Dextran 40-induced coagulopathy confused with von Willebrand disease

In a patient who had undergone reconstructive surgery on the subclavian artery and was treated postoperatively with aspirin and dextran 40, a bleeding diathesis developed within 24 hours. This was at first thought to be von Willebrand disease, since the bleeding time was longer than ten minutes; the factor VIII level, 28%; and the activated partial thromboplastin time, 50 seconds (normal 30 to 38). The patient's defect responded to discontinuance of the low-molecular-weight, dextran and aspirin therapy and administration of a cryoprecipitate. Later studies of the coagulation mechanism up to two and one-half months were entirely normal. The postoperative defect therefore was assumed to have been the result of the administration of dextran and aspirin. It is possible that in a similar future case, discontinuance of dextran infusion and administration of a single bolus of 12 bags of cryoprecipitate may be adequate treatment.

Von Willebrand's disease in a Papua New Guinean

An example of von Willebrand's disease in a Papua New Guinean female is described; this is believed to be the first time that this disorder has been documented in a Melanesian. Some salient features of the diagnosis and management of the disease are discussed. Bleeding disorders in Papua New Guinea have been found with increasing frequency in recent years, and it is not unreasonable to expect that their true incidence will be similar to those seen elsewhere.

Classic hemophilia A in a female

A 53-year-old woman with a history of recurrent bleeding complications since childhood and a positive family bleeding history, previously diagnosed as von Willebrand's disease, was investigated. She was found to have a markedly reduced level of antihemophilic factor (AHF) activity, a low AHF activity/AHF antigen ratio, normal Ristocetin-induced platelet aggregation and a normal level of von Willebrand factor activity. These findings were consistent with the diagnosis of classic hemophilia A which was confirmed by the results of similar studies in nine of the patient's relatives. The report illustrates the usefulness of newer laboratory methods in the differentiation between classic hemophilia A and von Willebrand's disease which may have important clinical implications.

Spectrum of von Willebrand's Disease: a study of 100 cases. Italian Working Group

The clinical picture, family history and laboratory findings of 100 patients with von Willebrand's disease (VWD) have been studied in Italy in a multicentre survey from two rural areas with a known high incidence of the disease and from two large cities (Rome and Milan). Bleeding time, procoagulant factor-VIII (VIIIAHF) assay, platelet retention and PRP-ristocetin aggregation were measured in each centre, and plasma samples were frozen and subsequently assayed for factor VIII-related antigen (VIIIAGN) and ristocetin co-factor (VIIIVWF) in one laboratory (Milan). On the basis of the inheritance pattern, clinical severity of the disease and laboratory findings, patients with VWD were separated into two groups. In 17 patients the absence of a family history of bleeding, a high incidence of parental consanguinity and involvement of both sexes suggested an autosomal recessive mode of inheritance; the unusual severity of the disease with markedly abnormal results of all six laboratory measurements (and frequent reduced levels of VIIIAGN and VIIIVWF in the unaffected parents) were consistent with the homozygous state. In 83 patients, the disease was familial (being transmitted as an autosomal dominant trait) and of moderate clinical severity. In these, VIIIVWF was usually much lower than VIIIAHF and VIIIAGN. The findings suggest that although some patients may present with simultaneous abnormalities of all six studied laboratory measurements, the majority show a variation in the spectrum of the abnormal results, without any obvious simple pattern.

Von Willebrand's disease--a potential bleeding problem in plastic surgery

Von Willebrand's disease, a common hereditary bleeding disorder, may be responsible for undue or unanticipated intraoperative or postoperative hemorrhage. The diagnosis may be difficult to establish, although it may be suspected clinically and can usually be confirmed by adequate laboratory investigation. Patients with Von Willebrand's disease appear to be especially susceptible to developing significant prolongation of their bleeding time after the ingestion of aspirin.

Von Willebrand disease San Diego, a new variant

A reduced level of factor XII has been observed in 9 of 39 patients with von Willebrand's disease. This apparent common variant of von Willebrand's disease has not previously been described, and its significance is not known.

[The laboratory diagnosis of von Willebrand's disease (author's transl)]

This investigation was undertaken in order to determine the most suitable methods for diagnosing von Willebrand's disease (v. W. d.), with particular reference to "mild" cases. 50 healthy persons, 21 patients with "severe" v.W.d. (verified according to all hitherto-established criteria) and 39 persons suffering from "mild" v.W.d. were examined. Even though - as far as the latter group is concerned - some of the characteristic laboratory findings were absent, the fact that these persons are related to the patients with "severe" v.W.d. made verification of the diagnosis nevertheless possible. In the group with "mild" v.W.d. 85% had decreased functional factor VIII activity and 82% showed reduced platelet adhesiveness; a prolonged bleeding time according to Borchgrevink was recorded in 72% of the cases and 64% had pathological values for the Ristocetin-induced platelet aggregation were pathological in less than 50% of the group. There was a close relation between the diagnostic significance and reproducibility of the various methods; in regard to the group of patients with "mild" v.W.d., the methods yielding the greatest number of pathological findings (functional factor VIII and platelet adhesiveness) were the ones with the lowest variation coefficients, i.e. 3.1 and 2.1%, respectively. The consideration of a time-dependent rise in the aggregation capability of washed platelets with Ristocetin was of decisive importance in the reproducibility of the rather sophisticated technique of determining the Ristocetin cofactor. The addition of EDTA largely inhabited this effect. Even in the group of patients with "severe" v.W.d., part of the findings obtained with screening tests of the intrinsic coagulation system remained within the normal range. There was no statistical correlation between the individual laboratory findings in the group of healthy persons. In the group with "mild" v.W.d., there was a significant correlation between platelet adhesiveness and Ristocetin-induced platelet aggregation on the one hand, and platelet adhesiveness and the Ristocetin cofactor on the other. In addition, a verified correlation was found to exist between Ristocetin-induced platelet aggregation and Ristocetin cofactor and between functional factor VIII and factor VIII-related antigen. In the group of "severe" v.W.d., only platelet adhesiveness and functional factor VIII were not significantly correlated, whilst all other correlations were of statistical significance. Further problems involved in the diagnosis of v.W.d., such as the variablility of laboratory findings, the existence of subgroups, as well as the difficulties involved in the statistical evaluation of individual cases suffering from v.W.d. are discussed.

[Platelet anomaly in an eosinophilic myelophroliferative syndrome]

The authors report a case of chronic eosinophilic leukemia. Ristocetin did not aggregate patient's platelets in the absence of bleeding disorder. A possible relationship between arterial thrombosis observed in patients with eosinophilic leukemia and platelet abnormality is evoked.

Diagnosis of von Willebrand's disease. A comparative study of diagnostic tests on nine families with von Willebrand's disease and its differential diagnosis from hemophilia and thrombocytopathy

Nine probands with von Willebrand's disease, and their family members, totalling 43 people, were examined. Twenty-seven had a history of bleeding; 29 had an increased factor VIII activity:factor VIII related antigen ratio; 24 had a decreased factor VIII related antigen; 23 had a prolonged bleeding time; 19 had a reduced platelet adhesiveness; 16 had a decreased factor VIII activity; and 14 had an abnormal ristocetin-induced platelet aggregation. Eight members with both normal beleeding time and normal factor VIII activity were found to have other abnormal tests: elevated ratio of factor VIII activity to factor VIII related antigen in seven; decreased factor VIII related antigen in four; and reduced platelet adhesiveness in one. Therefore, ratio of factor VIII activity to factor VIII related antigen and factor VIII related antigen are more sensitive and may be used for the detection of heterozygous carriers of von Willebrand's disease. Although patients with thrombocytopathy may have a prolonged bleeding time, decreased platelet adhesiveness and reduced platelet aggregation by ristocetin, their factor VIII activity, factor VIII related antigen and ratio of factor VIII activity to factor VIII related antigen are normal and their abnormal ristocetin test cannot be corrected by the addition of factor VIII concentrate. Hemophilic subjects and hemophilic carriers, who are deficient in factor VIII activity, usually have a normal bleeding time, normal platelet adhesiveness, and normal ristocetin test. In contrast to patients with von Willebrand's disease, their factor VIII related antigen is normal or slightly increased and their ratio of factor VIII activity to factor VIII related antigen is significantly reduced. We conclude that ratio of factor VIII activity to factor VIII related antigen and factor VIII related antigen are not only more sensitive but also more specific for the diagnosis of von Willebrand's disease.

Thermal injury in von willebrand disease. Management of burn wound bleeding

A 51-year-old woman sustained a 40% third-degree burn. After five grafting procedures that were unsuccessful due to uncontrolled bleeding, the diagnosis of von Willebrand disease was established. Skin grafting was subsequently accomplished without difficulty using cryoprecipitate as a source of antihemophilic factor (factor VIII). Serial clinical and laboratory investigations demonstrated that using the level of factor VIII procoagulant activity alone as an in vitro index of hemostasis was insufficient as a guide to the control of pathologic burn wound bleeding in this patient.

The spectrum of von Willebrand's disease revisited

We have examined nine patients with presumed von Willebrand's disease who present the spectrum of that disorder. Two had findings that would be accepted generally as diagnostic of von Willebrand's disease, and seven had variations of the usual pattern. The commonest variation was the combination of borderline and variable levels of coagulant Factor VIII, commensurate levels of Factor VIII-related antigen, and low levels of ristocetin-Willebrand factor.

In vivo dissociation of factor VII (AHF) activity and factor VII-related antigen in von Willebrand's disease

Using monospecific rabbit antihuman factor VIII antiserum, we have examined the amounts of factor VIII-related antigen and compared these to the levels of factor VIII procoagulant activity in normal subjects and patients with von Willebrand's disease. We have observed that even without transfusion all nine probands with von Willebrand's disease and 20 of their 34 relatives possessed a significantly elevated factor VIII activity/factor VIII-related antigen ratio when compared to that of 55 normal subjects. It is suggested that an elevated factor VIII activity/factor VIII-related antigen ratio may be used for detection of the carriers of von Willebrand's disease.

Ristocetin in the diagnosis of von willebrand's disease: a comparison of rate and percent of aggregation with levels of the plasma factor(s) necessary for ristocetin aggregation

Percent aggregation and the aggregation rate of platelet rich plasma (PRP) in response to ristocetin (1.75 mg/ml) were measured in 20 normals and 16 patients with von Willebrand's disease (v Wd), with and without the addition of acetylsalicylic acid (ASA). Percent aggregation did not clearly distinguish between normals and patients with vWd. Aggregation rate was normal in only 2 of 16 patients, and after incubation of PRP with ASA 1 of these 2 remained normal. The corrective effect of dilutions of platelet poor plasma (PPP) on the ristocetin response of washed platelets (von Willebrand's factor, vWf) was measured in 21 normals and 12 patients with vWd. All patients with vWd had abnormal levels. There was a significant correlation between aggregation rate and vWf in patients with vWd but not in normals. Both tests appear to measure closely related defects, and the aggregation rate is as specific as the vWf level for the diagnosis of clinically affected patients.