Coagulation abnormalities in low birth weight infants with peri-intraventricular hemorrhage

Fifty-four appropriate for gestational age preterm infants (less than 35 weeks gestation) were followed prospectively from birth with coagulation and real-time ultrasound studies. Coagulation analyses included fibrinogen, prothrombin time, thrombin time and platelet count. The occurrence of peri-intraventricular hemorrhage (PIVH) was documented by portable 5 MHz Echo Scanner. Definite PIVH was present in 21 babies (38%). Coagulation studies showed especially lower values of fibrinogen levels in babies of less than 30 weeks gestation compared to a control group without PIVH (p less than 0.03). Furthermore, significant correlation was observed in these patients between platelet count and degree of PIVH. Infants with Grade 3 and 4 PIVH had lower platelet count than infants with less severe bleeding (Grade 1 and 2) (p less than 0.02). These data suggest that hemostatic abnormalities play a major role as co-factor in the incidence and severity of neonatal PIVH in very low birth weight infants of less than 30 weeks gestation.

Homozygous protein C deficiency in a newborn. Clinicopathologic correlation

A rare case of homozygous protein C deficiency occurred in a newborn. The patient presented with purpura fulminans in the first few hours after birth and showed multiple hemorrhagic lesions on computed tomography of the brain at 5 days of age. Neurologic symptoms developed at two weeks and the patient died at 37 weeks. His protein C level was less than 5%. Autopsy revealed thrombosis of the dural sinuses, multiple cortical infarcts, intraparenchymal hemorrhages, and hydrocephalus. The pathologic findings are correlated with the neurologic deficits and previously documented cases are reviewed.

Direct analysis of plasma fibrinogen-derived fibrinopeptides by high-performance liquid chromatography: investigation of nine congenital fibrinogen abnormalities

A simple method has been developed for the rapid analysis of fibrinopeptides contained on fibrinogen in small anticoagulated plasma samples. Following incubation with thrombin the plasma is diluted, boiled and then studied by high performance liquid chromatography (HPLC). The three forms of FPA (AP, A, AY) and two forms of FPB (B, des Arg B) can be identified and quantified in samples of less than 200 microliters. Additionally, the FPB peak height can be used to measure the plasma fibrinogen level. This method has been used to screen plasma samples with abnormal clotting times for possible congenital fibrinogen abnormalities. Results of the study of nine unrelated cases are presented. Four cases of congenital dysfibrinogenaemia were diagnosed directly from HPLC analysis alone. Fibrinogen Sheffield and Paris VI were identified as A alpha Arg 16----His substitutions and fibrinogens London VI and Madrid II were found to be heterozygous for an unknown substitution preventing thrombin cleavage at A alpha Arg 16. A case of dysfibrinogenaemia (fibrinogen Ashford) with a normal fibrinopeptide release stoichiometry was confirmed to have a primary polymerization abnormality using purified fibrin monomers. Similarly, a case of hypodysfibrinogenaemia (fibrinogen London V) had normal fibrinopeptides and a fibrin polymerization abnormality. In one case of hypofibrinogenaemia and two cases of afibrinogenaemia, no fibrinopeptide or functional abnormalities could be definitely established. This rapid and simple method of fibrinopeptide analysis is recommended for screening of plasma samples taken from patients suspected of having abnormalities of fibrinogen synthesis.

Reversal of coagulopathy in Kasabach-Merritt syndrome with tranexamic acid

An infant with a giant cavernous haemangioma developed a severe consumption coagulopathy and systemic bleeding. Replacement therapy with cryoprecipitate produced only a transient improvement in the abnormal clotting, but the addition of tranexamic acid resulted in sustained correction, permitting corrective surgery to be performed.

Fibrinogen Aarhus--a new case of dysfibrinogenemia

Fibrinogen Aarhus was found in a woman with slightly prolonged whole blood clotting time. The thrombin induced clotting of plasma and purified fibrinogen was much prolonged. Kinetic analysis of FPA and FPB release revealed larger apparent Km and Vmax values for fibrinogen Aarhus than for normal fibrinogen. No clot formation of fibrinogen Aarhus was demonstrated in the presence of Batroxobin and the release of FPA was slower than normal. Upon addition of the clotting enzyme from Agkistrodon contortrix contortrix clotting did occur but the clotting time was much prolonged in comparison with normal fibrinogen. The turbidity of fibrin gels obtained from fibrinogen Aarhus was similar to normal fibrin gels at low thrombin concentrations. Increasing thrombin concentration resulted in appearance of degradation products in the fibrin gels from fibrinogen Aarhus and at the same time a relative increase in turbidity of the gels was observed. Possibly reasons for the slow release of fibrinopeptides, the delayed gelation, and susceptibility to degradation by thrombin are discussed.

Fibrinogen Milano II: a congenital dysfibrinogenaemia associated with juvenile arterial and venous thrombosis

A congenitally abnormal fibrinogen was isolated from blood of a young man with deep-vein thrombosis. Two other affected members of his family had three episodes of severe arterial thrombosis. The fibrinogen showed a delayed clotting by thrombin, but a normal clotting by Arvin, Reptilase, and prothrombin-staphylocoagulase complex. Analysis of the fibrinopeptides A and B by High Performance Liquid Chromatography did not reveal an abnormal peptide structure. The rate of release of A and B peptides by thrombin was strongly delayed, whereas the rate of release of fibrinopeptide A by Arvin appeared to be normal. The fibrin polymerization rate was normal. Interactions between the abnormal fibrinogen, platelets and the fibrinolytic system were also normal. Evidence is presented that the defective interaction between fibrinogen Milano II and thrombin is associated with a defective binding of thrombin to the fibrin moiety of the abnormal fibrinogen.

Severe inherited "homozygous" protein C deficiency in a newborn infant

A relapsing clinical syndrome of skin lesions and disseminated intravascular coagulation (DIC) that showed remission with the infusion of fresh frozen plasma is described in a newborn infant with homozygous deficiency of protein C antigen. This patient presented since birth a recurrent clinical picture of DIC and ecchymotic skin lesions that resembled typical ecchymosis except for the fact that they showed immediate improvement with the administration of fresh frozen plasma. Using an enzyme linked immunosorbent assay method, the determination of protein C antigen levels in the patient, without ingestion of coumarin drugs, showed very low values (less than 1%). No other deficiencies in the vitamin-K-dependent factors or in antithrombin III, antiplasmin, and plasminogen were found. Seven relatives of the infant had heterozygous deficiency in protein C antigen (values between 40-55%), without clinical history of venous thrombosis. The pedigree analysis of this family suggests an autosomal recessive pattern of inheritance for the clinical phenotype, although an autosomal dominant pattern has been postulated until now in other reported families. We conclude that our patient has a homozygous deficiency in protein C and this homozygous state may be compatible with survival beyond the neonatal period.

A functional assay of protein C in human plasma

A three-step spectrophotometric assay was developed for measuring functional protein C (PC) in human plasma. The assay is based on: (1) adsorption of citrated platelet-poor plasma on barium citrate and elution of the vitamin K-dependent factors with EDTA; (2) activation of PC by incubation of the mixture of vitamin K-dependent factors with a complex of thrombin and its endothelial cell cofactor, thrombomodulin; (3) addition of antithrombin III and heparin to the system to inhibit thrombin and other coagulation enzymes generated during incubation and measurement of the activated PC with a synthetic (chromogenic) substrate. The assay appears to be specific for PC because: (a) PC-depleted plasma (by immunoadsorption) is inactive; (b) addition of purified PC to PC-depleted plasma reconstitutes its activity; and (c) no enzymatic activity is generated in the absence of the thrombin-thrombomodulin complex. Mixtures of a normal plasma pool with PC-depleted plasma yielded an amount of enzymatic activity proportional to the fraction of normal plasma. Using this as a standard curve, the amount of PC in the plasma of 23 normal subjects was 97% +/- 15%. The within-assay coefficient of variation was 3.5% and the between-assay coefficient 6.5%. A linear correlation (r = 0.86) was found between PC as measured with the functional assay and with a radioimmunoassay. In 3 patients with congenital PC deficiency, the functional PC level was 37% +/- 9% and the antigen level 64% +/- 11%. It is concluded that the present assay may be used for reliable and accurate estimation of activatable PC in human plasma.

[Congenital dysfibrinogenemia. Apropos of 13 cases]

Approximately 100 families with congenital dysfibrinogenemia have already been reported in the literature. We have had the opportunity to study 13 affected families in France. The study of these dysfibrinogenemias has two purposes: 1) analysis of the relationships between the structural and functional abnormalities of the fibrinogen defect, since it appears that, in a significant percentage of dysfibrinogenemias, recurrent thrombosis has been observed. The diagnosis of dysfibrinogenemia is easily presumed in hemostasis laboratories since it rests upon prolonged thrombin and/or reptilase clotting times and the discrepancy between the fibrinogen levels obtained by an immunological method and a coagulation method. Many studies have been carried out during the last few years, and in at least seven cases the fibrinogen molecular defect has been elucidated.

Thrombosis or myocardial infarction in congenital clotting factor abnormalities and chronic thrombocytopenias: a report of 21 patients and a review of 50 previously reported cases

Nine patients are described with hereditary clotting factor abnormalities and thrombosis and 35 others previously reported in the literature. An additional 11 patients with myocardial infarction observed by the authors and 12 more reported by others are also included. A patient with non-immune thrombocytopenia and myocardial infarction is presented, as well as three additional patients recorded in the literature. This study underscores the little-recognized phenomenon of uncontrolled thrombosis in these patients with "experiments of nature," in whom clotting studies reflect an impairment of coagulation comparable in degree to that achieved by oral anticoagulant therapy.

Stroke in two young siblings with congenital dysfibrinogenemia

Two young siblings (a male of 21 and his sister of 26 years) suffered from arterial thrombosis episodes of the carotid and abdominal aorta documented by angiographic studies. In the absence of any known predisposing factor in the family and personal history, the laboratory investigation of both patients revealed coagulation abnormalities compatible with a dysfibrinogenemia. The occurrence of a similar defect also in plasma of one of the propositi's asymptomatic relatives is suggestive of an inherited fibrinogen disorder.

A new type of congenital dysfibrinogenaemia with defective fibrin lysis--Dusard syndrome: possible relation to thrombosis

Congenital dysfibrinogenaemia is described in three members of a family presenting with recurrent thrombosis and in two other young members not yet affected. An abnormality in the polymerization of fibrin monomers was noted. In addition, the pathological fibrin clots were found to be less sensitive to degradation by a post venous occlusion euglobulin solution than normal fibrin. After fibrin clot incubation with lys-plasminogen at different concentrations, the biological activity of plasminogen in patient fibrin clot on S 2251 after SK-addition, was less than that observed with normal fibrin. It is speculated that defective in vivo thrombolysis might explain the recurrent thrombosis observed in this family. This finding represents a new concept in understanding thromboembolic diseases.