Congenital dysprothrombinemia: an inherited structural disorder of human prothrombin.

A large family has been studied, 11 of whose members have half-normal plasma concentrations of biological prothrombin activity. The pattern of inheritance is autosomal. By use of a specific immunoassay, affected family members have been shown to possess normal quantities of immunoreactive prothrombin, whose immunologic properties seem identical with those of the normal zymogen. Prothrombin isolation from the plasma of one such individual gave normal yields of protein but half-normal amounts of prothrombin activity. Activation of this material in the "intrinsic" and "extrinsic" systems, in concentrated sodium citrate, or by trypsin, gives rise to half, or less, of the thrombin clotting and esterase activities expected from a comparable normal prothrombin preparation. During the clotting of blood from an affected individual, all material with the mobility of prothrombin disappears. Immunoelectrophoresis of the serum reveals a normal nonthrombin "pro piece," and an additional activation product with an electrophoretic mobility intermediate between that of prothrombin and of "pro piece." These results suggest that affected individuals are heterozygotes in whom half the prothrombin molecules synthesized are structurally abnormal, since they undergo some alterations during activation, but are incapable of releasing the active enzyme, thrombin.

Relationship of milk intake and vitamin K supplementation to vitamin K status in newborns.

Vitamin K status was evaluated by measuring blood acarboxyprothrombin (PIVKA-II) levels on the fifth day of life. The incidence of PIVKA-II-positive infants was higher in breast-fed babies than in those given supplementary (mixed) feeding. The median of total amount of milk intake during the first 3 days was significantly lower in PIVKA-II-positive infants than in PIVKA-II-negative infants among infants given both types of feedings. In addition, there was a significant negative correlation between a positive PIVKA-II proportion and the amount of milk intake in the breast-fed babies. The minimum dose of vitamin K2 necessary to prevent a positive PIVKA-II reading was 15 micrograms among babies with a normal absorption potential.

Vitamin K effect in low birth weight infants.

Factor II coagulant antigen (FII-AG), the protein induced by vitamin K absence or antagonist II (PIVKA-II), and coagulant activity (normotest) were measured in low birth weight infants. The factor II coagulant antigen and normotest levels in one-day-old babies were lower than those of full-term infants (P less than .005, P less than .01, respectively). Infants whose normotest levels were less than 30% at one day (group A) received vitamin K2, and the others whose normotest levels were greater than 30% at one day (group B) were not treated. At this time, the mean factor II coagulant antigen level was significantly lower in group A than in group B (P less than .05). During the first seven days of life, in 65.2% of the infants in group B the PIVKA-II level became positive, but this did not occur in any infant in group A. After vitamin K treatment, there was greater improvement in the normotest level in infants with positive PIVKA-II levels than in those with negative PIVKA-II levels. This observation indicates that the hypoprothrombinemia found in low birth weight infants at one day of age is attributable to reduced synthesis of factor II coagulant antigen in the liver at this stage, but the prophylactic administration of vitamin K seemed to be effective even in such infants, probably because of the increase in factor II coagulant antigen synthesis (P less than .001) during the first seven days of life.

Activation of duck prothrombin by factor Xa and thrombin.

Prothrombin isolated from duck sodium citrate plasma was activated in a system containing duck factor Xa and calcium ions. Polyacrylamide gel electrophoresis showed that intermediates and the final product, thrombin, of Mr in the range 21 500-52 000 were present in the incubation mixture Serine and isoleucine were found to be the N-terminal amino acids of the intermediate form 1 and thrombin, respectively.

Coagulation and fibrinolysis in chronic subdural hematoma.

In 19 patients with chronic subdural hematoma, coagulation and fibrinolysis in venous blood taken at the time of surgery and in the hematoma contents aspirated from chronic subdural hematoma were studied. Compared with coagulation results for venous blood, the hematoma contents demonstrated marked prolongation of the recalcification time, prothrombin time, and activated partial thromboplastin time, and marked reduction of clotting factor V, the hepaplastin test, prothrombin, and fibrinogen. Antithrombin III was also decreased, and fibrinopeptide A was increased in the hematomas. Fibrinolytic results demonstrated that both plasminogen and alpha 2-plasmin inhibitor were decreased, and both fibrinopeptide B beta 15-42 and fibrin and fibrinogen degradation products were increased in the hematomas. These findings indicate excessive activation of the clotting system, thrombin generation, and increased fibrinolytic activity occurring in the hematomas. From these results, excessive activation of both the clotting and fibrinolytic systems is emphasized to be the possible etiological factor for the origin and development of chronic subdural hematoma.

Interference of coumarin therapy with the "Heptest" owing to declining prothrombin concentrations.

The Heptest kit (Haemachem, Inc., St. Louis, MO) for quantifying heparin in plasma is based on heparin-mediated inhibition of factor Xa, resulting in prolongation of clotting time. In 19 of 55 plasma samples obtained from 32 patients concurrently receiving coumarin and heparin, Heptest results exceeded true heparin values by more than 0.2 int. unit/mL; four samples showed a deviation exceeding 0.4 int. unit/mL. We show here that these deviations are caused by coumarin-induced decreases of plasma prothrombin. This problem can be circumvented by adding purified prothrombin or normal plasma to the assay mixture.

Effect of vitamin K administration on acarboxy prothrombin (PIVKA-II) levels in newborns.

PIVKA-II (protein induced by vitamin K absence or antagonist-II) was measured in two groups of newborns, one group being given 5 mg vitamin K at birth and the other untreated. The untreated group had a significantly higher proportion of PIVKA-II positive babies at 3 and 5 days of age than did the treated group. When vitamin K was administered to newborn babies whose normotest levels were less than 30%, it was found that the higher the pre-treatment PIVKA-II levels the greater the response to vitamin K, as monitored by the normotest. Thus PIVKA-II levels might be more useful than a coagulation test, since the low activity of vitamin K dependent coagulation factors sometimes reflects not vitamin K deficiency but impaired production of these factors because of immaturity. The findings support the view that vitamin K given prophylactically at birth will help to prevent neonatal bleeding.

Influence of the type of feeding on the presence of PIVKA-II in infants.

PIVKA-II levels were studied by a highly sensitive immunological method in two groups of infants, breast-fed and bottle-fed, at the age of 4 days, 1 month, 2 months, and 3 months. PIVKA-II could be demonstrated in 9 infants after the age of 1 month when they were breast-fed. In none of the bottle-fed infants PIVKA-II was present during the same period. This significant difference can probably be explained by the lower vitamin K1 content of human milk compared to commercial formulas. The frequently occurring biochemical deficiency of vitamin K indicates the need of prophylactic administration of vitamin K to all newborns.

Application of des-gamma-carboxy prothrombin as a complementary tumor marker with alpha-fetoprotein in the diagnosis of hepatocellular carcinoma.

By means of staphylocoagulase, plasma des-gamma-carboxy prothrombin (DCP) was measured in 255 subjects. Of these, 59 were healthy controls, 100 had primary hepatocellular carcinoma (PHC), 33 had cirrhosis of the liver, 16 had hepatitis, 11 had metastatic carcinoma of the liver (MCL), and 36 subjects had previously been treated with anti-vitamin K drugs. The mean plasma DCP level in the healthy subjects was 3.02 VGH U/l. Of PHC patients 80% had DCP levels greater than 6 VGH U/l, which we regarded as probably abnormal. None of the patients with benign liver diseases (cirrhosis of liver or hepatitis) had DCP greater than 10 VGH U/l. Of the patients with MCL 54.54% had DCP greater than 6 VGH U/l. In our study DCP was found to be as sensitive a tumor marker as alpha-fetoprotein (AFP) in the diagnosis of PHC and was better in distinguishing PHC from benign liver disease. Of PHC patients 92% had at least one of the two tumor markers. Simultaneous determination of DCP and AFP should be applied in mass survey programs for detecting PHC, especially in countries with a high prevalence of hepatitis B virus infection.

[Assay of decarboxy-prothrombin: its value in the diagnosis of hepatocellular carcinoma]. / Le dosage de la décarboxy-prothrombine: son intérêt dans le diagnostic des carcinomes hépatocellulaires.

Serum decarboxy-prothrombin (DCP) was raised in 70.7% of histologically confirmed cases of hepatocellular carcinoma and, with alpha foetoprotein, constitutes a complementary biochemical marker for this disease. It is usually normal in other hepatic diseases but pathological values of DCP have been observed in a few cases of cirrhosis and in some pancreatic carcinomas with hepatic metastases. The differential diagnosis may be established by administering 20 mg of Vitamin K1 by slow intravenous injection: if the DCP remains pathological 15 days after Vitamin K1 the diagnosis of hepatocellular carcinoma is very probable. On the other hand, if the DCP is normal a Vitamin K deficiency may be diagnosed.

Mother-infant prothrombin precursor status at birth.

Previous work from this laboratory has suggested there is a risk of hemorrhagic disease of the newborn (HDNB) in approximately one-third of term neonates, presumably as a result of vitamin K deficiency. Using the same assay for PIVKA (protein induced by vitamin K absence, prothrombin precursor), we studied 46 normal mother-infant pairs at term to investigate the relationship between neonatal and maternal PIVKA status. PIVKA was found in 13 infants (28%) and in seven mothers (15%). Maternal PIVKA status correlated with infant status (p less than 0.03). These data suggest that fetal vitamin K deficiency and risk of HDNB may be a consequence of maternal deficiency of the vitamin.

Assay of des-gamma-carboxyprothrombin using staphylocoagulase. Application to the diagnosis of cellular hepatocarcinoma.

A new clotting method is described to assay des-gamma-carboxyprothrombin (DCP), using staphylocoagulase and adsorbed undiluted citrated plasma. The thrombin-coagulase formed was tested with a chromogenic substrate. The results were expressed in milliunits (m.u.). All 96 normal plasmas had less than 15 m.u. (mean 3.58 m.u.). Out of 56 non-hepatectomized cellular hepatocarcinomas, 40 had DCP levels between 20 and 420 m.u. (average between 40 and 60 m.u.); 71.4% of cellular hepatocarcinoma had an increased DCP and 90% were positive either in alpha-foetoprotein or in DCP. Ten cases of non-cellular hepatocarcinomas had normal DCP levels. We found no cases of cirrhosis or chronic hepatitis, whether active or persistent, with abnormal level of DCP. Out of 127 patients tested, no case was found with a high DCP and a low level of "total factor II", which could be interpreted as a vitamin K deficiency. Only one case of hepatocarcinoma had 25 m.u. of DCP and a low total factor II (20%) and 2 had less than 10% total factor II with no detectable DCP.