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6 THROMBOSIS RESEARCH Suppl. VI, 1986 11 Two NEW cases OF CONGENITAL DYSFIBRINOGENEMIA WITH IMPAIRED AGGREGATION OF MONOMERS: ElBRlNOGENS SALAMAN...

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THROMBOSIS

RESEARCH

Suppl. VI,

1986

11 Two NEW cases OF CONGENITAL DYSFIBRINOGENEMIA WITH IMPAIRED AGGREGATION OF MONOMERS: ElBRlNOGENS SALAMANCA II AND SANTANDER I. J.Eerngndes*, V-Vice*te**, G.Sedano***, J.A.P&amo*, I.Alberca**, G.Richard***, E.Rocha*. Hematology Service. University of Navarra*, University Of Sda~anca** and C.M.N. Marques de Valdecilla***. 31080-Pamplona. Spain. Two abnormal fibrinogens were described in two unrelated Spanish families with no history of clinical hemorrhage or thrombotic events. Both cases had prolonged thrombin and reptilase times and their functional levels of fibrinogen were diminished although with normal immunologic concentrations. Normal plasma thrombin time was inhibited by increasing concentrations of the first patient's plasma. Thrombin times of both purified fibrinogens were corrected by increasing concentrations of bovine thrombin, calcium ions (0.025 M), low ionic strength (0.05), pH= 6.2-7.4 and by the addition of protamine sulfate (1%). Aggregation of fibrin monomers was impaired in both cases but showed normal fibrinopeptide release and fibrin crosslinking. Chromatofocusing of both purified fibrinogens showed abnormal elution. Crossed immunoelectrophoresis of plasma and purified fibrinogen showed normal pattherns in both cases. The binding of tissue-type plasminogen activator (t-PA) to fibrin as well as the activation of plasminogen by t-PA in the presence of fibrin were normal in the two patients. These data suggest two new cases of congenital dysfibrinogenemia that could be tentatively designated as fibrinogens Salamanca II and Santander 1.

12 EPITOPIC SPECIFICITY IN IDENTIFYING CROSSLINKED (XL) FIBRIN DERIVATIVES THE MCNOCLONAL ANTIBODY (MAb) DD-3B6/22. A N Whitaker, P P Masci, A Dunstan Dept Medicine, University of Queensland, Princess Alexandra Hospital, Woolloongabba, Qld, Australia, 4102.

BY

MAb specific for XL fibrin degradation products have been applied in plasma enzyme immunoassays for detecting thrombosis and disseminated intravascular coagulation (J Clin Path01 1984;37:882-7). The precision in quantifying fibrin derivatives has been evaluated using the MAb DD-3B6/22. This MAb does not interact with soluble non-XL fibrin oligomers (unlike a B-chain specific MAb). There is significant interaction with fibrin oligomers XL with XIIIa and Ca2+, further enhanced on partial digestion with plasmin (0.2 U/ml for 30 min), comparable to the HMW complexes resulting from the lysis of XL fibrin clot (1 U/ml plasmin, pH5.0,lOm Ca2+). The interaction with D dimer varies with the method of preparation. The reactivity of D dimer purified by chromatofocusing (Anal Biochem 1985:147:128-135) is rapidly destroyed by trypsin without detectable loss of molecular weight, but enhances progressively in the presence of pepsin. Carboxymethylated chains of D dimer are non-reactive. The epitope recognized by DD-3B6/22 appears to be conformational, to depend upon the presence of the YY-XL and to be sensitive to minor surface cleavages of lysyl and arginyl bonds.