On von Willebrand's disease (vWd)

Variations in the hereditary patterns of factor VIII complex in a large kindred: coexistence of hemophilia A with Von Willebrand

Coagulation studies and clinical observations were carried out in 47 members belonging to three generations in one kindred. Classical Hemophilia A, Von Willebrand (VWD) variants, and normal individuals were revealed in this study. The coexistence of Hemophilia A and VWD in different siblings of the same progenitors indicates the difficulty to distinguish between these two major factor VIII abnormalities as two different traits. A hypothesis based on these findings is elaborated.

von Willebrand syndromes and mitral-valve prolapse; linked mesenchymal dysplasias

We searched for mitral-valve prolapse by two-dimensional echocardiography in 15 patients with von Willebrand syndromes to test the hypothesis that this bleeding disorder is actually a mesenchymal dysplasia that resembles the heritable disorders of connective tissue. This valvular abnormality was found in nine (60 per cent) of these patients, as compared with four (13.3 per cent) of 30 sex-matched and age-matched healthy controls. This difference was statistically significant (P less than 0.01). The association between these two disorders encourages a search for mitral-valve prolapse in persons with a von Willebrand syndrome. The complex of a von Willebrand syndrome and mitral-valve prolapse may be an example of a newly recognized category of related coagulation and cardiovascular disorders.

Gastrointestinal bleeding, angiodysplasia of the colon and acquired von Willebrand's disease

A 66-year-old man is reported who was found to have acquired von Willebrand's disease, which presented when the patient was 63 with iron deficiency anaemia and gastrointestinal bleeding. He subsequently bled from various sites in the gastrointestinal tract including an angiodysplasia of the right colon, which was successfully treated by right hemicolectomy. This is the second reported association between acquired von Willebrand's disease and angiodysplasia of the intestinal tract.

Severe factor VIII and factor IX deficiency in females

A survey of 11 hemophilia centers produced data concerning 28 females with extremely low levels of factor VIII or IX coagulant activity. Ten of the 28 have hemophilia A, six have hemophilia B, and 12 have severe von Willebrand's disease. The 16 females who have severe factor VIII or factor IX deficiency as an isolated defect exemplify several of the possible genetic explanations for the occurrence of hemophilia in females. All 16 bruise excessively, and several have had recurrent hemarthroses. Three of these girls, ages five, 10 and 23 years, have evidence of chronic hemophilic arthropathy. The 12 females with severe von Willebrand's disease are either homozygous for von Willebrand's disease or severely affected heterozygotes. All 12 have mucous membrane bleeding. In addition, five of the 12 have recurrent hemarthroses and three have evidence of chronic joint disease. However, the major problem in the adult females with von Willebrand's disease has been extreme menorrhagia. One of the seven adults underwent irradiation sterilization and another had a hysterectomy because of menorrhagia. The others have been managed with anovulatory drugs or plasma infusions and EACA. Despite menorrhagia, five pregnancies and deliveries have been uneventful in three of these women.

Procoagulant specificity of factor VIII inhibitor

Nine haemophilia A patients with an inhibitor to factor VIII procoagulant and eight without an inhibitor were studied for the presence of an inhibitor to von Willebrand factor (vWf) in a quantitative ristocetin-induced platelet aggregation system. The mean vWf, factor VIII related antigen (FVIII Ag) and vWf:FVIII Ag ratio were not significantly different in the two groups (P greater than 0.6). The inhibitor plasmas did not reduce the wWf level in normal plasma after a 2 h incubation. The factor VIII inhibitor is highly specific for the procoagulant function of the factor VIII complex.