Blut (1983) 47:123-130

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© Springer-Verlag 1983

Leading Article The von Willebrand-Syndrome I. Scharrer Abteilung ftir Angiologie des Zentrums der Inneren Medizin der Universit~itskliniken Frankfurt am Main, Theodor Stern Kai 7, D-6000 Frankfurt am Main, Federal Republic of Germany

Von Willebrand described in his original publication in 1926 [48] an autosomal inherited hemorrhagic disorder with prolonged bleeding time. Now, 57 years later, it has become apparent that the pathogenesis of the von Willebrand disease (v Wd) is not homogeneous; quantitative as well as qualitative defects of the factor VIII protein complex have been described. The so-called classical vWd has characteristic laboratory findings: these include a reduced level of procoagulant factor VIII (VIIRC); after infusing plasma, factor VIII concentrates or even hemophilic plasma a typical secondary rise of VIII:C will appear; characteristic also are reduced levels of factor VIII related antigen (VIII R: Ag), which were detected by Laurell electroimmuno-assay, immunoradiometric- or radioimmuno-assay. Another characteristic parameter is a reduced level of a plasma factor needed for platelet aggregation by the antibiotic ristocetin (ristocetin cofactor activity = VIII R: RCF). The bleeding time (BT) is prolonged and platelet retention in glass-bead columns is reduced. Immunohistological studies localized the factor VIII related antigen on the vascular endothelium of all blood vessels [4, 28]. In severe cases of the vWd it was proved that factor VIII related antigen was missing from the endothelial cells of these patients and also lacking in the platelets of most patients with severe or homozygous vWd [13, 23]. It is now generally accepted that the von Willebrand factor (VIII R" WF) is essential for adhesion of platelets to the subendothelium [3], for a normal bleeding time, for normalisation of the glass-bead retention test [10] and for ristocetin induced aggregation [50]. The only specific test for the in vivo "bleeding time factor" (VIIIR:WF) is its ability to correct the bleeding time. At the present time there is no simple quantitative in vitro test for estimating VIII R: WF. It is suggested [23] that the von Willebrand factor activity is primarily a function of very highly aggregated factor VIII and that material with a lower degree of polymerization will not function satisfactorily in primary haemostasis. Unique antigenic and functional characteristics of VIII R: WF have been associated with the larger multimers. Through various electrophoretic procedures the multimeric structure of unreduced F. VIII R: WF was demonstrated. The molecular weight of the multimers were estimated to vary between 1 and 20 × 106 daltons [53]. VIII R: WF is present in plasma, platelets, megakaryocytes and endothelial ceils [53]. Cellular VIII R ' W F

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contains VIII R:Ag and VIII R:RCF [411. The concentration of F. VIII R : W F in plasma is 5-10 # g / m l [53]. Purified F. VIII R: WF is a large sized molecule with a Mr in excess of 106 daltons [26] although other authors have suggested a smaller size [36]. These multimers are apparently built up out of the basic 200000 subunits [291. In the classical type of vWd there is no qualitative but only a quantitative defect of the factor VIII complex and all activities are reduced. In addition to the classical vWd many genetic variants of vWd habe been established. Several genetic variants occur as a result of inherited molecular abnormality of the factor VIII protein. The presence of multiple molecular forms of VIII R: WF can be demonstrated through crossed-immunoelectrophoresis (CIP), ion-exchange chromatography and sucrosedensity ultracentrifugation [52]. CIP of plasma VIII R: Ag shows an asymmetrical pattern which results from the presence of multiple forms of VIII R: Ag. The larger forms have the least anodic electrophoretic mobility in agarose; these larger forms of VIII R: WF appear to possess von Willebrand factor activity in vivo. Generally these patients (variants) have an alteration in their crossed-immunoelectrophoretic patterns, shifting to the faster migrating anodal forms of VIII. A carbohydrate deficiency [7, 8] or abnormality has been demonstrated in the purified VIII from some of these patients using periodic acid Schiff (PAS) for staining of sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE), by the measurement of the sialic acid content and by the precipitation through the lectin concanavalin-A and the binding to 125I-Con-A. The International Committee on Thrombosis and Haemostasis [241 and the European Thrombosis Research Organization (ETRO) [23] have set up working parties who investigate these variants. In the ETRO Working Party a classification with four types was suggested [23]. Recent advances in biochemistry of the VIIIR: WF molecular complex have shed new light on vWd, and therefore we would like to suggest the following modified classification of v Wd. (Table 1) Type I was described by Nilsson et al. [22], Barrow and Graham [1], Silwer [38], Veltkamp and yon Tilburg [46], Stableforth et al. [40], Sultan et al. [42], Italian Working Group [16], Ruggeri et al. [301, Nyman et al. [25] and many other authors. Type III was reported by Holmberg et al. [12] and by Shoa'i et al. [37]. Type I V was detected by Veltkamp and von Tilburg [47], Thomson et al. [44] and by Peake et al. [27]. Type II is at the present time the most interesting. In type II, a qualitative abnormality of VIII R: WF is demonstrated through an abnormal pattern on CIP with a marked reduction of the larger, slower moving forms of VIIIR: WF [431. Meyer et al. [20] demonstrated a polymerization defect of VIII R: WF in type II with an accumulation of the small multimers and absence of the large multimers. In the analysis of a normal multimeric composition of VIII R: WF in plasma and in platelet lysates 10 distinct multimers were found [32]. In subtype I I A VIII R: WF consisted of five smaller multimers with trace amounts of the sixth and seventh. In subtype II B, all these multimers were easily detected and additional bands of intermediate size were present. The multimeric composition of IIB platelet VIII R: WF was identical to that of the normal platelet. However in subtype II A the larger multimers were missing from the platelets as well as from the plasma [321. Further, in type IIB an increased sensitivity to ristocetin was shown [311. These patients presented a prolonged bleeding time and an abnormal CIP of plasma VIII R:Ag excluding larger molecular forms. The ristocetin cofactor activity was normal or moderately reduced. Increased

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The von Willebrand-Syndrome Table 1. Classification of von Willebrand's disease (1983) Type Type I

VIIIR: Ag

VIIIR: RCF

VIII: C

BT

reduced qualitative abnormality of F.VIII/vWF plasma; platelets+ plasma; platelets normal plasma normal platelets;

reduced

reduced

prolonged

normal or nearly normal (quantitative) qualitative abnormality of F.VIII/vWF

reduced

normal or reduced

prolonged

no

1 2 3 Type II

A

abnormal multimeric structure of vWF in plasma and platelets abnormal multimeric structure of vWF only in plasma not in platelets, increased Ristocetin induced aggregation, abnormal response to DDAVP

C

abnormal multimeric triplet of VIII/vWF, lack of larger multimers of VIII/vWF in plasma and platelets, abnormal response to DDAVP

Type III

reduced

reduced (normal)

normal

prolonged

Type IV

reduced

reduced

reduced

normal (slightly prolonged)

Pseudo vWd: increased Ristocetin induced aggregation, abnormal multimeric structure of VIII/vWF, (secondary to platelets abnormalities) abnormal adsorption of VIII/vWF multimers to platelets, intermittent thrombocytopenia, basic defect in platelets VIIIR: Ag = Factor VIII related antigen, VIIIR: RCF = Ristocetin cofactor, VIII: C = procoagulant factor VIII, BT = bleeding time

ristocetin-induced VII1 R: WF-platelet interaction was demonstrated by the study of ristocetin-induced platelet aggregation and ristocetin-induced binding o f V I I I R: W F to platelets. This enhanced interaction was f o u n d even in patients with reduced ristocetin cofactor activity [31]. In type I I A disease ristocetin usually fails to induce platelet aggregation, even with a high dose of 2 m g / m l . Ruggeri et al. [33] described a t e m p o r a r y improvement o f the a b n o r m a l multimeric composition in type I I B after infusing D D A V P ; the larger mnltimers disappear faster in the circulation in these patients than in type I v W d patients or in n o r m a l individuals. The rate o f disappearance o f large yon Willebrand factor multimers after infusing cryoprecipitate is similar in II B, II A and severe homozygous-like v W d [33]. The slower disappearance

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of larger normal vWF multimers transfused with cryoprecipitate compared to those endogenously released supports the hypothesis of an intrinsic vWF abnormality in IIB vWd, rather than enhanced affinity of abnormal cellular or tissue binding sites [33]. Ruggeri et al. introduced in the XXVIII annual meeting of the International Committee on Thrombosis and Haemostasis in Bergamo in July 1982 and in "Symposium on factor VIII R: W F " in the Scripps Clinic, la Jolla, in October 1982 a new variant, the type II C [2]. In this type the triplet structure can not be detected. The larger multimers of yon Willebrand factor were lacking in plasma and platelets and they did not appear in the circulation after infusion of DDAVP. The triplet structure is an inherent feature of normal vWF multimers. Weiss et al. [51] discovered the "Pseudo von Willebrand disease". This is a mild bleeding disorder which includes intermittent thrombocytopenia and decreased plasma levels of VIII R: WF, absence of high-molecular-weight forms of VIII R: WF in the plasma, but a normal multimeric structure in the platelets and increased ristocetin-induced platelet aggregation, as in type IIB vWd. The basic defect in this disease is in the platelets which adsorb multimers at lower concentrations of ristocetin than normal plasma does. These platelets are aggregated by unmodified normal human VIII R: WF without ristocetin. Since abnormalities of plasma VIII R: WF in this disease may be secondary to the platelet abnormalities, the authors called this disease pseudo von Willebrand disease. Korninger et al. described in 1981 [17] an impaired fibrinolytic response to DDAVP and venous occlusion in a sub-group of patients with vWd. They suggest a combined endothelial cell deficiency resulting in impaired production/release of VIII R: Ag and of vascular plasminogen activator. Abnormal fibrinolysis in some patients with vWd strongly indicates that vWd is even more heterogeneous than already known. Several patients with acquired bleeding disorders resembling vWd have been reported. These patients did not suffer from a previous haemorrhagic disorder and had no family history of vWd. Most of these patients had an associated autoimmune or lymphoproliferative disease [11, 15, 39]. They presented a prolonged bleeding time, reduced VIII:C, VIII R: Ag and VIII R: RCF. After transfusion of cryoprecipitates there was a smaller than expected immediate increase of VIII:C, VIII R:Ag and VIII R: RCF, with a rapid return to baseline level and no secondary increase of VIII:C. In some cases an inhibitory activity was described [9, 49]. In other patients no circulating antibody was detected. The mechanism which is responsible for the defective function of the factor VIII protein complex in acquired vWd is heterogeneous and until today generally unknown. The v Wd is one of the most wide-spread congenital haemorrhagic diathesis. For example 10 out of 100000 inhabitants of Sweden are affected by this disease compared to the prevalence for hemophilia which affects seven out of 100000 inhabitants [23]. The above figures compare to 167/165 in our hospital (center of internal medicine), which indicates the relation of patients with vWd to those with hemophilia. Type 2, the classical type, seems to be most frequent, affecting 75% of all patients. In the Italian working group from 100 patients 71 presented the classical type [16]. Through the detection of vWd variants the diagnosis became more difficult. Quite often mild cases of vWd are only discovered very late in adulthood and therefore the true incidence of vWd is difficult to establish. In contrast to hemophilia A vWd is

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inherited as an autosomal dominant or recessive trait. From a genetic point of view patients may be classified as homozygous or "double-heterozygous" and heterozygous vWd. In its usual heterozygous form the onset of bleeding occurs in early childhood. Mucosal and cutaneous hemorrhages including epistaxis, gingival bleeding, gastrointestinal bleeding and bruising are very frequent and menorrhagia and postpartum bleeding occur often. Commonly excessive bleeding after tonsillectomy, after other surgery or dental extraction is observed. Haemarthroses are rare except in severe cases of vWd. In our center haemarthroses occur in 10% of the patients with vWd; this corresponds with a figure of 50% of our patients with homozygous, severely affected vWd. The manifestation of bleeding is often variable in the same patient at different seasons and different ages [5]. The symptoms often decrease with increasing age. Types I and II do not differ in bleeding manifestations except during pregnancy, in liver disease and some other disorders. In these cases of type I the F VIII vWF often increases whereas this usually does not happen in type II [21]. Transfusion therapy should correct the bleeding time, the platelet retention and the abnormalities of VIII R: WF. Correcting only VIII:C levels, as in haemophilia, is not sufficient. Bleeding may occur even if VIII:C is high. Presently cryoprecipitates and Cohn Fractions I-0 are generally the treatment of choice for severe cases of vWd, the dose is 20-40 U/kg body weight, twice daily. Cryoprecipitates contain the large, slow-moving forms of F VIII R: WF, the HMW multimers, which seem to be responsible for the correction of the bleeding time. Use of fresh plasma alone, has generally not been shown to prevent post-operative bleeding. Despite their very high levels of F. VIII:C the new commercially prepared, highly purified, high potency AHF concentrates were generally disappointing in the treatment of vWd patients because of the lack of antibleeding factor. However, recently we observed a correction of the bleeding time and VIII R: WF activities in patients with severe vWd after infusing the new commercially available HS-AHG-concentrates. This phenomenon will need further investigation. Operations on patients with severe forms of vWd have been made possible using either cryoprecipitates or Cohn fraction I-0. We felt it necessary to continue treatment for a two-week period after surgery because often postoperative bleedings occurred relatively late [34]. Based on our experience VIII R:RCF and VIII: C levels must be determined during the postoperative days, the Duke bleeding time every 2nd day; the level of VIIIR:RCF has to be kept at 50%. Aspirin should be avoided. Recognized complications following the use of either Cohn fraction or cryoprecipitates include hepatitis, febrile reactions, inhibitors to VIII R: WF and intravascular haemolysis. In patients with mild vWd DDAVP was successfully used to control haemostasis, whereas this treatment failed in severely affected patients. The usual dose is: 0.4 #g/kg body weight. The dosage interval is every 12 h. The half-disappearance time of VIII:C after increase induced by i.v. DDAVP is similar in healthy persons and in patients with vWd [19]. Two-fold or greater increase in the levels of VIII:C, VIII R:Ag and VIII R:RCF was demonstrated by us [35], Mannucci et al. [19] and other authors. Repeatedly treated patients showed varied patterns, ranging from no change of response to its early abolition [19]. Discrepancies with respect to bleeding time changes were described. Reasons for it may be different methods and the different response of the various types of vWd to DDAVP. Nevertheless DDAVP is a useful alternative to replacement therapy in mild vWd without the side effect of hepatitis.

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Oral contraceptives showed a good effect in menorrhagia. For prophylaxis of bleeding in connection with teeth extractions tranexamic acid (AMCA) was used successfully. Prenatal exclusion of vWd is possible [14]; F VIII R: Ag can be detected in normal 16-20 weeks old fetuses. A prenatal diagnosis of vWd should be considered in families where one severely afflicted child was born or where both parents are evidently affected. The typical decreased platelet adhesion to subendothelium in patients with vWd [45] and the findings that pigs with severe, homozygous vWd were resistant to spontaneous and high-cholesterol diet-induced atherosclerosis [6] have prompted the E u r o p e a n Thrombosis Research Organization (ETRO) to initiate a study to determine the incidence of atherosclerosis and its consequences to patients with severe, homozygous-like vWd. The study is n a m e d "'Rokitansky-Duguid project" [8]. Further work will shed light on the interesting and important abnormalities of factor VIII protein complex in vWd and furthermore on platelet-vessel wall interactions a n d the development of atherosclerosis.

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17. Korninger C, Niessner H, Lechner K (1981) Impaired fibrinolytic response to DDAVP and venous occlusion in a sub-group of patients with von Willebrand's disease. Thromb Res 23:365 18. Mannucci PM (1981) The Rokitanski-Duguid Project. Thromb Haemost 45:300 19. Mannucci PM, Canciani MT, Rota L, Donovan BS (1981) Response of factor VIII/yon Willebrand factor to DDAVP in healthy subjects and patients with haemophilia A and von Willebrand's disease. Br J Haematol 47:283 20. Meyer D, Obert B, Pietu G, Lavergne JM, Zimmerman TS (1980) Multimeric structure of factor VIII/yon Willebrand factor in yon Willebrand's disease. J Lab Clin Med 95:590 21. Meyer D, Zimmerman TS (1982) Von Willebrand's disease. In: Colman RW, Hirsh J, Marder VJ, Salzman EW (eds) Haemostasis and thrombosis - basic principles and clinical practice. J.B. Lippincott, Philadelphia, pp 64-74 22. Nilsson IM, Blomb/ick M, v. Francken I (1957) On an inherited autosomal hemorrhagic diathesis with antihemophilic globulin (AHG) deficiency and prolonged bleeding time. Acta Med Scand 159:35 23. Nilsson IM, Holmberg L (1979) Von Willebrand's disease today. Clin Haematol 8:147 24. Nilsson IM, Meyer D, Hoyer LW, Ingram GIC, Rizza CR (1980) Report of the subcommittee on factor VIII activities. Thromb Haemost 43:163 25. Nyman D, Eriksson AW, Blomb/ick M, Frants RR, Wahlberg P (1981) Recent investigations of the first bleeder family in Aland (Finland) described by yon Willebrand. Thromb Haemost 45:73 26. Olson ID, Brockway W J, Fass DN, Bowie EJW, Mann KG (1977) Purification of porcine and human ristocetin Willebrand factor. J Lab Clin Med 89:1278 27. Peake IR, Bloom AL, Giddings JC (1975) Different types of von Willebrand's disease. Haemophilia (Excerpta Medica) 107 28. Rand JH, Sussmann II, Gordon RE, Chu SV, Solomon V (1980) Localization of factorVIII-related antigen in human vascular subendothelium. Blood 55:752 29. Rock GA, Palmer DS, Tackaberry ES, Cruickshank WH (1978) The presence of high and low molecular weight forms of factor VIII in heparinized plasma. Thromb Res 13:85 30. Ruggeri ZM, Mannucci PM, Jeffcoate SL, Ingram GIC (1976) Immunoradiometric assay of factor VIII related antigen, with observations in 32 patients with yon Willebrand's disease. Br J Haematol 33:221 31. Ruggeri ZM, Pareti FI, Mannucci PM, Ciavarella N, Zimmerman TS (1980) Heightened interaction between platelets and factor VIII/von Willebrand factor in a new subtype of von Willebrand's disease. N Engl J Med 302:1047 32. Ruggeri ZM, Zimmerman TS (1980) Variant von Willebrand's disesase. J Clin Invest 65: 1318 33. Ruggeri ZM, Lombardi R, Gatti L, Bader R, Valsecchi C, Zimmerman TS (1982) Type II B von Willebrand's disease: differential clearance of endogenous versus transfused large multimer yon Willebrand factor. Blood 60:1453 34. Scharrer I (1980) Treatment of yon Willebrand's disease. In: Mammen EF, Barnhart MI, Lusher JM, Walsh RT (eds) Treatment of bleeding disorders. PJD Publications Limited, Westbury (NY), pp 101-110 35. Scharrer I (1981) Klinische Anwendung des DDAVP bei zahn~rztlichen Eingriffen. In: Sutor AH (ed) Vasopressin analogues and hemostasis. DDAVP (Minirin). TGLVP (Glycylpressin). FK Schattauer, Stuttgart New York, pp 14-15 36. Seghatchian M J, Nilsson IM, Holmberg L, Miller-Anderson M (1979) Molecular size distribution of Factor VIII in native plasma. Thromb Res 14:589 37. Shoa'i I, Lavergne JM, Ardaillon N, Obert B, Ala F, Meyer D (1977) Heterogeneity of von Willebrand's disease: study of 40 Iranian cases. Br J Haematol 37:67 38. Silwer J (1973) Von Willebrand's disease in Sweden. Acta Paediatr Scand [Suppl] 238 39. Simone JV, Cornet JA, Abildgaard CF (1968) Acquired von Willebrand's syndrome in systemic erythematosis. Blood 31:806 40. Stableforth P, Hughes J, Wilson E, Dormandy KM (1975) The von Willebrand syndrome. Br J Haematol 29:605 41. Stead NW, McKee PA (1978) Destruction of Factor VIII procoagulant activity in tissue culture media. Blood 52:408

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42. Sultan Y, Simeon J, Caen JP (1975) Detection of heterozygotes in both parents of homozygous patients with von Willebrand's disease. J Clin Pathol 28:309 43. Sultan Y, Simeon J, Caen JP (1976) Electrophoretic heterogeneity of normal Factor VIII/von Willebrand protein and abnormal electrophoretic mobility in patients with von Willebrand's disease. J Lab Clin Med 87:185 44. Thomson C, Forbes CD, Prentice CRM (1974) Evidence for a qualitative defect in factor VIII related antigen in yon Willebrand's disease. Lancet I:594 45. Tschopp TB, Weiss H J, Baumgartner HR (1974) Decreased adhesion of platelets to subendothelium in yon Willebrand's disease. J Lab Clin Med 83:296 46. Veltkamp J J, von Tilburg NH (1973) Detection of heterozygotes for recessive von Willebrand's disease by the assay of antihemophilic factor antigen. N Engl. J Med 289:882 47. Veltkamp J J, von Tilburg NH (1974) "Autosomal haemophilia": a variant of von Willebrand's disease. Br J Haematol 26:141 48. Von Willebrand EA (1926) Heredit~ir pseudohemofili. Finska L~ikars~illsk Handl 67:7 49. Wantier JL, Levy S, Caen JP (1976) Acquired von Willebrand syndrome with inhibitors both to Factor VIII clotting activity and ristocetin-induced platelet aggregation. Br J Haematol 33:565 50. Weiss H J, Rogers J, Brand J (1973) Defective ristocetin-induced platelet aggregation in von Willebrand's disease and its correction by factor VIII. J Clin Invest 52:2697 51. Weiss H J, Meyer D, Rabinowitz R, Pietu G, Girma JP, Vicic W J, Rogers J (1982) Pseudovon-Willebrand's disease. N Engl J Med 306:326 52. Zimmerman TS, Roberts J, Edgington TS (1975) Factor VIII related antigen. Multiple molecular forms in human plasma. Proc Nail Acad Sci USA 72:5121 53. Zimmerman TS, Meyer D (1982) Factor VIII-yon Willebrand factor and the molecular basis of von Willebrand's disease. In: Colman RW, Hirsh J, Marder VJ, Salzman EW (eds) Haemostasis and thrombosis - basic principles and clinical practice. JB Lippincott, Philadelphia, pp 54-63

Received April 10, 1983/Accepted April 20, 1983