defects. Increasing amounts of thrombin progressively shortened the clotting times of patient fibrinogens but not to the level of normal. Addition of equal amounts of patient fibrinogen to normal fibrinogen resulted in a prolongation of the thrombin time of the normal protein. Thrombin-induced fibrinopeptide release was normal. Fibrin monomers prepared from patient plasmas and purified fibrinogens demonstrated impaired aggregation at low (0.12) and high (0.24) ionic strength. These studies demonstrate that some patients with liver disease and prolonged plasma thrombin times have a dysfibrinogenemia functionally characterized by an abnormality of fibrin monomer polymerization.

Abnormal fibrin polymerization in liver disease

Although there have been isolated reports of an acquired abnormal fibrinogen in patients with liver disease, its frequency and clinical significance is not known. In this study 121 consecutive patients with a wide spectrum of hepatic disorders were screened for abnormal fibrin polymerization. A simple colorimetric method using Reptilase was employed. Of 32 patients with proven cirrhosis, 16 (50%) showed abnormal fibrin polymerization. The incidence in decompensated alcoholic cirrhosis was particularly high. The abnormality was also detected in all patients with acute liver failure and seven of 15 with chronic active liver disease. Clinical improvement often correlated with its disappearance. Two patients with primary liver cell tumours demonstrated the abnormal polymerization. In patients with bleeding oesophageal varices the detection of abnormal fibrin polymerization was associated with a poor prognosis. None of the patients with surgical obstructive jaundice (26) or miscellaneous liver disorders (37) had abnormal fibrin polymerization. The occurrence of abnormal fibrin polymerization in liver disease is more frequent than previously suspected and usually signifies severe primary hepatocellular dysfunction. Evidence is presented to support the presence of a primary abnormality of fibrinogen as the cause of impaired fibrin monomer polymerization.